cyclin-d1 and Stomach-Neoplasms

Published data on the association between cyclin D1 (CCND1) G870A polymorphism and gastric cancer (GC) risk are inconclusive. Thus, we conducted a meta-analysis to evaluate the relationship between CCND1 G870A polymorphism and GC risk. We searched PubMed, EMBASE, Web of science and the Cochrane Library up to June 12, 2015 for relevant studies. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to estimate the strength of associations. Nine studies published from 2003 to 2014, with a total of 1813 cases and 2173 controls, were included in this meta-analysis. The pooled results showed that there was no association between CCND1 G870A polymorphism and GC risk in any genetic model. The subgroup analysis stratified by ethnicity showed an increased breast cancer risk in Caucasian based on heterozygote comparison (GA vs. GG: OR=1.49, 95% CI=1.06-2.10, P=0.02). We found the same association in population based (PB) stratified analyses by Source of controls (AA vs. GG: OR=1.39, 95% CI=1.01-1.93, 0.05). When stratifying by the type, Sex and H. pylori infection in dominant model, Interestingly, we found the opposite result in Male (AA + GA vs. GG: OR=0.5, 95% CI=0.33-0.76, P=0.001), there were no association between CCND1 G870A polymorphism and GC risk in any other subgroup. This meta-analysis suggests that CCND1 G870A polymorphism is a risk factor for susceptibility to GC in Caucasians and in general populations. While, CCND1 G870A polymorphism plays a possible protective effect in GC in Male. Further large scale multicenter epidemiological studies are warranted to confirm this finding.

Topics: Case-Control Studies; Cyclin D1; Genetic Association Studies; Genetic Predisposition to Disease; Humans; Polymorphism, Single Nucleotide; Prognosis; Risk Factors; Stomach Neoplasms

Carcinomas of the upper gastrointestinal tract have been intensively studied for decades in order to identify markers for a) design of simple blood tests to detect presence or recurrence of the disease, b) prediction of therapy response, c) identification of molecular targets for novel therapies. These aims have not yet been fully reached by analysing single genes. However, some genes, including E-cadherin that is altered in sporadic and familial cases of gastric cancer and interleukin 1-beta whose polymorphisms together with Helicobacter pylori infection are associated with an increased risk for gastric cancer, may have the potential for clinical use. In this review we summarize current data for the single gene approach and provide an overview for recent results from cDNA microarray studies.

Topics: Adenocarcinoma; Barrett Esophagus; Cadherins; Cyclin D1; Disease Progression; Esophageal Neoplasms; Humans; Mutation; Stomach Neoplasms

We evaluated DNA polymorphisms in genes related to DNA repair, cell-cycle control and tumour microenvironment to determine possible associations with response and survival in neoadjuvant-treated gastric cancer patients.. One hundred and seventy eight patients who received platinum/5FU-based chemotherapy were genotyped for 10 polymorphisms in nine genes (ERCC1: Asn118Asn, C > T; ERCC1: 8092C > A; TP53: Arg72Pro, G < C; cyclinD1: Pro241Pro, G > A; STK15: Phe31Ile, A > T; VEGF: 936C > T; TNF-alpha: -308G > A; interleukin-1b (IL-1B): -511C >T; IL-1 receptor antagonist (IL-1RN): variable tandem repeat; IL-8: -251T>A). Genotypes were correlated with histopathological and clinical response and overall (OS) and progression-free survival (PFS).. Only the cyclinD1 genotypes were associated with clinical response (P(x)(2)=0.044). Significantly worse survival rates were noted in patients homozygous for the G-allele as compared to patients with the AG or AA genotypes of the cyclinD1 polymorphism (OS: P(log-rank) = 0.024; PFS: P(log-rank)=0.007) and in patients homozygous for the short allele compared to all other genotypes at the IL-1RN polymorphic locus (OS: P(log-rank) = 0.026; PFS: P(log-rank) = 0.013). The combination of both unfavourable genotypes demonstrated strong prognostic relevance (OS: P(log-rank) = 0.006; PFS: P(log-rank) = 0.001). Multivariate analysis for OS in the group of completely resected patients (n = 139) revealed statistical significance for ypM (P < 0.001), histopathological response (P < 0.001) and the combined cyclinD1/IL-1RN genotypes (P = 0.043).. The cyclinD1 and IL-1RN polymorphisms were associated with survival. The combination of specific cyclinD1 and IL-1RN genotypes showed a particular prognostic relevance and should be considered an independent prognostic marker for neoadjuvant-treated gastric cancer patients.

Topics: Adenocarcinoma; Adult; Aged; Alleles; Antineoplastic Agents; Cell Cycle; Cisplatin; Cyclin D1; DNA Repair; Female; Fluorouracil; Gene Frequency; Genotype; Humans; Interleukin 1 Receptor Antagonist Protein; Kaplan-Meier Estimate; Male; Middle Aged; Multivariate Analysis; Neoadjuvant Therapy; Neoplasm Staging; Polymerase Chain Reaction; Polymorphism, Single Nucleotide; Stomach Neoplasms; Survival Rate; Young Adult

The reversible post-translational modifications of protein ubiquitination and deubiquitination play a crucial regulatory role in cellular homeostasis. Deubiquitinases (DUBs) are responsible for the removal of ubiquitin from the protein substrates. The dysregulation of the DUBs may give rise to the occurrence and development of tumors. In this study, we investigated the gastric cancer (GC) data from the TCGA and GEO databases and found that ubiquitin-specific protease USP13 was significantly up-regulated in GC samples. The higher expression of USP13 was associated with the worse prognosis and shorter overall survival (OS) of GC patients. Enforced expression of USP13 in GC cells promoted the cell cycle progression and cell proliferation in an enzymatically dependent manner. Conversely, suppression of USP13 led to GC cell cycle arrest in G1 phase and the inhibition of cell proliferation. Nude mouse experiments indicated that depletion of USP13 in GC cells dramatically suppressed tumor growth in vivo. Mechanistically, USP13 physically bound to the N-terminal domain of cyclin D1 and removed its K48- but not K63-linked polyubiquitination chain, thereby stabilizing and increasing cyclin D1. Furthermore, re-expression of cyclin D1 partially reversed the cell cycle arrest and cell proliferation inhibition induced by USP13 depletion in GC cells. Additionally, USP13 protein abundance was positively correlated with the protein level of cyclin D1 in human GC tissues. Taken together, our data demonstrate that USP13 deubiquitinates and stabilizes cyclin D1, thereby promoting cell cycle progression and cell proliferation in GC. These findings suggest that USP13 might be a promising therapeutic target for the treatment of GC.

Topics: Animals; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Cyclin D1; G1 Phase; Humans; Mice; Stomach Neoplasms; Ubiquitin-Specific Proteases

Insulin like growth factor II mRNA binding protein 3 (IGF2BP3) is an RNA binding protein with multiple roles in regulation of gene expression at the post-transcriptional level and is implicated in tumorigenesis and progression of numerous cancers including gastric cancer (GC). Circular RNAs (circRNAs) are a diverse endogenous noncoding RNA population that have important regulatory roles in cancer. However, circRNAs that regulate the expression of IGF2BP3 in GC is largely unknown.. CircRNAs that bound to IGF2BP3 were screened in GC cells using RNA immunoprecipitation and sequencing (RIP-seq). The identification and localization of circular nuclear factor of activated T cells 3 (circNFATC3) were identified using Sanger sequencing, RNase R assays, qRT-PCR, nuclear-cytoplasmic fractionation and RNA-FISH assays. CircNFATC3 expression in human GC tissues and adjacent normal tissues were measured by qRT-PCR and ISH. The biological role of circNFATC3 in GC was confirmed by in vivo and in vitro experiments. Furthermore, RIP, RNA-FISH/IF, IP and rescue experiments were performed to uncover interactions between circNFATC3, IGF2BP3 and cyclin D1 (CCND1).. We identified a GC-associated circRNA, circNFATC3, that interacted with IGF2BP3. CircNFATC3 was significantly overexpressed in GC tissues and was positively associated with tumor volume. Functionally, the proliferation of GC cells decreased significantly after circNFATC3 knockdown in vivo and in vitro. Mechanistically, circNFATC3 bound to IGF2BP3 in the cytoplasm, which enhanced the stability of IGF2BP3 by preventing ubiquitin E3 ligase TRIM25-mediated ubiquitination, thereby enhancing the regulatory axis of IGF2BP3-CCND1 and promoting CCND1 mRNA stability.. Our findings demonstrate that circNFATC3 promotes GC proliferation by stabilizing IGF2BP3 protein to enhance CCND1 mRNA stability. Therefore, circNFATC3 is a potential novel target for the treatment of GC.

Topics: Cell Line, Tumor; Cell Proliferation; Cyclin D1; Humans; RNA; RNA Stability; RNA, Circular; Stomach Neoplasms; Ubiquitination

Due to the essential role of cyclin D1 in regulating transition from G1 to S phase in cell cycle, aberrant cyclin D1 expression is a major oncogenic event in many types of cancers. In particular, the dysregulation of ubiquitination-dependent degradation of cyclin D1 contributes to not only the pathogenesis of malignancies but also the refractory to cancer treatment regiments with CDK4/6 inhibitors. Here we show that in colorectal and gastric cancer patients, MG53 is downregulated in more than 80% of tumors compared to the normal gastrointestinal tissues from the same patient, and the reduced MG53 expression is correlated with increased cyclin D1 abundance and inferior survival. Mechanistically, MG53 catalyzes the K48-linked ubiquitination and subsequent degradation of cyclin D1. Thus, increased expression of MG53 leads to cell cycle arrest at G1, and thereby markedly suppresses cancer cell proliferation in vitro as well as tumor growth in mice with xenograft tumors or AOM/DSS induced-colorectal cancer. Consistently, MG53 deficiency results in accumulation of cyclin D1 protein and accelerates cancer cell growth both in culture and in animal models. These findings define MG53 as a tumor suppressor via facilitating cyclin D1 degradation, highlighting the therapeutic potential of targeting MG53 in treating cancers with dysregulated cyclin D1 turnover.

Topics: Animals; Cell Cycle Checkpoints; Cell Proliferation; Cyclin D1; Humans; Membrane Proteins; Mice; Stomach Neoplasms; Ubiquitin-Protein Ligases

Globally, gastric cancer (GC) is a major cause of cancer death. This study is aimed at investigating the biological functions of activating transcription factor 2 (ATF2) and the underlying mechanism in GC. In the present work, GEPIA, UALCAN, Human Protein Atlas and StarBase databases were adopted to analyze ATF2 expression characteristics in GC tissues and normal gastric tissues, and its relationships with tumor grade and patients' survival time. Quantitative real-time polymerase chain reaction (qRT-PCR) method was employed to examine ATF2 mRNA expression in normal gastric tissues, GC tissues, and GC cell lines. Cell counting kit-8 (CCK-8) and EdU assays were utilized for detecting GC cell proliferation. Cell apoptosis was detected by flow cytometry. PROMO database was applied to predict the binding site of ATF2 with the METTL3 promoter region. The binding relationship between ATF2 and the METTL3 promoter region was verified through dual-luciferase reporter gene assay and chromatin immunoprecipitation-quantitative PCR (ChIP-qPCR) assay. Western blot was performed to evaluate the effect of ATF2 on METTL3 expression. METTL3-related signaling pathways were predicted using Gene Set Enrichment Analysis (GSEA) in the LinkedOmics database. It was found that, ATF2 level was elevated in GC tissues and cell lines in comparison with normal tissues and correlated with short patients' survival time. ATF2 overexpression facilitated GC cell growth and suppressed the apoptosis, whereas ATF2 knockdown suppressed GC cell proliferation and facilitated the apoptosis. ATF2 bound to the METTL3 promoter region, and ATF2 overexpression promoted the transcription of METTL3, and ATF2 knockdown restrained the transcription of METTL3. METTL3 was associated with cell cycle progression, and ATF2 overexpression enhanced cyclin D1 expression, and METTL3 knockdown reduced cyclin D1 expression. In summary, ATF2 facilitates GC cell proliferation and suppresses the apoptosis via activating the METTL3/cyclin D1 signaling pathway, and ATF2 is promising to be an anti-drug target for GC.

Topics: Activating Transcription Factor 2; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Gene Expression Regulation, Neoplastic; Humans; Methyltransferases; Stomach Neoplasms; Transcription Factors

Cyclin D1 is a protein that can increase the proliferation of cancer cells. Its expression has been found in various malignancies, including gastric cancer. Cyclin D1 examinations have not been routinely performed for gastric cancer cases in Indonesia. A recent study of cyclin D1 in gastric cancer was associated with lymph node involvement, metastasis, poor prognosis, and a lack of response to platinum chemotherapy.. This study aimed to determine the relationships among cyclin D1 expression, clinicopathological features, and 2-year survival rates in gastric cancer.. This retrospective cohort study used medical records and paraffin blocks of patients suffering from gastric cancer at Cipto Mangunkusumo General Hospital, Jakarta, between 2015 and 2020. Data analysis was performed using Statistical Package for the Social Sciences (SPSS) version 20. The data were collected from 39 subjects, most of whom experienced eating disorder (69.23%), weight loss (76.92%), melena (53.85%), and anemia (51.28%). Tumor location was mostly found in the cardia and corpus of the gaster.. This study found that the proportion of overexpression of cyclin D1 was 30.77%. Cyclin D1 expression was greater in subjects with liver metastases (50% vs. 14.8%, P = 0.04). Cyclin D1 expression was not associated with tumor location, tumor, node, and metastasis (TNM) stage, or histopathological findings. Analysis of the 2-year survival rate did not find any differences between patients with cyclin D1 overexpression and those with cyclin D1 negative.. Cyclin D1 expression was associated with liver metastases in patients with gastric cancer.

Topics: Cyclin D1; Hospitals, General; Humans; Liver Neoplasms; Retrospective Studies; Stomach Neoplasms; Survival Rate

LncRNA ubiquitin-like with PHD and RING finger domains 1 (UHRF1) protein associated transcript (UPAT) regulates the progression of many cancers. However, its role in gastric cancer (GC) is less frequently reported.. In the context of the promoting effect of lncRNA on modulating GC progression, detailed insights into the role and underlying mechanism of UPAT in GC are the foothold in this study.. Overall survival was calculated. The mRNA expressions of UPAT and UHRF1 were measured by qRT-PCR, and the protein expressions of UHRF1, Cyclin D1 and cleaved caspase-3 were determined by western blot. Cell viability, growth, migration and invasion were assessed by CCK-8, colony formation, wound healing and Transwell assays, respectively. Apoptosis rate and cell cycle were assayed by flow cytometry.. UPAT was overexpressed in GC tissue and cell lines. Decreased UPAT level was associated with higher overall survival. Down-regulation of UPAT diminished cell proliferation, Cyclin D1 expression, and migration and invasion rates, increased apoptosis rate and cleaved caspase-3 expression, and blocked cell cycle in AGS and NCI-N87 cells. UPAT expression in GC was positively correlated with UHRF1 expression. UHRF1 overexpression offset the inhibitory effects of UPAT down-regulation on cell proliferation, migration, invasion and cell cycle, and partially reversed the positive effect of UPAT down-regulation on apoptosis.. UPAT might positively regulate the progression of GC via interacting with UHRF1. The UHRF1/UPAT axis revealed in the present study may provide a promising approach to intervene in the progression of GC.

Topics: Caspase 3; CCAAT-Enhancer-Binding Proteins; Cell Line, Tumor; Cyclin D1; Humans; RNA, Long Noncoding; RNA, Messenger; Sincalide; Stomach Neoplasms; Ubiquitin-Protein Ligases; Ubiquitins

Studies have shown that resveratrol (Res) exerts significant antiproliferative effects in cancer, and regulating the expression of microRNAs (miRNAs) is one the underlying mechanisms of these effects. Overexpression of miR-155-5p leads to oncogenesis. However, it is unclear whether Res exerts antitumor effects by regulating the expression of miR-155-5p, and its specific mechanism in gastric cancer remains unknown. In this study, qRT-PCR was performed to assess the expression of miR-155-5p in gastric cells and clinical tissues, and the MTT assay, plate clone formation test, cell scratch test, Transwell assay, and flow cytometry were performed to investigate the functions of Res on the growth of gastric cancer cells after treatment with miR-155-5p. Western blot analysis was performed to detect the expression of claudin 1, c-Myc, cyclin D1, Bcl-2, and caspase-3 proteins in gastric cancer cell lines after treatment with miR-155-5p and Res. We found that miR-155-5p was overexpressed in gastric cancer cells and clinical tissues, while Res inhibited gastric cancer cell growth by regulating miR-155-5p expression. The results of MTT assay, plate clone formation test, cell scratch test, Transwell test, and flow cytometry showed that miR-155-5p promoted the proliferation, invasion, and metastasis of gastric cancer cell lines and inhibited apoptosis, while Res addition inhibited this effect (

Topics: Caspase 3; Cell Line, Tumor; Cell Proliferation; Claudin-1; Cyclin D1; Gene Expression Regulation, Neoplastic; Humans; MicroRNAs; Proto-Oncogene Proteins c-bcl-2; Resveratrol; Stomach Neoplasms

Gastric cancer has one of the highest incidence rates of cancer worldwide while also contributing to increased drug resistance among patients in clinical practice. Herein, we have investigated the role of diclofenac (DCF) on sensitizing cisplatin resistance in signet ring cell gastric carcinoma cells (SRCGC). Non-toxic concentrations of DCF significantly augmented cisplatin-induced cell death in cisplatin-resistant SRCGC cells (KATO/DDP) but not in cisplatin-sensitive SRCGC cells (KATOIII). Consistently, concomitant treatment of DCF and cisplatin significantly enhanced autophagic cell death due to overproduction of intracellular reactive oxygen species (ROS). At the molecular level, the induction of ROS has been associated with a reduction in antioxidant enzymes expression while inhibiting nuclear factor erythroid 2-related factor 2 (Nrf2) activity. Moreover, the combination of DCF and cisplatin also inhibited the expression of survival proteins including Bcl-2, Bcl-xL, cIAP1 and cyclin D1 in KATO/DDP cells when compared with cisplatin alone. This was due, at least in part, to reduce MAPKs, Akt, NF-κB, AP-1 and STAT-3 activation. Taken together, our results suggested that DCF potentiated the anticancer effect of cisplatin in SRCGC via the regeneration of intracellular ROS, which in turn promoted cell death as an autophagy mechanism and potentially modulated the cell survival signal transduction pathway.

Topics: Antioxidants; Apoptosis; Autophagy; Carcinoma, Signet Ring Cell; Cisplatin; Cyclin D1; Diclofenac; Drug Resistance, Neoplasm; Humans; NF-E2-Related Factor 2; NF-kappa B; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-bcl-2; Reactive Oxygen Species; Signal Transduction; Stomach Neoplasms; Transcription Factor AP-1

To explore the mechanisms underlying the proliferative inhibition of Chinese herbal medicine Kang-Ai injection (KAI) in gastric cancer cells.. Gastric cancer cell lines MGC803 and BGC823 were treated by 0, 0.3%, 1%, 3% and 10% KAI for 24, 48 and 72 h, respectively. The cell proliferation was evaluated by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. The apoptosis and cell cycle were evaluated by flow cytometry. Interleukin (IL)-6 mRNA and protein expression levels were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and enzyme-linked immune sorbent assay (ELISA), respectively. The protein expression levels of cyclin A, cyclin E, cyclin B1, cyclin D1, p21, retinoblastoma (RB), protein kinase B (AKT), extracellular regulated protein kinases (ERK), signal transducer and activator of transcription (STAT) 1 and STAT3 were detected by Western blot.. KAI inhibited the proliferation of MGC803 and BGC823 gastric cancer cells in dose- and time-dependent manner. After treated with KAI for 48 h, the proportion of G1 phase was increased, expression level of cyclin D1 and phosphorylation-RB were down-regulated, whereas the expression of p21 was up-regulated (all P<0.01). Furthermore, 48-h treatment with KAI decreased the phosphorylation level of STAT3, inhibited the mRNA and protein expressions of IL-6 (all P<0.01). IL-6 at dose of 10 ng/mL significantly attenuated the proliferative effect of both 3% and 10% KAI, and recovered KAI-inhibited STAT3 phosphorylation and cyclin D1 expression level (all P<0.01).. KAI exerted an anti-proliferative function by inhibiting IL-6/STAT3 signaling pathway followed by the induction of G

Topics: Apoptosis; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Humans; Interleukin-6; RNA, Messenger; STAT3 Transcription Factor; Stomach Neoplasms

SETDB1 is a histone lysine methyltransferase that has critical roles in cancers. However, its potential role in gastric cancer (GC) remains obscure. Here, we mainly investigate the clinical significance and the possible role of SETDB1 in GC. We find that SETDB1 expression is upregulated in GC tissues and its high-level expression was a predictor of poor prognosis in patients. Overexpression of SETDB1 promoted cell proliferation and metastasis, while SETDB1 suppression had an opposite effect both in vitro and in vivo. Mechanistically, SETDB1 was shown to interact with ERG to promote the transcription of cyclin D1 (CCND1) and matrix metalloproteinase 9 (MMP9) through binding to their promoter regions. In addition, the expression of SETDB1 was also enhanced by the transcription factor TCF4 at the transcriptional level in GC. Furthermore, SETDB1 expression was found to be induced by Helicobacter pylori (H. pylori) infection in a TCF4-dependent manner. Taken together, our results indicate that SETDB1 is aberrantly overexpressed in GC and plays key roles in gastric carcinogenesis and metastasis via upregulation of CCND1 and MMP9. Our work also suggests that SETDB1 could be a potential oncogenic factor and a therapeutic target for GC. © 2020 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Topics: Animals; Carcinogenesis; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Disease Progression; Female; Helicobacter Infections; Histone-Lysine N-Methyltransferase; Humans; Matrix Metalloproteinase 9; Mice, Inbred BALB C; Neoplasm Invasiveness; Neoplasm Metastasis; Promoter Regions, Genetic; Stomach; Stomach Neoplasms; Transcription Factor 4; Up-Regulation

MicroRNAs (MiRNAs) play critical roles in regulating target gene expression and multiple cellular processes in human cancer malignant progression. However, the function of miR-194 in gastric cancer (GC) remains unclear and controversial. In this study, we identified a series of miRNAs that can serve as prognostic biomarkers for GC by analysis of miRNA expression using The Cancer Genome Atlas data. Among them, miR-100, miR-125b, miR-199a, and miR-194 were the four most promising prognostic biomarkers in GC due to their significant associations with various clinical characteristics of patients. miR-100, miR-125b, and miR-199a predicted poor prognosis in GC, while miR-194 predicted favorable prognosis in GC. We also provide the first comprehensive transcriptome analysis of miR-194 in GC. Our data suggest that miR-194 tends to regulate target genes by binding to their 3' UTRs in a 7-mer-A1, 7-mer-m8, or 8-mer manner. KEGG pathway analysis showed that the cell cycle was one of the pathways most affected by miR-194 in GC. Moreover, CCND1 was shown to be a novel target gene of miR-194 in GC. Additionally, downregulation of CCND1 by miR-194 in GC further led to cell growth inhibition and cell cycle arrest. In conclusion, miR-100, miR-125b, miR-199a, and miR-194 may have potential as prognostic and diagnostic biomarkers for GC. miR-194 suppresses GC cell growth mainly through targeting CCND1 and induction of cell cycle arrest.

Topics: Cyclin D1; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Humans; MicroRNAs; Stomach Neoplasms

Vitamin C has re-emerged as a promising anticancer agent. This study attempts to analyze the differential gene expression of profiles GSE11919 to look for some clues, and the most significant cell cycle pathway caused by vitamin C was identified by integrated bioinformatics analysis. Inspired by this, we investigated the effect of vitamin C treatment on gastric carcinoma cells by detection of cell cycle, apoptosis, and autophagy. Vitamin C significantly elevated the percentage of cells at G0/G1 phase, whereas the percentage of S phase cells was decreased. Meanwhile, vitamin C treatment resulted in downregulation of cell cycle-related protein Cyclin D1. We deduced that the downregulation of Cyclin D1 by vitamin C accompanied by significantly increased 5'AMP-activated protein kinase and induced autophagy in MKN45 cells. These results suggest that vitamin C has the antiproliferation effect on gastric carcinoma cells via the regulation of cell cycle and autophagy by Cyclin D1.

Topics: Ascorbic Acid; Autophagy; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Down-Regulation; G1 Phase; Gene Expression Profiling; Humans; Stomach Neoplasms

Purpose - The high expression of positive regulatory domain zinc finger protein2 (PRDM2) is an important factor in inducing the formation and progression of gastric cancer. The current study was performed to explore the effect of micro-RNA-362 (miR-362) targeting PRDM2 on the proliferation and apoptosis of gastric cancer cells. Methods - The expression of miR-362 in gastric adenocarcinoma and normal gastric mucosa was detected by real-time fluorescence quantitative PCR (qPCR), and the expression of PRDM2 in gastric adenocarcinoma was detected by im-munohistochemical method. Gastric cancer cell line MGC-803 and human normal gastric mucosal epithelial cell line (GES-1) were selected for study. Blank control group, empty vector transfection group, miR-362 transfection group, and miR-362 and PRDM2 co-transfection group were established. CCK-8 assay was utilized to detect cell activity, flow cytometry was used to detect cell cycle and apoptosis, and invasion capability of cells was observed through transwell experiment. The expression of Cyclin D1 and Caspases-3 was detected by western blot method. Results - The expression of miR-362 in gastric adenocarcinoma was significantly lower than that in normal gastric mucosa. The expression of miR-362 in gastric adenocarcinoma was significantly different in the maximum diameter, depth of invasion, and different TNM stages. The expression of miR-362 was linked to prognosis. In addition, there was a negative correlation between miR-362 and PRDM2. The expression of miR-362 in gastric cancer cell line MGC-803 was significantly lower than that in GES-1. Compared with the blank control group and empty vector transfection group, the proliferation level of gastric cancer cells in miR-362 transfection group was remarkably decreased, the cells in S phase and G2/M phase were significantly decreased, the capability for invasion was evidently decreased, while the apoptosis was significantly increased. The expression of Caspases-3 increased significantly and the expression of Cyclin D1 decreased significantly. MiR-362 and PRDM2 co-transfection groups could reverse the abovementioned expression levels. Conclusion - MiR-362 can regulate the proliferation, invasion and apoptosis of gastric cancer by inhibiting the expression of tumor-promoting factor PRDM2. The expression of miR-362 in gastric adenocarcinoma is significantly decreased, which can regulate the formation and development of gastric adenocarcinoma by promoting the expressi

Topics: Adenocarcinoma; Apoptosis; Biomarkers, Tumor; Caspases; Cell Cycle; Cell Line; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; DNA-Binding Proteins; Gene Expression Regulation, Neoplastic; Histone-Lysine N-Methyltransferase; Humans; MicroRNAs; Nuclear Proteins; Prognosis; Real-Time Polymerase Chain Reaction; Stomach Neoplasms; Transcription Factors

The aim of the present study was to elucidate the functional role of hsa-miR-328-3p/STAT3 pathway in the effects of propofol on gastric cancer proliferation.. Bioinformatics was used to analyze the molecular expression differences of hsa-miR-328-3p/STAT3 axis in stomach adenocarcinoma (n = 435) and normal samples (n = 41) from TCGA database. The expression of the above molecules in gastric cancer cells SGC-7901 and normal gastric mucosal cells GES-1 was verified via qPCR. The dual-luciferase assay was carried out to confirm the interaction between hsa-miR-328-3p and STAT3. Subsequently, the cell proliferation and the expression of the above molecules in SGC-7901 and GES-1 cells were evaluated after 10 μM propofol treatment. Finally, we analyzed whether propofol still inhibited the proliferation of gastric cancer by suppressing STAT3 pathway after hsa-miR-328-3p down-regulation.. Compared with normal samples, the expression of hsa-miR-328-3p was significantly down-regulated in stomach adenocarcinoma samples, while the expression of STAT3 and downstream target genes (MMP2, CCND1 and COX2) was up-regulated. The results were consistent with those in GES-1 and SGC-7901 cell lines. Meanwhile, we found that hsa-miR-328-3p can bind to the 3'-UTR of the potential target gene STAT3. Furthermore, propofol significantly inhibited the proliferation of gastric cancer cell line SGC-7901, where hsa-miR-328-3p was up-regulated and the expression of STAT3 and downstream proliferation-related target genes were down-regulated. However, the growth inhibition of propofol on SGC-7901 cell was significantly reversed after the inhibition of hsa-miR-328-3p.. To sum up, propofol suppressed the STAT3 pathway via up-regulating hsa-miR-328-3p to inhibit gastric cancer proliferation.

Topics: 3' Untranslated Regions; Adenocarcinoma; Anesthetics, Intravenous; Cell Line, Tumor; Cell Proliferation; Computational Biology; Cyclin D1; Cyclooxygenase 2; Down-Regulation; Gastric Mucosa; Humans; Luciferases; Matrix Metalloproteinase 2; MicroRNAs; Propofol; STAT3 Transcription Factor; Stomach Neoplasms; Up-Regulation

The regulation of gene expression by miRNAs plays an important role in cancer progression. Here, we investigated the role of miR-3663-3p in gastric cancer.. The relationship between miR-3663-3p expression, clinicopathological features and prognosis were retrospectively analyzed in 80 gastric cancer patients.. miR-3663-3p expression was significantly lower in gastric cancer tissue than adjacent non-cancerous tissue (p=0.002). Recurrence free survival was significantly lower in patients with low miR-3663-3p expression (p=0.016). Low miR-3663-3p expression was also an independent predictive factor for recurrence (p=0.029). Overexpression of miR-3663-3p in gastric cancer cell lines significantly suppressed cell proliferation, migration/invasion, and induced G0/G1 arrest (p<0.01). Furthermore, overexpression of miR-3663-3p decreased Cyclin D1 mRNA and protein, and reduced the phosphorylation of Retinoblastoma (Rb) protein.. miR-3663-3p is a clinically useful predictor of gastric cancer recurrence. It exhibits tumor suppressive features through limited entry into the cell cycle in a Cyclin D1-Rb dependent manner.

Topics: Aged; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Disease Progression; Female; Gene Expression Regulation, Neoplastic; Humans; Male; MicroRNAs; Neoplasm Invasiveness; Neoplasm Staging; Retinoblastoma Binding Proteins; Stomach Neoplasms; Ubiquitin-Protein Ligases

N6-methyladenosine (m6A) is a well-known modification of RNA. However, as a key m6A methyltransferase, METTL16 has not been thoroughly studied in gastric cancer (GC). Here, the biological role of METTL16 in GC and its underlying mechanism was studied. Immunohistochemistry was used to detect the expression of METTL16 and relationship between METTL16 level and prognosis of GC was analysed. CCK8, colony formation assay, EdU assay and xenograft mouse model were used to study the effect of METTL16. Regulatory mechanism of METTL16 in the progression of GC was studied through flow cytometry analysis, RNA degradation assay, methyltransferase inhibition assay, RT-qPCR and Western blotting. METTL16 was highly expressed in GC cells and tissues and was associated with prognosis. In vitro and in vivo experiments confirmed that METTL16 promoted proliferation of GC cells and tumour growth. Furthermore, down-regulation of METTL16 inhibited proliferation by G1/S blocking. Significantly, we identified cyclin D1 as a downstream effector of METTL16. Knock-down METTL16 decreased the overall level of m6A and the stability of cyclin D1 mRNA in GC cells. Meanwhile, inhibition of methyltransferase activity reduced the level of cyclin D1. METTL16-mediated m6A methylation promotes proliferation of GC cells through enhancing cyclin D1 expression.

Topics: Adenosine; Adult; Aged; Animals; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Female; Gene Expression Regulation, Neoplastic; Heterografts; Humans; Male; Methylation; Methyltransferases; Mice; Middle Aged; Prognosis; RNA Stability; Stomach Neoplasms

Gastric cancer is a malignant tumor with a poor prognosis. Therefore, it is important to search for molecules that play a vital role in the development, diagnosis, and treatment of this disease. Placenta-specific 1 (PLAC1) is one of the cancer-testis antigens; it plays an important role in both placental development and tumorigenesis. However, the role of PLAC1 in gastric cancer has not been fully investigated, and its underlying mechanism needs further study. We first explored the expression and clinical relevance of PLAC1 in gastric cancer and performed gene set enrichment analysis of PLAC1-related genes using online databases. Subsequently, we studied the function and mechanism of PLAC1 in gastric cancer cells through in vitro experiments. Our results showed that PLAC1 is highly expressed in gastric cancer, is associated with poor prognosis, and can promote gastric cancer cell proliferation through the AKT/GSK-3β/cyclin D1 signaling pathway. Moreover, we discovered that AKTi attenuates the effect of PLAC1. Our study further revealed the role and mechanism of PLAC1 in gastric cancer and suggested that this antigen might be a useful molecular marker for gastric cancer diagnosis, prognosis, and treatment.

Topics: Adenocarcinoma; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Gene Expression Regulation, Neoplastic; Glycogen Synthase Kinase 3 beta; Humans; Kaplan-Meier Estimate; Pregnancy Proteins; Prognosis; Proto-Oncogene Proteins c-akt; Signal Transduction; Stomach Neoplasms

The present study investigated the oncogenic functions of TACC3 in the progression of gastric cancer (GC).. We analysed TACC3 in relation to cell growth, invasion capability, expression of epithelial-mesenchymal transition (EMT)-related markers, and ERK/Akt/cyclin D1 signaling factors. The correlation between the immunohistochemically confirmed expression of TACC3 and clinical factors was also analyzed.. The increased proliferation and invasion of TACC3-over-expressing GC cells was accompanied by altered regulation of EMT-associated markers and activation of ERK/Akt/cyclin D1 signaling. Immunohistochemical analysis of TACC3 in human GC tissues revealed that its expression is correlated with aggressive characteristics and poor prognosis of intestinal-type GC.. TACC3 contributes to gastric tumorigenesis by promoting EMT via the ERK/Akt/cyclin D1 signaling pathway. The correlation between TACC3 expression and multiple clinicopathological variables implies that its effective therapeutic targeting in GC will depend on the tumor subtype.

Topics: Carcinogenesis; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Epithelial-Mesenchymal Transition; Gene Expression Regulation, Neoplastic; Humans; MAP Kinase Signaling System; Microtubule-Associated Proteins; Neoplasm Invasiveness; Proto-Oncogene Proteins c-akt; Signal Transduction; Stomach; Stomach Neoplasms

Topics: Antineoplastic Agents, Immunological; Antineoplastic Combined Chemotherapy Protocols; Carcinoma; Cardia; Cisplatin; Cyclin D1; Docetaxel; Humans; Neoplasm Proteins; Receptor, ErbB-2; Stomach Neoplasms; Trastuzumab

Leucine zipper-EF-hand containing transmembrane protein 1 (LETM1) is closely linked to the occurrence and development of many malignant tumors. Many studies have reported that enhanced expression of LETM1 in several types of human cancers was associated with poor clinical outcomes; however, its clinical significance in gastric adenocarcinoma (GA) has not been elucidated. In this study, we assessed the expression of LETM1 along with the genes related to cancer stemness, cell cycle, and PI3K/Akt signaling in 189 paraffin-embedded GA tissue samples and GA-derived cell lines using immunohistochemistry (IHC), western blotting, and immunofluorescence. Our results showed that the expression of LETM1 was strongly correlated with the tumor grade, primary tumor (pT) stage, lymph node metastasis, clinical stage, and tumor gross type of GA. The Kaplan-Meier survival analysis revealed that patients with GA with high expression of LETM1 exhibit a shorter overall survival (OS) rate. Univariate and multivariate Cox regression analysis indicated that LETM1 is an independent poor prognostic factor of GA. Significantly, LETM1 expression was positively correlated with the expression of cancer stemness-related genes such as CD44 and LGR5 and expression of cell-cycle related gene, cyclin D1. Further, the expression of proteins involved in PI3K/Akt signaling pathway, such as pPI3K-p85 and pAkt-Thr308, was also increased. Additionally, small interfering RNA (esiRNA)-mediated silencing of LETM1 expression in GA-derived cell lines MKN28 and MKN74 strongly inhibited the expression of stemness and cell cycle-related proteins, suppressed cancer cell spheroid formation, migration and invasion ability, and affected cell cycle distribution. Furthermore, the GA-derived cell line AGS exhibited enhanced expression of LETM1, CD44, LGR5, and HIF1-α under hypoxic conditions. Lastly, we blocked PI3K expression using an inhibitor LY294002, which downregulated the expression of LETM1, pPI3K-p85, and pAkt-Thr308. Taken together, our results demonstrate that LETM1 regulates cell proliferation and promotes tumorigenicity of GA, and its overexpression is associated with the poor progression of GA. Therefore, LETM1 could serve as a potential prognostic biomarker and a therapeutic target for the better clinical management of GA.

Topics: Adenocarcinoma; Aged; Biomarkers, Tumor; Calcium-Binding Proteins; Cell Proliferation; Cyclin D1; Disease-Free Survival; Female; Gene Expression Regulation, Neoplastic; Humans; Hyaluronan Receptors; Kaplan-Meier Estimate; Male; Membrane Proteins; Middle Aged; Oncogene Protein v-akt; Phosphatidylinositol 3-Kinases; Prognosis; Stomach Neoplasms

Dihydroartemisinin (DHA), a semisynthetic derivative of artemisinin, has a broad range of biological properties, including antitumor activity. However, the mechanisms by which DHA affects the tumorigenesis of gastric carcinoma (GC) are poorly understood.. The targets of DHA were identified by network pharmacology, and the association of CDK4 with clinicopathological characteristics and prognosis in patients with GC was analyzed by using TCGA data. CCK8, Transwell and flow cytometric analyses, as well as a tumor xenograft model, were used to assess the effects of DHA on the growth and migration of GC cells. qRT-PCR and Western blot analyses were used to determine the effects of DHA on the cyclin D1-CDK4-Rb signaling pathway.. We identified 13 DHA targets and measured their expression of whichCDK4 expression levels were substantially higher in GC tissues than those in adjacent normal tissues, and high CDK4 expression acted as an independent prognostic factor of poor survival in patients with GC. DHA suppressed cell proliferation, migration and invasion in vitro and in vivo and induced G1 phase cell cycle arrest in a dose-dependent manner by regulating cyclin D1-CDK4-Rb signaling.. DHA inhibits the tumorigenesis and invasion of GC by regulating cyclin D1-CDK4-Rb signaling and may provide therapeutic strategies for the treatment of GC.

Topics: Animals; Artemisinins; Carcinogenesis; Cell Cycle Checkpoints; Cell Proliferation; Cyclin D1; Cyclin-Dependent Kinase 4; Female; Humans; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Middle Aged; Neoplasm Invasiveness; Prognosis; Signal Transduction; Stomach; Stomach Neoplasms; Xenograft Model Antitumor Assays

Topics: Aged; Binding Sites; Binding, Competitive; Carcinogenesis; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Female; Gene Expression Regulation, Neoplastic; Gene Silencing; Humans; Male; MicroRNAs; Neoplasm Invasiveness; RNA, Circular; Stomach Neoplasms; Up-Regulation

Colorectal cancer (CRC) is one of the most frequent neoplasms worldwide, and up to 15% have a family history. Lynch syndrome (LS) is a hereditary cause of CRC and gastric (GC). Individuals with LS have mutations in mismatch genes repair. p53, cyclin D1, β-catenin, APC and c-myc proteins are involved in the cell cycle and carcinogenesis.. To study the expression of p53, Cyclin D1, β-catenin, APC and c-myc proteins in patients with CRC and GC with at least one of the Bethesda positive criteria. Compare the expression of these proteins with the presence or absence of expression of the DNA repair proteins.. We included 70 individuals with CRC or GC with at least one of the Bethesda positive criteria. Protein expression of MLH1, MSH2, MSH6, PMS2, p53, cyclin D1, β-catenin, APC and c-myc were analized by immunohistochemistry tumours tissues.. Deficient expression of MLH1, MSH2, MSH6 and PMS2 were respectively 38.7%; 17.7%; 26.22% and 48.38%. We found a negative association between deficiency of PMS2 and age, and positive association between PMS2 deficiency and APC positive. The positive imunoexpression of APC increases by 4 times the chance of having deficiency of PMS2.. Patients with loss of expression of PMS2 had a higher risk of mutation or deletion of APC and tumours with positive immunoexpression of cyclin D1 had an increased risk of loss of expression of MSH2. These results suggest that tumours with loss of expression of DNA repair proteins had a higher loss of cell control cycle.
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Topics: Adenomatous Polyposis Coli Protein; beta Catenin; Biomarkers, Tumor; Brazil; Colorectal Neoplasms; Colorectal Neoplasms, Hereditary Nonpolyposis; Cyclin D1; DNA Repair Enzymes; Female; Follow-Up Studies; Humans; Male; Middle Aged; Prognosis; Proto-Oncogene Proteins c-myc; Retrospective Studies; Stomach Neoplasms; Tumor Suppressor Protein p53

MicroRNAs (miRNAs) play important roles in posttranscriptional regulation and may serve as targets for the diagnosis and treatment of cancers. Nevertheless, a comprehensive understanding of miRNAs profiles in gastric cancer progression is still lacking. Here, we report that miR-129-5p is downregulated in gastric cancer by analyzing TCGA database (n = 41) and clinical tumor samples (n = 60). MiR-129-5p transfection suppressed gastric cancer cell proliferation through inducing G1 phase arrest in vitro and inhibit xenograft tumor growth in vivo. MiR-129-5p directly targeted the 3' untranslated regions (3' UTR) of HOXC10 mRNA and downregulated its expression. Importantly, miR-129-5p could reverse the oncogenic effect induced by HOXC10. We systemically screened the downstream target of HOXC10 by ChIP sequencing, and found that HOXC10 could transcriptionally regulate the expression of Cyclin D1 and facilitate G1/S cell cycle transition. Notably, high levels of HOXC10 and Cyclin D1 were related with poor prognosis of gastric cancer patients (n = 90). These findings reveal a novel role of miR-129-5p/HOXC10/Cyclin D1 axis in modulating cell cycle and gastric tumorigenesis, which might provide potential prognostic biomarkers and therapeutic targets for gastric cancer patients.

Topics: 3' Untranslated Regions; Animals; Cell Cycle Checkpoints; Cell Line; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Disease Progression; Down-Regulation; Female; G1 Phase; Gene Expression Regulation, Neoplastic; HEK293 Cells; Homeodomain Proteins; Humans; Mice; Mice, Inbred BALB C; MicroRNAs; Oncogenes; S Phase; Stomach; Stomach Neoplasms

Increasing evidence indicates that aberrantly expressed microRNAs play a role in tumorigenesis and progression of gastric cancer. Recently, a novel cancer-related microRNA, miR-621, was found to be involved in cancer pathogenesis. However, the precise molecular mechanisms underlying the oncogenic activity of miR-621 remain unclear and require further investigation. In the current study, we demonstrate that miR-621 expression is downregulated in gastric cancer tissues and cell lines, and its reduction is associated with malignant clinical features including tumor size, lymph node metastasis, tumor-node-metastasis stage and poor prognosis. Functional studies involving gain- and loss-of-function experiments revealed that miR-621 represses cell viability, colony formation, cell cycle progression and proliferation in vitro, and miR-621 overexpression inhibited tumor growth in a gastric cancer xenograft model. SYF2 was identified as a direct target gene of miR-621 in gastric cancer. MiR-621 directly interacts with the SYF2 3'-UTR and post-transcriptionally repressed SYF2 expression in gastric cancer cells. SYF2 was significantly overexpressed in gastric cancer tissues and negatively correlated with miR-621 expression. Moreover, inhibition of SYF2 expression reversed the effects of miR-621 loss in gastric cancer cells. SYF2 overexpression was similar to that induced by miR-621 loss in gastric cancer. Taken together, these studies suggest that miR-621 may be a viable therapeutic target in gastric cancer.

Topics: Animals; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Down-Regulation; Gene Expression Regulation, Neoplastic; Humans; Male; Mice, Inbred BALB C; MicroRNAs; Prognosis; RNA-Binding Proteins; Stomach Neoplasms; Up-Regulation

Gastric cancer is one of the most common malignancies diagnosed worldwide. Telmisartan, an angiotensin receptor blocker (ARB), suppresses the proliferation of cancer cells and the growth of tumors through an unknown mechanism. To identify the mechanism, the present study was designed to evaluate the effects of telmisartan on gastric cancer cell lines and tumors in vitro and in vivo and the associated signaling molecules were identified. It was shown here that telmisartan suppressed the proliferation of the cultured human gastric cancer cell lines MKN74, MKN1 and MKN45 as detected in the CCK‑8 assay. In a mouse xenograft model of gastric cancer, telmisartan suppressed tumor growth by arresting the cell cycle at the G0/G1 phase through inhibition of the expression of cyclin D1, the catalytic subunit of cyclin dependent kinase 4 (CDK4), as well as the phosphorylation of the tumor suppressor retinoblastoma (pRb) protein as detected by western blotting. Notably, telmisartan did not induce apoptosis, as indicated by consistent levels of caspase‑cleaved keratin 18 in MKN74 cells. Furthermore, telmisartan inhibited the phosphorylation of epidermal growth factor receptor (EGFR) and increased the levels of the angiogenesis‑related protein tissue inhibitor of metalloproteinase‑1 (TIMP‑1). Analyses of microarrays revealed that telmisartan altered the expression of miRNAs in MKN74 cells. In conclusion, telmisartan suppressed the proliferation of human gastric cancer cells by inducing cell cycle arrest.

Topics: Animals; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cyclin D1; Cyclin-Dependent Kinase 4; Drug Repositioning; Gene Expression Regulation, Neoplastic; Humans; Mice; MicroRNAs; Phosphorylation; Retinoblastoma Protein; Stomach Neoplasms; Telmisartan; Xenograft Model Antitumor Assays

To investigate the effect of parthenolide (PTL), a sesquiterpene lactone medicinal compound, on the sensitivity of the gastric cancer cell line SGC7901 and the DPP- and ADR-resistant sublines SGC7901/DDP and SGC7901/ADR to cisplatin [diamminedichloroplatinum (Ⅱ), DDP] and adriamycin (ADR) in vitro.. SGC7901, SGC7901/DDP, and SGC7901/ADR were treated with various concentrations of PTL alone or in combination with DDP or ADR. The effects on cell proliferation, apoptosis, and expression/activity of several proliferation/apoptosis-related proteins [B-cell lymphoma-2 (Bcl-2), cyclin D1, nuclear factor-kappa B (NF-κB), and Caspase-8] and drug transporters (P-glycoprotein and multidrug resistance protein-1) were measured using flow cytometry, Western blotting, and in vitro activity assays.. Treatment of SGC7901 cells with PTL inhibited cell growth, increased apoptosis, and sensitized the cells to DPP. Mechanistically, PTL treatment resulted in downregulation of NF-κB activity and Bcl-2 expression, and upregulation of Caspase-8 activity. Similarly, PTL co-treatment of SGC7901/DDP and SGC7901/ADR overcame their resistance to DDP and ADR, respectively, with concomitant inhibition of NF-κB, Bcl-2, Cyclin D1, P-glycoprotein, and multidrug resistance protein-1 expression and/or activity.. PTL treatment decreases drug resistance in SGC7901, SGC7901/DDP, and SGC7901/ADR cells, as reflected by induction of apoptosis, inhibition of proliferation, downregulation of pro-survival and drug resistance pathways, and upregulation of pro-apoptotic pathways. Our results suggest that co-treatment with PTL may thus complement existing therapies for gastric cancer.

Topics: Antineoplastic Agents; ATP Binding Cassette Transporter, Subfamily B, Member 1; Cell Line, Tumor; Cell Proliferation; Cisplatin; Cyclin D1; Doxorubicin; Drug Resistance, Neoplasm; Drug Synergism; Humans; NF-kappa B; Proto-Oncogene Proteins c-bcl-2; Sesquiterpenes; Stomach Neoplasms

Reactive oxygen species (ROS) promote the development and progression of cancer by their effects on several signaling pathways. Lycopene, a major carotenoid natural product, is known to display antioxidant activity and to induce apoptosis of cancer cells. The aim of the present study was to investigate the mechanism by which lycopene induces apoptosis of the human gastric cancer AGS cells. In the present study, we showed that lycopene reduces the viability of AGS cells by inducing DNA fragmentation and increasing the Bax/Bcl-2 ratio. To determine the mechanistic basis for these effects, studies were conducted to assess the effects of this carotenoid on activation and nuclear translocation of β-catenin, and the expression of β-catenin target genes in AGS cells. The results showed that lycopene reduces the levels of ROS. It also inhibits activation of β-catenin signaling by changing the Wnt/β-catenin multi-protein complex such as a reduction in phosphorylation of glycogen synthase kinase 3β [GSK3β] and an increase in adenomatous polyposis coli [APC] and β-transducin repeats-containing proteins [β-TrCP]). It suppresses nuclear translocation of β-catenin and the expression of the β-catenin target survival genes c-myc and cyclin D1. Lycopene induces apoptosis by reducing ROS levels and suppressing β-catenin-c-myc/cyclin D1 axis. Thus, lycopene induces apoptosis of gastric cancer cells by disrupting nuclear translocation of β-catenin and expression of key cell survival genes.

Topics: Antineoplastic Agents; Apoptosis; beta Catenin; Cell Line, Tumor; Cell Nucleus; Cell Survival; Cyclin D1; DNA Fragmentation; Humans; Lycopene; Protein Transport; Proto-Oncogene Proteins c-bcl-2; Proto-Oncogene Proteins c-myc; Reactive Oxygen Species; Signal Transduction; Stomach Neoplasms

Gastric cancer is a common malignant tumor with high morbidity and mortality worldwide, which seriously affects human health. Gramicidin is a short peptide antibiotic which could be used for treating infection induced by bacteria or fungi. However, the anti-cancer effect of gramicidin on gastric cancer cells and its underlying mechanism remains largely unknown.. Gastric cancer cells SGC-7901, BGC-823 and normal gastric mucosal cells GES-1 were treated with different concentrations of gramicidin respectively. The results of CCK-8 experiment revealed cellular toxicity of gramicidin to cancer cells while cell colony formation assay showed that gramicidin significantly inhibited the proliferation of gastric cancer cells, but had little effect on normal gastric mucosal cells. In addition, the wound healing assay showed that gramicidin inhibited the migration of SGC-7901 cell. Meanwhile, apoptosis and cell cycle analysis revealed that gramicidin induced cell apoptosis with G2/M cell cycle inhibition. Furthermore, western blot analysis demonstrated that gramicidin down-regulated the expression of cyclinD1 and Bcl-2 as well as the FoxO1 phosphorylation.. The current study illustrated the anti-tumor activity of gramicidin on gastric cancer cells, providing a possibility for gramicidin to be applied in clinical practice for the treatment of gastric cancer.

Topics: Apoptosis; Cell Cycle; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Down-Regulation; Forkhead Box Protein O1; Gramicidin; Humans; Phosphorylation; Proto-Oncogene Proteins c-bcl-2; Stomach Neoplasms

Gastric cancer (GC) is one of the mostly terminal malignancies with poor prognosis. Long noncoding RNA EGOT (EGOT) acts as a crucial regulator in the breast cancer. However, the function of EGOT in GC remains unknown. This work was to explore the clinical value and biological significance of EGOT in GC. EGOT levels in GC tissue and cell were analyzed by qRT-PCR. After knockdown of EGOT, GC cell growth and cycle progression were detected. The expression of EGOT was observably elevated in GC. Upregulation of EGOT was related with lymphatic metastasis and TNM stage. In addition, knockdown of EGOT by siRNA could significantly inhibit GC cell proliferation and arrest cycle progression in G1 phase. Moreover, EGOT mediated cyclin D1 expression in GC cells which was regulated by Hedgehog pathway. Further, loss of EGOT downregulated Hedgehog signaling pathway in GC cells. EGOT functions as an oncogene in GC, and may be useful as a conceivable diagnostic and prognostic biomarker for GC tumorigenesis.

Topics: Apoptosis; Biomarkers, Tumor; Carcinogenesis; Cell Line; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Disease Progression; Down-Regulation; Female; Gene Expression Regulation, Neoplastic; Hedgehog Proteins; Humans; Lymphatic Metastasis; Male; Middle Aged; RNA, Long Noncoding; Signal Transduction; Stomach Neoplasms; Up-Regulation

Worldwide, gastric carcinoma (GC) is the 5th most common malignancies in both sexes representing 6.8% of the total fatalities and is the 3rd leading cause of cancer death representing 8.8% of total fatalities. In Egypt, GC considers the 12th leading cause of cancer death representing 2.2% of the total cancer mortality. A growing body of evidence supports that cancer stem cells (CSCs) are resistant to chemotherapy or radiation, and the cell adhesion molecule CD44 has been identified as a cell surface marker associated with cancer stem cell in several types of tumors including gastric cancer. CD44 regulates gastric stem cell proliferation by increasing cyclin D1 expression which represents an important regulatory protein in the cell cycle transition from G1 phase to S phase. This study aimed to investigate whether cyclin D1 and CD44 can be used as prognostic indicators in gastric cancer.. Forty formalin-fixed and paraffin-embedded gastric tissues, obtained from patients who underwent endoscopic resection or surgical resection, constituted the group of our study. The immunohistochemical expression of cyclin D1 and CD44 was examined and correlated with clinical-pathological parameters and outcome of the patients.. Overexpression of CD44 and cyclin D1 was noted (in of 55 and 50% respectively). Cyclin D1 and CD44 positive expressions in GC were positively correlated with tumor differentiation (p = 0.020, p = 0.004 respectively), TNM stage (p < 0.001 for both), poor survival (p < 0.001 for both), and with increased rate of recurrence (p = 0.020, p = 0.005 respectively).. CD44 and cyclin D1 were associated with poor prognosis in gastric cancer, and so, they comprise an attractive target for anticancer drug development.

Topics: Adenocarcinoma; Adult; Biomarkers, Tumor; Case-Control Studies; Cyclin D1; Female; Follow-Up Studies; Humans; Hyaluronan Receptors; Male; Middle Aged; Neoplasm Recurrence, Local; Prognosis; Stomach Neoplasms; Survival Rate

The present study investigated the expression and potential influence of SHC SH2 domain‑binding protein 1 (SHCBP1) in gastric cancer (GC) cells. SHCBP1 is closely related to cell proliferation and cell cycle progression, but its role in GC remains unclear. The TCGA database revealed that SHCBP1 is highly expressed in GC tissues. Furthermore, SHCBP1 was revealed to be highly expressed in GC cell lines MGC‑803 and SGC‑7901 cells, and downregulation of SHCBP1 significantly inhibited GC cell proliferation. Furthermore, SHCBP1 expression promoted cell cycle progression and inhibition of apoptosis. Since the CDK4, cyclin D1 and caspase family proteins play important roles in cell cycle and apoptosis regulation, it was examined whether there was an association between SHCBP1 and these signaling pathways in GC. Our results revealed that SHCBP1 promoted cell cycle progression by regulating the CDK4‑cyclin D1 cascade and suppressed caspase‑3, caspase PARP‑dependent apoptotic pathways. Cell invasion and metastasis experiments also revealed that SHCBP1 promoted tumor growth and invasiveness. These tumor‑promoting functions of SHCBP1 may provide a potential molecular basis for the diagnosis and targeted therapy of GC.

Topics: Apoptosis; Biomarkers, Tumor; Caspase 3; Cell Cycle; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Cyclin-Dependent Kinase 4; Down-Regulation; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Humans; RNA, Small Interfering; Shc Signaling Adaptor Proteins; Signal Transduction; Stomach; Stomach Neoplasms

It is believed that the Wnt pathway is one of the most important signaling involved in gastric carcinogenesis.. To analyze the protein expression of canonical and non-canonical Wnt pathways in gastric carcinoma.. The immunohistochemistry was performed in 72 specimens of gastric carcinomas for evaluating the expression of Wnt-5a, FZD5, GSK3β, axin, CK1, ubiquitin, cyclin D1 and c-myc.. There were significant differences for cytoplasm and nucleus ubiquitin for moderately and well differentiated tumors (p=0.03) and for those of the intestinal type of the Lauren classification (p=0.03). The absence of c-myc was related to Lauren's intestinal tumors (p=0.03). Expression of CK1 in the cytoplasm was related to compromised margin (p=0.03). Expression of cyclin D1 protein was more intense in male patients (p=0.03) There was no relation of the positive or negative expression of the Wnt-5a, FZD5, GSK3 and Axin with any clinicopathological variables.. The canonical WNT pathway is involved in gastric carcinoma.

Topics: Axin Protein; Carcinogenesis; Carcinoma; Casein Kinase I; Cyclin D1; Female; Frizzled Receptors; Glycogen Synthase Kinase 3 beta; Humans; Immunohistochemistry; Male; Neoplasm Proteins; Neoplasm Staging; Proto-Oncogene Proteins c-myc; Reference Values; Stomach Neoplasms; Ubiquitin; Wnt Signaling Pathway; Wnt-5a Protein

RN181, a RING finger domain-containing protein, is an E3 ubiquitin ligase. However, its biological function and clinical significance in cancer biology are obscure. Here, we report that RN181 expression is significantly down-regulated in 165 tumour tissues of gastric carcinoma (GC) versus adjacent non-tumour tissues, and inversely associated with tumour differentiation, tumour size, clinical stage, and patient's overall survival. Alterations of RN181 expression in GC cells by retrovirus-transduced up-regulation and down-regulation demonstrated that RN181 functions as a tumour suppressor to inhibit growth of GC in both in vitro culture and in vivo animal models by decreasing tumour cell proliferation and increasing tumour cell apoptosis. Cell cycle analysis revealed that RN181 controls the cell cycle transition from G1 to S phase. Mechanistic studies demonstrated that RN181 inhibits ERK/MAPK signalling, thereby regulating the activity of cyclin D1-CDK4, and consequently controlling progression in the cell cycle from G1 to S phase. Restoring CDK4 in GC cells rescued the inhibitory phenotype produced by RN181 in vitro and in vivo, suggesting a dominant role of CDK4 in control of the tumour growth by RN181. Importantly, RN181 expression is inversely correlated with the expression of cyclin D1 and CDK4 in GC clinical samples, substantiating the role of the RN181-cyclin D1/CDK4 pathway in control of the tumour growth of GC. Our results provide new insights into the pathogenesis and development of GC and rationale for developing novel intervention strategies against GC by disruption of ERK/MAPK-cyclin D1/CDK4 signalling. In addition, RN181 may serve as a novel biomarker for predicting clinical outcome of GC. © 2019 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Topics: Adult; Aged; Aged, 80 and over; Animals; Apoptosis; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Cyclin-Dependent Kinase 4; Extracellular Signal-Regulated MAP Kinases; Female; G1 Phase Cell Cycle Checkpoints; Gene Expression Regulation, Neoplastic; Humans; Male; Mice, Inbred BALB C; Mice, Nude; Middle Aged; Signal Transduction; Stomach Neoplasms; Tumor Burden; Tumor Suppressor Proteins; Ubiquitin-Protein Ligases

BACKGROUND Gastric cancer is a common gastrointestinal tumor. The incidence and mortality of gastric cancer are very high. Therefore, it is important to study targeted drugs. Recent studies found long chain non-coding RNA (lncRNAs) and microRNAs (miRNAs) were abnormal in gastric cancer. MATERIAL AND METHODS We collected adjacent normal and cancer tissues of gastric cancer patients and measured HOTAIR, miR-454-3p, STAT3, and Cyclin D1 expression and analyzed the correlation with clinical status. We also measured AGS and SGC7901 cells proliferation rate of different groups by MTT assay, and we evaluated AGS and SGC7901 cell apoptosis and cell cycle by flow cytometry. In addition, we assessed the relative proteins expressions by WB assay. Finally, we explored the correlation between miR-454-3p and STAT3 by use of double luciferase reporter. RESULTS lncRNA HOTAIR was negatively correlated with miR-454-3p expression in gastric cancer tissues. lncRNA HOTAIR knockdown suppressed AGS and SGC7901, which are gastric cancer cell lines that promote cell proliferation by increasing cell apoptosis and keeping the cell cycle in G1 phase. In further mechanism research, we found that the STAT3 and Cyclin D1 proteins expressions were suppressed by lncRNA HOTAIR down-regulation in AGS and SGC7901 cells. CONCLUSIONS Our results suggest that lncRNA HOTAIR knockdown stimulates miR-454-3p expression to inhibit gastric cancer growth by depressing STAT3/Cyclin D1 activity.

Topics: Apoptosis; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Gene Knockdown Techniques; Genes, bcl-1; Humans; MicroRNAs; RNA, Long Noncoding; STAT3 Transcription Factor; Stomach Neoplasms

Cyclin‑dependent kinase 5 regulatory subunit‑​associated protein 3 (CDK5RAP3 or C53) is involved in the development of various types of tumor, and alternative splicing of C53 results in numerous transcription variants that encode different isoforms. The present study aimed to clone human C53 isoform d (IC53d) and explore its role in the proliferation of gastric cancer cells. Reverse transcription‑quantitative polymerase chain reaction was used to detect the expression levels of IC53d in 80 primary gastric adenocarcinoma tissues and adjacent normal tissues. In addition, the association between IC53d and clinicopathological parameters was determined. Gastric cancer cell lines stably overexpressing IC53d were established to observe its effects on cell proliferation, invasion and migration, and on in vivo tumorigenicity, and the mechanism of action was explored. The results of the presen study demonstrated that IC53d was upregulated in gastric cancer tissues and was associated with tumor T‑stage. Furthermore, overexpression of IC53d promoted the proliferation, colony formation and G1/S phase transition of gastric cancer cells, leading to enhancement of tumorigenesis in vitro and in vivo. Overexpression of IC53d also promoted phosphorylation of protein kinase B (AKT) and glycogen synthase kinase 3β (GSK3β), which increased the expression of cyclin D1. In addition, high cyclin D1 expression was associated with a significantly worse prognosis for patients compared with in patients with low cyclin D1 expression. These results indicated that IC53d may promote the phosphorylation of AKT and GSK3β, which in turn may increase cyclin D1 expression, enhancing G1/S phase transition, accelerating cell cycle progression, promoting the proliferation of gastric cancer cells, and inducing a poor prognosis in patients with gastric cancer.

Topics: Adenocarcinoma; Animals; Cell Cycle Proteins; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Female; Follow-Up Studies; Glycogen Synthase Kinase 3 beta; Humans; Intracellular Signaling Peptides and Proteins; Male; Mice, Inbred BALB C; Mice, Nude; Middle Aged; Neoplasm Staging; Nerve Tissue Proteins; Phosphorylation; Prognosis; Protein Isoforms; Proto-Oncogene Proteins c-akt; RNA, Small Interfering; Signal Transduction; Stomach; Stomach Neoplasms; Survival Analysis; Tumor Suppressor Proteins; Xenograft Model Antitumor Assays

Coronin-like actin-binding protein 1C (CORO1C) is a member of the WD repeat protein family that regulates actin-dependent processes by assembling F-actin. CORO1C was previously reported to promote metastasis in breast cancer and lung squamous cell carcinoma. Here, we investigated the role of CORO1C in gastric cancer. Higher expression levels of CORO1C were detected in gastric cancer tissues as compared with normal gastric tissues. In addition, CORO1C levels were found to be positively correlated with lymph node metastasis in gastric cancer patients. The expression levels of CORO1C were higher in stage III-IV gastric cancer patients (80.8%) than in stage I-II gastric cancer patients(57.1%). Gastric cancer patients positive for CORO1C expression showed lower relapse-free survival and overall survival rates. Knockdown of CORO1C dramatically suppressed total cell number, cell viability, cell colony formation, cell mitosis and cell metastasis, and promoted apoptosis of gastric cancer cells. Furthermore, cyclin D1 and vimentin were found to be positively regulated by CORO1C. As cyclin D1 and vimentin play an oncogenic role in gastric cancer, CORO1C may exert its tumor-promoting activity through these proteins.

Topics: Apoptosis; Biomarkers, Tumor; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Female; Follow-Up Studies; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Humans; Lymph Nodes; Lymphatic Metastasis; Male; Microfilament Proteins; Middle Aged; Mitosis; Neoplasm Invasiveness; RNA, Small Interfering; Stomach Neoplasms; Survival Rate; Transfection; Vimentin

Topics: Animals; Antineoplastic Agents, Phytogenic; beta Catenin; Betaine; Cyclin D1; Dendrobium; Gene Expression Regulation, Neoplastic; Glycogen Synthase Kinase 3 beta; Male; Metabolome; Methylnitronitrosoguanidine; Plant Extracts; Polysaccharides; Precancerous Conditions; Proliferating Cell Nuclear Antigen; Rats; Rats, Sprague-Dawley; Signal Transduction; Stomach Neoplasms; Wnt Proteins

Gastric cancer (GC) is the fourth common cancer and second leading cause of cancer-related mortality in the world. WD repeat domain 5 (WDR5) has been identified that its functions as an important role in various biological functions through the epigenetic regulation of gene transcription. However, the oncogenic effect of WDR5 in gastric cancer remains largely unknown. In this study, we investigated the role of WDR5 in gastric cancer genesis. We found that WDR5 expression is increased in gastric cancer patients. Through survival analysis, we found that high expression of WDR5 is associated with high risk gastric cancer; patients who with WDR5 high expression have poor survival rate compared with those who with WDR5 low expression. To make further investigation, we identified that WDR5 is targeted for cell cycle arrest by the Cyclin D1 in a process that is regulated by H3K4me3. Moreover, over-expression of WDR5 promotes cell proliferation, induces S/G2/M arrest in cell cycle, and promotes the expression of WDR5 targets, as well as that of H3K4me3 on the promoter of its targets. Inversely, WDR5 knockdown by shRNA inhibits cell proliferation, reverses S/G2/M arrest in cell cycle, and suppresses the expression of WDR5 targets, as well as that of H3K4me3. We also observed the positive correlation of WDR5 expression with its target in the cohort study of gastric patients. Taken together, our data reveal that WDR5 may have oncogenic effect and WDR5-mediated H3K4 methylation plays an important role in gastric cancer.

Topics: Animals; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Epigenesis, Genetic; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Histone-Lysine N-Methyltransferase; Histones; Humans; Intracellular Signaling Peptides and Proteins; Mice; Neoplasm Transplantation; Oligonucleotide Array Sequence Analysis; Promoter Regions, Genetic; Stomach Neoplasms; Survival Analysis; Up-Regulation

The dysregulation of microRNAs (miRNAs) plays an important function in the onset and progression of gastric cancer (GC). In addition, aberrantly expressed miRNAs affect the chemosensitivity of GC cells to chemotherapeutic drugs. Hence, miRNA-based targeted therapy might be applied to treat patients with GC exhibiting chemotherapeutic resistance. In this study, miRNA-623 (miR-623) expression was downregulated in GC tissues and cell lines. Functional analysis showed that the restored miR-623 expression could inhibit the proliferation of GC cells and enhance their chemosensitivity to 5-FU via the cell apoptosis pathway. Cyclin D1 (CCND1) was identified as a direct target gene of miR-623 in GC. The overexpressed CCND1 in GC tissues was negatively correlated with miR-623 level. The recovered CCND1 expression counteracted the effects of miR-623 on GC cell proliferation, chemosensitivity, and 5-FU-induced apoptosis. Thus, our results suggest that miR-623 might function as a tumor suppressor in GC and could be a promising therapeutic target for patients with GC, especially those with chemotherapeutic resistance.

Topics: Apoptosis; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Drug Resistance, Neoplasm; Fluorouracil; Gene Expression Regulation, Neoplastic; Humans; MicroRNAs; Stomach Neoplasms

NADPH Oxidase 4 (NOX4), a member of the NOX family, has emerged as a significant source of reactive oxygen species, playing an important role in tumor cell proliferation, apoptosis, and other physiological processes. However, the potential function of NOX4 in gastric cancer (GC) cell proliferation is yet unknown. The aim of this study was to illustrate whether NOX4 plays a role in regulating gastric cancer cell growth. First, the clinical information from 90 patients was utilized to explore the clinical value of NOX4 as a predictive tool for tumor size and prognosis. Results showed that NOX4 expression was correlated with tumor size and prognosis. In vitro assays confirmed that knockdown of NOX4 expression blocked cell proliferation and the expression of Cyclin D1, BAX, and so on. Interestingly, NOX4 promoted cell proliferation via activation of the GLI1 pathway. GLI1, a well-known transcription factor in the Hedgehog signaling pathway, was overexpressed to test whether NOX4 activates downstream signaling via GLI1. Overexpression of GLI1 reversed the inhibition of proliferation induced by NOX4 knockdown. In addition, overexpression of NOX4 increased GLI1 expression, and depletion of GLI1 expression decreased the effects induced by NOX4 overexpression. Further, ROS generated by NOX4 was required for GLI1 expression, as shown by use of the ROS inhibitor, diphenylene iodonium (DPI). In summary, the findings indicate that NOX4 plays an important role in gastric cancer cell growth and apoptosis through the generation of ROS and subsequent activation of GLI1 signaling. Hence, the targeting of NOX4 may be an attractive therapeutic strategy for blocking gastric cancer cell proliferation.

Topics: Apoptosis; bcl-2-Associated X Protein; Biomarkers, Tumor; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Disease Progression; Female; Humans; Male; Middle Aged; NADPH Oxidase 4; Reactive Oxygen Species; Stomach Neoplasms; Zinc Finger Protein GLI1

Objective To investigate the effect and molecular mechanism of β-lapachone combined with NVP-BEZ235 on the proliferation and migration of BGC-823 human gastric cancer cells. Methods BGC-823 cells were randomly divided into four groups: control group, 1 μmol/L β-lapachone group, 50 nmol/L NVP-BEZ235 group and 1 μmol/L β-lapachone combined with 50 nmol/L NVP-BEZ235 group. The proliferation of cells was determined using the MTT assay and colony formation assay. The expression levels of proliferation-related proteins phosphorylated AKT (p-AKT), phosphorylated NF-κB (p-NF-κB), phosphorylated extracellular signal-regulated kinase (p-ERK) and cyclin D1 were detected by Western blotting. The migration of cells was measured by wound healing assay and Transwell

Topics: Antineoplastic Agents; Apoptosis; beta Catenin; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Humans; Imidazoles; Naphthoquinones; NF-kappa B; Phosphatidylinositol 3-Kinases; Phosphorylation; Proto-Oncogene Proteins c-akt; Quinolines; Signal Transduction; Stomach Neoplasms; TOR Serine-Threonine Kinases

Gastric cancer (GC) is one of the most common malignant cancer around the world, however the mechanisms is still unclear. In the present study, we investigated the function of CREB3 regulatory factor (CREBRF) in human GC and explored its relevant molecular mechanism. We found that CREBRF was highly expressed in primary GC tissues and the expression level was associated with the clinicopathologic characteristics of GC. CREBRF silencing inhibited GC cell proliferation and induced G1/G0 to S phase cell cycle arrest through regulating Cyclin A, Cyclin D1 and CDK2 expressions. Furthermore, the results showed that knockdown of CREBRF suppressed the activation of AKT signaling pathway. We further discovered that activating of AKT rescued the effect of CREBRF silencing on cell growth and drove cell re-enter into the S phase of the cell cycle with SC79 (a AKT activator). Taken together, our study demonstrated that CREBRF might promote GC cell proliferation and induce G1-S phase transition through activating AKT signaling pathway. These findings suggest that CREBRF acts as a novel oncogene and may be a potential therapeutic target in therapy of GC.

Topics: Aged; Apoptosis; Cell Line, Tumor; Cell Proliferation; Cyclin A; Cyclin D1; Cyclin-Dependent Kinase 2; Female; G1 Phase Cell Cycle Checkpoints; Gene Expression Regulation, Neoplastic; Humans; Lymphatic Metastasis; Male; Middle Aged; Neoplasm Staging; Proto-Oncogene Proteins c-akt; RNA, Messenger; RNA, Small Interfering; Signal Transduction; Stomach Neoplasms; Tumor Suppressor Proteins

MicroRNAs (miRNAs) are small non-protein-coding RNAs, that can be generated from the 5p or 3p arm of precursor miRNA (pre-miRNA). Differential miRNA arm selection has been reported between tumor and normal tissue in many cancer types; however, the biological function and mechanism of miRNA arm switching in gastric cancer remain unclear.. Profiles of miRNA expression in gastric cancer were obtained from The Cancer Genome Atlas (TCGA). The biological role of miR-193a-5p/-3p in tumor growth and invasive abilities was assessed through a gain-of-function approach. Target genes of miR-193a-3p were identified using bioinformatics and an experimental approach.. The expression levels of miR-193a-5p, and not of miR-193a-3p, were significantly decreased in gastric cancer compared to adjacent normal tissues. Ectopic expressions of miR-193a-5p and miR-193a-3p revealed that they both inhibited gastric cancer cell growth, but only miR-193a-3p significantly suppressed cell invasion ability. Using a bioinformatics approach, we identified 18 putative target genes of miR-193a-3p. Both mRNA and protein levels of cyclin D1 (CCND1) and ETS proto-oncogene 1 (ETS1) were significantly decreased in AGS cells transfected with miR-193a-3p mimics. ETS1 or CCND1 knockdown significantly suppressed gastric cancer cell growth, similar to miR-193a-3p overexpression.. Our results indicated that miR-193a-3p suppressed gastric growth and motility, at least partly, by directly targeting CCND1 and ETS1 expression.

Topics: Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Humans; MicroRNAs; Proto-Oncogene Mas; Proto-Oncogene Protein c-ets-1; RNA Interference; Stomach Neoplasms

The present study investigated the effect and underling mechanisms of aclidinium bromide, a novel, inhaled long‑acting muscarinic antagonist, on the development of gastric cancer. Human gastric cancer MKN‑28 cells, as a model in vitro, were treated with aclidinium bromide and dimethyl sulfoxide. Cell Counting Kit‑8 assay, transwell assay and flow cytometry were used to assess cell proliferation, invasion/migration and apoptosis, respectively. In addition, western blotting was performed to determine the relative expression of proteins associated with apoptosis and the phosphatidylinositol‑3‑kinase (PI3K) signaling pathway. Optical density values of MKN‑28 cells were decreased in a time‑ and dose‑dependent manner in the aclidinium bromide treated group. Matrigel invasion analysis demonstrated the number of invasive cells were significantly decreased in the aclidinium bromide‑treated group when compared with the control group. Furthermore, aclidinium bromide led to the marked reduction of the number of MKN‑28 cells passing though the microwells of the transwell chamber. The expression levels of the anti‑apoptotic protein B‑cell lymphoma 2 (Bcl‑2) decreased, and the expression of pro‑apoptotic proteins active Caspase3 and Bcl‑2‑associated X protein increased concurrently following aclidinium bromide stimulation using western blotting. The phosphorylation of protein kinase B and mechanistic target of rapamycin were significantly inhibited in MKN‑28 cells treated with aclidinium bromide; and the activity of the downstream proteins such as p70S6K and Cyclin D1 were also significantly decreased. In conclusion, aclidinium bromide could inhibit gastric cancer cell proliferation and metastasis, which may be associated with the enhancement of apoptosis induced by the PI3K signaling pathway.

Topics: Apoptosis; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Flow Cytometry; Gene Expression Regulation, Neoplastic; Humans; Neoplasm Invasiveness; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Ribosomal Protein S6 Kinases, 70-kDa; Signal Transduction; Stomach Neoplasms; TOR Serine-Threonine Kinases; Tropanes

Topics: Amaryllidaceae Alkaloids; Apoptosis; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Down-Regulation; Humans; Phenanthridines; Stomach Neoplasms

The tripartite motif (TRIM) family comprises more than 70 members involved in the regulation of many cellular pathways. TRIM32 acts as an E3 ubiquitin ligase and has been reported to participate in many human cancers. Here, we aimed to investigate the role of TRIM32 in gastric cancer (GC) and the clinical implications. High expression of TRIM32 was observed in GC tissues and cell lines, and was significantly associated with poor prognosis. Knockdown TRIM32 expression remarkably suppressed the proliferation, migration, and invasion of GC cells in vitro and tumour growth in vivo, whereas overexpression of TRIM32 yielded the opposite results. Western blotting and quantitative reverse-transcription PCR (qRT-PCR) analyses revealed that up-regulation of TRIM32 significantly enhanced expression of β-catenin protein and of its downstream targets TCF1, cyclin D1, Axin2 and MMP7 mRNAs. Moreover, we found that the mechanism behind the TRIM32-promoted GC progression was related to the β-catenin signalling pathway. Collectively, these data suggest that TRIM32 promotes GC cell proliferation, migration, and invasion by activating the β-catenin signalling pathway.

Topics: Axin Protein; beta Catenin; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Epithelial-Mesenchymal Transition; Female; Gene Expression Regulation, Neoplastic; Hepatocyte Nuclear Factor 1-alpha; Humans; Male; Matrix Metalloproteinase 7; Neoplasm Invasiveness; Stomach Neoplasms; Transcription Factors; Tripartite Motif Proteins; Ubiquitin-Protein Ligases; Wnt Signaling Pathway

Gastric cancer (GC) develops from the lining of the stomach. The present study aimed to explore the effects of long non-coding RNA-ENST00000434223 (lncRNA ENST00000434223) on gastric cancer (GC) cells.. One hundred and four GC tissues and paracancerous tissues were collected from GC patients, and expression of ENST00000434223, Wnt2b, β-catenin, cyclinD1, E-cadherin, N-cadherin, vimentin, and snail was subsequently assessed. Morphological changes in cells were assessed using an inverted microscope, and expression of Bcl-2, Bax and caspase-3 was examined.. We found that expression of Wnt2b, β-catenin, cyclinD1, N-cadherin, vimentin, and snail was increased in GC tissues, while expression of ENST00000434223 and E-cadherin was decreased. SGC-7901 cells were closely arranged, and expression of Wnt2b, β-catenin, CyclinD1, N-cadherin, Vimentin, snail and Bcl-2 was increased, whereas expression of ENST00000434223, E-cadherin, Bax and caspase-3 was decreased. Furthermore, the rate of apoptosis was decreased and cell proliferation, invasion and migration were increased in response to downregulation of ENST00000434223. By contrast, upregulation of ENST00000434223 exhibited the opposite effects in MKN-45 cells.. The results of this study provide a promising experimental basis for the treatment of gastric cancer through interventional targeting of lncRNA ENST00000434223.

Topics: Adult; Aged; Aged, 80 and over; Apoptosis; beta Catenin; Cadherins; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Disease Progression; Epithelial-Mesenchymal Transition; Female; Gene Expression Regulation, Neoplastic; Glycoproteins; Humans; Male; Middle Aged; Neoplasm Invasiveness; RNA, Long Noncoding; Stomach Neoplasms; Wnt Proteins

Topics: Animals; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Down-Regulation; Histone Deacetylases; Humans; Integrin beta1; Mice; Mice, Nude; Neoplasm Invasiveness; Neoplasm Proteins; Phenotype; Repressor Proteins; Reverse Transcriptase Polymerase Chain Reaction; RNA, Small Interfering; Stomach Neoplasms; Trans-Activators; Transfection; Wound Healing

In the present study, we investigated the expression and cellular distribution of microRNA‑495 (miR‑495) in human gastric cancer. Prominent downregulation of miR‑495 activation was evident in patients with gastric cancer. Cell viability and Annexin V/PI apoptosis assays were used to assess cell proliferation and apoptosis. Then, western blot analysis was used to assess cyclin D1, PI3K, p‑Akt and p‑mTOR protein expression. Overexpression of miR‑495 significantly inhibited cell proliferation, and promoted cell apoptosis of gastric cancer cells. Overexpression of miR‑495 also promoted caspase‑3/‑9 and Bax protein expression, and suppressed cyclin D1 protein expression and the PI3K/Akt/mTOR pathway in gastric cancer cells. Downregulation of miR‑495 increased cell proliferation and inhibited cell apoptosis of gastric cancer cells through activation of the PI3K/Akt/mTOR pathway. The PI3K inhibitor, was used to suppress the PI3K/Akt/mTOR pathway, inhibit cell proliferation, promote cell apoptosis, promote caspase‑3/‑9 and Bax protein expression, and suppress cyclin D1 protein expression of gastric cancer cells through miR‑495 inhibition. In conclusion, miR‑495 is an important regulator of human gastric cancer cells and may contribute to cell apoptosis through the PI3K/Akt/mTOR/Bax‑caspase‑3/‑9 and cyclin D1 pathway.

Topics: Apoptosis; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Down-Regulation; Gene Expression Regulation, Neoplastic; Humans; MicroRNAs; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Signal Transduction; Stomach Neoplasms; Survival Analysis; TOR Serine-Threonine Kinases

DEAD (Asp-Glu-Ala-Asp) cassette helicase 21 (DDX21) is an ATP-dependent RNA helicase that is overexpressed in various malignancies. There is increasing evidence that DDX21 is involved in carcinogenesis and cancer progression by promoting cell proliferation. However, the functional role of DDX21 in gastric cancer is largely unknown. In this study, we observed that DDX21 was significantly up-regulated in gastric cancer tissues compared to paired adjacent normal tissues. The expression of DDX21 was closely related to the pathological stage of gastric cancer. In vitro and in vivo studies had shown that knockdown of DDX21 inhibited gastric cancer cell proliferation, colony formation, G1/S cell cycle transition and xenograft growth, while ectopic expression of DDX21 promoted these cell functions. Mechanically, DDX21 induced gastric cancer cell growth by up-regulating levels of Cyclin D1 and CDK2. Taken together, these results revealed a novel role for DDX21 in the proliferation of gastric cancer cells via the Cyclin D1 and CDK2 pathways. Therefore, DDX21 can be used as a therapeutic target for gastric cancer.

Topics: Animals; Carcinogenesis; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Cyclin-Dependent Kinase 2; DEAD-box RNA Helicases; Female; Humans; Male; Mice, Inbred BALB C; Mice, Nude; Middle Aged; Stomach Neoplasms

Sine oculis homeobox homologue 1 (SIX1) is a Six class homeobox gene conserved throughout many species. It has been reported to act as an oncogene and is overexpressed in many cancers. However, the function and regulatory mechanism of SIX1 in gastric cancer (GC) remains unclear. In our study, we detected protein levels of SIX1 via immunohistochemistry (IHC) and its proliferation and invasion effects via CCK8 and transwell assays. Additionally, expression of cyclin D1, MMP2, p-ERK, and EMT-related proteins was measured by western blotting. We found that SIX1 had significantly higher expression in GC tissues and that it could promote GC cell proliferation and invasion. Also, overexpression of SIX1 increased the expression of cyclin D1, MMP2, p-ERK, and EMT-related proteins, which could all be inhibited by knocking down SIX1. In conclusion, SIX1 is upregulated in GC tissues. It can promote GC cell proliferation by targeting cyclin D1, invasion via ERK signalling, and EMT pathways by targeting MMP2 and E-cadherin. SIGNIFICANCE OF THE STUDY: Our study showed that SIX1 was upregulated in GC tissues, and promoted GC cell proliferation by targeting cyclin D1, invasion via ERK signalling, and EMT pathways by targeting MMP2 and E-cadherin. These results suggested the potential regulatory mechanism of SIX1 in proliferation and invasion of gastric cancer.

Topics: Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Epithelial-Mesenchymal Transition; Female; Homeodomain Proteins; Humans; Kaplan-Meier Estimate; Male; MAP Kinase Signaling System; Matrix Metalloproteinase 2; Middle Aged; Proportional Hazards Models; RNA Interference; RNA, Small Interfering; Stomach Neoplasms; Up-Regulation

Histones chaperones have been found to play critical roles in tumor development and progression. However, the role of histone chaperone CHAF1A in gastric carcinogenesis and its underlying mechanisms remain elusive.. CHAF1A expression in gastric cancer (GC) was analyzed in GEO datasets and clinical specimens. CHAF1A knockdown and overexpression were used to explore its functions in gastric cancer cells. The regulation and potential molecular mechanism of CHAF1A expression in gastric cancer cells were studied by using cell and molecular biological methods.. CHAF1A was upregulated in GC tissues and its high expression predicted poor prognosis in GC patients. Overexpression of CHAF1A promoted gastric cancer cell proliferation both in vitro and in vivo, whereas CHAF1A suppression exhibited the opposite effects. Mechanistically, CHAF1A acted as a co-activator in the Wnt pathway. CHAF1A directly interacted with TCF4 to enhance the expression of c-MYC and CCND1 through binding to their promoter regions. In addition, the overexpression of CHAF1A was modulated by specificity protein 1 (Sp1) in GC. Sp1 transcriptionally enhanced the expression of CHAF1A in GC. Furthermore, CHAF1A expression induced by Helicobacter pylori was Sp1 dependent.. CHAF1A is a potential oncogene in GC, and may serve as a novel therapeutic target for GC treatment.

Topics: Animals; Cell Line, Tumor; Cell Proliferation; Cell Transformation, Neoplastic; Chromatin Assembly Factor-1; Cyclin D1; Disease Models, Animal; Gene Expression Regulation, Neoplastic; Heterografts; Humans; Mice; Models, Biological; Protein Binding; Proto-Oncogene Proteins c-myc; Sp1 Transcription Factor; Stomach Neoplasms; Transcription Factor 4

cAMP responsive element binding protein 1 (CREB1) gene, has been reported to play crucial roles in tumor progression and development in various types of cancer. Little is known, however, about its role and underlying mechanism in gastric cancer (GC). Herein, we investigated the biological roles and molecular mechanism of CREB1 in GC. The expression level was determined in four GC cell lines by quantitative RT-PCR and western blotting. Recombinant expression vector carrying small interfering RNA (siRNA) targeting CREB1 was constructed and then transfected into human GC cell line (SGC-7901). Cell proliferation, colony formation, cycle distribution, migration and invasion in vitro were determined by MTT, colony forming, flow cytometry, would healing and Transwell invasion assays after CREB1 knockdown. Tumor growth in vivo was assessed by measurement of tumor volume and weight in a nude mouse model. We found that CREB1 was highly expressed in the human GC cell lines. We also showed that knockdown of CREB1 in SGC-7901 cells significantly inhibited cell proliferation, colony formation, migration and invasion and induced cell arrest at G1/G0 phase in vitro, as well as suppressed tumor growth in vivo. In addition, CREB1 knockdown was able to significantly reduce expression of its downstream target genes cyclin D1, Bcl-2 and MMP-9 in vitro and in vivo. These findings suggest that CREB1 may be a potential therapeutic target for the treatment of gastric cancer.

Topics: Animals; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclic AMP Response Element-Binding Protein; Cyclin D1; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Humans; Matrix Metalloproteinase 9; Mice; Proto-Oncogene Proteins c-bcl-2; Stomach Neoplasms; Transfection; Xenograft Model Antitumor Assays

Long noncoding RNA UCA1 has emerged as a novel regulator in cancer initiation and progression of various cancers. However, function and underlying mechanism of UCA1 in the progression of gastric cancer (GC) remain unclear. In the present study, we report that UCA1 expressed highly in GC tissues and GC cells, which was partly induced by SP1. UCA1 promoted GC cell proliferation and G1/S transition in vitro and in vivo. Moreover, UCA1 exerted its function through interacting with EZH2, promoting direct interaction with cyclin D1 promoter to activate the translation of cyclin D1. Furthermore, AKT/GSK-3B/cyclin D1 axis was activated to upregulate cyclin D1 due to overexpression of UCA1. In addition, EZH2 and phosphorylated AKT induced by UCA1 could impact each other to form a positive feedback to promote cyclin D1 expression. This study demonstrated that UCA1 as a critical regulator involved in GC proliferation and cell cycle progression by promoting cyclin D1 expression, which indicates that it may be clinically a potential therapeutic target in GC.

Topics: Aged; Animals; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Disease Progression; Enhancer of Zeste Homolog 2 Protein; Feedback, Physiological; Female; Gene Expression Regulation, Neoplastic; Glycogen Synthase Kinase 3 beta; Humans; Male; Mice; Mice, Nude; Middle Aged; Neoplasm Transplantation; Prognosis; Promoter Regions, Genetic; Protein Biosynthesis; Proto-Oncogene Proteins c-akt; RNA, Long Noncoding; Signal Transduction; Sp1 Transcription Factor; Stomach Neoplasms

To evaluate associations between miRNA target genes. Gene polymorphisms were analyzed in 508 controls and 474 GC patients from 3 tertiary centers in Germany, Lithuania and Latvia. Controls were patients from the out-patient departments, who were referred for upper endoscopy because of dyspeptic symptoms and had no history of previous malignancy. Gastric cancer (GC) patients had histopathological verification of gastric adenocarcinoma. Genomic DNA was extracted using salting out method from peripheral blood mononuclear cells.. We observed similar distribution of genotypes and allelic frequencies of all polymorphisms between GC patients and controls except of

Topics: Adult; Aged; Antigens, CD; Case-Control Studies; Cyclin D1; Female; Genotype; Germany; Humans; Interleukin-10; Interleukin-12 Subunit p40; Latvia; Leukocytes, Mononuclear; Lithuania; Male; Middle Aged; Polymorphism, Single Nucleotide; Receptor, Insulin; Regression Analysis; Stomach Neoplasms

Studies in several cancers have suggested that miR-218 has anti-tumor activities, but its function is yet to be elucidated. In this study, we investigated the regulation and function of miR-218 (miR-218-5p) in the cell cycle progression of gastric cancer (GC). We found that miR-218 could suppress proliferation of gastric cancer cells, induce cell cycle arrest at the G1 phase and inhibit tumor growth and metastasis in vivo. We also demonstrated that miR-218 specifically targeted the 3'-UTR regions of CDK6 and cyclin D1 and inhibited the expression of these molecules, which in turn repressed the pRb/E2F1 signaling pathway. Overexpression of CDK6 and Cyclin D1 reversed miR-218-mediated inhibition of pRB/E2F1 signaling and attenuated the miR-218-induced cell cycle arrest. More importantly, miR-218 expression was significantly reduced and inversely correlated with the levels of CDK6 and Cyclin D1 in gastric cancer tissues. Decreased miR-218 expression was also correlated with advanced clinical stage, lymph node metastasis, and poor prognosis in gastric cancer patients. Furthermore, we showed that miR-218 expression was directly activated by E2F1 through the transactivation of miR-218 host genes, SLIT2 and SLIT3, revealing a negative feedback regulation of miR-218 expression. Taken together, our results describe a regulatory loop miR-218-CDK6/CyclinD1-E2F1 whose disruption may contribute to cell cycle progression in gastric cancer and indicate the potential application of miR-218 in cancer therapy.

Topics: 3' Untranslated Regions; Animals; Binding Sites; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Cyclin-Dependent Kinase 6; E2F1 Transcription Factor; Feedback, Physiological; G1 Phase Cell Cycle Checkpoints; Gene Expression Regulation, Neoplastic; Humans; Intercellular Signaling Peptides and Proteins; Lung Neoplasms; Lymphatic Metastasis; Membrane Proteins; Mice, Nude; MicroRNAs; Neoplasm Staging; Nerve Tissue Proteins; Protein Binding; Signal Transduction; Stomach Neoplasms; Time Factors; Transcription, Genetic; Transcriptional Activation; Transfection; Tumor Burden

Increasing evidence has suggested that MircroRNAs (miRNAs) dysregulated in pathogenesis and tumorigenicity in human cancers including gastric cancer (GC). MiR-143 had been reported to function as tumor suppressor in GC progression, however, the underlying function of miR-143 in GC still need to be well known. In the study, we revealed that miR-143 was significantly down-regulated in GC cell lines. Upregulation of miR-143 inhibited cell proliferation, invasion, S phase cell proportion and cell cycle related protein levels of Cyclin D1, CDK4 and CDK6 in GC. Furthermore, luciferase reporter assays demonstrated that DNMT3A was a direct target of miR-143 and Upregulation of miR-143 inhibited the DNMT3A mRNA and protein expression levels in GC cells. Moreover, we demonstrated that DNMT3A knockdown rescued the promoting effect of miR-143 inhibitor on cell proliferation in GC. Thus, these results demonstrated that miR-143 targeted DNMT3A in GC cells and inhibit GC tumorigenesis and progression, which may provide a novel therapeutic target of GC.

Topics: Carcinogenesis; Cell Cycle; Cell Movement; Cell Proliferation; Cyclin D1; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; DNA (Cytosine-5-)-Methyltransferases; DNA Methyltransferase 3A; Gene Expression Regulation, Neoplastic; Humans; MicroRNAs; Neoplasm Invasiveness; Stomach Neoplasms

MiR-302b is a major microRNA found in human embryonic stem cells and induced pluripotent stem cells. However, its function in gastric cancer progression remains unclear.. Quantitative reverse transcription-PCR was performed to detect the expression levels of miR-302b-3p in gastric cancer tissues. MTT, colony formation, and flow cytometer analyses were conducted to explore the function of miR-302b-3p in MKN-45/SGC-7901 cells. A dual-luciferase reporter was used to validate the bioinformatics-predicted target gene of miR-302b-3p. Western blotting and RNA interference were used to evaluate the expression of the AKT signaling pathway and determine the mechanisms underlying miR-302b-3p-induced anti-tumor effects.. MiR-302b-3p expression was decreased in gastric cancer tissues and cell lines. Enforced expression of miR-302b suppressed cell proliferation and cell cycle G1-S transition and induced apoptosis. IGF-1R was found to be a direct target of miR-302b-3p, and silencing of IGF-1R resulted in the same biological effects as those induced by miR-302b-3p overexpression in gastric cancer cells. Importantly, both overexpression of miR-302b-3p and silencing of IGF-1R decreased AKT phosphorylation, which modulated AKT related cell cycle regulators (cyclin A2, cyclin D1, CDK2, and CDk6) and apoptotic protein Bax/Bcl-2.. These results indicate the tumor suppressor role of miR-302b-3p in the pathogenesis of gastric cancer.

Topics: Adenocarcinoma; Apoptosis; Base Sequence; bcl-2-Associated X Protein; Cell Line, Tumor; Cell Proliferation; Cyclin A2; Cyclin D1; Cyclin-Dependent Kinase 2; Cyclin-Dependent Kinase 6; G1 Phase Cell Cycle Checkpoints; Gene Expression Regulation, Neoplastic; Genes, Reporter; Humans; Luciferases; MicroRNAs; Proto-Oncogene Proteins c-akt; Receptor, IGF Type 1; RNA, Small Interfering; Signal Transduction; Stomach Neoplasms

Estrogen receptor (ER)‑α36, a novel isoform of ER, primarily mediates non‑classical estrogen signaling. It has been reported that ER‑α36‑mediated growth stimulating signals are involved in the malignancy of gastric tumor cells. However, the mechanism underlying the regulation of ER‑α36 function in development of gastric cancer remains to be elucidated. The present study investigated the role of 78 kDa glucose‑regulated protein (GRP78) in the regulation of ER‑α36 expression and signaling during the growth of gastric tumor cells. It was demonstrated that GRP78 expression was detectable in gastric cancer tumor tissues, and was positively‑correlated with tumor stage, lymphatic metastasis and ER‑α36 expression (P<0.05). An increased growth rate, and increased expression of ER‑α36 and the cell cycle regulator cyclin D1 was detected in cells with GRP78 overexpression (SGC‑High78 cells). SGC‑High78 cells are more sensitive to estrogen compared with SGC‑Control cells. Therefore, the results of the present study demonstrated that GRP78 positively regulated ER‑α36 expression and signaling with cell growth in gastric cancer, which is involved in gastric carcinogenesis.

Topics: Adult; Aged; Aged, 80 and over; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Endoplasmic Reticulum Chaperone BiP; Estrogen Receptor alpha; Estrogens; Female; Gene Expression; Heat-Shock Proteins; Humans; Immunohistochemistry; Male; Middle Aged; Stomach Neoplasms; Tissue Array Analysis

New and effective treatments for advanced gastric cancer are urgently needed. Cyclins E and D1 form a complex with cyclin-dependent kinase 2, 4, or 6 to regulate G1-S transition. The G1-S regulatory genes encoding cyclin E (CCNE1), cyclin D1 (CCND1), and CDK6 (CDK6) are frequently amplified in gastric cancer and may therefore influence molecularly targeted therapies against ERBB2 or EGFR when coamplified. A total of 179 formalin-fixed and paraffin-embedded gastric cancer specimens were examined for these gene amplifications by multiplex ligation-dependent probe amplification and fluorescence in situ hybridization. Amplification of at least 1 G1-S regulatory gene was found in 35 tumors (CCNE1 amplification, 15% of samples; CCND1, 6%; CDK6, 1%). In 13 of the 35 tumors, dual-color fluorescence in situ hybridization identified coamplification of the G1-S regulatory genes with ERBB2, EGFR, and/or KRAS in single cancer nuclei. The observation that cells with G1-S regulatory gene amplification contained clonal subpopulations with coamplification of ERBB2, EGFR, or KRAS in 5 early and 3 advanced cancers suggests that amplification of the G1-S regulatory genes represents an early event, which precedes ERBB2, EGFR, or KRAS amplification. Amplified CCNE1, CCND1, and CDK6 in advanced gastric cancer may be potentially useful as direct targets for molecular therapy or for combination therapy with ERBB2 or EGFR inhibitors. Multiplex ligation-dependent probe amplification could be a useful tool for identification of patients who would benefit from such therapies.

Topics: Adenocarcinoma; Biomarkers, Tumor; Biopsy; Cell Cycle Checkpoints; Cell Proliferation; Cyclin D1; Cyclin E; Cyclin-Dependent Kinase 6; DNA Copy Number Variations; DNA Mutational Analysis; ErbB Receptors; Gene Amplification; Gene Dosage; Genetic Predisposition to Disease; Humans; Immunohistochemistry; In Situ Hybridization, Fluorescence; Multiplex Polymerase Chain Reaction; Mutation; Oncogene Proteins; Phenotype; Predictive Value of Tests; Proto-Oncogene Proteins p21(ras); Receptor, ErbB-2; Stomach Neoplasms

Na+/H+ exchanger isoform 1 (NHE1) is known to play a key role in regulating intracellular pH and osmotic homeostasis and is involved in the development and progression of several types of cancer. However, the function and specific mechanism of NHE1 in gastric cancer (GC) are not clearly understood. In the present study, we report that NHE1 is overexpressed in tissues and cell lines from GC patients, and knockdown or inhibition of NHE1 suppressed GC cell proliferation via regulation of G1/S and G2/M cell cycle phase transitions, concomitant with a marked decrease in positive cell cycle regulators, including cyclin D1 and cyclin B1. Likewise, NHE1 was required for GC cell migration and invasion through the regulation of epithelial-mesenchymal transition (EMT) proteins, and NHE1 inhibition resulted in an acidic intracellular environment, providing possible mechanisms underlying NHE1-mediated GC progression both in vitro and in vivo. These data highlight the important role of NHE1 in GC progression and suggest that NHE1 may be a useful target for GC therapy.

Topics: Animals; Apoptosis; Biomarkers, Tumor; Blotting, Western; Cation Transport Proteins; Cell Movement; Cell Proliferation; Cyclin D1; Epithelial-Mesenchymal Transition; Fluorescent Antibody Technique; Gene Expression Regulation, Neoplastic; Humans; Immunoenzyme Techniques; Male; Mice; Mice, Nude; Neoplasm Invasiveness; Neoplasm Staging; Prognosis; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Sodium-Hydrogen Exchanger 1; Sodium-Hydrogen Exchangers; Stomach Neoplasms; Tumor Cells, Cultured; Xenograft Model Antitumor Assays

To explore the effects of wogonin on the apoptosis,invasion,migration and Wnt / β-catenin signaling pathway of gastric cancer cells SGC7901.. Three common gastric cancer cell lines( SGC7901,BGC-823 and MKN-45) were conventionally cultured to logarithmic growth. The cell proliferation was detected by MTT assay after treatment with different concentrations of wogonin( 0,20,50,100 and 200 μmol / L) for 24,48,72 and 96 h. The apoptosis rate, migration and invasion ability of SGC7901 cells were detected by Annexin V-FITC / PI annexin double staining flow cytometry, scratch test and transwell cell invasion assay, respectively. After treament with different concentrations of wogonin for 48 h,the protein levels of β-catenin, C-myc and Cyclin D1 were detected by Western blotting.. Wogonin within the range of 20 ~ 200 mol / L could inhibit the proliferation of SGC7901,BGC-823 and MKN-45 cells in a dose-and time-dependent manner. Compared with 0 μmol / L wogonin group,After treament with different concentrations of wogonin for 24 h and 48 h,SGC7901 cells had elevated apoptosis rate and decreased migration distance and number of penetrating membrane cell in the rest concentrations( P < 0. 05). The protein levels of β-catenin,C-myc and Cyclin D1 were lower in 20 ~ 200μmol /L wogonin groups than 0 μmol /L wogonin group except for the concentration of 20 μmol /L wogonin groups( P < 0. 05),and the effects in a dose-dependent manner.. Wogonin has the ability to inhibit the proliferation of gastric cancer cells,and can induce apoptosis and inhibit cell migration and invasion,which may be related to the inhibition of Wnt / β-catenin signaling pathway activation.

Topics: Apoptosis; beta Catenin; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Flavanones; Humans; Stomach Neoplasms; Wnt Signaling Pathway

To investigate the effect of Ginkgo biloba extract (EGB) on the proliferation and cell cycles of gastric carcinoma SGC7901 cells, and make a preliminary exploration on possible molecular mechanisms associated with its inhibitory effect.. Human gastric carcinoma SGC7901 cells were cultured in vitro, and treated with various concentrations (100, 200, 300, 400 mg/L) of EGB for different incubation periods (24, 48 and 72 h). CCK-8 assay was used to detect cell proliferation and flow cytometry was performed to analyze the effect of EGB on cell cycles. In addition, mRNA and protein level of two cell cycle regulators cyclin D1 and c-myc in SGC7901 cells treated with EGB were determined using PCR and Western blot. And subcutaneous xenograft model of gastric carcinoma in nude mice was established to evaluate the anti-cancer effect of EGB in vivo.. The proliferation of gastric carcinoma SGC7901 cells was inhibited by EGB in dose- and time-dependent manner. Flow cytometry showed cell cycle arrest in EGB-treated cells, with increased percentage of cells in G1 phase and decreased percentage in S stage. In addition, the mRNA and protein level of cyclin D1 and c-myc genes were significantly down-regulated in cells with EGB treatment with the concentration increasing.. EGB conferred an inhibitory effect on the proliferation of gastric carcinoma SGC7901 cells both in vitro and in vivo. The inhibitory effect was dose dependent and possibly depended on inhibiting cell cycle through G1 arrest induction by suppressing cyclin D1 and c-myc expression.

Topics: Animals; Apoptosis; Blotting, Western; Cell Cycle; Cell Proliferation; Cyclin D1; Gene Expression Regulation, Neoplastic; Ginkgo biloba; Humans; Immunoenzyme Techniques; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Plant Extracts; Proto-Oncogene Proteins c-myc; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Stomach Neoplasms; Tumor Cells, Cultured; Xenograft Model Antitumor Assays

Previous studies by this group have shown that Helicobacter pylori with high thioredoxin-1 (Trx1) expression might be involved in stomach carcinogenesis in vitro. To study histopathological changes of the stomach mucosa in vivo, a Mongolian gerbil model infected with H. pylori with high Trx1 expression was established.. Healthy, male Mongolian gerbils (n=75) were randomly divided into 3 groups: controls (n=15), which were not infected with H. pylori, high Trx1 (n=30) which were infected with H. pylori with high Trx1 expression and low Trx1 (n=30) which were infected with low Trx1 expression H. pylori. The animals were sacrificed at 4, 20, 34, 48, 70 and 90 weeks after inoculation.. The Mongolian gerbil model of H. pylori infection was successfully established. Three animals died during the study, leaving 72 animals (controls, n=14; low Trx1, n=29; high Trx1, n=29) examined on schedule. Histopathological analysis of the stomach mucosa showed gradually increased aggravation over time in the high and low Trx1 groups. Compared with control and low Trx1, the histopathological changes were more serious in the high Trx1 group. At 90 weeks, no abnormal changes were found in the controls, but 62.5% of the high Trx1 group and 33.3% of the low Trx1 showed adenocarcinomas. The H. pylori Trx1 level in gastric cancer tissue was significantly higher than that from gastritis tissue. Within gastric cancer cells, high Trx1 expression in H. pylori significantly upregulated cyclin D1.. High Trx1 expression in H. pylori promoted stomach carcinogenesis. More studies are needed to confirm this finding.

Topics: Adenocarcinoma; Animals; Carcinogenesis; Cyclin D1; Disease Models, Animal; Gastric Mucosa; Gerbillinae; Helicobacter Infections; Helicobacter pylori; Male; Stomach Neoplasms; Thioredoxins; Up-Regulation

HOXA1 is a member of the Homeobox gene family, which encodes a group of highly conserved transcription factors that are important in embryonic development. However, it has been reported that HOXA1 exhibits oncogenic properties in many malignancies. This study focused on the expression and clinical significance of HOXA1 in gastric cancer (GC).. To assess the mRNA and protein expression of HOXA1 and cyclin D1 in GC tissues, we utilized qRT-PCR and western blotting, respectively. The effects of HOXA1 on GC cell proliferation, migration, and invasion, as well as xenograft tumor formation and the cell cycle were investigated in our established stable HOXA1 knockdown GC cell lines. The protein expression of HOXA1 and cyclin D1 was examined by immunohistochemistry using GC tissue microarrays (TMA) to analyze their relationship on a histological level. The Kaplan-Meier method and cox proportional hazards model were used to analyze the relationship of HOXA1 and cyclin D1 expression with GC clinical outcomes.. HOXA1 mRNA and protein expression were upregulated in GC tissues. Knockdown of HOXA1 in GC cells not only inhibited cell proliferation, migration, and invasion in vitro but also suppressed xenograft tumor formation in vivo. Moreover, HOXA1 knockdown induced changes in the cell cycle, and HOXA1 knockdown cells were arrested at the G1 phase, the number of cells in S phase was reduced, and the expression of cyclin D1 was decreased. In GC tissues, high cyclin D1 mRNA and protein expression were detected, and a significant correlation was found between the expression of HOXA1 and cyclin D1. Survival analysis indicated that HOXA1 and cyclin D1 expression were significantly associated with disease-free survival (DFS) and overall survival (OS). Interestingly, patients with tumors that were positive for HOXA1 and cyclin D1 expression showed worse prognosis. Multivariate analysis confirmed that the combination of HOXA1 and cyclin D1 was an independent prognostic indicator for OS and DFS.. Our data show that HOXA1 plays a crucial role in GC development and clinical prognosis. HOXA1, alone or combination with cyclin D1, may serve as a novel prognostic biomarker for GC.

Topics: Animals; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Female; Gene Expression Regulation, Neoplastic; Homeodomain Proteins; Humans; Male; Mice; Neoplasm Invasiveness; Neoplasm Transplantation; Prognosis; Stomach Neoplasms; Survival Analysis; Transcription Factors

Gastric cancer is one of the main causes of global mortality. Here, reactive oxygen species (ROS) could largely contribute to gastric carcinogenesis. Hence, the present work was aimed to assess the role of ROS, oxidant status, NADPH oxidases (NOXs) expression, during human gastric adenocarcinoma.. We obtained subcellular fraction from samples of gastric mucosa taken from control subjects (n = 20), and from 40 patients with gastric adenocarcinoma, as well as samples of distant areas (tumour-free gastric mucosa).. Parameters indicative of lipid peroxidation and cell proliferation were selectively increased in both tumour-free and in cancerous gastric mucosa, despite of glutathione (GSH) content, glutathione reductase (GR) and superoxide dismutase (SOD) activities were increased in the adenocarcinoma. These high levels of antioxidant defences inversely correlated with down-regulated expression for NOX2 and 4; however, over-expression of NOX1 occurred with increased caspase-3 activity and overexpressed checkpoint 1 (MDC1) and cyclin D1 proteins. In the tumour-free mucosa an oxidant stress took place, without changing total GSH but with decreased activities for GR and mitochondrial SOD; moreover, over-expression of checkpoint 1 (MDC1) correlated with lower NOX2 and 4 expression in this mucosa.. Chronically injured gastric mucosa increases lipoperoxidative events and cell proliferation. In the adenocarcinoma, cell proliferation was further enhanced, oxidant stress decreased which seemed to be linked to NOX1, MDC1 and cyclin D1 over-expression, but with a lower NOXs activity leading a 'low tone' of ROS formation. Therefore, our results could be useful for early detection and treatment of gastric adenocarcinoma.

Topics: Adenocarcinoma; Antioxidants; Apoptosis; Case-Control Studies; Caspases; Cell Proliferation; Checkpoint Kinase 1; Cyclin D1; Female; Gastric Mucosa; Humans; Male; NADPH Oxidases; Oxidants; Oxidative Stress; Protein Kinases; Reactive Oxygen Species; Stomach Neoplasms

Helicobacter pylori induces chronic inflammation and intestinal metaplasia (IM) through genetic and epigenetic changes and activation of intracellular signaling pathways that contribute to gastric carcinogenesis. However, the precise mechanism of IM in gastric carcinogenesis has not been fully elucidated. We previously found that intestine-specific homeobox (ISX) mRNA expression increased in organoids cultured from Helicobacter-infected mouse mucosa. In this study, we elucidate the role of ISX in the development of IM and gastric carcinogenesis.. ISX expression was assessed in Helicobacter-infected mouse and human gastric mucosa. MKN45 gastric cancer cells were co-cultured with H. pylori to determine whether Helicobacter infection induced ISX expression. We established stable MKN45 transfected cells expressing ISX (Stable-ISX MKN45) and performed a spheroid colony formation assay and a xenograft model. We performed ISX immunohistochemistry in cancer and adjacent gastric tissues.. ISX expression was increased in mouse and human gastric mucosa infected with Helicobacter. The presence of IM and H. pylori infection in human stomach was correlated with ISX expression. H. pylori induced ISX mRNA and protein expression. CDX1/2, cyclinD1, and MUC2 were upregulated in Stable-ISX MKN45, whereas MUC5AC was downregulated. Stable-ISX MKN45 cells formed more spheroid colonies, and had high tumorigenic ability. ISX expression in gastric cancer and adjacent mucosa were correlated.. ISX expression induced by H. pylori infection may lead to IM and hyperproliferation of gastric mucosa through CDX1/2 and cyclinD1 expression, contributing to gastric carcinogenesis.

Topics: Animals; CDX2 Transcription Factor; Cell Line, Tumor; Cell Proliferation; Cell Transformation, Neoplastic; Coculture Techniques; Cyclin D1; Down-Regulation; Gastric Mucosa; Gene Knockdown Techniques; Helicobacter Infections; Helicobacter pylori; Homeodomain Proteins; Humans; Metaplasia; Mice; Mucin 5AC; Mucin-2; RNA, Messenger; Spheroids, Cellular; Stomach Neoplasms; Transcription Factors; Up-Regulation

MicroRNAs (miRs) have been frequently reported dysregulating in tumors and playing a crucial role in tumor development and progression. However, the expression of miR-155 and its role in gastric cancer (GC) are still obscure.. qRT-PCR was applied to detect miR-155 expression in 60 matched GC samples and four GC cell lines, and the relationship between miR-155 levels and clinicopathological features of GC was analyzed. Next, the effects of miR-155 on GC cell growth were evaluated by gain- and loss-of-function analysis. Finally, the target gene(s) of miR-155 in GC cells were explored.. Our results revealed that miR-155 levels were significantly lower in both GC tissues and GC cell lines than in their normal controls, and its expression inversely correlated with tumor size and the pathologic stage. Moreover, our study showed that enforced expression of miR-155 impaired GC cell proliferation, promoted G1 phase arrest and induced apoptosis in vitro. In addition, we identified cyclin D1 as the direct target of miR-155, and knockdown of cyclin D1 partially phenocopied the role of miR-155 in GC cells.. Our findings suggest that miR-155 may act as a potential diagnostic marker for early-stage GC and may represent a novel therapeutic target for GC treatment.

Topics: Apoptosis; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Down-Regulation; Humans; MicroRNAs; Stomach Neoplasms

Cell cycle regulators cyclin D1 and cyclin E2 function in G1/S transition by activating downstream cyclin-dependent kinases. Deregulated expression of these cyclins has been reported in various cancers. However, little is known about their clinical significance in gastric carcinoma. We aimed to explore that whether there is differential expression of these cyclins in clinically distinct gastric cancer patients. In this study we recruited a total of 92 subjects including 20 controls and 72 cases of histopathologically proven gastric carcinoma. Expression profiling at transcript level was done by semiquantitative RT-PCR and of protein by immunohistochemistry. Receiver operator characteristics analysis was done for determining diagnostic utility of cyclin D1 and cyclin E2. We demonstrate that cyclins D1 and E2 are frequently overexpressed in early stages of gastric carcinoma. Interestingly, expression of cyclins D1 and E2 significantly correlates with different clinical parameters such as gender, histological type (intestinal and diffuse), tumor location (proximal, middle, and distal), tumor differentiation (differentiated and undifferentiated), tumor invasion (serosal, lymphatic, and venous) and tumor metastasis (lymph node, peritoneal, ascites, and liver). Cyclin D1 has significantly higher sensitivity and specificity as diagnostic biomarker than cyclin E2. Our results suggest that overexpression of cyclin D1 and cyclin E2 is an early event in gastric carcinogenesis. The differential expression of these cyclins may be useful as diagnostic biomarkers for early detection of gastric carcinoma.

Topics: Biomarkers, Tumor; Case-Control Studies; Cyclin D1; Cyclins; Female; Gene Expression Regulation, Neoplastic; Humans; Immunohistochemistry; Male; Reverse Transcriptase Polymerase Chain Reaction; ROC Curve; Sensitivity and Specificity; Stomach Neoplasms

MicroRNAs have been involved in RNA silencing and post-transcriptional regulation of gene expression and also play important roles in tumorigenesis and tumor progression. MiR-193b was previously reported to act as tumor suppressor in diverse cancers. However, little is known about the expression, function and mechanism of miR-193b in gastric cancer (GC). In this study, we investigated the expression of miR-193b in 50 GC cases and found that miR-193b was significantly reduced in GC tissues compared with the adjacent normal gastric tissues. Moreover, lower-level of miR-193b was also associated with a more aggressive GC phenotype. We further demonstrated that miR-193b can inhibit the proliferation, migration and invasion of HGC-27 and MGC-803 GC cells. Further mechanism study indicated that CCND1 was a direct target of miR-193b in GC. Overexpression of miR-193b inhibited the expression of CCND1, and knock-down of CCND1 inhibited the proliferation of GC cells, suggesting that miR-193b exerted its anti-tumorigenic role in GC cells through targeting CCND1 gene.

Topics: Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Gene Expression Regulation, Neoplastic; Humans; MicroRNAs; Neoplasm Invasiveness; RNA Interference; Stomach Neoplasms

Previous research has demonstrated that type II cyclic guanosine monophosphate (cGMP)-dependent protein kinase (PKG II) inhibited epidermal growth factor (EGF)‑initiated signal transduction of MAPK‑mediated, PI3K/Akt‑mediated and PLCγ1‑mediated pathways through blocking EGF‑induced phosphorylation/activation of EGF receptor (EGFR). As EGF/EGFR signaling also initiated signal transduction of the Janus kinase (JAK)/signal transducer and activator of transcription (STAT)‑mediated pathway, the present study was performed to investigate whether PKG II exerts an inhibitory effect this pathway. AGS human gastric cancer cell line was infected with adenoviral constructs encoding the cDNA of PKG II (Ad‑PKG II), to increase the expression of PKG II, and treated with 8‑pCPT‑cGMP to activate the kinase. Western blotting was performed to detect the phosphorylation/activation of EGFR, JAK1, JAK2, STAT1 and STAT3 and the expression of cell cycle‑associated proteins, including cyclin D1 and cyclin E. EGF‑induced cell cycle changes were detected by flow cytometry. Transcriptional activity was determined by a reporter gene assay. The results demonstrated that EGF treatment increased the phosphorylation of EGFR, JAK1, JAK2, STAT1 and STAT3, increased the expression levels of cyclin D1 and cyclin E, promoted the cells to enter S phase, and stimulated transcriptional activity in the cells. Increased PKG II activity through infecting the cells with Ad‑PKG II and activating the kinase with 8‑pCPT‑cGMP efficiently reversed the changes caused by EGF. The results suggest that PKG II inhibits EGF‑induced signal transduction of the JAK/STAT‑mediated pathway and further confirms that PKG II may be a cancer inhibitor.

Topics: Cell Cycle; Cell Line, Tumor; Cyclic GMP-Dependent Protein Kinase Type II; Cyclin D1; Cyclin E; Epidermal Growth Factor; ErbB Receptors; Gene Expression Regulation, Neoplastic; Humans; Janus Kinase 1; Janus Kinase 2; Janus Kinases; Phosphorylation; Signal Transduction; STAT Transcription Factors; STAT1 Transcription Factor; STAT3 Transcription Factor; Stomach Neoplasms; Transcriptional Activation

Myosin VI (MYO6) is a unique member of the myosin superfamily. Although it has been reported to participate in human cancer progression, the role of MYO6 in gastric cancer remains unclear. In this study, we found the expression of MYO6 gene was higher in gastric cancer tissues than in the normal tissues by Oncomine database mining and affects patient overall survival using the Kaplan-Meier plotter online analysis. Additionally, the expression levels of MYO6 were widely expressed in gastric cancer cells by quantitative real-time Polymerase Chain Reaction (qRT-PCR) and western blot assay. Then knockdown of MYO6 significantly suppressed the proliferation and colony formation abilities of AGS and MGC80-3 cells. Moreover, cell cycle analysis showed that inhibition of MYO6 induced cell cycle arrested in G0/G1 phase in AGS and MGC80-3 cells. Further analysis showed knockdown of MYO6 downregulated cell-cycle activators cyclin A and cyclin D1 and upregulated cell-cycle inhibitor p21, as determined by qRT-PCR and western blot analysis in MGC80-3 cells. Meanwhile, MYO6 inhibition significantly induced apoptosis in AGS and MGC80-3 cells. Also, knockdown of MYO6 increased the expression of apoptosis-related proteins Bax and cleaved Caspase-3, and decreased Bcl-2 expression by western blot analysis in MGC80-3 cells. In addition, MYO6 knockdown also inhibited cell migration ability in MGC80-3 cells. Taken together, our study indicates that MYO6 may play an important role in gastric cancer tumorigenesis and may serve as a potential therapeutic target in human gastric cancer.

Topics: bcl-2-Associated X Protein; Caspase 3; Cell Line, Tumor; Cyclin A; Cyclin D1; G1 Phase; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Humans; Myosin Heavy Chains; Proto-Oncogene Proteins c-bcl-2; Resting Phase, Cell Cycle; Stomach Neoplasms; Up-Regulation

O-GlcNAc transferase (OGT) is the only enzyme in mammals that catalyzes the attachment of β-D-N-acetylglucosamine (GlcNAc) to serine or threonine residues of target proteins. Hyper-O-GlcNAcylation is becoming increasingly realized as a general feature of cancer and contributes to rapid proliferation of cancer cells. In this study, we demonstrated that O-GlcNAc and OGT levels were increased in all six gastric cancer (GC) cell lines as compared with immortal gastric epithelial cells. Downregulation of the O-GlcNAcylation level by silencing OGT inhibited cell viability and growth rate via the cdk-2, cyclin D1 and ERK 1/2 pathways. In vivo xenograft assays also demonstrated that the hyper-O-GlcNAc level markedly promoted the proliferation of tumors. Moreover, compared with noncancerous tissues, the O-GlcNAcylation level was increased in cancerous tissues. GC patients with higher levels of O-GlcNAcylation exhibited large tumor sizes (≥5 cm), deep tumor invasion (T3 and T4), high AJCC stages (stage III and IV), more lymph node metastases and lower overall survival. Notably, the phosphorylation level of ERK 1/2 was increased progressively with the increase of O-GlcNAcylation in both SGC 7901 and AGS cells. Consistently, human GC tissue arrays also revealed that ERK 1/2 signaling was positively correlated to O-GlcNAcylation (r = 0.348; P = 0.015). Taken together, here we reported that hyper-O-GlcNAcylation significantly promotes GC cells proliferation by modulating cell cycle related proteins and ERK 1/2 signaling, suggesting that inhibition of OGT may be a potential novel therapeutic target of GC.

Topics: Acetylglucosamine; Animals; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Cyclin-Dependent Kinase 2; Down-Regulation; Female; Gene Knockdown Techniques; Humans; Male; MAP Kinase Signaling System; Mice; Mice, Inbred BALB C; Mice, Nude; Middle Aged; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; N-Acetylglucosaminyltransferases; Phosphorylation; Protein Processing, Post-Translational; RNA Interference; RNA, Small Interfering; Serine; Stomach Neoplasms; Threonine; Up-Regulation; Xenograft Model Antitumor Assays

5-Fluorouracil (5-FU) has been a mainstay of chemotherapy for gastric cancer. Vandetanib is a tyrosine kinase inhibitor with inhibitory activity against vascular endothelial growth factor receptor and epidermal growth factor receptor (EGFR). We investigated the combination effect of vandetanib with 5-FU on gastric cancer cells.. Anticancer efficacy was assessed by 3-(4,5-dimethyl-2-tetrazolyl)-2,5-diphenyl-2H tetrazolium bromide assay of five gastric cancer cell lines, MKN1, MKN7, MKN45, MKN74, and TMK1. Signal expression was examined by western blot, and the cell-cycle distribution was assessed by flow cytometry. In vivo anticancer activity of vandetanib with/without 5-FU was tested in MKN74 cells on nude mice.. Vandetanib inhibited the growth of all cell lines. In MKN7 and MKN74 cells, the combination of 5-FU and vandetanib had synergistic effects, but effects were only additional against the other cell lines in vitro. Combination chemotherapy in vivo also significantly inhibited tumor growth compared to single use of each drug. Flow cytometry showed vandetanib increased the proportion in the G. The synergistic effect of vandetanib with 5-FU is related to vandetanib-induced reduction of TYMS via down-regulation of cyclin D1. Hyperexpression of cyclin D1 might be a biomarker of the synergistic effect.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Drug Synergism; E2F1 Transcription Factor; ErbB Receptors; Female; Fluorouracil; Humans; Mice; Mice, Nude; Piperidines; Quinazolines; Stomach Neoplasms; Thymidylate Synthase; Tumor Burden

Hypoxia-inducible factor-2α (HIF2α) is a major determinant factor of invasion and metastasis in various tumors. It has been reported that HIF2α is overexpressed in many tumors, including gastric cancer. However, the roles of HIF2α in the progression of gastric cancer are still not clear. In this study, we first examined the levels of HIF2α in gastric cancer by using immunohistochemistry, western blot and real-time PCR analysis. The results showed that HIF2α was highly expressed in gastric cancers compared to non-neoplastic mucosa and significantly correlated with histologic grade, TNM stages and peritoneal dissemination. MTT and colony formation assay revealed HIF2α overexpression induced high proliferation in BGC823 cells and HIF2α knockdown significantly inhibited proliferation in SGC7901 cells. Furthermore, we demonstrated that HIF2α could promote migration and invasion in gastric cancer cells. The results of western blot and RT-PCR analysis indicated that Survivin, Cyclin D1, MMP2 and MMP9 are upregulated with HIF2α overexpression. Finally, similar roles of HIF2α also in vivo were demonstrated. Taken together, the present study suggested that HIF-2α was involved in proliferation, metastasis and invasion of gastric cancer cells, with the induction of Survivin, Cyclin D1, MMP2 and MMP9 expression.

Topics: Adenocarcinoma; Adult; Aged; Aged, 80 and over; Animals; Basic Helix-Loop-Helix Transcription Factors; Cells, Cultured; Cyclin D1; Female; Humans; Inhibitor of Apoptosis Proteins; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Middle Aged; Neoplasm Invasiveness; Prognosis; Stomach Neoplasms; Survivin

We have previously demonstrated that novel 1-alkyl-tryptophan analogs 1-butyltryptophan (1-BT) can serve as a potential antitumor agent. However, the molecular mechanisms of 1-BT on cancer cells remain to be elucidated. The effect of 1-BT on cell proliferation was detected by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay and clone formation assay in SGC7901 and AGS cells. Cell cycle was determined by flow cytometry. Cell migration and invasion was determined by wound healing assay and transwell assay. The expression of cyclin-dependent kinase 4 (CDK4), cyclin D1, p16, PCNA, phosphorylated Akt, total Akt, phosphorylated ERK1/2, and total ERK1/2 was examined using Western blotting. Our data demonstrated that 1-BT inhibited cell proliferation in a dose- and time-dependent manner by the downregulation of expression of cyclin D1 and CDK4 and by the upregulation of p16 expression. The inhibition of cell growth was also demonstrated by cell cycle arrest at the G1/S phase. Furthermore, 1-BT inhibited cell migration and invasion in SGC7901 cells. In addition, we found that phosphorylated Akt was suppressed in 1-BT treated SGC7901 cells. Overexpression of activated Akt reversed the effects of 1-BT on cell migration and invasion in SGC7901 cells. These results indicated that 1-BT inhibited gastric cancer cells proliferation and migration through the Akt pathway, which has the potential clinical significance in the prevention and treatment of gastric cancer.

Topics: Apoptosis; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Humans; Neoplasm Invasiveness; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Stomach Neoplasms; Tryptophan

Cyclin D1 (CCND1) plays essential roles in cancer progression. In this study, CCND1 expression patterns in 211 cases of resected gastric adenocarcinoma (RGA) tissue were determined by immunohistochemistry, and the association between CCND1 expression levels and RGA prognosis was analyzed. RGA tissues displayed differential CCND1 expression (high expression, 52.1 %; n = 110, and low expression, 47.9 %; n = 101). CCND1 expression levels were related with median overall survival time (MST). MST in patients with high CCND1 expression was 43 months, whereas with low CCND1 expression it was 62 months (P = 0.013). When data were stratified by postoperative treatments and CCND1 expression levels, the MST for patients treated with fluoropyrimidine plus platinum (n = 140) was significantly longer than for those treated with fluoropyrimidine only (n = 71) in both high and low CCND1 expression groups (65.0 vs. 29.0 months, P = 0.041; and 74.5 vs. 33.0 months, P = 0.003, respectively). Cox multivariate analyses further confirmed that high CCND1 expression was related with poor prognosis in both treatment groups [hazard ratio (HR) 1.91, 95 % confidence interval (CI) 1.12-3.23; P = 0.017, and HR 2.14, 95 % CI 1.08-4.25; P = 0.029] and that fluoropyrimidine plus platinum was more effective than fluoropyrimidine only in high CCND1 (HR 0.47, 95 % CI 0.28-0.78; P = 0.004) and low CCND1 (HR 0.44; 95 % CI 0.23-0.82; P = 0.01) expression patients. Therefore, CCND1 may be used as a prognostic biomarker for patients with RGA.

Topics: Adenocarcinoma; Adult; Aged; Biomarkers, Tumor; Cyclin D1; Female; Humans; Immunohistochemistry; Kaplan-Meier Estimate; Male; Middle Aged; Prognosis; Proportional Hazards Models; Stomach Neoplasms

Gastric cancer is the fourth most common cancer and is one of the leading causes of cancer-related mortality worldwide. Forkhead box M1 (FOXM1) is overexpressed in gastric cancer, suggesting that it is important in gastric cancer oncogenesis. However, no studies have investigated the role of 3,3'-diindolylmethane (DIM), a component of cruciferous vegetables, in the regulation of FOXM1 and its signaling pathway in gastric cancer. Here, we report for the first time that DIM effectively downregulated Akt/FOXM1 in gastric cancer cells. Combination treatment with DIM and paclitaxel significantly and dose-dependently inhibited the proliferation of SNU638 cells when compared to treatment with DIM or paclitaxel alone. Colony formation of SNU638 cells was significantly attenuated by treatment with DIM and paclitaxel, and DIM potentiated the inhibition of colony formation in SNU638 cells by paclitaxel when compared to treatment with a single agent. Treatment with DIM plus paclitaxel substantially increased apoptosis as indicated by increased levels of cleaved polyADP-ribose polymerase (PARP) and cleaved caspase-9 protein. DIM dose-dependently sensitized gastric cancer cells through downregulation of FOXM1 and potentiated the effects of paclitaxel. FOXM1 effector genes such as CDK4, p53 and cyclin D1 were downregulated in gastric cancer cells by combination treatment with DIM and paclitaxel. In addition, DIM significantly and dose-dependently inhibited phosphorylation of Akt and potentiated paclitaxel-induced inhibition of Akt function in gastric cancer cells. Therefore, our results indicate that DIM effectively potentiates the efficacy of chemotherapeutic agents such as paclitaxel by downregulation of the Akt/FOXM1 signaling cascade in gastric cancer cells. Our findings suggest that DIM enhances the therapeutic efficacy of paclitaxel in gastric cancer and is a potential clinical anticancer agent for the prevention and/or treatment of gastric cancer.

Topics: Antineoplastic Agents; Apoptosis; Caspase 9; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Cyclin-Dependent Kinase 4; Down-Regulation; Drug Synergism; Forkhead Box Protein M1; Forkhead Transcription Factors; Humans; Indoles; Paclitaxel; Phosphorylation; Proto-Oncogene Proteins c-akt; Signal Transduction; Stomach Neoplasms; Tumor Suppressor Protein p53

Intra-tumor heterogeneity is a potential cause for failure of targeted therapy in gastric cancer, but the extent of heterogeneity of established (HER2) or potential (EGFR, CCND1) target genes and prognostic gene alterations (MYC) had not been systematically studied.. To study heterogeneity of these genes in a large patient cohort, a heterogeneity tissue microarray was constructed containing 0.6 mm tissue cores from 9 different areas of the primary gastric cancers of 113 patients and matched lymph node metastases from 61 of these patients. Dual color fluorescence in-situ hybridization was performed to assess amplification of HER2, EGFR, CCND1 and MYC using established thresholds (ratio ≥ 2.0). Her2 immunohistochemistry (IHC) was performed in addition.. Amplification was found in 17.4% of 109 interpretable cases for HER2, 6.4% for EGFR, 17.4% for CCND1, and 24.8% for MYC. HER2 amplification was strongly linked to protein overexpression by IHC in a spot-by-spot analysis (p < 0.0001). Intra-tumor heterogeneity was found in the primary tumors of 9 of 19 (47.3%) cancers with HER2, 8 of 17 (47.0%) cancers with CCND1, 5 of 7 (71.4%) cancers with EGFR, and 23 of 27 (85.2%) cancers with MYC amplification. Amplification heterogeneity was particularly frequent in case of low-level amplification (<10 gene copies). While the amplification status was often different between metastases, unequivocal intra-tumor heterogeneity was not found in individual metastases.. The data of our study demonstrate that heterogeneity is common for biomarkers in gastric cancer. Given that both TMA tissue cores and clinical tumor biopsies analyze only a small fraction of the tumor bulk, it can be concluded that such heterogeneity may potentially limit treatment decisions based on the analysis of a single clinical cancer biopsy.

Topics: Adult; Aged; Aged, 80 and over; Biomarkers, Tumor; Cyclin D1; Gene Amplification; Genes, erbB-1; Genes, erbB-2; Genes, myc; Genetic Heterogeneity; Humans; Immunohistochemistry; In Situ Hybridization, Fluorescence; Lymphatic Metastasis; Middle Aged; Stomach Neoplasms; Tissue Array Analysis

MicroRNAs (miRNAs) play crucial roles in the development and progression of human cancers, including gastric cancer. The discovery of miRNAs may provide a new and powerful tool for studying the mechanism, diagnosis, and treatment of gastric cancer. Here we show that miR-181a levels were significantly downregulated in gastric cancer tissues compared with the adjacent normal regions in 80 paired samples. Moreover, the lower levels of miR-181a were associated with the pM or pTNM stage in clinical gastric cancer patients. In addition, the ectopic expression of miR-181a in the gastric cancer cell line HGC-27 inhibited cell proliferation, cell migration, and invasion by directly interacting with the mRNA encoding the oncogenic factor Prox1. Taken together, our results indicate that miR-181a might act as a tumor suppressor in gastric cancer, which may provide a novel diagnostic and therapeutic option for human gastric cancer in the near future.

Topics: Adult; Aged; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Down-Regulation; Female; Gene Expression Regulation, Neoplastic; Homeodomain Proteins; Humans; Male; MicroRNAs; Middle Aged; Neoplasm Invasiveness; Neoplasm Staging; Stomach Neoplasms; Tumor Suppressor Proteins

Caudal type homeobox transcription factor 2 (CDX2) is important in intestinal cell fate specification and multiple lines of evidence have substantiated that CDX2 is important in carcinogenesis of the digestive tract. The CDX2 regulatory network is intricate and remains to be fully elucidated in gastric cancer. The aim of the present study was to examine the effects of CDX2 on the growth of the MGC-803 human gastric cancer cell line in vivo, and to elucidate the mechanism involved. The effects of the overexpression of CDX2 in xenograft tumors of MGC-803 cells was investigated in nude mice through the injection of CDX2 recombinant lentiviral vectors. The tumor size was measured using vernier callipers. The expression levels of CDX2, survivin, B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax), cyclin D1, s-phase kinase-associated protein 2 (Skp2) and c-Myc in the tumor cells were analyzed by western blotting and semi-quantitative reverse transcription polymerase chain reaction. The apoptotic rates were determined using a terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay. The overexpression of CDX2 was observed in the group subjected to the injection of CDX2 recombinant lentiviral vectors. CDX2 had an inhibitory effect on the MGC-803 human gastric cancer cell line and promoted tumor cell apoptosis in vivo. Furthermore, the overexpression of CDX2 upregulated the expression of Bax and downregulated the expression levels of survivin, Bcl-2, cyclin D1, Skp2 and c-Myc in the tumor tissues. These results indicated that CDX2 may serve as a tumor suppressor in gastric cancer, and inhibits gastric cancer cell growth by suppressing the nuclear factor-κB signaling pathway.

Topics: Animals; bcl-2-Associated X Protein; Carcinoma; CDX2 Transcription Factor; Cell Line, Tumor; Cyclin D1; Gene Expression Regulation, Neoplastic; Genetic Vectors; HEK293 Cells; Homeodomain Proteins; Humans; Inhibitor of Apoptosis Proteins; Lentivirus; Mice; Mice, Inbred BALB C; Mice, Nude; Neoplasm Transplantation; Proto-Oncogene Proteins c-bcl-2; Proto-Oncogene Proteins c-myc; S-Phase Kinase-Associated Proteins; Signal Transduction; Stomach Neoplasms; Survivin; Transgenes; Tumor Burden

Alocasia cucullata (Lour.) G. Don was applied in traditional Chinese medicine for the treatment of cancer in Chinese Southwest area. Its antitumor effect was scrutinized in vitro and in vivo. And for the first time, the mechanism of extract of A. cucullata (EAC) against human gastric cancer cell was well examined.. To detect the most effective fraction, the antiproliferation efficacy of four fractions (namely derivatives by adding EAC to n-BuOH, petroleum ether, EtOAc and water until dissolve fully) against five cancer cell lines were screened by MTT assay. Among four fractions, the IC50s of n-BuOH fraction of EAC (EAC-B) against the five cell lines and time-dependent inhibition to gastric cancer cell line (MGC-803) were further investigated (MTT assay). In vivo antitumor efficacy of EAC-B was examined by MGC-803 bearing tumor nude mice. Especially, the paper focused on the relevant mechanism study of EAC-B against MGC-803 included cell cycle distribution (flow cytometry) and cyclin D1 expression (RT-PCR and western blot), apoptosis (Hoechst 33342 stain and flow cytometry), apoptosis-related protein expression (Akt, p-Akt, ERK, p-ERK, Bcl-2, Bax) by western blot, and caspase3/7 activity assay.. EAC-B showed its cytotoxicity against various tumor cell lines, particularly against gastric cancer cells with IC50 value of 18.8 μg/mL in vitro. Tumor weight was significantly reduced by EAC-B in vivo. In the mechanism study, EAC-B increased cell ratio at G0/G1 phase and reduced cyclin D1 expression both at protein and mRNA level on MGC-803. Chromatin condensation and apoptosis were also observed. EAC-B down-regulated p-Akt, p-ERK expression and up-regulated Bax/Bcl-2 ratio. Further, caspase 3/7 activation was enhanced as well.. This study demonstrated that EAC-B had potent antitumor activity both in vitro and in vivo. Its mechanism is primarily via antiproliferation of G0/G1 arrest and cell pro-apoptosis, including PI-3 K/Akt pathway, ERK activity, stimulated cytochrome C release and caspase 3/7 activity accompanied with an increase of Bax/Bcl-2 ratio. EAC-B may be a potential source of novel compounds for gastric cancer treatment.

Topics: Alocasia; Animals; Antineoplastic Agents, Phytogenic; Apoptosis; Caspases; Cell Cycle; Cell Line, Tumor; Cyclin D1; Down-Regulation; Drugs, Chinese Herbal; G1 Phase; Humans; In Vitro Techniques; Mice, Inbred BALB C; Mice, Nude; Phytotherapy; RNA, Messenger; Stomach Neoplasms

The purpose of this study was to investigate the effect and mechanism of Vav3 gene on the proliferation of human gastric cancer cell line SGC7901.. The expressions of Vav3 proten in gastric cancer tissue, tumor-adjacent tissue, human gastric cancer cell line SGC7901 and gastric epithelial cell line GES-1 cells were tested by Western blot. Vav3-siRNA was transfected into the SGC7901 cells. The proliferation of SGC7901 cells in vitro was measured by MTT assay. Cell cycle of SGC7901 cells was determined by flow cytometry.The expressions of proliferation-related genes PCNA, p16, cyclin D1, Rb were determined by qPCR and Western blot assay. Orthotopic transplantation nude mouse models of gastric cancer were prepared, and the tumor growth and expressions of PCNA, P16, cyclin D1, and Rb proteins were examined.. The relative expressions of Vav3 in the gastric cancer and peritumoral tissue were 0.910±0.242 and 0.243±0.045, respectively; the relative expressions of Vav3 in SGC7901 and GSE-1 cells were 0.925±0.127 and 0.277±0.038, respevtively (both P<0.05). The expression of Vav3 protein in SGC7901 cells was effectively inhibited by Vav3-siRNA. Proliferation of SGC7901 cells was inhibited by (83.43±10.17)% after 80 nmol/L Vav3-siRNA transfection (P<0.05). The ratio of SGC7901 cells in G0/G1 phase was increased, and in S phase decreased after Vav3-siRNA transfection (both P<0.05). The expressions of PCNA and cyclin D1 were decreased in cells after Vav3-siRNA transfection, and expressions of p16 and Rb were increased after Vav3-siRNA transfection (P<0.05 for all). The tumor growth in the Vav3-siRNA group was much slower than that in the other 2 control groups of nude mouse models. Compared with the two control groups, expressions of PCNA and cyclin D1 were significantly lower in the Vav3-siRNA group, while expressions of p16 and Rb were increased (P<0.05 for all).. Vav3 can promote the proliferation of gastric cancer cells by regulating proliferation-related genes.

Topics: Animals; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Humans; Mice; Mice, Nude; Proto-Oncogene Proteins c-vav; RNA, Small Interfering; Stomach Neoplasms; Transfection

Hematopoietic pre-B cell leukemia transcription factor interacting protein (HPIP) has been shown to play an important role in the development and progression of some cancers. However, the role of HPIP in gastric cancer (GC) is unclear. Here, we show that HPIP is upregulated in most GC patients and promotes GC cell proliferation, migration, and invasion. In GC patients, HPIP positively associates with tumor size and nodal metastasis, and negatively associates with tumor differentiation. Hematopoietic pre-B cell leukemia transcription factor interacting protein increases GC cell proliferation through activation of G1 /S and G2 /M cell cycle transitions, accompanied by a marked increase of the positive cell cycle regulators, including cyclin D1, cyclin A, and cyclin B1. Hematopoietic pre-B cell leukemia transcription factor interacting protein enhances GC cell migration and invasion, and modulates epithelial-mesenchymal transition, which plays a key role in cancer cell migration and invasion. These data underscore the critical role of HPIP in GC cell proliferation and progression and suggest that HPIP inhibition may be a useful therapeutic strategy for GC treatment.

Topics: Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin A1; Cyclin B1; Cyclin D1; DNA-Binding Proteins; Epithelial-Mesenchymal Transition; Female; G1 Phase Cell Cycle Checkpoints; G2 Phase Cell Cycle Checkpoints; Gene Expression Regulation, Neoplastic; Humans; Lymphatic Metastasis; Male; Middle Aged; Neoplasm Invasiveness; Pre-B-Cell Leukemia Transcription Factor 1; Proto-Oncogene Proteins; RNA Interference; RNA, Small Interfering; Stomach Neoplasms

Although microRNA‑33 (miR‑33) family members are known to be involved in the regulation and balancing of cholesterol metabolism, fatty acid oxidation and insulin signaling, their functions in carcinogenesis are controversial and the underlying mechanisms have remained elusive. Gastric cancer is the fourth most common malignancy in the world; however, the dysregulation and function of miR‑33 family members in gastric cancer have not been extensively studied. The present study reported that a miR‑33 family member, miR‑33a, was significantly downregulated in gastric cancer tissues and gastric cancer cell lines. Of note, the expression of miR‑33a was inversely correlated with pathological differentiation and metastasis as well as gastric cancer biomarker CA199. A cell‑counting kit‑8 assay showed that transfection of the SGC‑7901 gastric cell line with miR‑33a‑overexpression plasmid inhibited the capability of the cells to proliferate. Furthermore, overexpression of miR‑33a led to cell cycle arrest of SGC‑7901 cells in G1 phase. In addition, a luciferase reporter assay showed that miR‑33a directly targeted cyclin‑dependent kinase 6 (CDK6), cyclin D1 (CCND1) and serine/threonine kinase PIM‑1. In gastric cancer specimens, the reduced expression of miR‑33a was associated with increased expression of CDK‑6, CCND1 and PIM1. However, only PIM1 expression was significantly increased in cancer tissues compared with that in their adjacent tissues. The present study revealed that miR‑33a was downregulated in gastric cancer tissues and cell lines, while forced overexpression of miR‑33a decreased CDK‑6, CCND1 and PIM1 expression to inhibit gastric cancer cell proliferation by causing G1 phase arrest. miR‑33a overexpression may therefore resemble an efficient strategy for gastric cancer therapy.

Topics: Adenocarcinoma; Aged; Antigens, Tumor-Associated, Carbohydrate; Base Sequence; Carcinoembryonic Antigen; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Cyclin-Dependent Kinase 6; Female; G1 Phase Cell Cycle Checkpoints; Gene Expression Regulation, Neoplastic; Humans; Male; MicroRNAs; Middle Aged; Molecular Sequence Data; Neoplasm Staging; Oligonucleotides; Proto-Oncogene Proteins c-pim-1; Signal Transduction; Stomach Neoplasms

HOX (homeobox) genes encode a family of transcriptional regulators, which have an important role in morphogenesis and differentiation during embryonic development. Their deregulated expression is involved in the carcinogenesis of many human solid tumours. In the present study, we show that HOXB5 mRNA was significantly overexpressed in gastric cancer tissues compared with adjacent normal tissues. HOXB5-up-regulated cancer cells showed increased invasion and migration activity, but no change in proliferation activity, whereas HOXB5-down-regulated cells showed decreased invasion and migration activity. Up-regulation of HOXB5 resulted in up-regulation of β-catenin, whereas inhibition of HOXB5 expression by siRNA led to the down-regulation of β-catenin. Moreover, a significant correlation between HOXB5 and CTNNB1 (β-catenin) mRNA expression was detected in gastric cancer tissues. Furthermore, we found that HOXB5 binds directly to the CTNNB1 promoter region and activates the transcriptional expression of β-catenin, as well as its downstream target genes, encoding cyclin D1 and c-Myc, leading to an increase in the invasion and migration activity of human gastric cancer cells. Thus HOXB5 may be an important regulator of the Wnt/β-catenin signalling pathway, thereby contributing to gastric cancer progression and metastasis.

Topics: beta Catenin; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Gene Expression Regulation, Neoplastic; Homeodomain Proteins; Humans; Neoplasm Invasiveness; Protein Binding; Proto-Oncogene Proteins c-myc; Stomach Neoplasms; Transcription, Genetic; Up-Regulation; Wnt Signaling Pathway

Gastric cancer remains one of the most prevalent and lethal malignancies in the world. Despite new advances in treatment and diagnosis, patients with advanced gastric cancer are still difficult to cure resulting in a high mortality rate and poor prognosis. Signal transducer and activator of transcription 3 (Stat3) is observed aberrant in multiple tumours, including gastric cancer. Stat3 overexpression was confirmed performing a vital role in tumorigenesis. In the present study, we constructed a pSi-Stat3 plasmid to silence Stat3 and investigated the effect of pSi-Stat3 on cell proliferation, apoptosis and cell cycle progression in gastric cancer cell line SGC-7901 and mice xenograft model. Downstream proteins of Stat3, including Cyclin-D1, Survivin and Bcl-2, were detected as well for the underlying mechanism exploration. It showed that pSi-Stat3 can effectively silence the expression of Stat3 and inhibits the growth of gastric tumour both in vitro and in vivo significantly via cell apoptosis and cell cycle shift induction. The findings suggest that Stat3 signal pathway might be a promising therapeutic target for tumour treatment, including gastric cancer.

Topics: Animals; Antineoplastic Agents; Apoptosis; Cell Cycle; Cell Line, Tumor; Cyclin D1; Female; Genes, bcl-2; Heterografts; Humans; Inhibitor of Apoptosis Proteins; Mice; Mice, Inbred BALB C; Mice, Nude; RNA, Messenger; RNA, Small Interfering; STAT3 Transcription Factor; Stomach Neoplasms; Survivin

Gastric cancer stem cells (GCSCs) have an important role in metastasis and recurrence of gastric cancer, and novel treatment strategies that target GCSCs are urgently required. Although evodiamine (Evo), a derivative of the traditional herbal medicine Evodia rutaecarpa, has been reported to have various biological effects, its effect on GCSCs remains unknown. In order to determine the effect of Evo on apoptosis of GCSCs, an MTS assay, flow cytometry and western blot analysis were performed. The effect of Evo on self‑renewal in GCSCs was measured by alterations in the sphere formation ability, the expression of induced‑pluripotent stem cell factors, expression of epithelial-to-mesenchymal transition (EMT) factors and oxaliplatin resistance of gastric cancer cells (GCCs). Evo inhibited proliferation, promoted the Bax/B‑cell lymphoma 2 ratio and altered active caspase‑3 expression of GCSCs. In addition, Evo decreased the sphere formation ability, the expression of Sox2, KLF4, Bmi‑1 and Oct4, and oxaliplatin resistance in GCCs. Evo decreased the expression of Slug, Twist, Zeb1 and vimentin, suggesting an inhibitory effect on EMT. Furthermore, the expression of β‑catenin, c‑Myc and cyclin D1 was decreased in Evo‑treated spheroids from GCCs. In conclusion, Evo inhibited the Wnt/β‑catenin signaling pathway to inhibit proliferation and stem cell properties of GCSCs and repressed the EMT. The present findings highlight the prospect of Evo as a CSCs-targeted therapy in gastric cancer.

Topics: Animals; Apoptosis; bcl-2-Associated X Protein; beta Catenin; Blotting, Western; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cyclin D1; Epithelial-Mesenchymal Transition; Flow Cytometry; Humans; Kruppel-Like Factor 4; Molecular Structure; Neoplastic Stem Cells; Proto-Oncogene Proteins c-bcl-2; Proto-Oncogene Proteins c-myc; Quinazolines; Snail Family Transcription Factors; Stomach Neoplasms; Transcription Factors; Twist-Related Protein 1; Wnt Signaling Pathway

To observe the effect of Jianpi Yangzheng Xiaozheng Recipe (JYXR) on the tumor inhibition rate of subcutaneous transplanted tumor gastric cancer cell line MGC-803 in BALB/c nude mice, and to study its molecular mechanism of apoptosis and autophagy.. Gastric cancer cell line MGC-803 was subcutaneously inoculated to nude mice for preparing transplanted gastric cancer models. Totally 32 BALB/c nude mice were randomly divided into 4 groups according to random digit table, i.e., the negative control group, the positive control group, the high dose JYXR group, the low dose JYXR group, 8 in each group. Normal saline was administered to mice in the negative control group by gastrogavage. 5-fluorouracil (5-Fu) at 2. 5 mg/kg was administered to mice in the positive control group by gastrogavage. JYXR at 85 and 43 g/kg was administered to mice in the high dose JYXR group and the low dose JYXR group by gastrogavage, once per day for 10 successive days. The effect of JYXR on the tumor inhibition rate of subcutaneous transplanted tumor was observed. Effects of JYXR on gene expression levels of Bax, Bcl-2, Fas, Cyclin D1, Cyclin D2, and Cyclin D3 in transplanted tumor were observed by real-time PCR. Effects of JYXR on protein expression levels of Procaspase-3, Procaspase-8, Procaspase-9, cleaved-PARP, Beclin-1, and LC3B were detected using Western blot.. (1) Compared with the negative control group, the tumor weight was obviously reduced in the rest three groups (P <0. 05). The tumor weight was higher in the high dose JYXR group and the low dose JYXR group than in the positive control group (P <0. 05). (2) Results of RT-PCR indicated that, compared with the negative control group, expression levels of Bax were up-regulated, but expression levels of Bcl-2, Cyclin D1, Cyclin D2, and Cyclin D3 were down-regulated in the positive control group and JYXR groups (P <0. 05). The expression level of Fas was up-regulated in the positive control group and the high dose JYXR group (P <0. 05). Compared with the positive control group, expression levels of Fas, and Bax were all down-regulated, but expression levels of Bcl-2, Cyclin D2, and Cyclin D3 were all up-regulated in the high dose JYXR group and the low dose JYXR group (all P <0. 05). The expression level of Cyclin D1 was down-regulated in the high dose JYXR group, but it was up-regulated in the low dose JYXR group ( both P <0. 05). (3) Results of Western blot showed, compared with the negative control group, expression levels of Procaspase-3, Procaspase-8, and Procaspase-9 were down-regulated, but expression levels of cleaved-PARP, Beclin-1, and LC3B II were up-regulated in the high dose JYXR group and the low dose JYXR group (all P <0.05). Compared with the negative control group, expression levels of Procaspase-3, Procaspase-8, Procaspase-9, and LC3B II were down-regulated, but expression levels of cleaved-PARP, Beclin-1, and LC3B I were up-regulated in the positive control group (all P <0. 05).. JYXR showed significant inhibition on subcutaneous transplanted tumor gastric cancer cell line MGC-803 in BALB/c nude mice. Its mechanism might be associated with activating apoptosis and autophagy correlated factors.

Topics: Animals; Antineoplastic Agents; Apoptosis; Autophagy; Caspase 3; Caspase 8; Caspase 9; Cell Line, Tumor; Chemistry, Pharmaceutical; Cyclin D1; Drugs, Chinese Herbal; Fluorouracil; Humans; Mice; Mice, Inbred BALB C; Mice, Nude; Neoplasm Transplantation; Proto-Oncogene Proteins c-bcl-2; Stomach Neoplasms

Transcription Factor E2F-1 plays a critical role in cell cycle regulation and other biological processes in cells. However whether or not it is involved in the multi-drug resistance (MDR) process of gastric cancer has not been fully elucidated yet. To explore the role of E2F-1 in the MDR process of gastric cancer in vitro and in vivo, a cisplatin-resistant gastric cancer cell line with stable downregulation of E2F-1 was established. E2F-1 shRNA led to downregulation of endogenous E2F-1 mRNA and protein. It significantly promoted the sensitivity of SGC7901/DDP cells to cisplatin, doxorubicin, and fluorouracil. Flow cytometry confirmed that the percentage of apoptotic cells increased after E2F-1 downregulation. This notion was further supported by the observation that downregulation of E2F-1 blocked entry into the S-phase of the cell cycle. Furthermore, downregulation of E2F-1 significantly increased intracellular accumulation of doxorubicin. In addition, we determined the in vivo effects of E2F-1 small interfering RNA (shRNA) on tumor size, and apoptotic cells in tumor tissues were detected by deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling and hematoxylin and eosin staining. In molecular studies, semiquantitative RT-PCR and western blotting revealed that E2F-1 downregulation could inhibit expression of MDR1, MRP, Bcl-2/Bax, c-Myc, Skp2, Survivin, and Cyclin D1.. E2F-1 may be involved in regulating multiple signaling pathways in reversing MDR, suggesting that E2F-1 may represent a novel target for gastric cancer therapy.

Topics: Animals; Antineoplastic Agents; Apoptosis; ATP Binding Cassette Transporter, Subfamily B; ATP Binding Cassette Transporter, Subfamily B, Member 1; Cell Line, Tumor; Cisplatin; Cyclin D1; Down-Regulation; Doxorubicin; Drug Resistance, Multiple; Drug Resistance, Neoplasm; E2F1 Transcription Factor; Gene Expression Regulation, Neoplastic; Genes, myc; Humans; Inhibitor of Apoptosis Proteins; Male; Mice; Mice, Nude; RNA, Messenger; RNA, Small Interfering; S-Phase Kinase-Associated Proteins; Stomach Neoplasms; Survivin

Recently, several miRNAs have been determined as tumor suppressors in various cancers, such as microRNA-449a. However, the exact molecular mechanisms underlying miR-449a regulated cell proliferation and chemosensitivity in gastric cancer cells have not been well documented.. The present study was designed to test whether miR-449a mediates cell proliferation and chemosensitivity in gastric cancer cells via regulating cyclin D1 and BCL2.. In vitro, the ability of cell proliferation and cell viability were measured by MTT assay; cell cycle and cell apoptosis was detected by FCM. qRT-PCR was used to measure the expression of miR-449a. Western blot and real-time PCR assays were used to detect the expression of cyclin D1 and BCL2 in gastric cancer cell line SGC7901.. miR-449a expression was downregulated in gastric cancer cell line SGC7901 and human gastric cancer tissues, compared to the gastric epithelial cell line GES-1 and matched non-tumor associated tissues. Upregulation of miR-449a reduced the proliferation of SGC7901 cells. Ectopic expression of miR-449a decreased the percentage of S phase cells, increased the percentage of G1/G0 phase cells and increased the apoptosis induced by cisplatin. Moreover, miR-449a inhibited SGC7901 cells proliferation and enhanced cisplatin chemosensitivity by downregulating expression of BCL2 and cyclin D1, respectively, via directly targeting the 3'-untranslated regions of BCL2 and cyclin D1 mRNA.. This is the first report to provide evidence that miR-449a could modulate cell cycle and apoptosis through regulating cyclin D1 and BCL2 expression in SGC7901 cells.

Topics: 3' Untranslated Regions; Antineoplastic Agents; Apoptosis; Binding Sites; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cisplatin; Cyclin D1; Gene Expression Regulation, Neoplastic; Humans; MicroRNAs; Proto-Oncogene Proteins c-bcl-2; Signal Transduction; Stomach Neoplasms; Time Factors; Transfection

MicroRNA-107 (miR-107) has been demonstrated to regulate proliferation and apoptosis in many types of cancers. Nevertheless, its biological function in gastric cancer remains largely unexplored. Here, we found that the expression level of miR-107 was increased in gastric cancer in comparison with the adjacent normal tissues. The enforced expression of miR-107 was able to promote cell proliferation in NCI-N87 and AGS cells, while miR-107 antisense oligonucleotides (antisense miR-107) blocked cell proliferation. At the molecular level, our results further revealed that expression of FOXO1 was negatively regulated by miR-107. Therefore, the data reported here demonstrate that miR-107 is an important regulator in gastric cancer, which will contribute to a better understanding of the important mis-regulated miRNAs in gastric cancer.

Topics: Base Sequence; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p21; Cyclin-Dependent Kinase Inhibitor p27; Forkhead Box Protein O1; Forkhead Transcription Factors; Gene Expression Regulation, Neoplastic; Humans; MicroRNAs; NF-kappa B; Stomach Neoplasms; Up-Regulation

Gastric cancer is the second most common cause of cancer-related death in males and the fourth in females. Traditional treatment has poor prognosis because of recurrence and systemic side effects. Therefore, the development of new therapeutic strategies is an important issue. Lentivirus-mediated shRNA stably inhibits target genes and can efficiently transduce most cells. Since overexpressed cyclin D1 is closely related to human gastric cancer progression, inhibition of cyclin D1 using specific targeting could be an effective treatment method of human gastric cancer.. The therapeutic effect of lentivirus-mediated shRNA targeting of cyclin D1 (ShCCND1) was analyzed both in vitro and in vivo experiments.. In vitro, NCI-N87 cells with downregulation of cyclin D1 by ShCCND1 showed significant inhibition of cell proliferation, cell motility, and clonogenicity. Downregulation of cyclin D1 in NCI-N87 cells also resulted in significantly increased G1 arrest and apoptosis. In vivo, stable NCI-N87 cells expressing ShCCND1 were engrafted into nude mice. Then, the cancer-growth inhibition effect of lentivirus was confirmed. To assess lentivirus including ShCCND1 as a therapeutic agent, intratumoral injection was conducted. Tumor growth of the lentivirus-treated group was significantly inhibited compared to growth of the control group. These results are in accordance with the in vitro data and lend support to the mitotic figure count and apoptosis analysis of the tumor mass.. The lentivirus-mediated ShCCND1 was constructed, which effectively inhibited growth of NCI-N87-derived cancer both in vitro and in vivo. The efficiency of shRNA knockdown and variation in the degree of inhibition is mediated by different shRNA sequences and cancer cell lines. These experimental results suggest the possibility of developing new gastric cancer therapies using lentivirus-mediated shRNA.

Topics: Animals; Cell Line, Tumor; Cyclin D1; Female; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Genetic Vectors; Humans; Lentivirus; Male; Mice; Mice, Nude; Molecular Targeted Therapy; Neoplasms, Experimental; RNA, Small Interfering; Stomach Neoplasms

MicroRNAs play important roles in the development and progression of various cancers. Recent studies have shown that miR-638 was downregulated in several tumors; however, its role in gastric cancer (GC) has not been investigated in detail.. The purpose of this study was to determine the role of miR-638 and to elucidate its regulatory mechanism in GC.. The expression levels of miR-638 and specificity protein 2 (Sp2) were detected by real-time PCR and Western blotting in GC. After pcDNA6.2-GW/EmGFP-miR-638 vector, miR-638 inhibitor and Sp2-siRNA transfection, the AGS cell proliferation was investigated by MTT assay and cell cycle, and apoptosis was detected using the Annexin V/PI. In addition, the regulation of Sp2 by miR-638 was evaluated by real-time RT-PCR, Western blot and luciferase reporter assays; cyclin D1 expression was measured by Western blotting.. The expression of miR-638 is dramatically down-regulated and Sp2 expression is remarkably up-regulated in GC tissues. Luciferase assays revealed that miR-638 inhibited Sp2 expression by targeting the 3'-UTR of Sp2 mRNA. Overexpression of miR-638 and Sp2-siRNA reduced Sp2 expression at both the mRNA and protein levels in vitro, and inhibition of miR-638 increased Sp2 expression. Moreover, we found that miR-638 overexpression and Sp2-siRNA markedly suppressed cell proliferation with decreasing expression of cyclin D1 and inducing G1-phase cell-cycle arrest in vitro; inhibition of miR-638 significantly promoted cell proliferation by increasing expression of cyclin D1 and leading more cells into the S and G2/M phase.. Our results demonstrated that miR-638 suppressed GC cell proliferation by targeting Sp2 with influence on the expression of cyclin D1. We suggest that miR-638 might be a candidate predictor or an anticancer therapeutic target for GC patients.

Topics: Cell Line, Tumor; Cell Proliferation; Cyclin D1; Cyclin D2; Down-Regulation; Gene Knockdown Techniques; Humans; MicroRNAs; Sp2 Transcription Factor; Stomach Neoplasms

FOXO1, a forkhead box O (FOXO) transcription factor, and nuclear factor-κB (NF-κB) are prognostically significant transcription factors in gastric cancer. As their relationship has been inconsistent depending on the cell type, we aimed to investigate whether FOXO1 is associated with NF-κB p65 (RelA) in gastric cancer. Immunohistochemistry was performed on tissue array slides containing 298 gastric carcinoma specimens. We found that the cytoplasmic expression of pFOXO1, the inactive form of FOXO1, was positively correlated with nuclear RelA expression (p = 0.024). In addition, the expressions of pFOXO1 and RelA were positively related with cyclin D1 expression (p = 0.014 and p = 0.001, respectively) and Ki-67 labeling index (p = 0.025 and p = 0.017, respectively). However, they did not show association with the expressions of cyclin E, p53 and pRb. Cell culture experiments showed that FOXO1 overexpression by transfection of FOXO1 AAA mutant gene suppressed NF-κB activation in SNU-484 gastric cancer cells. These results suggest that FOXO1 and NF-κB are negatively associated and that FOXO1 is a negative upstream regulator of NF-κB in gastric cancer.

Topics: Cell Line, Tumor; Cyclin D1; Cyclin E; Forkhead Box Protein O1; Forkhead Transcription Factors; Gene Expression Regulation, Neoplastic; Humans; Immunohistochemistry; Ki-67 Antigen; Mutation; Retinoblastoma Protein; Stomach Neoplasms; Transcription Factor RelA; Tumor Suppressor Protein p53

Studies have shown that FRZB correlates with gastric tumorigenicity and may play role in regulating the Wnt/β‑catenin signaling pathway. In the present study, we investigated the correlation between FRZB and the Wnt/β‑catenin signaling pathway using gastric cancer tissues and an FRZB‑knockdown gastric cancer cell line model. The protein levels of FRZB and β‑catenin were examined using immunohistochemical staining. FRZB-specific shRNAs were used to generate FRZB‑knockdown MKN45 gastric cancer cells. Cell proliferation assay, suspending culture and Annexin V/PI double staining analysis were used to investigate the role of FRZB knockdown in cell growth. In vitro migration/invasion assays were performed. The expression of Wnt/β‑catenin downstream targets was analyzed by RT-PCR. FRZB mRNA levels showed negative correlation with β‑catenin levels in paired non-tumor and tumor tissues. FRZB protein levels were negatively correlated with β‑catenin levels analyzed by IHC staining. Furthermore, high FRZB protein levels were correlated with membrane localization of β‑catenin. FRZB knockdown increased gastric cancer cell growth in monolayer and soft agar culture; it increased cell aggregates in suspending culture and rendered less apoptosis which indicated increased anti-anoikis growth. FRZB knockdown increased cell migration and invasion and increased the expression of Wnt/β‑catenin downstream targets such as MMP7 and cyclin D1. Our studies revealed that FRZB levels were correlated with β‑catenin subcellular localization. Knockdown of FRZB in gastric cancer cells increased cell growth and migration/invasion which was also accompanied by activation of Wnt/β‑catenin downstream targets. FRZB knockdown may upregulate the Wnt/β‑catenin pathway and promote aggressiveness in gastric cancer.

Topics: Apoptosis; beta Catenin; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Gene Expression Regulation, Neoplastic; Glycoproteins; Humans; Intracellular Signaling Peptides and Proteins; Matrix Metalloproteinase 7; Neoplasm Invasiveness; RNA Interference; RNA, Small Interfering; Stomach Neoplasms; Up-Regulation; Wnt Proteins; Wnt Signaling Pathway

To investigate the effects of E2F-1 gene silencing on multidrug resistance of human gastric cancer SGC7901/DDP cells and its possible mechanisms.. Gastric cancer SGC7901/DDP cells were seeded in 6 well plates and divided into three groups: the experimental group, blank control and the negative control groups. For the experimental group, the SGC7901/DDP cells were transfected with recombinant lentivirus vector (Lv-shRNA-E2F-1), while the negative control with an control lentiviral vector (Lv-shRNA-NC) and the blank control with no treatment. The E2F-1 protein level was analyzed by Western blot. MTT assay was used to detect the half maximal inhibitory concentration (IC50) of three chemotherapy drugs including adriamycin, 5-fluorouracil (5-Fu) and cisplatine (DDP) of the three cell groups. Flow cytometry (FCM) was used to detect the pump-out rate of adriamycin and apoptosis rate of the three cell groups. Semi-quantitative RT-PCR and Western blot were also used to detect the protein and mRNA levels of multidrug resistance-associated genes (MDR1, MRP) and apoptosis-related genes (c-Myc, Skp2, cyclinD1).. The expression of E2F-1 protein in the experimental group was significantly lower than that in the negative control and blank control groups (0.794 ± 0.033 vs. 1.487 ± 0.082 vs. 1.511 ± 0.084, P < 0.01). The IC50 of the three chemotherapy drugs (adriamycin, 5-Fu and cisplatine) in the experimental group was significantly lower than that of the negative control and blank control groups, respectively (P < 0.01). Compared with the negative control and blank control groups, the pump-out rate of adriamycin of the experimental group was significantly declined [(0.16 ± 0.01)% vs. (0.37 ± 0.01)% vs. (0.35 ± 0.02)%, P < 0.01]. However, the apoptosis rate of the experimental group was significantly higher than that of the negative control and blank control groups [(33.82 ± 1.26)% vs. (17.34 ± 0.81)% vs. (13.16 ± 1.06)%, P < 0.01]. The results of RT-PCR and Western blot assays showed that mRNA and protein expressions of five genes (MDR1, MRP, CyclinD1, c-Myc, Skp2) in the experimental group were significantly lower than that in the negative control and blank control groups, respectively (P < 0.01).. E2F-1 gene silencing enhances the chemosensitivity of gastric cancer SGC7901/DDP cells to the chemotherapeutic drugs, directly or indirectly downregulated the expression of MDR1 and MRP, and finally reverses the multidrug resistance of the gastric cancer cells. The mechanism may be associated with the suppression of cyclinD1, c-Myc and Skp2.

Topics: Antibiotics, Antineoplastic; Antimetabolites, Antineoplastic; Antineoplastic Agents; Apoptosis; ATP Binding Cassette Transporter, Subfamily B, Member 1; Cell Line, Tumor; Cisplatin; Cyclin D1; Doxorubicin; Drug Resistance, Multiple; Drug Resistance, Neoplasm; E2F1 Transcription Factor; Fluorouracil; Gene Silencing; Genetic Vectors; Humans; Lentivirus; Multidrug Resistance-Associated Proteins; Proto-Oncogene Proteins c-myc; Recombinant Proteins; RNA, Messenger; S-Phase Kinase-Associated Proteins; Stomach Neoplasms; Transfection

Gastric cancer is the second most common cause of cancer-related death worldwide. This study was designed to examine the role of CUGBP1 in cell growth via an RNA interference (RNAi) lentivirus system in gastric cancer cells in vitro. The expression of CUGBP1 was much stronger in gastric cancer tissues than that in adjacent normal tissues. The lentivirus-mediated knockdown of CUGBP1 resulted in a significant reduction of CUGBP1 expression in MGC-803 gastric cancer cells. The cell viability was remarkably decreased by 50 % after 5 days of infection, as determined by MTT assay. Moreover, the size and the number of colonies formed in MGC-803 cells were markedly reduced in the absence of CUGBP1. Furthermore, the silencing of CUGBP1 downregulated the expression levels of cyclin B1 and cyclin D1, which are involved in cell cycle control. These results clearly indicated that CUGBP1 is essential for the growth of gastric cancer cells. Therefore, silencing of CUGBP1 by RNAi could be developed as a promising therapeutic approach for gastric cancer.

Topics: CELF1 Protein; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cyclin B1; Cyclin D1; Gene Knockdown Techniques; Humans; Lentivirus; RNA Interference; RNA-Binding Proteins; Signal Transduction; Stomach Neoplasms; Tumor Stem Cell Assay

To investigate the effects of tetramethypyrazine (TMP) on proliferation and apoptosis of the human gastric carcinoma cell line 7901 and its possible mechanism of action.. The viability of TMP-treated 7901 cells was measured with a 3-(4, 5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide assay (MTT) and cell apoptosis was analyzed by flow cytometry. The distribution of cells in different phases of cell cycle after exposure of TMPs was analyzed with flow cytometry. To investigate the molecular mechanisms of TMP-mediated apoptosis, the expression of NF-xBp65, cyclinD1 and p16 in SGC-7901 cells was analyzed by reverse transcription- polymerase chain reaction (RT-PCR) and western blotting.. TMP inhibited the proliferation of human gastric carcinoma cell line 7901 in dose and time dependent manners. Cell growth was suppressed by TMP at different concentrations (0.25, 0.5, 1.0, 2.0 mg/ml), the inhibition rate is 0.46%, 4.36%, 14.8%, 76.1% (48h) and 15.5%, 18.5%, 41.2%, 89.8% (72h) respectively. When the concentration of TMPs was 2.0mg/ml, G1-phase arrest in the SGC-7901 cells was significant based on the data for cell cycle distribution. RT-PCR demonstrated that NF-xBp65 and cyclin D1 mRNA expression was significantly down-regulated in 7901 cells treated with 2.0 mg/ml TMP for 72h (p<0.05), while the p16 mRNA level was up-regulated (p<0.05). The protein expression of NF-xBp65 and cyclin D1 decreased gradually with the increase in TMP concentration, compared with control cells (p<0.05), while expression of protein p16 was up-regulated (p<0.01).. TMP exhibits significant anti-proliferative and pro-apoptotic effects on the human gastric carcinoma cell line SGC-7901. NF-xBp65, cyclinD1 and p16 may also play important roles in the regulation mechanisms.

Topics: Apoptosis; Blotting, Western; Carcinoma; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p16; Down-Regulation; Drug Screening Assays, Antitumor; Gene Expression Regulation, Neoplastic; Humans; Neoplasm Proteins; NF-kappa B; Pyrazines; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Stomach Neoplasms; Up-Regulation

Little is known about gastric neoplasms arising from hyperplastic polyps (HPs).. To investigate the risk factors associated with neoplasms within HPs and to evaluate the role of alterations of the p16-cyclin D1-pRb pathway in the malignant transformation of HPs.. Retrospective, case-control study.. Tertiary-care center.. Between May 1995 and January 2011, a total of 809 HPs >1 cm were investigated. Associated neoplasms were present in 30 HPs (case group); 30 HPs without neoplasms were selected as a control group.. Gastric polypectomy.. The risk factors associated with neoplasms within HPs and immunohistochemical expression of p16, cyclin D1, p53, and Ki-67 between case and control groups.. Of the 809 HPs, 15 had associated dysplasia, and 15 had carcinoma. Multivariate analysis showed that neoplasm was associated with patient age (odds ratio [OR] 1.159; 95% confidence interval [CI], 1.243-2.044; P < .001), polyp size (OR 1.103; 95% CI, 1.055-1.152; P < .001), and polyp lobulation (OR 4.549; 95% CI, 1.759-11.0766; P < .001) but not with location, multiplicity, intestinal metaplasia, growth pattern, or Helicobacter pylori infection. Loss of p16 expression and high Ki-67 expression were observed in dysplastic areas of HPs compared with the control group (p16 = 14.3% vs 60%; P = .001, Ki-67 = 60.7% vs 36.7%; P < .001). However, no significant differences were found in nondysplastic areas in both groups.. Single-center, retrospective study.. HPs >1 cm may indicate the presence of neoplasms. Loss of p16 and high Ki-67 expression may be markers of HP-associated dysplasia.

Topics: Age Factors; Aged; Carcinoma; Case-Control Studies; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p16; Female; Helicobacter Infections; Humans; Immunohistochemistry; Ki-67 Antigen; Male; Middle Aged; Neoplasm Proteins; Polyps; Retrospective Studies; Risk Factors; Stomach Diseases; Stomach Neoplasms; Tumor Burden; Tumor Suppressor Protein p53

Aberrant expression of microRNAs (miRNAs) has been shown to play important roles in cancer progression as a result of changes in expression of their target genes. In this study, we investigated the roles of miR-520d-3p on gastric cancer (GC) cell proliferation, migration, and invasion, and confirmed that this miRNA regulates EphA2 expression. The mRNA expression levels of miR-520d-3p and EphA2 in GC tissues and cell lines were evaluated. The clinical and prognostic significance of miR-520d-3p was assessed. The biological function of miR-520d-3p in GC cells was investigated using a methylthiazolyldiphenyl-tetrazolium bromide assay, cell cycle assay, transwell invasion assay, and wound-healing assay. miR-520d-3p expression was down-regulated and inversely correlated with the expression of EphA2 in GC tissues and cell lines. Lower expression of miR-520d-3p was associated with tumor invasion (P = 0.0357), lymph nodes metastasis (P = 0.0272), a higher clinical stage (P = 0.0041), and poorer overall survival (P = 0.0105). Luciferase assays revealed that miR-520d-3p inhibited EphA2 expression by targeting the 3'-untranslated region of EphA2 mRNA. Overexpression of miR-520d-3p dramatically inhibited the proliferation, cell cycle progression, invasion, and migration of GC cells, while down-regulation substantially promoted these properties. Moreover, c-Myc, CyclinD1, and matrix metalloproteinase-9 expression levels were down-regulated in miR-520d-3p mimic-transfected cells and up-regulated in miR-520d-3p inhibitor-transfected cells. Taken together, our data showed that miR-520d-3p appears to contribute to GC progression via the regulation of EphA2 and could serve as a novel prognostic and potential therapeutic marker.

Topics: 3' Untranslated Regions; Aged; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Female; Gene Expression Regulation, Neoplastic; Genes, myc; Genes, Tumor Suppressor; Humans; Male; Matrix Metalloproteinase 9; MicroRNAs; Middle Aged; Receptor, EphA2; Stomach Neoplasms

Gastric cancer is one of the most common malignant tumors worldwide. Due to the complex initiation and intricate progression mechanisms, early detection and effective treatment of gastric cancer are both difficult to achieve. The genetic polymorphisms encoding critical protein cyclin D1 (CCND1) to regulate cell cycle transition from G1 phase to S phase may determine the susceptibility of individuals to gastric cancer. The study aimed to examine the contribution of CCND1 genotypes to gastric cancer risk in Taiwan.. The genotypes of CCND1 A870G (rs9344) and G1722C (rs678653) were determined by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis among 358 gastric patients and 358 cancer-free controls, and the distribution of genotypic and allelic frequencies among the two groups were compared.. The results showed that there were significant differences between gastric cancer and control groups in the distribution of the genotypes (p=6.86×10(-4)) and allelic frequency (p=0.0016) in the CCND1 A870G genotype. In addition, individuals who carried the AG or GG genotype had 0.55- and 0.51-fold of odds ratios of developing gastric cancer compared to those who carried the AA genotype (95% confidence intervals [CI]=0.39-0.76 and 0.32-0.81, respectively). There was no such association of CCND1 G1722C with gastric cancer. Furthermore, there was an obvious interaction of the CCND1 A870G genotype with personal smoking habit on gastric cancer risk (p=0.0005).. Cell-cycle regulation may play a role in gastric cancer initiation and development and the CCND1 A870G genotype maybe a useful biomarker for detection of early gastric cancer.

Topics: Aged; Alleles; Case-Control Studies; Cyclin D1; Female; Gene Frequency; Genetic Association Studies; Genetic Predisposition to Disease; Genotype; Humans; Male; Middle Aged; Neoplasm Staging; Risk Factors; Stomach Neoplasms; Taiwan

To examine the expression patterns of ER-α36 and Cyclin D1 in human gastric cancer tissues and to investigate the effects of ER-α36-mediated estrogen signaling on the growth of gastric cancer cells, 117 samples of formalin-fixed and paraffin-embedded gastric cancer tumor tissues and 40 fresh gastric cancer tumor tissues were analyzed with immunohistochemistry assay and western blot analysis. ER-α36 expression was well correlated with gender (male:female ratio 2.88:1, P=0.01), invasion to serosa (P=0.01) as well as Cyclin D1 expression (P<0.01). The effects of different concentrations of estrogen on the growth of different gastric cancer cells and normal gastric cells as well as gastric cancer SGC7901 cells with different levels of ER-α36 expression were examined. SGC7901 cells with high levels of ER-α36 expression exhibited estrogen hypersensitivity, high growth rate and high levels of Cyclin D1 expression while SGC7901 cells with knocked-down levels of ER-α36 expression were insensitive to estrogen stimulation, grew slowly and expressed less Cyclin D1. Our results indicate that ER-α36 mediates biphasic estrogen signaling in the growth of gastric cancer cells.

Topics: Adult; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Estrogen Receptor alpha; Estrogens; Female; Humans; Male; Middle Aged; Neoplasms, Hormone-Dependent; Phosphorylation; Signal Transduction; Stomach Neoplasms

RKIP is proposed as a new metastasis suppressor. Our recent study showed that RKIP inhibits malignant phenotypes of gastric cancer cells. However, the underlying mechanism of RKIP function in gastric cancer is unclear. This study aimed to investigate the correlation of RKIP, STAT3 and cyclin D1 expression in the tumorigenesis of gastric cancer. RKIP, STAT3 and cyclin D1 proteins were detected by immunohistochemistry in tissues of gastric ulcer (n = 27), gastric adenomatous polyp (n = 7), intestinal metaplasia (n = 26), dysplasia (n = 40), gastric carcinoma (n = 169) and metastatic lymph node (n = 36). RKIP, STAT3 and cyclin D1 mRNA levels were analyzed by RT-PCR in SGC7901 cells. We found that RKIP protein expression was significantly decreased in advanced gastric cancer and metastatic lymph node tissues while cyclin D1 and STAT3 protein expression was markedly increased in severe dysplasia, gastric cancer and metastatic lymph node tissue (P < 0.01). RKIP expression in gastric cancer was negatively correlated with the invasion, TNM stage and lymphoid node metastasis (P < 0.01), while cyclin D1 and STAT3 expression was positively correlated with histological differentiation and lymphoid node metastasis (P < 0.01). RKIP protein level was negatively correlated with cyclin D1 and STAT3 protein level, while cyclin D1 protein level was positively correlated with STAT3 protein level in gastric cancer samples. Moreover, reconstitution of RKIP in SGC7901 gastric cancer cells led to reduced cyclin D1 and STAT3 mRNA levels. In conclusion, these data suggest that RKIP inhibits gastric cancer metastasis via the downregulation of its downstream target genes STAT3 and cyclin D1.

Topics: Adenomatous Polyps; Biomarkers, Tumor; Carcinoma; Cell Line, Tumor; Cyclin D1; Female; Gene Expression Regulation, Neoplastic; Humans; Immunohistochemistry; Lymphatic Metastasis; Male; Metaplasia; Middle Aged; Neoplasm Invasiveness; Phosphatidylethanolamine Binding Protein; Prognosis; Real-Time Polymerase Chain Reaction; RNA, Messenger; STAT3 Transcription Factor; Stomach Neoplasms

To investigate the effects of eukaryotic translation initiation factor 5A2 (EIF5A2) down-regulation by small interfering RNA (siRNA) on aggressiveness of human gastric cancer cell and its potential mechanisms.. The expressions of EIF5A2 in human gastric cancer cell lines (MKN28 and HGC27) and immortalized gastric mucosal epithelial cells (GES-1) were measured by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blotting. EIF5A2 gene in MKN28 cells was silenced by RNA interference and the inhibitory effect was evaluated by both qRT-PCR and Western blotting. Cell proliferation was assessed by CCK-8 assay. Cell migration and invasion were assessed by Transwell assay. The possible downstream targets of EIF5A2, such as CyclinD1, CyclinD3, matrix metallopeptidase-9 (MMP-9), E-cadherin, vimintin, C-myc, and metastasis-associated protein 1 (MTA1) expression levels, were examined by Western blotting.. High expressions of EIF5A2 were found in MKN28 cells and human gastric adenocarcinoma tissues. Both EIF5A2 mRNA and protein expression in MKN28 cells were significantly down-regulated by siRNA#1 and siRNA#2, especially siRNA#1. Knockdown of EIF5A2 caused an apparent suppression of MKN28 cell proliferation (all P<0.01), migration (P<0.001), and invasion (P<0.001). After the knockdown of EIF5A2 in MKN28 cells, E-cadherin levels were upregulated, whereas vimentin, Cyclin D1, Cyclin D3, C-myc and MTA1 levels were downregulated.. Knockdown of EIF5A2 may inhibit MKN28 cell proliferation by downregulating the CyclinD1 and CyclinD3 and suppressing the cell migration and invasion by inhibiting MTA1, C-myc and epithelial-mesenchymal transition.

Topics: Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Cyclin D3; Down-Regulation; Eukaryotic Translation Initiation Factor 5A; Gene Expression Regulation, Neoplastic; Genes, myc; Histone Deacetylases; Humans; Peptide Initiation Factors; Repressor Proteins; RNA Interference; RNA-Binding Proteins; RNA, Small Interfering; Stomach Neoplasms; Trans-Activators

CCN6/Wnt1-inducible signaling protein-3 (CCN6/WISP3) is a cysteine-rich protein that belongs to the CCN (Cyr61, CTGF, Nov) family of matricellular proteins, which are often dysregulated in cancers. However, the functional role and clinical significance of WISP3 in gastric cancer remain unclear. In this study, we found that silencing of WISP3 suppressed gastric cancer cell proliferation, migration and invasion. Cell adhesion to collagens (collagen I and IV), but not to fibronectin, were significantly inhibited by silencing of WISP3. Furthermore, silencing of WISP3 prevented β-catenin transferring from cell cytoplasm to nuclear, and suppressed canonical Wnt/β-catenin signaling and its downstream target genes, cyclin D1 and TCF-4. By immunohistochemical analysis of 379 patients, we found that the expression of WISP3 is closely associated with gastric cancer size and tumor invasion, and indicates a poor prognosis in both test cohort (253 patients) and validation cohort (126 patients). Moreover, the expression of WISP3 was positively correlated with the expression of cyclin D1 and TCF-4 in gastric cancer tissues. Taken together, our data suggests that WISP3 might be a promising prognostic factor and WISP3-Wnt/β-catenin axis may be a new therapeutic target for the intervention of gastric cancer growth and metastasis.

Topics: Active Transport, Cell Nucleus; Adenocarcinoma; Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; beta Catenin; CCN Intercellular Signaling Proteins; Cell Adhesion; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Down-Regulation; Extracellular Matrix Proteins; Female; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Humans; Male; Middle Aged; Neoplasm Invasiveness; Prognosis; RNA Interference; Stomach Neoplasms; Time Factors; Transcription Factor 4; Transcription Factors; Transfection; Tumor Burden; Wnt Signaling Pathway

Acetyl-11-keto-beta-boswellic acid (AKBA) is a derivative of boswellic acid, an active component of Boswellia serrata gum resin. We examined the effect of AKBA on human gastric carcinoma growth and explored the underlying molecular mechanisms.. Inhibition of cancer cell growth was estimated by colorimetric and clonogenic assays. Cell cycle distribution was analyzed by flow cytometry and apoptosis determined using Annexin V-FITC/PI staining and DNA ladder quantification. After three weeks of oral AKBA administration in nude mice bearing cancer xenografts, animals were sacrificed and xenografts removed for TUNEL staining and western blot analysis.. AKBA exhibited anti-cancer activity in vitro and in vivo. With oral application in mice, AKBA significantly inhibited SGC-7901 and MKN-45 xenografts without toxicity. This effect might be associated with its roles in cell cycle arrest and apoptosis induction. The results also showed activation of p21(Waf1/Cip1) and p53 in mitochondria and increased cleaved caspase-9, caspase-3, and PARP and Bax/Bcl-2 ratio after AKBA treatment. Further analysis suggested that these effects might arise from AKBA's modulation of the aberrant Wnt/β-catenin signaling pathway. Upon AKBA treatment, β-catenin expression in nuclei was inhibited, and membrane β-catenin was activated. In the same sample, active GSK3β was increased and its non-active form decreased. Levels of cyclin D1, PCNA, survivin, c-Myc, MMP-2, and MMP-7, downstream targets of Wnt/β-catenin, were inhibited.. AKBA effects on human gastric carcinoma growth were associated with its activity in modulating the Wnt/β-catenin signaling pathway.. AKBA could be useful in the treatment of gastric cancers.

Topics: Animals; Antineoplastic Agents; bcl-2-Associated X Protein; beta Catenin; Caspase 3; Caspase 9; Cell Line, Tumor; Cell Nucleus; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p21; Female; Gene Expression Regulation, Neoplastic; Humans; Mice; Mice, Inbred BALB C; Mice, Nude; Proliferating Cell Nuclear Antigen; Proto-Oncogene Proteins c-myc; Stomach Neoplasms; Triterpenes; Tumor Suppressor Protein p53; Wnt Signaling Pathway; Xenograft Model Antitumor Assays

Conventional classifications of gastroenteropancreatic neuroendocrine tumours (GEP- NETs) are rather unsatisfactory because of the variation in survival within each subgroup. Molecular markers are being found able to predict patient outcome in more and more tumours. The aim of this study was to characterize the expression of the proteins cyclin D1, cyclin E and P53 in GEP- NETs and assess any prognostic impact. Tumor specimens from 68 patients with a complete follow-up were studied immunohistochemically for cyclin D1, cyclin E and P53 expression. High cyclin D1 and cyclin E immunostaining (≥ 5% positive nuclei) was found in 48 (71%) and 24 (35%) cases, and high P53 staining (≥ 10% positive nuclei) in 33 (49%) . High expression of P53 was more common in gastric neuroendocrine tumors and related to malignant behavior, being associate with a worse prognosis on univariate analysis (RR=1.9, 95%CI=1.1-3.2). High expression of cyclin E was significantly associated with shorter survival in the univariate analysis (RR=2.0, 95%CI=1.2-3.6) and multivariate analysis (RR=2.1, 95%CI=1.1-4.0). We found no significant correlation between the expression of cyclin D1 and any clinicopathological variables. Our study indicated a prognostic relevance for cyclin E and P53 immunoreactivity. Cyclin E may be an independent prognostic factor from the 2010 WHO Classification which should be evaluated in further studies.

Topics: Aged; Colorectal Neoplasms; Cyclin D1; Cyclin E; Female; Humans; Kaplan-Meier Estimate; Male; Middle Aged; Multivariate Analysis; Neuroendocrine Tumors; Pancreatic Neoplasms; Proportional Hazards Models; Retrospective Studies; Stomach Neoplasms; Tumor Suppressor Protein p53

Helicobacter pylori infection is related to the development of gastric diseases. Various virulence factors are responsible for the pathogenic mechanisms of H. pylori infection. Our previous studies using two-dimensional gel electrophoresis showed that H. pylori thioredoxin-1 (Trx1) is overexpressed in gastric carcinomas. Here, we examined whether H. pylori Trx1 is a novel virulence factor associated with gastric tumorigenesis. We found that Trx1 expression in H. pylori isolated from gastric cancer tissues was significantly higher than that from tissues exhibiting gastritis. In the gastric epithelial cell line GES-1, infection of H. pylori with high Trx1 expression significantly induced cell apoptosis, decreased the expression of cyclin D1 and upregulated p21. However, in the gastric cancer cell line BGC823, high Trx1 expression in H. pylori significantly increased cell proliferation, and upregulated cyclin D1. The effects on cell lines were confirmed using the H. pylori Trx1-knockout mutant strain. Our observations indicate that high Trx1 expression in H. pylori is associated with gastric carcinogenesis. In H. pylori, Trx1 likely participates in the pathogenesis of gastric cancer and H. pylori expressing high levels of Trx1 would be expected to be highly pathogenic in gastric diseases in China.

Topics: Apoptosis; Bacterial Proteins; Cell Line; Cell Proliferation; Cell Survival; Cell Transformation, Neoplastic; China; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p21; Gastritis; Gene Expression Regulation, Bacterial; Gene Knockout Techniques; Helicobacter Infections; Helicobacter pylori; Humans; Mutation; Organ Specificity; Stomach Neoplasms; Thioredoxins; Up-Regulation; Virulence Factors

To explore the effect of down-regulation of astrocyte elevated gene-1 (AEG-1) expression on cell proliferation and cell cycle of gastric carcinoma cells, and its possible molecular mechanism.. Control siRNA and AEG-1 siRNA were transfected into gastric carcinoma SGC-7901 cells. 48 h after transfection, the cells were divided into 3 groups including untransfected, siRNA control and AEG-1 siRNA transfection groups. Expressions of AEG-1 mRNA and protein in the 3 group cells were detected by real-time quantitative PCR and Western blot. The changes of cell proliferation were examined using CCK-8 kit, and the cell cycle distribution was detected by flow cytometry. Finally, expressions of cell proliferation and cell cycle related proteins were detected by Western blot.. Real-time quantitative PCR and Western blot demonstrated that compared with the untransfected and siRNA control groups, expressions of AEG-1 mRNA and protein were significantly down-regulated in the AEG-1 siRNA transfection group (P < 0.05), but there was no significant difference between the untransfected and siRNA control groups (P > 0.05). Furthermore, in vivo experiment confirmed a significant down-regulation of AEG-1 protein in the AEG-1 siRNA transfection group (P < 0.05). In addition, AEG-1 siRNA obviously inhibited the proliferation of SGC-7901 cells at different time points after transfection with AEG-1 siRNA. The percentage of cells in G0/G1 phase in the AEG-1 siRNA transfection group [(61.26 ± 1.25)%] was significantly higher than those in the untransfected group [(46.17 ± 1.91)%] and siRNA control group [(46.46 ± 1.96)%], and there was a significant difference between them (all P < 0.001). Furthermore, the result of Western blotting revealed that down-regulation of AEG-1 expression evoked the down-regulation of cdk2 and cyclin D1 expressions and elevation of p21 expression in vitro and in vivo.. The inhibition of cell proliferation and cell cycle arrest mediated by down-regulation of AEG-1 expression may be closely associated with the changes of expression of cell cycle related proteins including cdk2, cyclin D1 and p21.

Topics: Animals; Cell Adhesion Molecules; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Cyclin-Dependent Kinase 2; Cyclin-Dependent Kinase Inhibitor p21; Down-Regulation; Female; Humans; Membrane Proteins; Mice; Mice, Inbred BALB C; Mice, Nude; Neoplasm Transplantation; RNA Interference; RNA-Binding Proteins; RNA, Messenger; RNA, Small Interfering; Stomach Neoplasms; Transfection

To characterize the human primary cyclins (D1, E, A, B1) expressed in gastric carcinoma, and to clarify the relationship between the types of expressed primary cyclins and clinicopathological features of gastric carcinoma.. Primary cyclins (D1, E, A, B1) expressed in single cells separated from 68 cases gastric carcinoma tissues were analyzed by flow cytometry. We classified the gastric carcinomas by different types of the expressed primary cyclins, and explore the roles of primary cyclins expressed in cell cycle and the expression patterns of the cyclins. The results were analyzed together with clinicopathological features.. The patterns of expressed primary cyclins could be classified into five types. The proportion was 10.3% (7/68), 22.1% (15/68), 25.0% (17/68), 29.4% (20/68), and 13.2% (9/68), respectively, from type I to type V. Each type could be, according to the degree of in-cycle cyclins expressed, divided into different sub-types. The types of primary cyclins expressed were strongly linked to invasive depth and lymph node metastasis of the gastric carcinoma (P < 0.01). The rates of lymph node metastasis were 26.6%, 43.8%, 82.3%, 95.0%, and 100.0%, respectively, from type I to type V. The type of primary cyclins expressed was also significantly associated with disease stage (TNM stage). The proportion of stage IV disease was 0, 6.7%, 17.6%, 25.0% and 55.6%, respectively, from type I to type V. It was shown that there were relationships between the sub-types of primary cyclins expressed and different growth-types, degree of cell differentiation, or, the tumor gross types (P < 0.01).. The types of primary cyclins expression are different in the process of the occurrence, development and metastasis of gastric carcinoma, and are correlated with clinicopathological features of gastric carcinoma.

Topics: Adult; Aged; Aged, 80 and over; Cell Differentiation; Cyclin A1; Cyclin B1; Cyclin D1; Cyclin E; Cyclins; Female; Humans; Lymphatic Metastasis; Male; Middle Aged; Neoplasm Invasiveness; Neoplasm Staging; Oncogene Proteins; Stomach Neoplasms

Recent studies have found that an acidic tumor microenvironment is the key to managing cancer progression and metastasis. Our previous study found that proton pump inhibitors (PPIs) inhibit the expression of vacuolar-ATPases (V-ATPases) and reverse the transmembrane pH gradient. The present study was conducted to explore the effect of pantoprazole on gastric adenocarcinoma through the regulation of Wnt/β-catenin signaling. We used SGC7901 human gastric cancer cells as an in vitro model to study the effect of pantoprazole. The antiproliferative, pro-apoptotic and anti‑invasive effects of pantoprazole were examined. The effects of pantoprazole on the expression of the Wnt/β-catenin signaling pathway were also studied by western blotting. Our study found that pantoprazole inhibited the proliferation and induced the apoptosis of SGC7901 human gastric cancer cells. The expression of V-ATPases was decreased following treatment with pantoprazole. Further study found that pantoprazole treatment caused a decrease in phospho-LRP6, but not in LRP6. β-catenin in Wnt/β-catenin signaling and its target genes c-Myc and cyclin D1 were also decreased upon the inhibition of V-ATPases. Therefore, pantoprazole could be characterized as a V-ATPase inhibitor for treating gastric cancer by inhibiting the phosphorylation of LRP6 in Wnt/β-catenin signaling.

Topics: 2-Pyridinylmethylsulfinylbenzimidazoles; Adenocarcinoma; Apoptosis; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Humans; Low Density Lipoprotein Receptor-Related Protein-6; Neoplasm Invasiveness; Pantoprazole; Phosphorylation; Proto-Oncogene Proteins c-myc; Stomach Neoplasms; Tumor Microenvironment; Vacuolar Proton-Translocating ATPases; Wnt Signaling Pathway

To explore the role of CDX2 in the multi-drug resistance (MDR) process of gastric cancer in vitro and in vivo.. A cisplatin-resistant gastric cancer cell line with stable downregulation of CDX2 was established. mRNA and protein expression levels of CDX2, survivin, cyclin D1, and c-Myc were detected by western blotting and semi-quantitative reverse-transcriptase polymerase chain reaction (RT-PCR). The influence of downregulation of CDX2 on MDR was assessed by measuring IC50 of SGC7901/DDP cells to cisplatin, doxorubicin, and 5-fluorouracil, rate of doxorubicin efflux, apoptosis, and cell cycle progression detected by flow cytometry. In addition, we determined the in vivo effects of CDX2 small interfering RNA (siRNA) on tumor size, and apoptotic cells in tumor tissues were detected by deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling and hematoxylin and eosin staining.. CDX2 siRNA led to downregulation of endogenous CDX2 mRNA (0.31 ± 0.05 vs 1.10 ± 0.51, 0.31 ± 0.05 vs 1.05 ± 0.21, P = 0.003) and protein (0.12 ± 0.08 vs 0.51 ± 0.07, 0.12 ± 0.08 vs 0.55 ± 0.16, P = 2.57 × 10(-4)) expression. It significantly promoted the sensitivity of SGC7901/DDP cells to cisplatin (0.12 ± 0.05 vs 0.33 ± 0.08, 0.12 ± 0.05 vs 0.39 ± 0.15, P = 0.001), doxorubicin (0.52 ± 0.13 vs 4.11 ± 1.25, 0.52 ± 0.13 vs 4.05 ± 1.44, P = 2.81 × 10(-4)), and 5-fluorouracil (0.82 ± 0.13 vs 2.81 ± 0.51, 0.82 ± 0.13 vs 3.28 ± 1.03, P = 1.71 × 10(-4)). Flow cytometry confirmed that the percentage of apoptotic cells increased after CDX2 downregulation (32.15% ± 2.15% vs 17.63% ± 3.16%, 32.15% ± 2.15% vs 19.3% ± 2.25%, P = 1.73 × 10(-6)). This notion was further supported by the observation that downregulation of CDX2 blocked entry into the S-phase of the cell cycle (31.53% ± 3.78% vs 65.05% ± 7.25%, 31.53% ± 3.78% vs 62.27% ± 5.02%, P = 7.55 × 10(-7)). Furthermore, downregulation of CDX2 significantly increased intracellular accumulation of doxorubicin (0.21 ± 0.06 vs 0.41 ± 0.11, 0.21 ± 0.06 vs 0.40 ± 0.08, P = 0.003). In molecular studies, semiquantitative RT-PCR and western blotting revealed that CDX2 downregulation could inhibit expression of c-Myc, survivin and cyclin D1.. CDX2 may be involved in regulating multiple signaling pathways in reversing MDR, suggesting that CDX2 may represent a novel target for gastric cancer therapy.

Topics: Animals; Antineoplastic Agents; Apoptosis; CDX2 Transcription Factor; Cell Cycle; Cell Line, Tumor; Cisplatin; Cyclin D1; Down-Regulation; Doxorubicin; Drug Resistance, Multiple; Drug Resistance, Neoplasm; Fluorouracil; Gene Expression Regulation, Neoplastic; Homeodomain Proteins; Humans; Inhibitor of Apoptosis Proteins; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Proto-Oncogene Proteins c-myc; RNA Interference; RNA, Messenger; Stomach Neoplasms; Survivin; Time Factors; Transfection

Metallothionein 2A (MT2A) as a stress protein, plays a protective role in gastric mucosal barrier. Its role in the development of gastric cancer (GC) is unclear. The mechanism of MT2A will be investigated in gastric tumorigenesis.. MT2A expression was detected in 973 gastric specimens. The biological function was determined through ectopic expressing MT2A in vitro and in vivo. The possible downstream effectors of MT2A were investigated in NF-κB signaling. The protein levels of MT2A, IκB-α and p-IκB-α (ser32/36) expression were analyzed in a subset of 258 patients by IHC staining. The prognostic effects of MT2A, status of IκB-α and TNM stage were evaluated using the Kaplan-Meier method and compared using the log-rank test.. Decreased MT2A expression was detected in cell lines and primary tumors of GC. In clinical data, loss of MT2A (MT2A + in Normal (n =171, 76.0%); Intestinal metaplasia (n = 118, 50.8%); GC (n = 684. 22.4%, P < 0.001)) was associated with poor prognosis (P < 0.001), advanced TNM stage (P = 0.05), and down-regulation of IκB-α expression (P < 0.001). Furthermore, MT2A was the independent prognostic signature segregated from the status of IκB-α and pathological features. In addition, MT2A inhibited cell growth through apoptosis and G2/M arrest, which negatively regulated NF-κB pathway through up-regulation of IκB-α and down-regulation of p-IκB-α and cyclin D1 expression.. MT2A might play a tumor suppressive activity through inhibiting NF-κB signaling and may be a prognostic biomarker and potential target for individual therapy of GC patients.

Topics: Adult; Aged; Aged, 80 and over; Cell Line, Tumor; Cyclin D1; Female; Gene Expression Regulation, Neoplastic; Humans; I-kappa B Proteins; Immunohistochemistry; Male; Metallothionein; Middle Aged; NF-kappa B; NF-KappaB Inhibitor alpha; Prognosis; Signal Transduction; Stomach Neoplasms; Treatment Outcome; Up-Regulation; Young Adult

Perifosine, an alkylphospholipid, is an Akt inhibitor which inhibits the growth of diverse cancer cells. We have reported its inhibitory effects on the growth of gastric cancer cells recently, but its molecular mechanisms are still largely unknown.. The purpose of this study was to investigate the effect and regulatory mechanism of perifosine in gastric cancer.. Cell viability was determined by sulforhodamine B assay after transiently transfected with AEG-1 specific siRNAs. qRT-PCR and western blot assay were used to determine the mRNA expression and proteins levels of cell signaling molecules examined. Immunohistochemistry was used to detect the AEG-1 expression in 87 gastric carcinomas, 60 dysplasia, and 47 normal gastric mucosa.. Perifosine decreased AEG-1 gene expression along with inhibition of Akt/GSK3β/C-MYC signaling pathway. Knockdown of AEG-1 using siRNA led to significant down-regulation of cyclin D1 expression at both mRNA level and protein level, and inhibited the growth of gastric cancer cells. AEG-1 expression was elevated in gastric dysplasia and cancer tissues compared to normal gastric mucosa (P < 0.01). AEG-1 over-expression correlated with diffuse type of gastric cancer and advanced tumor stages.. Perifosine inhibits the growth of gastric cancer cells possibly through inhibition of the Akt/GSK3β/C-MYC signaling pathway-mediated down-regulation of AEG-1 that subsequently down-regulated cyclin D1. AEG-1 may play an important role in the carcinogenesis and progression of gastric cancer and could be a therapeutic target of perifosine.

Topics: Adenocarcinoma; Adult; Aged; Cell Adhesion Molecules; Cell Line; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cells, Cultured; Cyclin D1; Down-Regulation; Female; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Humans; Male; Membrane Proteins; Middle Aged; Phosphorylcholine; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-myc; RNA-Binding Proteins; Signal Transduction; Stomach Diseases; Stomach Neoplasms; Up-Regulation

Gastric cancer is one of the major public health problems. Despite new chemotherapeutic treatments, the prognosis of gastric cancer remains poor. 5-Fluorouracil (5-FU) is used as a standard chemotherapy drug in gastric cancer. However, 5-FU resistance develops frequently and is a main cause of chemotherapy failure in human gastric cancer. Overexpression of cyclin D1 is related to rapid cell growth, a poor prognosis and increased chemoresistance in several types of cancers. In this study, we investigated whether treatment of gastric cancer cells with shRNA targeting cyclin D1 (ShCCND1) or 5-FU, alone or in combination, influences the activation of phosphorylated AKT (pAKT) and pNFκB, which are markers that are increased in 5-FU chemoresistance. We also investigated the effect of combined treatment with ShCCND1 and 5-FU on cell growth and chemosensitivity to 5-FU in the gastric cancer cell line AGS. The data showed that ShCCND1-mediated cyclin D1 downregulation in AGS cells significantly inhibited cell proliferation, cell mobility and clonogenicity. In addition, combined treatment with ShCCND1 and 5-FU significantly decreased the survival rate of AGS cells, compared to single-treatment with either agent. These results demonstrated that ShCCND1 increases 5-FU chemosensitivity, a conclusion that is also supported by the concomitant reduction in expression of pAKT and pNFκB, increase of G1 arrest and induction of apoptosis. Taken together, these data provide further evidence that therapeutic strategies targeting cyclin D1 may have the dual advantage of suppressing the growth of cancer cells, while enhancing their chemosensitivity.

Topics: Antimetabolites, Antineoplastic; Apoptosis; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cell Survival; Cyclin D1; Down-Regulation; Drug Resistance, Neoplasm; Fluorouracil; G1 Phase Cell Cycle Checkpoints; Humans; Lentivirus; NF-kappa B; Phosphorylation; Proto-Oncogene Proteins c-akt; RNA Interference; RNA, Small Interfering; Stomach Neoplasms

Sirtuin 1 (SIRT1) is a class III histone/protein deacetylase, and its activation status has been well documented to have physiologic benefits in human health. However, the function of SIRT1 in cancer remains controversial. Here, the expression and role of SIRT1 in gastric cancer is delineated. SIRT1 was present in all normal gastric mucosa specimens; however, it was only present in a portion of the matched gastric cancer tumor specimens. In SIRT1-positive tumors, both mRNA and protein levels were downregulated as compared with the corresponding nonneoplastic tissue. Ectopic expression of SIRT1 inhibited cell proliferation, diminished clonogenic potential, and induced a G1-phase cell-cycle arrest, the effects of which were not apparent when a catalytic-domain mutant form of SIRT1 was introduced, suggesting that SIRT1 functions in gastric cancer are dependent on its deacetylase activity. Further evidence was obtained from depletion of SIRT1. At the molecular level, SIRT1 inhibited the transcription of Cyclin D1 (CCND1), and inhibition of NF-κB in SIRT1-depleted cells rescued Cyclin D1 expression. Furthermore, inhibition of either NF-κB or Cyclin D1 in SIRT1-depleted cells reversed the inhibitory effects of SIRT1. The inhibitory role of SIRT1 was also verified in vivo using xenografts. This work characterizes SIRT1 status and demonstrates its inhibitory function in gastric cancer development, which involves NF-κB/Cyclin D1 signaling, offering a therapeutic role for SIRT1 activators.. The inhibitory functions of SIRT1, which involve NF-κB/Cyclin D1 signaling, suggest the utility of SIRT1 activators in the prevention and therapy of gastric cancer.

Topics: Adult; Aged; Aged, 80 and over; Animals; Catalytic Domain; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Down-Regulation; Female; G1 Phase Cell Cycle Checkpoints; Gene Expression Regulation, Neoplastic; Humans; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Middle Aged; NF-kappa B; Signal Transduction; Sirtuin 1; Stomach Neoplasms; Xenograft Model Antitumor Assays

Although PTEN/Akt signaling is frequently deregulated in human gastric cancers, the in vivo causal link between its dysregulation and gastric tumorigenesis has not been established. Here we show that inactivation of PTEN in mouse gastric epithelium initiates spontaneous carcinogenesis with complete penetrance by 2 months of age. Mechanistically, activation of Akt suppresses the abundance of p53, leading to decreased transcription of miR-365, thus causing upregulation of cyclin D1 and cdc25A, which promotes gastric cell proliferation. Importantly, genetic ablation of Akt1 restores miR-365 expression and effectively rescues gastric tumorigenesis in PTEN-mutant mice. Moreover, orthotopic restoration of miR-365 represses PTEN-deficient-induced hyperplasia. In human gastric cancer tissues, miR-365 reduction correlates with poorly differentiated histology, deep invasion and advanced stage, as well as the deregulation of PTEN, phosphorylated Akt, p53, cyclin D1 and cdc25A. These data demonstrate that the PTEN-Akt-p53-miR-365-cyclin D1/cdc25A axis serves as a new mechanism underlying gastric tumorigenesis, providing potential new therapeutic targets.

Topics: Aged; Animals; cdc25 Phosphatases; Cell Proliferation; Cell Transformation, Neoplastic; Cyclin D1; Female; Gene Expression Regulation, Neoplastic; Humans; Male; Mice; MicroRNAs; Middle Aged; Phosphorylation; Proto-Oncogene Proteins c-akt; PTEN Phosphohydrolase; Signal Transduction; Stomach Neoplasms; Survival Analysis; Tumor Suppressor Protein p53

Inflammation is a common phenomenon present in gastric mucosa of patients infected with H. pylori. Activation of the RAGE/multiligand axis is thought to be a relevant factor in cancer-mediated inflammation. RAGE is a membrane receptor, belonging to the immunoglobulin family, and the over-expression of RAGE has been associated with increased invasiveness and metastasis generation in different types of cancer, including gastric cancer. Furthermore recent experiences show that the use of its soluble form (sRAGE) or silencing of the gene coding for this receptor could provide therapeutic benefits in cancer.. To evaluate the immunohistochemical expression of RAGE, MUC-1, β-Catenin free and phosphorylated, Cyclin-D1 and GSK3 in gastric biopsy specimens infected with H. pylori.. Immunohistochemical analysis was carried out in gastric biopsies from 138 patients: 55 with inflammatory injury (no atrophic gastritis), 42 with pre-cancerous conditions (atrophy or intestinal metaplasia) and 41 with dysplastic lesions or in situ adenocarcinoma.. There was a high rate of positive RAGE expression in the three groups of biopsies. Biopsies with dysplasia or in situ carcinoma had a significantly higher percentage of RAGE expression than the other groups of biopsies.. The increased RAGE expression reported in both dysplasia and incipient cancer support the role of the multiligand/RAGE axis in gastric carcinogenesis.

Topics: Adult; Aged; beta Catenin; Biomarkers; Biopsy; Cyclin D1; Female; Gastric Mucosa; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Helicobacter Infections; Helicobacter pylori; Humans; Immunohistochemistry; Male; Middle Aged; Mucin-1; Precancerous Conditions; Receptor for Advanced Glycation End Products; Receptors, Immunologic; Stomach Neoplasms; Young Adult

Here, we describe the efficacy of the novel small molecule c-Met inhibitor BAY 853474 in reducing tumor growth in the Hs746T gastric cancer xenograft model and tested the suitability of 2-deoxy-2-[(18)F]fluoro-D-glucose ([(18)F]FDG) versus 3'-deoxy-3'-18F-fluorothymidine ([(18)F]FLT) for response monitoring in a gastric cancer xenograft mouse model using small animal PET.. The c-Met inhibitor or vehicle control was administered orally at various doses in tumor-bearing mice. Glucose uptake and proliferation was measured using PET before, 48 and 96 h after the first treatment. The PET data were compared to data from tumor growth curves, autoradiography, Glut-1 and Ki-67 staining of tumor sections, and biochemical analysis of tissue probes, i.e., c-Met and ERK phosphorylation and cyclin D1 levels.. BAY 853474 significantly reduces tumor growth. [(18)F]FDG uptake in Hs746T tumors was significantly reduced in the groups receiving the drug, compared with the control group. The [(18)F]FLT uptake in the tumor tissue was completely absent 96 h after treatment. Autoradiographic, immunohistochemical, and biochemical analyses confirmed the PET findings. Treatment with the c-Met inhibitor did not affect body weight or glucose levels, and no adverse effects were observed in the animals.. These preclinical findings suggest that clinical PET imaging is a useful tool for early response monitoring in clinical studies.

Topics: Analysis of Variance; Animals; Antineoplastic Agents; Cyclin D1; Extracellular Signal-Regulated MAP Kinases; Female; Fluorodeoxyglucose F18; Humans; Immunohistochemistry; Mice; Mice, Nude; Phosphorylation; Positron-Emission Tomography; Proto-Oncogene Proteins c-met; Stomach Neoplasms; Xenograft Model Antitumor Assays

p21-activated kinase (PAK)7 (also known as PAK5) is a member of the group B PAK family of serine/threonine protein kinases, which are effectors of the small GTPases Rac and CDC42. PAK7 can promote neurite outgrowth, induce microtubule stabilization, and activate cell survival signaling pathways. However, the role of PAK7 in cancer is still poorly understood. Here, we showed that PAK7 expression was upregulated in different gastric cancer cell lines and gastric cancer tissues, as compared with human embryonic kidney 293 cells and adjacent normal tissues, respectively. The results suggested that PAK7 expression was related to gastric cancer progression. Thus, we employed lentivirus-mediated small interfering RNA to inhibit PAK7 expression, to investigate the role of PAK7 in human gastric carcinogenesis. RNA interference efficiently downregulated expression of PAK7 in SGC-7901 and MGC-803 cells at both mRNA and protein levels. Knockdown of PAK7 inhibited human gastric cancer cell proliferation by inducing cell cycle arrest in G(0)/G(1) phase, in concordance with the downregulation of CDK2, CDC25A, and cyclin D1. Our data suggest that PAK7 is a new hallmark of gastric cancer, in which PAK7 might contribute to gain of tumor growth potential, acting by affecting the expression of cell cycle regulators. Therefore, PAK7 may be an attractive candidate as a therapeutic target in gastric cancer.

Topics: Adenocarcinoma; cdc25 Phosphatases; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Cyclin-Dependent Kinase 2; Female; G1 Phase Cell Cycle Checkpoints; Gene Expression; Gene Knockdown Techniques; Humans; Male; Middle Aged; p21-Activated Kinases; RNA Interference; Stomach Neoplasms

Recent evidence shows that altered microRNA-9 (miR-9) expression is implicated in the progression of gastric cancer. However, the exact roles and underlying mechanisms of miR-9 in the proliferation, invasion and metastasis of gastric cancer still remain unknown. In this study, miR-9 was found to be down-regulated and inversely correlated with the expression of cyclin D1 and v-ets erythroblastosis virus E26 oncogene homolog 1 (Ets1) in gastric cancer tissues and cell lines. Bioinformatics analysis revealed the putative miR-9 binding sites in the 3'-untranslated regions (3'-UTR) of cyclin D1 and Ets1 mRNA. Ectopic expression or knockdown of miR-9 resulted in responsively altered expression of cyclin D1, Ets1 and their downstream targets phosphorylated retinoblastoma and matrix metalloproteinase 9 in cultured gastric cancer cell lines SGC-7901 and AGS. In the luciferase reporter system, miR-9 directly targeted the 3'-UTR of cyclin D1 and Ets1, and these effects were abolished by mutating the miR-9 binding sites. Over-expression of miR-9 suppressed the proliferation, invasion, and metastasis of SGC-7901 and AGS cells in vitro and in vivo. Restoration of miR-9-mediated down-regulation of cyclin D1 and Ets1 by transient transfection, rescued the cancer cells from decrease in proliferation, migration and invasion. Furthermore, anti-miR-9 inhibitor promoted the proliferation, migration and invasion of gastric cancer cells, while knocking down of cyclin D1 or Ets1 partially phenocopied the effects of miR-9 over-expression. These data indicate that miR-9 suppresses the expression of cyclin D1 and Ets1 via the binding sites in their 3'-UTR, thus inhibiting the proliferation, invasion and metastasis of gastric cancer.

Topics: Base Sequence; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Gene Expression Regulation, Neoplastic; Humans; MicroRNAs; Neoplasm Invasiveness; Neoplasm Metastasis; Proto-Oncogene Protein c-ets-1; RNA Interference; RNA Processing, Post-Transcriptional; Stomach Neoplasms; Tumor Burden

High-mobility group box 1 (HMGB1) is a multifunctional protein with intranuclear and extracellular functions. Although HMGB1 is overexpressed in approximately 85% of gastric cancers, the role of HMGB1 in gastric cancer biology remains unclear. In this study, we investigate the effect of downregulation of HMGB1 on the biological behavior of gastric cancer cells. MGC-803 gastric cancer cells were transduced with HMGB1-specific RNAi lentiviral vectors. Real-time polymerase chain reaction and Western blot analysis of HMGB1 mRNA and protein, respectively, validated the silencing effects. HMGB1-specific silencing significantly decreased cell proliferation. The impact on proliferation was observed at the cell cycle level--the number of cells in the G0/G1 phase increased, whereas that in S and G2/M phases decreased. Cell cycle changes were accompanied by decreases in cyclin D1 expression. Furthermore, HMGB1 silencing sensitized cells to apoptosis that was induced by oxaliplatin and mediated by the caspase-3 pathway. Finally, silencing of HMGB1 expression significantly reduced cellular metastatic ability and MMP-9 expression in MGC-803 cells. In summary, HMGB1 not only plays an essential role in the proliferation and invasion of MGC-803 cells but also represents a potential target for the therapeutic intervention of gastric cancer.

Topics: Antineoplastic Agents; Apoptosis; Caspase 3; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Genetic Vectors; HMGB1 Protein; Humans; Lentivirus; Matrix Metalloproteinase 9; Neoplasm Invasiveness; Organoplatinum Compounds; Oxaliplatin; Stomach Neoplasms

P21-activated kinase 4 (PAK4), a serine/threonine protein kinase, has involved in the regulation of cytoskeletal reorganization, cell proliferation, gene transcription, oncogenic transformation and cell invasion. Moreover, PAK4 overexpression, genetic amplification and mutations were detected in a variety of human tumors, which make it potential therapeutic target. In this paper we found that LCH-7749944, a novel and potent PAK4 inhibitor, effectively suppressed the proliferation of human gastric cancer cells through downregulation of PAK4/c-Src/EGFR/cyclin D1 pathway. In addition, LCH-7749944 significantly inhibited the migration and invasion of human gastric cancer cells in conjunction with concomitant blockage of PAK4/LIMK1/cofilin and PAK4/MEK-1/ERK1/2/MMP2 pathways. Interestingly, LCH-7749944 also inhibited the formation of filopodia and induced cell elongation in SGC7901 cells. Importantly, LCH-7749944 caused successful inhibition of EGFR activity due to its inhibitory effect on PAK4. Taken together, these results provided novel insights into the development of PAK4 inhibitor and potential therapeutic strategies for gastric cancer.

Topics: Actin Depolymerizing Factors; Antineoplastic Agents; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Dose-Response Relationship, Drug; ErbB Receptors; Humans; Lim Kinases; MAP Kinase Kinase 1; Matrix Metalloproteinase 2; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Models, Molecular; Molecular Structure; Neoplasm Invasiveness; p21-Activated Kinases; Protein Conformation; Protein Kinase Inhibitors; Proto-Oncogene Proteins pp60(c-src); Pseudopodia; Quinazolines; Signal Transduction; Stomach Neoplasms; Structure-Activity Relationship; Transfection

Activation of Akt signaling pathway has been suggested involving in chemoresistance, metastasis and tumorigenesis of gastric cancer. However, the mechanism of Akt regulation in gastric cancer is not fully understood. RUNX3, which was first identified as a transcription factor, suppresses gastric tumorigenesis through regulating expression of target genes. Here, we found that restoration of RUNX3 significantly downregulates the protein and mRNA expression of Akt1 in gastric cancer cell lines, AGS and SNU-1. Knockdown of RUNX3 upregulates protein and mRNA expression of Akt1 in normal gastric epithelial cell line, GES-1. The negative correlation of RUNX3 and Akt expression and downstream β-catenin/cyclin D1 effectors was further confirmed in AGS and GES-1 cell lines, as well as clinical specimens of gastric cancer. We identified two RUNX3-binding sites in Akt1 promoter and the binding of RUNX3 on Akt1 promoter significantly inhibits Akt1 expression. The RUNX3-mediated inhibition of Akt1 caused β-catenin protein degradation and then cyclin D1 downregulation. Restoration of cyclin D1 reverses cell growth inhibition and G1 phase arrest induced by RUNX3 in gastric cancer cells. Our results show that loss of RUNX3 expression can enhance the Akt1-mediated signaling pathway and promote the tumorigenesis process in human gastric cancer.

Topics: Adenocarcinoma; beta Catenin; Binding Sites; Cell Line, Tumor; Cell Transformation, Neoplastic; Core Binding Factor Alpha 3 Subunit; Cyclin D1; Down-Regulation; Gene Knockdown Techniques; Humans; Promoter Regions, Genetic; Proto-Oncogene Proteins c-akt; Signal Transduction; Stomach Neoplasms

Because of poor prognosis and development of resistance against chemotherapeutic drugs, the existing treatment modalities for gastric cancer are ineffective. Hence, novel agents that are safe and effective are urgently needed. Whether γ-tocotrienol can sensitize gastric cancer to capecitabine in vitro and in a xenograft mouse model was investigated.. The effect of γ-tocotrienol on proliferation of gastric cancer cell lines was examined by mitochondrial dye uptake assay, apoptosis by esterase staining, NF-κB activation by DNA-binding assay, and gene expression by Western blotting. The effect of γ-tocotrienol on the growth and chemosensitization was also examined in subcutaneously implanted tumors in nude mice.. γ-Tocotrienol inhibited the proliferation of various gastric cancer cell lines, potentiated the apoptotic effects of capecitabine, inhibited the constitutive activation of NF-κB, and suppressed the NF-κB-regulated expression of COX-2, cyclin D1, Bcl-2, CXCR4, VEGF, and matrix metalloproteinase-9 (MMP-9). In a xenograft model of human gastric cancer in nude mice, we found that administration of γ-tocotrienol alone (1 mg/kg body weight, intraperitoneally 3 times/wk) significantly suppressed the growth of the tumor and this effect was further enhanced by capecitabine. Both the markers of proliferation index Ki-67 and for microvessel density CD31 were downregulated in tumor tissue by the combination of capecitabine and γ-tocotrienol. As compared with vehicle control, γ-tocotrienol also suppressed the NF-κB activation and the expression of cyclin D1, COX-2, intercellular adhesion molecule-1 (ICAM-1), MMP-9, survivin, Bcl-xL, and XIAP.. Overall our results show that γ-tocotrienol can potentiate the effects of capecitabine through suppression of NF-κB-regulated markers of proliferation, invasion, angiogenesis, and metastasis.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; bcl-X Protein; Capecitabine; Cell Line, Tumor; Cell Proliferation; Chromans; Cyclin D1; Cyclooxygenase 2; Deoxycytidine; Disease Models, Animal; Fluorouracil; Gene Expression Regulation, Neoplastic; Humans; Inhibitor of Apoptosis Proteins; Intercellular Adhesion Molecule-1; Ki-67 Antigen; Matrix Metalloproteinase 9; Mice; Mice, Nude; Mitochondria; Neovascularization, Pathologic; NF-kappa B; Platelet Endothelial Cell Adhesion Molecule-1; Proto-Oncogene Proteins c-bcl-2; Receptors, CXCR4; Repressor Proteins; Stomach Neoplasms; Survivin; Vascular Endothelial Growth Factor A; Vitamin E; Xenograft Model Antitumor Assays

AP-4 belongs to the basic helix-loop-helix leucine-zipper subgroup; it controls target gene expression, regulates growth, development and cell apoptosis and has been implicated in tumorigenesis. Our previous studies indicated that AP-4 was frequently overexpressed in gastric cancers and may be associated with the poor prognosis. The purpose of this study is to examine whether silencing of AP-4 can alter biological characteristics of gastric cancer cells.. Two specific siRNAs targeting AP-4 were designed, synthesized, and transfected into gastric cancer cell lines and human normal mucosa cells. AP-4 expression was measured with real-time quantitative PCR and Western blot. Cell proliferation and chemo-sensitivity were detected by CCK-8 assay. Cell cycle assay and apoptosis assay were performed by flow cytometer, and relative expression of cell cycle regulators were detected by real-time quantitative PCR and Western blot, expression of the factors involved in the apoptosis pathway were examined in mRNA and protein level.. The expression of AP-4 was silenced by the siRNAs transfection and the effects of AP-4 knockdown lasted 24 to 96 hrs. The siRNA-mediated silencing of AP-4 suppressed the cellular proliferation, induced apoptosis and sensitized cancer cells to anticancer drugs. In addition, the expression level of p21, p53 and Caspase-9 were increased when AP-4 was knockdown, but the expression of cyclin D1, Bcl-2 and Bcl-x(L) was inhibited. It didn't induce cell cycle arrest when AP-4 was knockdown in p53 defect gastric cancer cell line Kato-III.. These results illustrated that gene silencing of AP-4 can efficiently inhibited cell proliferation, triggered apoptosis and sensitized cancer cells to anticancer drugs in vitro, suggesting that AP-4 siRNAs mediated silencing has a potential value in the treatment of human gastric cancer.

Topics: Adaptor Protein Complex 4; Apoptosis; bcl-X Protein; Caspase 9; Cell Cycle Checkpoints; Cell Growth Processes; Cell Line, Tumor; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p21; Down-Regulation; Gene Expression Regulation, Neoplastic; Humans; Proto-Oncogene Proteins c-bcl-2; RNA, Messenger; RNA, Small Interfering; Stomach Neoplasms

To determine effects of curcumin on N-methyl-N-nitrosourea (MNU) and saturated sodium chloride (s-NaCl)-induced gastric cancer in rats. Male Wistar rats were divided into 5 groups: control (CO), control supplemented with 200 mg/kg curcumin (CC), MNU + s-NaCl, MNU + s-NaCl supplemented with 200 mg/kg curcumin daily for the first 3 weeks (MNU + s-NaCl + C3W), and MNU + s-NaCl supplemented with curcumin for 20 weeks (MNU + s-NaCl + C20W). To induce stomach cancer, rats except for CO and CC were orally treated with 100 mg/kg MNU on day 0 and 14, and s-NaCl twice-a-week for the first 3 weeks. The experiment was finished and rats were sacrificed at the end of 20 weeks. Cancers were found in forestomachs of all rats in MNU + s-NaCl. The expressions of phosphorylated inhibitor kappaB alpha (phospho-IκBα), 8-hydroxy-2'-deoxyguanosine (8-OHdG), and cyclin D1 significantly increased in MNU + s-NaCl compared with CO. Curcumin treatments for 3 and 20 weeks reduced the cancer incidence resulting in a decrease of phospho-IκBα expression in benign tumor-bearing rats compared with MNU + s-NaCl. Curcumin treatment for 20 weeks also decreased 8-OHdG expression in benign tumor-bearing rats compared with MNU + s-NaCl. Curcumin can attenuate cancer via a reduction of phospho-IκBα and 8-OHdG expressions, which may play a promising role in gastric carcinogenesis.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Analysis of Variance; Animals; Antineoplastic Agents; Curcumin; Cyclin D1; Deoxyguanosine; I-kappa B Proteins; Immunohistochemistry; Male; Methylnitrosourea; Rats; Rats, Wistar; Sodium Chloride; Stomach Neoplasms

Transducer of ErbB-2.1 (Tob1), a tumor suppressor protein, is inactivated in a variety of cancers including stomach cancer. However, the role of Tob1 in gastric carcinogenesis remains elusive. The present study aimed to investigate whether Tob1 could inhibit gastric cancer progression in vitro, and to elucidate its underlying molecular mechanisms. We found differential expression of Tob1 in human gastric cancer (MKN28, AGS and MKN1) cells. The overexpression of Tob1 induced apoptosis in MKN28 and AGS cells, which was associated with sub-G1 arrest, activation of caspase-3, induction of Bax, inhibition of Bcl-2 and cleavage of poly (ADP-ribose) polymerase (PARP). In addition, Tob1 inhibited proliferation, migration and invasion, which were reversed in MKN1 and AGS cells transfected with Tob1 siRNA. Overexpression of Tob1 in MKN28 and AGS cells induced the expression of Smad4, leading to the increased expression and the promoter activity of p15, which was diminished by silencing of Tob1 using specific siRNA. Tob1 decreased the phosphorylation of Akt and glycogen synthase kinase-3β (GSK3β) in MKN28 and AGS cells, resulting in the reduced protein expression and the transcriptional activity of β‑catenin, which in turn decreased the expression of cyclin D1, cyclin-dependent kinase-4 (CDK4), urokinase plasminogen activator receptor (uPAR) and peroxisome proliferator and activator receptor-δ (PPARδ). Conversely, silencing of Tob1 induced the phosphorylation of Akt and GSK-3β, and increased the expression of β‑catenin and its target genes. Collectively, our study demonstrates that the overexpression of Tob1 inhibits gastric cancer progression by activating Smad4- and inhibiting β‑catenin-mediated signaling pathways.

Topics: Apoptosis; beta Catenin; Caspase 3; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclin D1; Cyclin-Dependent Kinase 4; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Humans; Intracellular Signaling Peptides and Proteins; Neoplasm Invasiveness; Phosphorylation; Poly(ADP-ribose) Polymerases; PPAR delta; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-bcl-2; Receptors, Urokinase Plasminogen Activator; RNA Interference; RNA, Small Interfering; Signal Transduction; Smad4 Protein; Stomach Neoplasms; Tumor Suppressor Proteins

HER2 overexpression is observed in ∼6-35% of all gastric cancers, while co-amplification of topoisomerase IIα occurs in ∼32-90% of all cancers with HER2 amplification. The present study reports that HER2 expression is down-regulated by A-62176, a fluoroquinophenoxazine derivative that we previously demonstrated to inhibit topoisomerase I and IIα. The results suggest that A-62176 inhibits the interaction between the ESX, an ets transcription factor, and its co-activator Sur2, leading to the attenuation of HER2-mediated phosphorylation of MAPK/Akt. A-62176 arrests the cell cycle in the G1 phase via the down-regulation of cyclin D1 and the up-regulation of p27(Kip1) in NCI-N87 gastric cancer cells. The combination of A-62176 with doxorubicin provides a strong synergistic activity. We propose that A-62176 is a dual inhibitor that impairs the expression of HER2 and restrains the activity of topoisomerase IIα. Our results may lead to the rational design of anticancer molecules targeting a subgroup of gastric cancer cells overexpressing both HER2 and topoisomerase IIα.

Topics: Antigens, Neoplasm; Apoptosis; Cell Cycle Checkpoints; Cell Line, Tumor; Cyclin D1; DNA Topoisomerases, Type I; DNA Topoisomerases, Type II; DNA-Binding Proteins; Down-Regulation; Doxorubicin; G1 Phase; HEK293 Cells; Humans; Mediator Complex; Mitogen-Activated Protein Kinase Kinases; Oxazines; Phosphorylation; Proliferating Cell Nuclear Antigen; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-ets; Quinolones; Receptor, ErbB-2; Signal Transduction; Stomach Neoplasms; Topoisomerase Inhibitors; Transcription Factors; Up-Regulation

While there is strong evidence for phosphatidylinositol 3-kinase (PI3K) involvement in cancer development, there is limited information about the role of PI3K regulatory subunits. PIK3R3, the gene that encodes the PI3K regulatory subunit p55γ, is over-expressed in glioblastoma and ovarian cancers, but its expression in gastric cancer (GC) is not known. We thus used genetic and bioinformatic approaches to examine PIK3R3 expression and function in GC, the second leading cause of cancer mortality world-wide and highly prevalent among Asians.. Primary GC and matched non-neoplastic mucosa tissue specimens from a unique Asian patient gastric cancer library were comprehensively profiled with platforms that measured genome-wide mRNA expression, DNA copy number variation, and DNA methylation status. Function of PIK3R3 was predicted by IPA pathway analysis of co-regulated genes with PIK3R3, and further investigated by siRNA knockdown studies. Cell proliferation was estimated by crystal violet dye elution and BrdU incorporation assay. Cell cycle distribution was analysed by FACS.. PIK3R3 was significantly up-regulated in GC specimens (n = 126, p < 0.05), and 9.5 to 15% tumors showed more than 2 fold increase compare to the paired mucosa tissues. IPA pathway analysis showed that PIK3R3 promoted cellular growth and proliferation. Knockdown of PIK3R3 decreased the growth of GC cells, induced G0/G1 cell cycle arrest, decreased retinoblastoma protein (Rb) phosphorylation, cyclin D1, and PCNA expression.. Using a combination of genetic, bioinformatic, and molecular biological approaches, we showed that PIK3R3 was up-regulated in GC and promoted cell cycle progression and proliferation; and thus may be a potential new therapeutic target for GC.

Topics: Asian People; Cell Proliferation; Computational Biology; Cyclin D1; G1 Phase Cell Cycle Checkpoints; Gastric Mucosa; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Humans; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Phosphorylation; Protein Subunits; Proto-Oncogene Proteins c-akt; Resting Phase, Cell Cycle; Retinoblastoma Protein; RNA, Messenger; RNA, Small Interfering; Signal Transduction; Stomach Neoplasms

Mitogen-activated protein kinase (MAPK) pathways regulate multiple cellular functions and are highly active in many types of human cancers. Apoptosis signal-regulating kinase 1 (ASK1) is an upstream MAPK involved in apoptosis, inflammation, and carcinogenesis. This study investigated the role of ASK1 in the development of gastric cancer. In human gastric cancer specimens, we observed increased ASK1 expression, compared to nontumor epithelium. Using a chemically induced murine gastric tumorigenesis model, we observed increased tumor ASK1 expression, and ASK1 knockout mice had both fewer and smaller tumors than wild-type (WT) mice. ASK1 siRNA inhibited cell proliferation through the accumulation of cells in G1 phase of the cell cycle, and reduced cyclin D1 expression in gastric cancer cells, whereas these effects were uncommon in other cancer cells. ASK1 overexpression induced the transcription of cyclin D1, through AP-1 activation, and ASK1 levels were regulated by cyclin D1, via the Rb-E2F pathway. Exogenous ASK1 induced cyclin D1 expression, followed by elevated expression of endogenous ASK1. These results indicate an autoregulatory mechanism of ASK1 in the development of gastric cancer. Targeting this positive feedback loop, ASK1 may present a potential therapeutic target for the treatment of advanced gastric cancer.

Topics: Animals; Apoptosis; Cell Cycle; Cell Line, Tumor; Cyclin D1; Disease Models, Animal; E2F Transcription Factors; Gene Expression Regulation, Neoplastic; Humans; MAP Kinase Kinase Kinase 5; Mice; Mice, Inbred C57BL; Mice, Transgenic; Signal Transduction; Stomach Neoplasms

The canonical Wnt signalling pathway plays a key role during embryogenesis and pathogenesis of various types of tumors. Recently, several studies have shown that the promoter hypermethylation of Wnt-antagonist genes, including sFRP-1, sFRP-2, sFRP-4, sFRP-5, Wif-1 and Dkk-3, have been certified to contribute to the tumorigenesis of several cancers. The aim of this study was to investigate the promoter methylation of Wnt-antagonist genes in gastric cardia adenocarcinoma (GCA) and corresponding adjacent non-cancerous tissues, and to establish the possible relationship between DNA methylation status and the pathogenesis of GCA. MSP, RT-PCR methods were applied respectively to examine the CpG methylation of the Wnt-antagonist genes and its mRNA expression in tumors and corresponding non-cancerous tissues, and immunohistochemistry method was used to determine protein expression of β-catenin(the key factor of the Wnt signalling pathway) and cyclin D1(the target gene of this pathway). The frequency of promoter methylation of sFRP-1, sFRP-2, sFRP-4, sFRP-5, Wif-1 and Dkk-3 genes in GCA tumor tissues were 78.7%(74/94), 76.6%(72/94), 70.2%(66/94), 77.1%(73/94), 61.7%(58/94) and 21.3%(20/94), respectively, which were significantly higher than those in adjacent non-cancerous tissues. Furthermore, the frequencies of silenced mRNA expression of these six genes in GCA tumor tissues were significantly higher than those in adjacent non-cancerous tissues. Methylation levels of these six genes were all correlated with loss of mRNA expression. The ectopic expression of β-catenin and cyclin D1 was significantly more frequent in GCA tumor tissues than that in adjacent non-cancerous tissues and correlated with each Wnt-antagonist genes hypermethylation status. Epigenetic silencing of Wnt-antagonist genes expression by promoter hypermethylation may play an important role in gastric cardia adenocarcinoma.

Topics: Adenocarcinoma; Adult; Aged; beta Catenin; Cardia; Cyclin D1; DNA Methylation; Female; Humans; Male; Middle Aged; RNA, Messenger; Signal Transduction; Stomach Neoplasms; Wnt Proteins

Hyperproliferative cell growth due to cyclin D1/cdk4, marker of cellular proliferation, is considered to be regulated by the expression of estrogen receptors (ERs). We investigated the immunohistochemical expression of cyclin D1/cdk4 and ERs in N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced rat gastric carcinogenesis. The gastric cancer incidence and expression of cyclin D1/ckd4 in gastric carcinogenesis were significantly higher in males than females. Although the ERα expression index was similar in both sexes, the ERβ expression in preneoplastic hyperplastic lesions as well as gastric cancers was significantly higher in females than in males. The present study revealed a gender difference in MNNG-induced rat gastric carcinogenesis that seemed to involve the sex difference in cyclin D1/cdk4 expression, and ERβ expression became evident at the preneoplastic promotion stage in gastric carcinogenesis.

Topics: Adenocarcinoma; Animals; Biomarkers, Tumor; Carcinogens; Cyclin D1; Cyclin-Dependent Kinase 4; Estrogen Receptor alpha; Estrogen Receptor beta; Female; Gastric Mucosa; Immunohistochemistry; Male; Methylnitronitrosoguanidine; Rats; Rats, Wistar; Sex Factors; Stomach Neoplasms

To study the role of the Twist gene in growth of gastric cancer cell line MKN45 and the possible mechanisms involved.. Human gastric carcinoma MKN45 cells were stably transfected with Twist antisense plasmid using the lipofectamine transfection technique. Expression of Twist in Twist antisense plasmid transfected cells (TwistAS), non-transfected cells (NT) and non-specific Twist antisense plasmid transfected cells (CON) were examined by Western blotting. Cell growth ability in vitro was evaluated by MTT and clone formation assays. Xenograft cancer models were established by nude mouse transfer method. Activator protein-1 (AP-1) DNA binding activity was measured by electrophoretic mobility shift assay (EMSA). The expression of c-Jun and c-Fos were examined by Western blotting. The mRNA level of cyclin D1 was detected by RT-PCR.. TwistAS inhibited cell growth and proliferation. In vitro, the cloning efficiency of TwistAS cells (8.0  ±  0.6%) was significantly lower compared to that in NT (26.5  ±  1.1%) and CON (22.7  ±  1.2%). In vivo, the average tumour weight was lighter in the TwistAS group (425.3  ±  20.8  mg) compared with the CON group (1217.0  ±  50.2  mg) and the NT group (1120.6  ±  75  mg). TwistAS inhibited AP-1 activity in MKN45 cells (15.3  ±  3.2% versus 50.2  ±  3.6% and 52.4  ±  3.8%). TwistAS inhibited the expression of c-Fos in MKN45 cells (20.4  ±  3.8% versus 72.5  ±  3.6% and 75.3  ±  4.0%) but not c-Jun (p < 0.05). cyclin D1 mRNA level was significantly lower in TwistAS cells (40.5  ±  3.8%) than that in CON (132  ±  5.4%) and NT cells (130  ±  5.2%).. This study demonstrated that down-regulation of the Twist gene suppressed the proliferation of MKN45 gastric cancer cells by negatively regulating the AP-1 activity resulting in the cyclin D1 mRNA level decreasing.

Topics: Animals; Blotting, Western; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Electrophoretic Mobility Shift Assay; Female; Gene Expression Regulation, Neoplastic; Gene Silencing; Humans; Mice; Mice, Nude; Nuclear Proteins; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Stomach Neoplasms; Transcription Factor AP-1; Transfection; Transplantation, Heterologous; Twist-Related Protein 1

As much as that a disturbance of tissue homeostasis through dysregulated apoptosis is generally associated with carcinogenesis, gastric carcinogenesis after Helicobacter pylori infection could be the accumulated consequence of imbalances between apoptosis and proliferation. Since sonic hedgehog (Shh) has been reported to play versatile roles in various tumorigenesis, we hypothesized that late reactivation of sonic hedgehog by H. pylori infection results in population of gastric epithelial cells that are resistant to apoptosis. The Resistant Clones against H. pylori-induced Apoptosis (RCHA) were established and maintained up to 19th cell passages, during which the serial changes of Shh expression were measured. Apoptosis was measured in N-Shh over-expressed stable cell lines and compared with parent cell line after either infected with H. pylori or treated with cyclopamine. For clinical relevance, the expressions of Shh were compared in tissues from gastric adenoma or adenocarcinoma according to H. pylori infection. Longer passages of RCHA after H. pylori infection, the higher expressions of Shh, suggesting RCHA was associated with the reactivation of Shh. Significant decrement in subG1 phase of cell cycle and attenuated executions of apoptosis after H. pylori infection in cells of Shh overexpression, whereas either Shh siRNA or cyclopamine increased the H. pylori-induced cytotoxicity and significantly abrogated anti-apoptotic actions imposed by Shh. Significantly higher expressions of Shh were seen in H. pylori-associated gastric cancers than H. pylori-not associated gastric cancer. Late reactivation of sonic hedgehog by H. pylori infection results in population of gastric epithelial cells that are resistant to apoptosis and imposes proliferative changes under the background of atrophic gastritis, providing the carcinogenic basis.

Topics: Apoptosis; Cell Line, Tumor; Cell Survival; Cyclin D1; Gastric Mucosa; Hedgehog Proteins; Helicobacter pylori; Humans; Stomach Neoplasms; Veratrum Alkaloids

Gastric cancer is the second leading cause of cancer death worldwide. Predisposing factors include achlorhydria, Helicobacter pylori infection, oxyntic atrophy and TFF2-expressing metaplasia. In parietal cells, apical potassium channels comprising the KCNQ1 alpha subunit and the KCNE2 beta subunit provide a K(+) efflux current to facilitate gastric acid secretion by the apical H(+)K(+)ATPase. Accordingly, genetic deletion of murine Kcnq1 or Kcne2 impairs gastric acid secretion. Other evidence has suggested a role for KCNE2 in human gastric cancer cell proliferation, independent of its role in gastric acidification. Here, we demonstrate that 1-year-old Kcne2(-/-) mice in a pathogen-free environment all exhibit a severe gastric preneoplastic phenotype comprising gastritis cystica profunda, 6-fold increased stomach mass, increased Ki67 and nuclear Cyclin D1 expression, and TFF2- and cytokeratin 7-expressing metaplasia. Some Kcne2(-/-) mice also exhibited pyloric polypoid adenomas extending into the duodenum, and neoplastic invasion of thin walled vessels in the sub-mucosa. Finally, analysis of human gastric cancer tissue indicated reduced parietal cell KCNE2 expression. Together with previous findings, the results suggest KCNE2 disruption as a possible risk factor for gastric neoplasia.

Topics: Animals; Blotting, Western; Cell Line; Cell Line, Tumor; Cyclin D1; Fluorescent Antibody Technique; Gastric Mucosa; Gastritis; Gene Deletion; H(+)-K(+)-Exchanging ATPase; Humans; Immunohistochemistry; KCNQ1 Potassium Channel; Ki-67 Antigen; Metaplasia; Mice; Mice, Mutant Strains; Peptides; Potassium Channels, Voltage-Gated; Stomach Neoplasms; Trefoil Factor-2

Aberrant regulation of glycogen synthase kinase-3beta (GSK-3beta) has been implicated in several human cancers; however, it has not been reported in the gastric cancer tissues to date. The present study was performed to determine the expression status of active form of GSK-3beta phosphorylated at Tyr216 (pGSK-3beta) and its relationship with other tumor-associated proteins in human gastric cancers.. Immunohistochemistry was performed on tissue array slides containing 281 human gastric carcinoma specimens. In addition, gastric cancer cells were cultured and treated with a GSK-3beta inhibitor lithium chloride (LiCl) for immunoblot analysis.. We found that pGSK-3beta was expressed in 129 (46%) of 281 cases examined, and was higher in the early-stages of pathologic tumor-node-metastasis (P < 0.001). The expression of pGSK-3beta inversely correlated with lymphatic invasion (P < 0.001) and lymph node metastasis (P < 0.001) and correlated with a longer patient survival (P < 0.001). In addition, pGSK-3beta expression positively correlated with that of p16, p21, p27, p53, APC, PTEN, MGMT, SMAD4, or KAI1 (P < 0.05), but not with that of cyclin D1. This was confirmed by immunoblot analysis using SNU-668 gastric cancer cells treated with LiCl.. GSK-3beta activation was frequently observed in early-stage gastric carcinoma and was significantly correlated with better prognosis. Thus, these findings suggest that GSK-3beta activation is a useful prognostic marker for the early-stage gastric cancer.

Topics: Biomarkers, Tumor; Cell Cycle; Cell Line, Tumor; Cyclin D1; Cyclin-Dependent Kinase Inhibitor Proteins; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Humans; Lithium Chloride; Prognosis; Stomach Neoplasms; Tumor Cells, Cultured

To investigate the prevalence of Epstein-Barr virus (EBV)-associated gastric carcinomas in Guangzhou, their clinicopathologic features and related protein expressions including DNMT1, p16, and cyclin D1.. A total of 676 cases of EBV-associated gastric carcinoma were included in the study. The presence of EBV-encoded small RNA1 (EBER1), a marker for EBV infection, was analyzed by in-situ hybridization using formalin-fixed and paraffin-embedded tumor samples. Expression of EBV-encoded proteins, DNMT1, p16 and cyclin D1 were detected by immunohistochemistry.. Forty-five of 676 gastric carcinomas showed EBER intranuclear positivity in all tumor cells. EBV involvement was significantly more frequent among the male than the female patients, especially in tumors of less differentiated types (diffuse type) and involving the upper stomach (P < 0.05). EBNA1 and LMP2A expression were detected in 42 (93.3%) and 24 (53.3%) cases, respectively. None expressed EBNA2, LMP1, and ZEBRA. Among 45 cases of EBV associated gastric carcinomas, DNMT1, p16 and cyclin D1 expression were seen in 35 (77.8%), 10 (22.2%), and 29 (64.4%) cases, respectively. In contrast, among 40 EBV negative gastric carcinomas, expression of the three proteins were 20 (50.0%), 25 (62.5%) and 12 (30.0%), respectively. The difference of expression of the three proteins between the two groups was significant (P < 0.05). Expression of p16 correlated with the depth of the tumor invasion. Correlated protein expression was seen between LMP2A and DNMT1, between DNMT1 and p16, and between p16 and cyclin D1 (P < 0.05).. EBV associated gastric carcinoma accounts for 6.7% of gastric carcinomas in Guangzhou with the Latency I pattern in some cases and between Latency I and II in others. The correlated expression of LMP2A, DNMT1, p16 and cyclin D1 may contribute to the pathogenesis of EBV associated gastric carcinomas.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; China; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p16; DNA (Cytosine-5-)-Methyltransferase 1; DNA (Cytosine-5-)-Methyltransferases; Epstein-Barr Virus Infections; Epstein-Barr Virus Nuclear Antigens; Female; Herpesvirus 4, Human; Humans; Male; Middle Aged; Neoplasm Invasiveness; RNA, Viral; Sex Factors; Stomach Neoplasms; Viral Matrix Proteins; Young Adult

Helicobacter pylori VacA toxin contributes to the pathogenesis and severity of gastric injury. We found that incubation of AZ-521 cells with VacA resulted in phosphorylation of protein kinase B (Akt) and glycogen synthase kinase-3beta (GSK3beta) through a PI3K-dependent pathway. Following phosphorylation and inhibition of GSK3beta,beta-catenin was released from a GSK3beta/beta-catenin complex, with subsequent nuclear translocation. Methyl-beta-cyclodextrin (MCD) and phosphatidylinositol-specific phospholipase C (PI-PLC), but not 5-nitro-2-(3-phenylpropylamino)-benzoic acid (NPPB) and bafilomycin A1, inhibited VacA-induced phosphorylation of Akt, indicating that it does not require VacA internalization and is independent of vacuolation. VacA treatment of AZ-521 cells transfected with TOPtkLuciferase reporter plasmid or control FOPtkLucifease reporter plasmid resulted in activation of TOPtkLuciferase, but not FOPtkLucifease. In addition, VacA transactivated the beta-catenin-dependent cyclin D1 promoter in a luciferase reporter assay. Infection of AZ-521 cells by a vacA mutant strain of H. pylori failed to induce phosphorylation of Akt and GSK3beta, or release of beta-catenin from a GSK3beta/beta-catenin complex. Taken together, these results support the conclusion that VacA activates the PI3K/Akt signaling pathway, resulting in phosphorylation and inhibition of GSK3beta, and subsequent translocation ofbeta-catenin to the nucleus, consistent with effects of VacA on beta-catenin-regulated transcriptional activity. These data introduce the possibility that Wnt-dependent signaling might play a role in the pathogenesis of H. pylori infection, including the development of gastric cancer.

Topics: Active Transport, Cell Nucleus; Bacterial Proteins; beta Catenin; Cell Line, Tumor; Cell Nucleus; Cyclin D1; Enzyme Inhibitors; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Helicobacter Infections; Helicobacter pylori; Humans; Mutation; Phosphatidylinositol 3-Kinases; Phospholipase C beta; Phosphorylation; Proto-Oncogene Proteins c-akt; Signal Transduction; Stomach Neoplasms; Transcriptional Activation; Wnt Proteins

Gamma-aminobutyric acid (GABA) is the principal inhibitory neurotransmitter in the adult mammalian brain. However, GABA is found not only in peripheral neuronal tissue, but also in many peripheral non-neuronal tissues, and is thought to have important physiological functions in addition to neurotransmission. We previously reported that GABA participates in chondrocyte proliferation. In the present study, we investigated the effects of GABA on the proliferation of a gastric cancer cell line, KATO III.. Reverse transcription polymerase chain reaction and immunohistochemical analyses were performed to examine the expression of the GABA synthesis enzyme, glutamate decarboxylase (GAD), and that of the GABA(A) and GABA(B) receptor subunits. The production of GABA was confirmed by immunohistochemistry. The proliferative effect of GABA on KATO III cells was analyzed by bromodeoxyuridine incorporation assay, and the activation status of mitogen-activated protein (MAP) kinases (extracellular signal-regulated kinase [ERK]-1/2, Jun-N-terminal kinase, and p38) and the expression of cyclin D1 were analyzed by western blotting.. KATO III cells expressed GAD and GABA. More than five GABA(A) receptor subunits, including the pi subunit, were expressed in KATO III cells; however, GABA(B) receptor subunits were not seen. The addition of GABA to the medium promoted KATO III proliferation, and maximum proliferative effects were observed in the presence of 10 or 1 microM GABA. The addition of 1 microM GABA predominantly activated ERK-1/2 among the three MAP kinases in addition to increasing cyclin D1 expression.. GABA is able to promote KATO III cell proliferation in an autocrine or a paracrine fashion through GABA(A) receptors followed by MAP kinase activation.

Topics: Cell Line, Tumor; Cell Proliferation; Cyclin D1; Enzyme Activation; gamma-Aminobutyric Acid; Gene Expression Regulation, Neoplastic; Glutamate Decarboxylase; Humans; Immunohistochemistry; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Protein Subunits; Receptors, GABA-A; Receptors, GABA-B; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Stomach Neoplasms

Because signal transducer and activator of transcription 3 (STAT3) is constitutively activated in most human solid tumors and is involved in the proliferation, angiogenesis, immune evasion, and antiapoptosis of cancer cells, researchers have focused on STAT3 as a target for cancer therapy. We screened for natural compounds that inhibit the activity of STAT3 using a dual-luciferase assay. Cryptotanshinone was identified as a potent STAT3 inhibitor. Cryptotanshinone rapidly inhibited STAT3 Tyr705 phosphorylation in DU145 prostate cancer cells and the growth of the cells through 96 hours of the treatment. Inhibition of STAT3 Tyr705 phosphorylation in DU145 cells decreased the expression of STAT3 downstream target proteins such as cyclin D1, survivin, and Bcl-xL. To investigate the cryptotanshinone inhibitory mechanism in DU145 cells, we analyzed proteins upstream of STAT3. Although phosphorylation of Janus-activated kinase (JAK) 2 was inhibited by 7 micromol/L cryptotanshinone at 24 hours, inhibition of STAT3 Tyr705 phosphorylation occurred within 30 minutes and the activity of the other proteins was not affected. These results suggest that inhibition of STAT3 phosphorylation is caused by a JAK2-independent mechanism, with suppression of JAK2 phosphorylation as a secondary effect of cryptotanshinone treatment. Continuing experiments revealed the possibility that cryptotanshinone might directly bind to STAT3 molecules. Cryptotanshinone was colocalized with STAT3 molecules in the cytoplasm and inhibited the formation of STAT3 dimers. Computational modeling showed that cryptotanshinone could bind to the SH2 domain of STAT3. These results suggest that cryptotanshinone is a potent anticancer agent targeting the activation STAT3 protein. It is the first report that cryptotanshinone has antitumor activity through the inhibition of STAT3.

Topics: bcl-X Protein; Breast Neoplasms; Cell Growth Processes; Cell Line, Tumor; Cyclin D1; Dimerization; Down-Regulation; Drugs, Chinese Herbal; HCT116 Cells; HeLa Cells; Humans; Inhibitor of Apoptosis Proteins; Luciferases; Male; Microtubule-Associated Proteins; Models, Molecular; Phenanthrenes; Phosphorylation; Prostatic Neoplasms; Protein-Tyrosine Kinases; STAT3 Transcription Factor; Stomach Neoplasms; Survivin

Abnormal regulation of the cell cycle is a feature of many neoplasms. The role of cell cycle regulators in oncogenesis has been investigated in many human tumors. Alteration of the retinoblastoma (pRb) and cyclin D1 disrupt the Rb pathway and occur in many carcinomas. However the expression of the Rb and cyclin D1 in intestinal type gastric carcinoma is unclear. The purpose of this study was to investigate the expression of Rb and cyclinD1 in resected gastric carcinoma, their adjacent nonneoplastic mucosa and normal gastric mucosa, and finally to provide insights into the role of the Rb and cyclin D1 in gastric carcinogenesis. We investigated Rb and cyclin D1 expression in 43 patients (32 men, 11 women; mean age: 64) with primary gastric adenocarcinoma and compared the results with adjacent nonneoplastic mucosa. Adjacent nonneoplastic mucosa consisted of atrophy, dysplasia, intestinal metaplasia and gastritis. Expression of Rb was detected in 30 (69.7%) of gastric carcinoma, 18 (41.8%) of the adjacent nonneoplastic mucosa. Expression of cyclinD1 protein was detected in 31 (72%) of gastric carcinoma, 24 (55.8%) of adjacent nonneoplastic mucosa. Expression of Rb and cyclinD1 was not detected in normal gastric mucosa. The positive rate of Rb and cyclin D1 expression in gastric carcinoma was significantly higher than that adjacent nonneoplastic mucosa (p<0.05). There were significant trends for increased expression of Rb and cyclinD1 from nonneoplastic mucosa including atrophy, dyplasia, intestinal metaplasia and gastritis to carcinoma. These results suggested that positive expression of pRb and cyclinD1 might be an early event in gastric carcinoma and it tend to begin at precursor lesions and maintain throughout the progression of infiltration. Key words: Retinoblastoma, cyclin D1, gastric carcinoma, dysplasia, atrophy, intestinal metaplasia.

Topics: Adenocarcinoma; Aged; Biomarkers, Tumor; Cyclin D1; Female; Humans; Immunohistochemistry; Male; Middle Aged; Precancerous Conditions; Retinoblastoma Protein; Stomach Neoplasms

Ras-association domain family 1A (RASSF1A) gene, a candidate tumor suppressor gene, is inactivated in several human tumors, usually by hypermethylation of its promoter region. RASSF1A induces cell cycle arrest through inhibition of cyclin D1 accumulation. In this work, the promoter methylation status of the RASSF1A in 92 gastric cardia adenocarcinoma (GCA) and corresponding normal tissues were investigated using Methylation-specific PCR (MSP) approach, immunohistochemistry method and RT-PCR were used respectively to examine the protein expression and mRNA expression of RASSF1A in tumors and corresponding normal tissues. Cyclin D1 expression was examined by immunohistochemistry. RASSF1A was methylated in 54/92 (58.7%) tumor specimens, which was significantly higher than that in corresponding normal tissues (p <.001). Methylation frequencies of stage III and IV tumor tissues were significantly higher than that in stage I and II tumor tissues (p <.05). By immunostaining, 43/92 (46.7%) tumor tissues demonstrated heterogeneous, positive immunostaining of tumor tissues was significantly reduced with comparison to matched normal tissues (p <.001). mRNA expressions of RASSF1A in GCA tumor tissues were reduced significantly with comparison to the corresponding normal tissues (OD value: 0.2376 +/- 0.2315 vs 0.6874 +/- 0.2668, p <.001). RASSF1A mRNA expression in methylation group of GCA was significantly different from that in unmethylation group (p <.001). Cyclin D1 hyper-expression was found in 72/92 (78.3%) cases and correlated with RASSF1A methylation (p <.05). Our data suggested that epigenetic silencing of RASSF1A gene expression by promoter hypermethylation may play an important role in GCA.

Topics: Adenocarcinoma; Adult; Aged; Asian People; Cardia; China; CpG Islands; Cyclin D1; DNA Methylation; Female; Gene Expression Regulation, Neoplastic; Gene Silencing; Humans; Immunohistochemistry; Male; Middle Aged; Neoplasm Staging; Promoter Regions, Genetic; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Stomach Neoplasms; Tumor Suppressor Proteins

Human mitochondrial Mrs2 protein (hsaMrs2p) is a magnesium transporter in mitochondria inner membrane. It was identified as an upregulated gene in a multidrug-resistant (MDR) gastric cancer cell line compared to its parental cells by subtractive hybridization. To further explore the role of hsaMrs2p in MDR of gastric cancer cells, the cDNA encoding hsaMrs2p was generated and mouse antisera against hsaMrs2p was raised with recombinant hsaMrs2p as the immunogen. HsaMrs2p expression could positively regulate adriamycin resistance of SGC7901/ADR cells both in vitro and in vivo. Further study showed that hsaMrs2p increased adriamycin-releasing index. Its upregulation inhibited adriamycin-induced apoptosis, probably by suppressing Bax induced cytochrome C release from mitochondria. Additionally, hsaMrs2p promoted cell growth and cells with decreased hsaMrs2p exhibited significant inhibition of cell growth with G(1) cell cycle arrest. By enhanced hsaMrs2p expression, p27 was downregulated whereas cyclinD1 was upregulated. Our results provide new insights into the function of hsaMrs2p that may be a promising target for MDR reversal therapy.

Topics: Animals; Cation Transport Proteins; Cell Line, Tumor; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p27; Cytochromes c; Doxorubicin; Drug Resistance, Neoplasm; Gene Expression Regulation, Neoplastic; Humans; Mice; Mitochondrial Proteins; Stomach Neoplasms; Up-Regulation

Curcumin (diferuloylmethane), is a natural chemopreventive agent known to inhibit the proliferation of several cancer cell lines. It has been previously demonstrated that curcumin is a potent inhibitor of EGF-receptor (EGFR) tyrosine kinase, but its inhibitive effect on p21-activated kinase 1 (PAK1), a downstream protein of EGFR, has not been defined. In this paper we found that curcumin repressed the expression of HER2 and inhibited the kinase activity of PAK1 without affecting its expression. Silencing HER2 in gastric cancer cells showed that even if PAK1 activity was transiently strengthened by EGF, curcumin still had a strong inhibitive effect. It should be emphasized that kinase assay in vitro showed that curcumin could act as an ATP-competitive inhibitor, which was supported by computer-aided molecular modeling. Curcumin also downregulated the mRNA and the protein expression of cyclin D1 and suppressed transition of the cells from G(1) to S phase. Therefore, curcumin inhibited the proliferation and invasion of gastric cancer cells. Overall, these results provided novel insights into the mechanisms of curcumin inhibition of gastric cancer cell growth and potential therapeutic strategies for gastric cancer.

Topics: Adenocarcinoma; Anticarcinogenic Agents; Cell Division; Cell Line, Tumor; Curcumin; Cyclin D1; Down-Regulation; Drug Screening Assays, Antitumor; Gene Expression Regulation, Neoplastic; Genes, erbB-2; Humans; Neoplasm Invasiveness; Neoplasm Proteins; p21-Activated Kinases; Protein Kinase Inhibitors; Receptor, ErbB-2; Stomach Neoplasms

Expression of the type I transmembrane glycoprotein CD44 has recently been recognized as a signature for cancer stem cells. In this study, we demonstrate that CD44, once engaged, is internalized and translocated to the nucleus, where it binds to various promoters, including that of cyclin D1, leading to cell fate change through transcriptional reprogramming. In regulating cyclin D1 expression, the internalized CD44 forms a complex with STAT3 and p300 (acetyltransferase), eliciting STAT3 acetylation at lysine 685 and dimer formation in a cytokine- and growth factor-independent manner. A bipartite nuclear localization signal (NLS) was mapped to the cytoplasmic tail of CD44, which mediates its nuclear translocation. Expression of CD44(NLS) mutant sequesters STAT3 in cytosol. In the nucleus, the acetylated STAT3 dimer remains associated with CD44 and binds to the cyclin D1 promoter, leading to increased cyclin D1 expression and cell proliferation. This study describes a novel function for CD44 in transcriptional modulation through nuclear translocation of the internalized CD44 and complex formation with transcription factors.

Topics: Acetylation; Active Transport, Cell Nucleus; Cell Cycle; Cell Line; Cell Nucleus; Cell Proliferation; Cyclin D1; Endosomes; Gastric Mucosa; Gene Expression Regulation; Humans; Hyaluronan Receptors; Nuclear Localization Signals; p300-CBP Transcription Factors; STAT3 Transcription Factor; Stomach Neoplasms

There are no known reliable biomarkers which can predict poor clinical outcome following curative resection of gastric adenocarcinoma. Given the importance of signal transducer and activator of transcription 3 (STAT3) activation in carcinogenesis, we attempted to determine whether STAT3 activation is prognostic of survival in curatively resected gastric cancer patients. We analyzed 311 surgically resected gastric cancer specimens for STAT3 activation and its downstream molecules such as matrix metalloproteinase (MMP)-9, MMP-10, cyclin D1, survivin, vascular endothelial growth factor (VEGF)-C, and VEGFR-3 using immunohistochemical studies and assessed their correlation with clinical outcome. Using immunohistochemistry, 303 specimens were interpretable for pSTAT3tyr705 expression. The pSTAT3 was detected in 79 (26.1%) of 303 gastric cancers. Of the downstream molecules tested, STAT3 activation was significantly associated with MMP-9 and MMP-10 expressions. On univariate analyses, 5-year disease-free survival (DFS) and overall survival (OS) for the tumors with STAT3 activation were considerably poorer than for those without STAT3 activation with statistical significance (5-year DFS 58.2% vs 68.3%; pSTAT3(-) vs pSTAT3(+); p = 0.0223; 5-year OS 59.5% vs 70.5%; pSTAT3(-) vs pSTAT3(+); p = 0.0128). On multivariate analyses, STAT3 activation was independently associated with inferior DFS (p = 0.049, hazard ratio [HR] = 1.445, 95% CI, 1.025, 2.120) along with AJCC stage IIIA or IIIB (p = 0.004, HR = 1.708, 95% CI, 1.178, 2.475). The STAT3 activation was also strongly correlated with inferior OS (p = 0.042, HR = 1.506, 95% CI, 1.025, 2.213). Based on our data, pSTAT3tyr705 may be a novel prognostic marker for poorer clinical outcome following curative resection and adjuvant therapy in gastric cancer. The clinical impact of a STAT3-targeted agent should be investigated in gastric cancer patients.

Topics: Adenocarcinoma; Adult; Aged; Biomarkers, Tumor; Cyclin D1; Female; Humans; Inhibitor of Apoptosis Proteins; Male; Matrix Metalloproteinase 10; Matrix Metalloproteinase 9; Microtubule-Associated Proteins; Middle Aged; Multivariate Analysis; Prognosis; STAT3 Transcription Factor; Stomach Neoplasms; Survivin; Tissue Array Analysis; Vascular Endothelial Growth Factor C; Vascular Endothelial Growth Factor Receptor-3

We investigated the antiproliferative effects of the cytoplasmic fraction of Lactococcus lactis ssp. lactis (L.lac CF) on the SNU-1 human stomach cancer cell line. The proliferation of SNU-1 cells was inhibited by treatment with L.lac CF in a time- and dose-dependent manner. L.lac CF caused G0/G1 cell cycle arrest, which was associated with an increase in p53 and p21 expression, the reduction of cyclin D1 expression, and retinoblastoma protein phosphorylation. L.lac CF induced apoptosis in SNU-1 cells, as demonstrated by increased nucleus condensation and a sub-G1 peak. Caspase-3 activation, the induction of p53, and the downregulation of Bcl-2 were also observed in L.lac CF-treated cells. Thus, the inhibitory effect of L.lac CF on SNU-1 cell growth is mainly attributable to the induction of G0/G1 cell cycle arrest and apoptosis.

Topics: Apoptosis; Biological Factors; Blotting, Western; Caspase 3; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p21; Dose-Response Relationship, Drug; Flow Cytometry; G1 Phase; Humans; Lactococcus lactis; Phosphorylation; Resting Phase, Cell Cycle; Retinoblastoma Protein; Stomach Neoplasms; Time Factors; Tumor Suppressor Protein p53

To determine the effect of human DNA binding protein (dbpA) on the biology of gastric cancer cells.. DbpA expression was analyzed by Western blot analysis and immunofluorescence staining in gastric cancer tissues and cell lines. A dbpA-specific small interference (si) RNA was designed and synthesized. Suppressive effect of siRNA on dbpA expression was assessed by real-time RT-PCR. Transwell migration and colony formation assays were used to assess the inhibitory effects of dbpA siRNA on cell invasion and tumorigenesis in vitro. Drug-sensitivity was evaluated using a conventional 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay.. The expression of dbpA was upregulated in gastric cancer tissues and cell lines as compared to adjacent normal tissues or gastric epithelial cells. siRNA treatment successfully silenced dbpA expression. Silencing of dbpA increased expression of E-cadherin, decreased expression of adenomatous polyposis coli (APC), beta-catenin and cyclin D1, but had no effect on expression of NF-kappaB. Silencing of dbpA also suppressed cell invasion and colony formation of SGC7901 cells, and enhanced their chemosensitivity to 5-fluorouracil.. DbpA plays an important role in the pathogenesis and development of gastric cancer, and the process involves E-cadherin, APC, beta-catenin and cyclin D1. Silencing of dbpA might be a novel therapeutic strategy for increasing chemosensitivity to 5-fluorouracil in gastric cancer.

Topics: Adenomatous Polyposis Coli Protein; Antineoplastic Agents; beta Catenin; Cadherins; CCAAT-Enhancer-Binding Proteins; Cell Line, Transformed; Cell Line, Tumor; Coloring Agents; Culture Media, Serum-Free; Cyclin D1; Fluorescent Antibody Technique, Direct; Fluorouracil; Heat-Shock Proteins; Humans; RNA, Messenger; RNA, Small Interfering; Stomach Neoplasms; Tetrazolium Salts; Thiazoles; Transfection; Up-Regulation

To investigate the relationship between the sensitivity to chemotherapeutic drugs and the expression of cyclin D1 and P21WAF1 in gastric carcinoma.. The sensitivity of 80 samples of gastric cancer cells to HCPT, CDDP, 5-FU, ADM and MMC was evaluated with MTT assay. The protein expression of cyclin D1 and P21WAF1 was detected by immunohistochemistry.. The sensitivity of gastric carcinoma cells to chemotherapeutic drugs was different. Inhibitory rates of tumor cells exposed to 5-FU, MMC and DDP were significantly higher than those exposed to ADM and HCPT (P <0.05). Positive expression rates of cyclin D1 and P21WAF1 in gastric cancer were 70.0% and 47.5% respectively. Cyclin D1 positive cells showed more sensitive to 5-FU and HCPT than cyclin D1 negative cells. P21WAF1 negative cells showed more sensitive to MMC, 5-FU and DDP than P21WAF1 positive cells.. Expression of cyclin D1 and P21WAF1 is related with drug-resistance of tumor. Examination of cyclinD1 and P21WAF1 would have reference value in selection of chemotherapeutic drugs.

Topics: Adult; Aged; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p21; Drug Screening Assays, Antitumor; Female; Humans; Male; Middle Aged; Stomach Neoplasms

Currently, few studies have reported the different expression of molecular markers between distal gastric cancer and cardiac cancer. Here, we sought to make an investigation about it by a retrospective analysis.. The expression of 8 proteins, including epidermal growth factor receptor, glutathione S-transferase pi (GST-pi), cyclin D1, Neu/Her-2, C-myc, p53, p27 and p21, were evaluated in 110 cases with cardiac cancer and 101 cases with distal gastric cancer who underwent curative surgery at the Cancer Hospital, Fudan University, in 2005 by immunohistochemistry method.. The TNM stage, differentiation grade, invasion depth and lymph node metastasis were significantly different between cardiac cancer and distal gastric cancer. p21 (p = 0.034), Neu (p = 0.017), and GST-pi (p = 0.003) were expressed in relatively higher levels in cardiac cancer than in distal gastric cancer. Furthermore, the clinical pathological parameters were significantly correlated with the expression of molecules mentioned above.. Different molecular mechanisms may be involved in the tumorigenesis and development of cardiac cancer and distal gastric cancer.

Topics: Adult; Aged; Aged, 80 and over; Biomarkers, Tumor; Cardia; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p21; Cyclin-Dependent Kinase Inhibitor p27; DNA-Binding Proteins; ErbB Receptors; Female; Glutathione S-Transferase pi; Humans; Male; Middle Aged; Neuraminidase; Retrospective Studies; Stomach Neoplasms; Survival Rate; Transcription Factors; Treatment Outcome

To investigate the effects of macrophage migration inhibitory factor (MIF) on proliferation of human gastric cancer MGC-803 cells and expression of cyclin D1 and p27(Kip1) in them, and further determine whether the effects are related to the PI3K/Akt signal transduction pathway.. Gastric cancer MGC-803 cells were cultured and then treated with 50 microg/L recombinant human MIF (rhMIF) with and without a PI3K inhibitor, LY294002 (25 micromol/L). MTT assay was used to detect the proliferation of MGC-803 cells. Cell cycle was detected by flow cytometry. Expression of cyclin D1 and p27(Kip1) mRNA was by reverse transcription-polymerase chain reaction. Protein expression of phosphorylated Akt (p-Akt), Akt, cyclin D1 and p27(Kip1) was examined by immunocytochemistry and Western blotting.. rhMIF significantly stimulated the proliferation of MGC-803 cells and cell cycle progression from G1 phase to S phase in a concentration- and time-dependent manner. After the MGC-803 cells were treated with rhMIF for 24 h, the expression of cyclin D1 was significantly up-regulated compared with the cells not treated with rhMIF at both mRNA and protein levels (0.97 +/- 0.02 vs 0.74 +/- 0.01, P = 0.002; 0.98 +/- 0.05 vs 0.69 +/- 0.04, P = 0.003). The p27(Kip1) was down-regulated but only statistically significant at the protein level. rhMIF significantly increased the expression of p-Akt, which reached the peak at 30 min, but did not affect the expression of Akt. However, LY294002 inhibited all the effects of rhMIF.. Macrophage MIF increases the proliferation of gastric cancer cells, induces the expression of cyclin D1 at the transcriptional level and inhibits the expression of p27(Kip1) at the post-transcriptional level via the PI3K/Akt pathway.

Topics: Cell Line, Tumor; Cell Proliferation; Chromones; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p27; Enzyme Inhibitors; Humans; Intramolecular Oxidoreductases; Macrophage Migration-Inhibitory Factors; Morpholines; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Signal Transduction; Stomach Neoplasms; Tetrazolium Salts; Thiazoles

Cyclin D1 (CCND1) is a regulatory protein involved in the cell cycle of both normal and neoplastic cells. Polymorphism of this gene at codon 242 in exon 4 (A870G) has an impact on the risk of several human cancers. The purpose of this study was to study the relation between the CCND1 A870G gene polymorphism and the risk of non-cardiac gastric cancer in a Chinese population.. The study population consisted of 159 patients with non-cardiac gastric cancer and 162 cancer-free controls. CCND1 870A/G polymorphism was genotyped by a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay and sequencing.. CCND1 genotype distribution among the patients was significantly different from that among controls; AA (odds ratio (OR)=0.348, 95% CI: 0.163-0.742) and GA (OR=0.715, 95% CI: 0.506-1.012) genotypes were significantly lower in the gastric cancer patients than in the controls when subjects with the GG genotype served as the reference category. In other words, the risk of gastric cancer for subjects with the GG genotype was 2.8 times that of subjects with the AA genotype, and 1.4 times that of subjects with the GA genotype. Furthermore, in the stratification analyses, the risk of GG genotype was more evident in subjects >or=60 years of age and those positive for Helicobacter pylori (H. pylori) infection.. The CCND1870 GG genotype is associated with an increased risk for non-cardiac gastric cancer in patients in a high-risk area of China. Larger studies with multiple polymorphisms are needed to verify this finding and the function of this polymorphism needs to be further investigated.

Topics: Aged; Aged, 80 and over; Case-Control Studies; China; Cyclin D1; Female; Genotype; Humans; Male; Middle Aged; Polymorphism, Restriction Fragment Length; Risk Factors; Stomach Neoplasms

Various molecular changes characterizing organ-specific carcinogenesis have been identified in human tumors; however, the molecular mechanisms of the genomic changes specific for each cancer are not well defined. A transgenic (Tg) mouse model with constitutive expression of the nucleotide-editing enzyme, activation-induced cytidine deaminase (AID), develops tumors in various organs as a result of the mutagenic activities of AID. This phenotypic character of AID Tg mice allowed us to analyze the organ-specific genetic changes in tumor-related genes commonly triggered by AID-mediated mutagenesis. Among the 80 AID Tg mice analyzed, 11 mice developed hepatocellular carcinomas, and 7 developed lung cancers. In addition, 1 developed the gastric cancer and 3 developed gastric adenomas. Organ-specific preferences for nucleotide changes were observed in some of the tumor-related genes in each epithelial tissue of the AID Tg mice. Of note, the c-myc and K-ras genes were the preferential targets of the mutagenic activity of AID in lung and stomach cancers, respectively, whereas mutations in the p53 and beta-catenin genes were commonly observed in all 3 organs. Quantitative RT-PCR analyses revealed that alpha-fetoprotein, insulin-like growth factor-2 and cyclin D1 genes were specifically upregulated in HCC, whereas upregulation of the matrix metalloproteinase-7 gene was more marked in lung cancer. Our findings suggest that AID, a DNA mutator that plays a critical role linking inflammation to human cancers, might be involved in the generation of organ-specific genetic diversity in oncogenic pathways during cancer development.

Topics: alpha-Fetoproteins; Animals; beta Catenin; Cyclin D1; Cytidine Deaminase; Enzyme Activation; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Neoplastic; Genes, myc; Genes, ras; Insulin-Like Growth Factor II; Liver Neoplasms, Experimental; Lung Neoplasms; Matrix Metalloproteinase 7; Mice; Mice, Transgenic; Mutation; Neoplasms, Experimental; Organ Specificity; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction; Stomach Neoplasms; Tumor Suppressor Protein p53; Up-Regulation

We previously showed that antral gastric tumors develop in gastrin-deficient (Gas(-/-)) mice. Therefore Gas(-/-) mice were studied sequentially over 12 months to identify molecular mechanisms underlying gastric transformation. Fundic atrophy developed by 9 months in Gas(-/-) mice. Antral mucosal hyperplasia developed coincident with the focal loss of TFF1 and Muc5AC. Microarray analysis of 12 month Gas(-/-) tumors revealed an increase in follistatin, an activin/BMP antagonist. We found that elevated follistatin expression occurred in the proliferative neck zone of hyperplastic antrums, in antral tumors of Gas(-/-) mice, and also in human gastric cancers. Follistatin induced cyclin D1 and the trefoil factors TFF1 and TFF2 in a gastric cancer cell line. We concluded that antral hyperplasia in Gas(-/-) mice involves amplification of mucous cell lineages due to follistatin, suggesting its role in the development of antral gastric tumors.

Topics: Animals; Cell Line, Tumor; Cell Transformation, Neoplastic; Cyclin D1; Follistatin; Gastric Mucosa; Gastrins; Hyperplasia; Mice; Mice, Knockout; Mucins; Muscle Proteins; Peptides; Pyloric Antrum; Stomach Neoplasms; Trefoil Factor-1; Trefoil Factor-2

Induction of cyclooxygenase-2 (COX-2) associates with cigarette smoke exposure in many malignancies. Nicotine and its derivative, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), are the two important components in cigarette smoke that contributes to cancer development. However, the molecular mechanism(s) by which nicotine or NNK promotes gastric carcinogenesis remains largely unknown. We found that nicotine and NNK significantly enhanced cell proliferation in AGS cells that expressed both alpha7 nicotinic acetylcholine receptor (alpha7 nAChR) and beta-adrenergic receptors. Treatment of cells with alpha-bungarotoxin (alpha-BTX, alpha7nAChR antagonist) or propranolol (beta-adrenergic receptor antagonist) blocked NNK-induced COX-2/PGE(2) and cell proliferation, while nicotine-mediated cell growth and COX-2/PGE(2) induction can only be suppressed by propranolol, but not alpha-BTX. Moreover, in contrast to the dependence of growth promoting effect of nicotine on Erk activation, inhibitor of p38 mitogen-activated protein kinase (MAPK) repressed NNK-induced COX-2 upregulation and resulted in suppression of cell growth. In addition, nicotine and NNK mediated COX-2 induction via different receptors to modulate several G1/S transition regulatory proteins and promote gastric cancer cell growth. Selective COX-2 inhibitor (SC-236) caused G1 arrest and abrogated nicotine/NNK-induced cell proliferation. Aberrant expression of cyclin D1 and other G1 regulatory proteins are reversed by blockade of COX-2. These results pointed to the importance of adrenergic and nicotinic receptors in gastric tumor growth through MAPK/COX-2 activation, which may perhaps provide a chemoprevention strategy for cigarette smoke-related gastric carcinogenesis.

Topics: Adenocarcinoma; alpha7 Nicotinic Acetylcholine Receptor; Bungarotoxins; Carcinogens; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Cyclooxygenase 2; Dinoprostone; Gene Expression Regulation; Humans; Nicotine; Nitrosamines; p38 Mitogen-Activated Protein Kinases; Propranolol; Receptors, Adrenergic, beta; Receptors, Nicotinic; Signal Transduction; Stomach Neoplasms

The immunohistochemical expression of phosphorylated (activated) Akt (pAkt) in 50 advanced gastric carcinomas has been analyzed and the results correlated with age, sex, location in the stomach, histotype, stage, survival, mitotic and apoptotic index, some cell cycle regulators (cyclin D1, cyclin E, p34/cdc2, p27/kip1), and cell proliferation. There was a statistically significant direct correlation between pAkt expression (both cytoplasmatic and nuclear) and depth of infiltration of the tumor, number of infiltrated lymph nodes and p34/cdc2 expression, and between prevalently nuclear pAkt and cyclin D1 and cyclin E. Conversely, there was a significant inverse correlation between nuclear pAkt and apoptotic index and between cytoplasmatic and nuclear pAkt and patient survival. No correlation was found between pAkt and sex, age, tumor location, histotype, mitotic index, and cell proliferation. These findings suggest that pAkt may be considered an indicator of tumor progression and patient survival in gastric cancer.

Topics: Adult; Aged; Aged, 80 and over; Apoptosis; Biomarkers, Tumor; CDC2 Protein Kinase; Cell Proliferation; Cyclin D1; Cyclin E; Cyclin-Dependent Kinase Inhibitor p27; Disease Progression; Female; Humans; Male; Middle Aged; Prognosis; Proto-Oncogene Proteins c-akt; Retrospective Studies; Stomach Neoplasms; Survival Analysis; Ubiquitin-Protein Ligases

Tumor cells with genomic amplification of MET display constitutive activation of the MET tyrosine kinase, which renders them highly sensitive to MET inhibition. Several MET inhibitors have recently entered clinical trials; however, as with other molecularly targeted agents, resistance is likely to develop. Therefore, elucidating possible mechanisms of resistance is of clinical interest. We hypothesized that collateral growth factor receptor pathway activation can overcome the effects of MET inhibition in MET-amplified cancer cells by reactivating key survival pathways. Treatment of MET-amplified GTL-16 and MKN-45 gastric cancer cells with the highly selective MET inhibitor PHA-665752 abrogated MEK/mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K)/AKT signaling, resulting in cyclin D1 loss and G(1) arrest. PHA-665752 also inhibited baseline phosphorylation of epidermal growth factor receptor (EGFR) and HER-3, which are transactivated via MET-driven receptor cross-talk in these cells. However, MET-independent HER kinase activation using EGF (which binds to and activates EGFR) or heregulin-beta1 (which binds to and activates HER-3) was able to overcome the growth-inhibitory effects of MET inhibition by restimulating MEK/MAPK and/or PI3K/AKT signaling, suggesting a possible escape mechanism. Importantly, dual inhibition of MET and HER kinase signaling using PHA-665752 in combination with the EGFR inhibitor gefitinib or in combination with inhibitors of MEK and AKT prevented the above rescue effects. Our results illustrate that highly targeted MET tyrosine kinase inhibition leaves MET oncogene-"addicted" cancer cells vulnerable to HER kinase-mediated reactivation of the MEK/MAPK and PI3K/AKT pathways, providing a rationale for combined inhibition of MET and HER kinase signaling in MET-amplified tumors that coexpress EGFR and/or HER-3.

Topics: Antineoplastic Agents; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Drug Resistance, Neoplasm; Enzyme Activation; ErbB Receptors; Humans; Indoles; Mitogen-Activated Protein Kinase Kinases; Phosphatidylinositol 3-Kinases; Phosphorylation; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-met; Receptor, ErbB-3; Signal Transduction; Stomach Neoplasms; Sulfones; Transfection

Cyclin D1 (CCND1) is known to regulate function in G1 arrest and therefore may play an important role in carcinogenesis. The aim of this study was to investigate the effect of G870A polymorphism of the CCND1 gene on gastric precancerous condition, on histological chronic gastritis, and on the risk of peptic ulcer diseases.. Restriction fragment length polymorphism analysis was performed for polymorphisms at 870GA in the CCND1 gene in 524 cancer-free subjects, including 111 gastric and 54 duodenal ulcers, and 359 non-ulcer subjects. Gastritis scores of antral gastric mucosa were assessed according to the updated Sydney system in 384 subjects.. CCND1 genotype was significantly associated with the severity of intestinal metaplasia by the Kruskal-Wallis test, and this tendency was especially stronger among older subjects of 61 years or older (overall subjects: p=0.035, 61 years approximately : p=0.007). We also found that the 870AA genotype held a significant high risk of intestinal metaplasia [Helicobacter pylori infection adjusted odds ratio (OR)=1.8, 95% confidence interval (CI)=1.03-3.15, p=0.04]. The same genotype was more closely associated with the risk of intestinal metaplasia in older subjects of 61 years or older (H. pylori infection adjusted OR=3.45, 95% CI=1.48-8.08, p=0.004). A non-significant association was found between CCND1 G870A genotypes and the risk of peptic ulcer diseases as well as histological severity of acute or chronic inflammation.. It appears that the G870A polymorphism of CCND1 is associated with gastric premalignant condition especially in older subjects.

Topics: Cyclin D1; Female; Gastritis; Genetic Predisposition to Disease; Humans; Japan; Male; Middle Aged; Peptic Ulcer; Polymorphism, Genetic; Precancerous Conditions; Severity of Illness Index; Stomach Neoplasms

To rapidly detect molecular alterations in different malignancies and investigate the possible role of Tp53, C-myc, and CCND1 genes in development of tumors in human organs and their adjacent normal tissues, as well as the possible relation between well- and poorly-differentiated tumors.. A tissue array consisting of seven different tumors was generated. The tissue array included 120 points of esophagus, 120 points of stomach, 80 points of rectum, 60 points of thyroid gland, 100 points of mammary gland, 80 points of liver, and 80 points of colon. Expressions of Tp53, C-myc, and CCND1 were determined by RNA in situ hybridization. 3' terminal digoxin-labeled anti-sense single stranded oligonucleotide and locked nucleic acid modifying probe were used.. The expression level of Tp53 gene was higher in six different carcinoma tissue samples than in paracancerous tissue samples with the exception in colon carcinoma tissue samples (P < 0.05). The expression level of CCND1 gene was significantly different in different carcinoma tissue samples with the exception in esophagus and colon carcinoma tissue samples. The expression level of C-myc gene was different in esophagus carcinoma tissue samples (chi2 = 18.495, P = 0.000), stomach carcinoma tissue samples (chi2 = 23.750, P = 0.000), and thyroid gland tissue samples (chi2 = 10.999, P = 0.004). The intensity of signals was also different in different carcinoma tissue samples and paracancerous tissue samples.. Over-expression of the Tp53, CCND1, and C-myc genes appears to play a role in development of human cancer by regulating the expression of mRNA. Tp53, CCND1 and C-myc genes are significantly correlated with the development of different carcinomas.

Topics: Breast Neoplasms; China; Colonic Neoplasms; Cyclin D1; Esophageal Neoplasms; Gene Expression Regulation, Neoplastic; Humans; Liver Neoplasms; Proto-Oncogene Proteins c-myc; Rectal Neoplasms; RNA, Messenger; Stomach Neoplasms; Thyroid Neoplasms; Tissue Array Analysis; Tumor Suppressor Protein p53

We aimed to investigate the biological significance of cell cycle regulators in gastric carcinoma.. Immunohistochemistry and TUNEL staining were performed on tissue array slides containing 293 gastric carcinoma specimens. The relationship between the protein expression of each of the cell cycle regulators and prognosis, clinicopathological features, proliferation, or apoptosis was evaluated.. The nuclear immunoreactivity for cyclin D1, cyclin E, p21, and p27 was observed in 22, 14, 31 and 27% of cases, respectively. The expression of cyclin D1, p21, or p27 positively correlated with early pTNM stages, tumor cell proliferation (represented by Ki-67 labeling) and good prognosis, whereas it inversely correlated with the lymph node metastasis (p < 0.05). On the other hand, p27 expression inversely correlated with the apoptosis index represented by TUNEL staining (p < 0.001). In addition, the expression of cyclin D1 positively correlated with that of p21 or p27 (p < 0.05).. Our results showed that the expression of cyclin D1, p21 and p27, alone or in combination, are early events in gastric tumorigenesis and may serve as a candidate molecular marker for the early gastric carcinoma.

Topics: Adult; Aged; Aged, 80 and over; Apoptosis; Biomarkers, Tumor; Carcinoma; Cell Cycle; Cell Cycle Proteins; Cell Division; Cyclin D1; Cyclin E; Cyclin-Dependent Kinase Inhibitor p21; Cyclin-Dependent Kinase Inhibitor p27; Disease-Free Survival; Female; Humans; Immunohistochemistry; Lymphatic Metastasis; Male; Middle Aged; Neoplasm Invasiveness; Neoplasm Staging; Prognosis; Stomach Neoplasms

Altered signaling pathways or deregulated transcription factors represent an important category of molecular events leading to aberrant gene regulation in gastric cancer, among which the role of WNT/beta-catenin pathway remains unclear. LRH-1 is a critical transcription factor in controlling cell proliferation via crosstalk with the beta-catenin signaling pathway. In order to gain a knowledge of the expression of hLRH-1v1 and hLRH-1 in gastric cancer, a Q-PCR analysis was carried out. Our results showed that in about 50 and 47.6% of 42 tested patients with gastric cancer, the mRNA expression of hLRH-1v1 and hLRH-1 was significantly upregulated, as compared with self-paired normal control, respectively. Besides, overexpression of hLRH-1 was shown to promote the proliferation of gastric adenocarcinoma cell SGC-7901 via induction of cyclin E1. Taken together, our present study demonstrated for the first time the increased expression of hLRH-1v1 and hLRH-1 in human gastric cancer, an alteration which may implicate in tumorigenesis.

Topics: beta Catenin; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Cyclin E; DNA-Binding Proteins; Gastric Mucosa; Gene Expression Regulation, Neoplastic; Humans; Protein Isoforms; Receptors, Cytoplasmic and Nuclear; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Stomach; Stomach Neoplasms; Transcription Factors; Transfection; Up-Regulation

The early indicator for the subject predisposed to gastric cancer is abnormal proliferation of gastric epithelial cells, such as atrophic gastritis (AG), intestinal metaplasia (IM), and dysplasia, which have been considered as precancerous lesions of gastric cancer. To determine whether p53 protein, cyclins D1, and D3, and p27(kip1) play a role in the carcinogenesis pathway of gastric cancer, we performed an immunohistochemical study of their expression in gastric precancerous lesions.. A total of 1 45 endoscopic gastric biopsy specimens of AG, IM, and gastric dysplasia were studied. These molecular markers were localized by immunohistochemistry.. P53 was expressed in 15% of cases with gastric dysplasia and not in the pre-dysplastic stages of the gastric mucosa. All cases were concerning high-grade dysplasia. Cyclin D1 protein was almost undetectable in the precancerous lesions of gastric cancer. Cyclin D3 protein overexpression was seen in 10% of biopsies with IM, and 50% of biopsies with gastric dysplasia. High expression of p27(kip1) protein was demonstrated in all cases of chronic gastritis. As atrophy, IM, and dysplasia develop, expression of p27(kip1) protein is suppressed. In total, 15% of dysplastic cases showed no expression of p27(kip1) protein.. (i) P53 mutation must be a late event during the development of gastric cancer. (ii) Cyclin D1 protein overexpression may not play a role in the progression from normal to neoplastic gastric mucosa, while overexpression of cyclin D3 is an earlier event during gastric carcinogenesis, and its role must be further evaluated. (iii) Reduced expression of p27(kip1) is a rather early event in gastric tumorigenesis, before dysplastic changes occur.

Topics: Adult; Aged; Aged, 80 and over; Cell Cycle Proteins; Cyclin D1; Cyclin D3; Cyclin-Dependent Kinase Inhibitor p27; Cyclins; Female; Humans; Immunohistochemistry; Male; Middle Aged; Precancerous Conditions; Stomach Neoplasms; Tumor Suppressor Protein p53

To study the effect of the transfected Twist gene on invasion and metastasis of gastric carcinoma cells and the possible mechanisms involved.. Human gastric carcinoma MKN28 cells were stably transfected with Twist sense plasmid, and MKN45 cells were stably transfected with Twist antisense plasmid using the lipofectamine transfection technique. RT-PCR, Western blotting, EMSA, gelatin zymography assay, and in vitro invasion and migration assays were performed. Nude mice metastasis models were established by the abdominal cavity transfer method.. Cell models (TwistS-MKN28) that steadily expressed high Twist protein were obtained. Compared with MKN28 and pcDNA3-MKN28 cells, adherence, migration and invasion ability of TwistS-MKN28 cells were clearly raised. The number of cancer nodules was increased significantly in the abdominal cavity and liver of nude mice inoculated with TwistS-MKN28 cells. Overexpression of Twist in MKN28 cells increased Tcf-4/Lef DNA binding activity, and promoted expression of Tcf-4's downstream target genes cyclin D1 and MMP-2. However, suppression of Twist (TwistAS-MKN45) inhibited MKN45 cell invasion and the expression of cyclin D1 was reduced. The activity of MMP-2 was also decreased.. These results indicate that Twist promotes gastric cancer cell migration, invasion and metastasis, and Twist may play an important role in Wnt/Tcf-4 signaling.

Topics: Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; Cell Adhesion; Cell Line, Tumor; Cell Movement; Cyclin D1; DNA Primers; DNA-Binding Proteins; DNA, Antisense; DNA, Neoplasm; Electrophoretic Mobility Shift Assay; Humans; Neoplasm Invasiveness; Neoplasm Metastasis; Neoplasm Proteins; Nuclear Proteins; Stomach Neoplasms; Transcription Factor 4; Transcription Factors; Transfection; Twist-Related Protein 1

The p16(INK4a) (p16), cyclin D1, cyclin-dependent kinase (CDK) 4 and retinoblastoma (Rb) genes are components of the Rb pathway that controls the G1-S checkpoint of the cell cycle. The aim of this study was to assess the relationship between their abnormalities and clinicopathological features in gastric carcinomas.. Immunohistochemical analysis of the encoded proteins was performed on a series of 158 cases.. Loss of p16/Rb protein (pRb) expression and overexpression of cyclin D1/CDK4 were observed in 49%/40% and 37%/37% of gastric carcinomas, respectively. At least 1 of these abnormalities was found in 86% of the cases and a positive correlation was noted between p16 and pRb (P = 0.009). Cyclin D1 (P = 0.042) and CDK4 (P = 0.008) overexpession was inversely associated with lymph node metastasis and depth of invasion, respectively. Loss of pRb expression was more frequently in diffuse type lesions than in the intestinal type (P = 0.022). The patients with p16+/pRb-/cyclin D1-/CDK4- or p16-/pRb+/cyclin D1-/CDK4- tumors demonstrated particularly poor survival. With multivariate survival analysis, only depth of invasion and TNM stage could be proven as independent predictors.. The Rb pathway is disrupted in the vast majority of gastric carcinomas. This study also identified specific immunohistochemical marker profiles for prognosis.

Topics: Biomarkers, Tumor; Carcinoma; Cyclin D1; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase Inhibitor p16; Humans; Immunohistochemistry; Lymphatic Metastasis; Multivariate Analysis; Neoplasm Invasiveness; Neoplasm Staging; Prognosis; Retinoblastoma Protein; Stomach Neoplasms; Survival Rate

It is important to identify the differentially expressed gene in gastric cancer for elucidating the molecular mechanisms of tumorigenesis of stomach. Here, 38 genes differentially expressed genes between gastric cancer and normal gastric mucosa by in silico approaches. A potassium channel protein KCNE2, identified as a down-regulated gene in gastric cancer, was chosen for further study. We investigated the expression of KCNE2 in gastric cancer tissues and cell lines and examined the effect of KCNE2 on proliferation of gastric cancer. The expression of KCNE2 was markedly down-regulated in gastric cancer tissues and cell lines. Forced overexpression of KCNE2 suppressed the growth of SGC7901 cells and cell cycle progression significantly, which might be related to the down-regulation of Cyclin D1. KCNE2 also inhibited SGC7901 cell growth in soft agar and its tumorigenicity in nude mice. Taken together, our work showed that in silico analysis approaches could be used to identify cancer-related genes effectively. KCNE2, as a novel down-regulated gene in gastric cancer, suppressed cell proliferation and tumorigenesis of stomach.

Topics: Animals; Blotting, Western; Cell Cycle; Cell Line, Transformed; Cell Line, Tumor; Cell Proliferation; Computational Biology; Cyclin B; Cyclin B1; Cyclin D1; Down-Regulation; Flow Cytometry; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Humans; Immunohistochemistry; Mice; Mice, Nude; Potassium Channels, Voltage-Gated; Stomach Neoplasms; Transfection; Xenograft Model Antitumor Assays

Beta-catenin can function as an oncogene when it is translocated to the nucleus, binds to T-cell factor (TCF) or lymphoid enhance factor and transactivate its target gene. The mechanism responsible for the activation of Wnt signaling pathway in the Cytotoxin-associated antigen A (CagA) Helicobacter pylori (H. pylori)-infected gastric carcinoma has not been elucidated. We hypothesize that whether interaction of MUC1 with beta-catenin modulates the Wnt signaling and its target gene cyclinD1 in CagA H. pylori-infected gastric carcinoma. The result demonstrate that binding of MUC1 CT with Protein Kinase C delta (PKC delta), tyrosine phosphorylation of MUC1 CT, and CagA are strongly associated with the interaction of MUC1 with beta-catenin in CagA H. pylori-infected gastric carcinoma. A statistically significant difference (chi(2) = 24.49; P < 0.001) was found when the binding of MUC1 CT and beta-catenin was compared to subcellular localization of beta-catenin. We also observed significant statistical correlation (chi(2) = 14.885; P < 0.001) between the cyclinD1 overexpression and the subcellular localization of beta-catenin. The overexpression of cyclinD1 was significantly higher (chi(2) = 13.785; P < 0.002) in advanced gastric carcinoma with CagA H. pylori infection. In addition cyclinD1 overexpression was significantly higher (chi(2) = 37.267; P < 0.001) with the interaction of MUC1 CT with beta-catenin in advanced gastric cancer. These findings indicate that MUC1 CT plays a role in the intracellular signaling through its interaction with beta-catenin and upregulate the Wnt target gene cyclinD1 in CagA H. pylori-infected gastric carcinoma.

Topics: Adenocarcinoma; Adult; Antigens, Bacterial; Bacterial Proteins; beta Catenin; Cell Nucleus; Cyclin D1; Female; Gene Expression Regulation, Neoplastic; Helicobacter Infections; Helicobacter pylori; Humans; Male; Middle Aged; Mucin-1; Phosphorylation; Signal Transduction; Stomach Neoplasms; Wnt Proteins

Identifying an effective therapeutic target is pivotal in the treatment of gastric cancer. In this study, we investigated the expression of p75 neurotrophin receptor (p75NTR) in gastric cancer and the impact of its alteration on tumor growth. p75NTR expression was absent or significantly decreased in 212 cases of gastric cancers compared with the normal gastric mucosa (P < .05). Moreover, p75NTR expression was also lost or significantly decreased in various human gastric cancer cell lines. p75NTR inhibited in vitro growth activities and caused dramatic attenuation of tumor growth in animal models by induction of cell cycle arrest. Upregulation of p75NTR led to downregulation of cyclin A, cyclin D1, cyclin E, cyclin-dependent kinase 2, p-Rb, and PCNA, but to upregulation of Rb and p27 expressions. Conversely, downregulating p75NTR with specific siRNA yielded inverse results. The rescue of tumor cells from cell cycle progression by a death domain-deleted dominant-negative antagonist of p75NTR (Deltap75NTR) showed that the death domain transduced antiproliferative activity in a ligand-independent manner and further demonstrated the inhibitive effect of p75NTR on growth in gastric cancer. Therefore, we provided evidence that p75NTR was a potential tumor suppressor and may be used as a therapeutic target for gastric cancer.

Topics: Animals; Apoptosis; Blotting, Western; Cell Cycle; Cell Proliferation; Colony-Forming Units Assay; Cyclin A; Cyclin A1; Cyclin D1; Cyclin E; Cyclin-Dependent Kinase 2; Gastric Mucosa; Humans; Mice; Proliferating Cell Nuclear Antigen; Receptor, Nerve Growth Factor; Receptor, trkC; Retinoblastoma Protein; RNA, Small Interfering; Stomach Neoplasms; Survival Rate; Tumor Cells, Cultured

Synchronous occurrence of mantle cell lymphoma (MCL) and gastric cancer in the same patient has not yet been reported in the English literature. MCL comprises 2.5-7% of non-Hodgkin's lymphomas and is characterized by a poor prognosis with a median survival probability of 3-4 years in most series. A 62-year-old man was referred to our hospital for evaluation of an abnormal gastric lesion. The endoscopic finding was compatible with type IIc early gastric cancer (EGC) in the middle third of the stomach, and a biopsy of the lesion proved to be carcinoma. Radical total gastrectomy with splenectomy and Roux-en-Y esophagojejunostomy were performed. The resected specimen revealed two grossly separated lesions. Postoperative histological examination reported both adenocarcinoma and MCL. Immunohistochemical staining showed positivity for CD5, CD20, and cyclin D1 in the infiltrated lymphoid cells. MCL is an aggressive non-Hodgkin's lymphoma, and the current treatment approach is still unsatisfactory. Further advancements in the understanding of the synchronous occurrence of both diseases, and more efforts on investigations of treatment are needed.

Topics: Adenocarcinoma; Antigens, CD20; CD5 Antigens; Cyclin D1; Humans; Immunohistochemistry; Lymphoma, Mantle-Cell; Male; Middle Aged; Stomach; Stomach Neoplasms

To investigate the inhibitory effect and possible mechanism of action of schisandrin B in SC-B on gastric cancer cells in vitro.. SC-B consisted of schisandrin B, aloe-emodin, and Astragalus polysaccharides. Exponentially growing human gastric cancer SGC-7901 cells were divided into six treatment groups: (1) control group (RPMI 1640 medium); (2) negative control group (2% DMSO); (3) positive control group (50 mg/L 5-Fluorouracil, 5-FU); (4) low-dose group (LSC, final concentration of schisandrin B, 25 mg/L); (5) moderate-dose group (MSC, final concentration of schisandrin B, 50 mg/L); (6) high-dose group (HSC, final concentration of schisandrin B, 100 mg/L). Follow-up was done at 12-48 h. An MTT (Methylthiazolyldiphenyl-tetrazolium bromide) assay was used to examine the inhibitory effect of SC-B on gastric cancer cells. The mitosis index was assessed using an inverted microscope. Flow cytometry was used to visualize the cell cycle. An RT-PCR (Reverse transcription-Polymerase chain reaction) -based assay was used to detect mRNA expression for cyclin D1 and glyceraldehyde-3-phosphate dehydrogenase (GAPDH).. The MTT assay showed that the number of living cells in the LSC, MSC and HSC groups was significantly smaller than that in the DMSO-treated group (P < 0.05) at 12-48 h. The inhibitory rate (IR) of the LSC group was 41.15% +/- 3.86%, 59.24% +/- 5.34% and 69.93% +/- 7.81% at 12, 24 and 48 h, respectively. The IR of the MSC group was 42.82% +/- 4.94%, 62.68% +/- 7.58% and 71.79% +/- 8.12% at 12, 24 and 48 h, respectively. The IR of the HSC group was 37.50% +/- 3.21%, 40.34% +/- 2.98% and 61.99% +/- 4.88% at 12, 24 and 48 h, respectively. These results suggested that a moderate dosage had the most obvious inhibitory efficacy at 48 h. Compared to the DMSO group, the mitosis index of the LSC, MSC, HSC groups was greatly decreased (P < 0.05) at all time points. Any dose of SC-B suppressed mitosis within 12-48 h. Compared to the DMSO group, the percentage of cells in the G0/G1 phase of the MSC group was greatly increased, and that of the S + G2M phase was greatly decreased, while the percentage of cell inhibition (PCI) in the MSC group was greatly increased (P < 0.05). This suggested that SC-B could exclusively arrest cells in the G0/G1 phase. Cyclin D1 mRNA expression was lower in the MSC group than that in the DMSO group (P < 0.05).. SC-B can inhibit the proliferation and aberrant mitosis of human gastric cancer SCG-7901 cells in vitro. This inhibitory effect may be due to the down-regulation of cyclin D1 mRNA expression, which causes cell cycle arrest of gastric cancer cells.

Topics: Astragalus Plant; Cell Cycle; Cell Line, Tumor; Cyclin D1; Cyclooctanes; Dose-Response Relationship, Drug; Drugs, Chinese Herbal; Emodin; Glucosides; Glyceraldehyde-3-Phosphate Dehydrogenases; Humans; Lignans; Medicine, Chinese Traditional; Mitosis; Polycyclic Compounds; Polysaccharides; RNA, Messenger; Stomach Neoplasms; Time Factors

CIAPIN1, a newly identified apoptosis-related molecule, was found to be downregulated in human gastric cancer tissues as compared to the matched adjacent nonneoplastic tissues. In this study, we investigated the effect of CIAPIN1 on in vitro and in vivo proliferation of gastric cancer cells. Ectopic expression and knockdown of CIAPIN1 in gastric cancer cells SGC7901 and MKN45 were achieved by transduction with recombinant adenoviruses expressing human CIAPIN1 (Ad-CIAPIN1) and human CIAPIN1-specific small interference RNA (Ad-CIAPIN1 siRNA). Gastric cancer cells with upregulated expression of CIAPIN1 exhibited significantly decreased proliferation, while cellswith downregulated CIAPIN1 expression showed significantly quicker growth rate as compared with their respective controls in both in vitro and in vivo tests. Also, CIAPIN1suppressed colony formation of SGC7901 and MKN45 cells in soft agar cloning test.Furthermore, cell cycle distribution analysis revealed that CIAPIN1 induced cell cycle arrest at G1/S phase. Downregulation of CyclyinD1 and upregulation of P27 might contribute, at least in part, to this altered cell cycle distribution. This study demonstrates that CIAPIN1 is a suppressor of gastric cancer cell proliferation and suggests CIAPIN1might play an important role in the development of human gastric cancer.

Topics: Cell Cycle; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p27; Down-Regulation; Humans; Intracellular Signaling Peptides and Proteins; RNA, Small Interfering; Stomach Neoplasms; Transduction, Genetic; Tumor Suppressor Proteins; Up-Regulation

We evaluated the relationship of amplification and polysomy of both the CCND1 and the ERBB2 (alias HER-2/NEU) genes to the overexpression of their proteins in esophageal and gastric cancers and also their association with clinicopathological features. CCND1 gene amplification (45%) was more prevalent than polysomy (25%) in esophageal carcinoma, but the pattern observed was similar in gastric adenocarcinoma (10% amplification, 15% polysomy). For ERBB2, polysomy was a more frequent mechanism than amplification in both esophageal (32.5 vs. 7.5%) and gastric (15 vs. 5%) cancers. Overexpression of cyclin D1 protein was identified in 37.5% of the specimens of esophageal tumors and 35% of gastric tumors, and overexpression of Her-2/neu protein in 12.5 and 7.5%, respectively. The kappa-statistics revealed a fair agreement in both types of tumors only in overexpression and amplification of the CCND1 gene; the ERBB2 gene showed a fair agreement in amplification and polysomy and the level of protein expression in gastric adenocarcinoma. Thus, polysomy 17 could contribute to a high Her-2/neu protein level, at least in gastric cancer. Our data indicated an association with alcohol consumption and the CCND1 gene or protein levels, in both esophageal and gastric cancers.

Topics: Adenocarcinoma; Aged; Cyclin D1; Esophageal Neoplasms; Female; Gene Amplification; Gene Expression Regulation, Neoplastic; Genes, erbB-2; Helicobacter Infections; Helicobacter pylori; Humans; Immunohistochemistry; In Situ Hybridization, Fluorescence; Male; Middle Aged; Receptor, ErbB-2; Stomach Neoplasms; Survival Analysis

p55PIK is one of the regulatory subunits of phosphoinositide-3 kinase (PI3K). The unique 24 amino acids at N-terminal of p55PIK can bind Rb, and their ectopic expression may inhibit cell cycle progression. This study was to observe the effects of ectopic expression of the 24 amino acids at N-terminal of p55PIK (N24p55PIK) on cell proliferation and tumor growth of gastric cancer, and explore possible mechanism.. Plasmid pEGFPN24 was transfected into gastric cancer cell line MGC803 (MGC803/GFP-N24); pEGFPC1 was transfected into MGC803 cells as control (MGC803/pEGFPC1). Transient expression of GFP-N24 fusion protein was confirmed by Western blot. The growth of cell clones was determined by MTT assay. Effect of N24p55PIK overexpression on cell clonogenic ability was detected by colony formation assay. Tumorigenic capacity of MGC803/GFR-N24 cells was tested by tumorigenicity assay in nude mice. Influence of N24p55PIK on the expression of cell cycle protein Cyclin D1 was analyzed by Western blot.. N24p55PIK was efficiently expressed in MGC803 cells, but the level of GFP-N24 fusion protein in MGC803/GFP-N24 cells was much lower than that of GFP in MGC803/pEGFPC1 cells. Compared with MGC803/pEGFPC1 cells, the growth of MGC803/GFP-N24 cells was suppressed and the cell doubling time was prolonged. The volume of MGC803/GFP-N24 cell colonies was smaller than that of MGC803/pEGFPC1 cell colonies. The tumorigenic capacity of MGC803 cells was decreased after transfection of pEGFPN24 in nude mice. The tumor weight and volume were (0.398+/-0.244) g and (408+/-268) mm(3) in MGC803/pEGFPN24 group, and were (0.763+/-0.193) g and (829+/-271) mm(3) in MGC803/pEGFPC1 group (P<0.05). The expression of Cyclin D1 was down-regulated in MGC803/GFP-N24 cells.. Ectopic expression of N24p55PIK might inhibit tumor cell growth both in vitro and in vivo through decreasing the expression of Cyclin D1. The N24 peptide, derived from PI3K regulatory subunit p55PIK, may be a potential drug in antitumor treatment.

Topics: Adenocarcinoma, Mucinous; Animals; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Down-Regulation; Humans; Mice; Mice, Nude; Neoplasm Transplantation; Phosphatidylinositol 3-Kinases; Plasmids; Recombinant Fusion Proteins; Stomach Neoplasms; Transfection

To examine the effects of cyclin D1 antisense oligodexoyneucleotides (ASODN) on growth and chemosensitivity of gastric carcinoma cell lines SGC7901 and its mechanism.. Phosphorothioate modified cyclin D1 ASODN was encapsulated by LipofectAMINE2000 (LF2000) and transfected into cells, the dose-effect curves and growth curves were observed. 5-FU, MTX, CDDP of different concentrations were given after transfecting cells with cyclin D1 ASODN for 24 h the dose-effect responses were observed and IC50s were calculated. The mRNA expression of cyclin D1, thymidylate synthase (TS), thymidine phosphorylase (TP) and dihydrofolate reductase (DHFR) was detected by reverse transcription-PCR (RT-PCR) at 24 h and 48 h after transfection.. Dose-dependent inhibitory effect was caused by cyclin D1 ASODN in SGC7901 cells. Transfecting gastric carcinoma cells with 0.2 micromol/L cyclin D1 ASODN for 24 h could inhibit growth significantly and reduce expression of cyclin D1 mRNA. Cyclin D1 ASODN could increase the chemosensitivity to 5-FU, MTX, CDDP in cells. The IC50s of different chemotherapeutic agents in ASODN plus chemotherapy groups were significantly lower than those in controls. Transfection with cyclin D1 ASODN leaded to an increase in TS and DHFR mRNA and a decrease in TP mRNA as determined by RT-PCR at 24 h, the alterations were more significant at 48 h.. Cyclin D1 ASODN can decrease mRNA expression of cyclin D1, inhibit growth and enhance the chemosensitivity by changing the expression of enzymes related to metabolism of chemotherapeutic agents in SGC7901 gastric carcinoma cells.

Topics: Adenocarcinoma; Antineoplastic Agents; Cell Line, Tumor; Cell Proliferation; Chemoreceptor Cells; Cisplatin; Cyclin D1; Dose-Response Relationship, Drug; Fluorouracil; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Neoplastic; Humans; Methotrexate; Oligodeoxyribonucleotides, Antisense; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Stomach Neoplasms; Tetrahydrofolate Dehydrogenase; Thymidine Phosphorylase; Thymidylate Synthase; Transfection

Ribosomal proteins are the components of ribosome, which also exhibit various secondary functions in DNA repair, apoptosis, drug resistance and proliferation. In our previous study of microarray, ribosomal protein L15 (RPL15) was identified as an upregulated gene in gastric cancer.. We investigated the expression of ribosomal protein L15 in gastric cancer and the effect of RPL15 on proliferation of gastric cancer.. It was found that the expression of RPL15 was markedly up-regulated in gastric cancer tissues. RPL15 was also highly expressed in gastric cancer cell lines AGS, MKN45, MKN28, SGC7901 and KATOIII. Inhibition of RPL15 expression by siRNA vector transfection suppressed the growth of SGC7901 cells significantly, which was independent of the expression of Cyclin D1 and B1. Down-regulation of RPL15 expression inhibited SGC7901 cell growth in soft agar and its tumorigenicity in nude mice.. RPL15 promotes cell proliferation and may be a potential target for anticancer therapy of gastric cancer.

Topics: Agar; Animals; Blotting, Western; Cell Line, Tumor; Cell Proliferation; Cyclin B; Cyclin B1; Cyclin D1; Down-Regulation; Flow Cytometry; Gene Expression Regulation, Neoplastic; Humans; Immunohistochemistry; Mice; Mice, Inbred BALB C; Mice, Nude; Neoplasm Transplantation; Oligonucleotide Array Sequence Analysis; Plasmids; Ribosomal Proteins; RNA, Small Interfering; Stomach Neoplasms; Tetrazolium Salts; Thiazoles; Transfection; Up-Regulation

The "Rosetta Stone" hypothesis proposes that the existence of a fusion protein in some organisms predicts that the separate polypeptides function in the same biochemical pathway in other organisms and may physically interact. In Drosophila melanogaster and Caenorhabditis elegans, NitFhit protein is composed of two domains, a fragile histidine triad homolog and a bacterial and plant nitrilase homolog. We assessed the biological effects of mammalian Nit1 expression in comparison with Fhit and observed that: 1) Nit1 expression was observed in most normal tissues and overlapped partially with Fhit expression; 2) Nit1-deficient mouse kidney cells exhibited accelerated proliferation, resistance to DNA damage stress, and increased cyclin D1 expression; 3) cyclin D1 was up-regulated in Nit1 null mammary gland and skin; 4) Nit1 overexpression induced caspase-dependent apoptosis in vitro; and 5) Nit1 allele deficiency led to increased incidence of N-nitrosomethylbenzylamine-induced murine forestomach tumors. Thus, the biological effects of Nit1 expression are similar to Fhit effects. Adenoviruses carrying recombinant NIT1 and FHIT induced apoptosis in Fhit- and Nit1-deficient cells, respectively, suggesting that Nit1-Fhit interaction is not essential for function of either protein. The results suggest that Nit1 and Fhit share tumor suppressor signaling pathways, while localization of the NIT1 gene at a stable, rather than fragile, chromosome site explains the paucity of gene alterations and in frequent loss of expression of the NIT1 gene in human malignancies.

Topics: Acid Anhydride Hydrolases; Amino Acid Sequence; Aminohydrolases; Animals; Apoptosis; Catalytic Domain; Cyclin D1; DNA Damage; Humans; Mammary Glands, Animal; Mice; Mice, Inbred C57BL; Molecular Sequence Data; Neoplasm Proteins; Recombinant Fusion Proteins; Stomach Neoplasms; Tumor Suppressor Proteins

To explore the effect of transforming growth factor alpha (TGFalpha) on the expression of cyclin E and D1 in gastric carcinoma cells.. Human gastric adenocarcinoma SGC7901 cells were cultured routinely and synchronized at G(0)/G(1) phase in serum-free RPMI-1640. The percentage of the cells at G(0)/G(1) phase was detected by propidium iodide staining and flow cytometry (FCM), and the synchronized cells were cultured in RPMI-1640 supplemented with 2.5% calf serum and treated with 10, 30, and 50 microg/L TGFalpha for 5 h. The expression of cyclin E and D1 in SGC7901 cells was detected by immunofluorescent staining and FCM.. The percentage of the cells at G(0)/G(1) phase increased from 54% in routine culture to 72% in the serum-free RPMI-1640 culture. TGFalpha treatment of the cells synchronized at G(0)/G(1) phase induced significant increment of cyclin E and D1 expressions (P<0.001), and at the dose of TGFalpha of 50 microg/L, their expressions increased by 25.18% and 27.52%, respectively (P<0.001).. TGFalpha can increase the expression of cyclin E and D1 in gastric carcinoma cells to promote their cell cycle progress.

Topics: Adenocarcinoma; Cell Cycle; Cell Line, Tumor; Cyclin D1; Cyclin E; Flow Cytometry; Fluorescent Antibody Technique; Humans; Stomach Neoplasms; Transforming Growth Factor alpha

Antitumor effect of 9-cis retinoic acid (9-cis RA) on gastric carcinoma is unclear yet. This study was to explore the inducement effect of 9-cis RA on cell cycle arrest and apoptosis of gastric carcinoma cell line MGC803 and its mechanism.. The expression of RXRalpha, Cyclin D1, and CDK4 in MGC803 cells was detected by reverse transcription-polymerase chain reaction (RT-PCR). Cell cycle was detected by flow cytometry. The growth inhibition was analyzed by MTT assay. The apoptosis was detected by agarose gel electrophoresis and Hoechst33342/PI staining. The expression of apoptosis-associated gene Bcl-2 was detected by SP immunocytochemistry.. When treated with 0.1-10 micromol/L 9-cis RA for 96 h, the proliferation of MGC803 cells was significantly inhibited. The proportion of MGC803 cells at G1 phase was significantly increased when treated with 10 micromol/L 9-cis RA for 48, 72, and 96 h, and showed an apparent G1 phase arrest. When treated with 9-cis RA for 72 h, typical apoptotic changes, such as chromatin condensation and DNA ladder, were observed in MGC803 cells. The expression of Bcl-2 was significantly decreased in MGC803 cells when treated with 10 micromol/L 9-cis RA for 48 h. RXRalpha expression was at a low level in MGC803 cells and up-regulated when treated with 10 micromol/L 9-cis RA for 48 h (P<0.01). The expression of Cyclin D1 and CDK4 in MGC803 cells was both significantly down-regulated when treated with 10 micromol/L 9-cis RA for 96 h (P<0.01).. 9-Cis RA could induce G1 phase arrest and apoptosis in MGC803 cells through down-regulating the expression of cell cycle factors Cyclin D1 and CDK4.

Topics: Alitretinoin; Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Cyclin-Dependent Kinase 4; G1 Phase; Humans; Proto-Oncogene Proteins c-bcl-2; Retinoid X Receptor alpha; RNA, Messenger; Stomach Neoplasms; Tretinoin

Upregulated gene 4 (URG4), a novel gene located on 7 chromosome (7p13), was found to contribute to hepatocarcinogenesis. However, the role of URG4 in the gastric carcinogenesis still remains unclear. In the present study, URG4 was found by immunohistochemistry to be upregulated in human gastric cancer tissues compared with matched adjacent nonneoplastic tissues. The proliferating cell nuclear antigen index is higher in gastric cancer tissues with high URG4 expression than in those with low URG4 expression. The growth of GES-1 cells, which are immortalized human gastric epithelial mucosa cells with baseline URG4 expression, was accelerated by URG4 induction. Downregulation of URG4 through URG4 small interfering RNA (siRNA) in SGC7901 and MKN28 cells, which had high endogenous URG4 expression, suppressed cell proliferation in both of these cells. URG4-siRNA also inhibited the proliferation of SGC7901 and MKN28 cells in soft agar and tumor formation in nude mice. Overexpression of URG4 in GES cells upregulated cyclin D1, whereas repression of URG4 in SGC7901 and MKN28 cells downregulated cyclin D1. The data suggested that URG4 played an important role in the development of human gastric cancer by regulating the expression of cyclin D1 and might be used as a potential therapeutic target for gastric cancer.

Topics: Animals; Cell Line, Transformed; Cell Line, Tumor; Cell Survival; Cyclin D1; Female; Gene Expression Regulation, Neoplastic; Humans; Mice; Mice, Inbred BALB C; Mice, Nude; Neoplasm Proteins; Stomach Neoplasms

To study the effect of calcyclin binding protein (CacyBP) on the proliferation of gastric cancer cells.. CacyBP siRNA expression vector was constructed and transfected into the gastric cancer cells of the line SGC7901 (SGC/CacyBP-siRNA cells). Blank vector mU6 was transfected too as control group (SGC/mU6 cells). Western blotting and semi-quantitative RT-PCR were used to detect the protein expression and mRNA expression of CacyBP in the transfected cells. Immunofluorescence staining was used to detect the intensity of green fluorescence. The cell growth was determined by MTT method. Western blotting and semi-quantitative RT-PCR were used to detect the protein expression and mRNA expression of beta-catenin, cyclooxygenase-2 (COX-2), cyclin D1, rac1, and heat shock protein (HSP) 70. The protein level of beta-catenin in the nuclei of the transfected cells was detected. Twenty-fife nude mice were randomly divided into 5 groups to be inoculated with the SGC7901 cells stably transfected with CacyBP siRNA expression vector and the size of tumor was observed 1, 2, 3, 4, and 5 weeks after the inoculation respectively. The blank vector mU6 was inoculated as control group.. The mRNA expression and protein expression of endogenous CacyBP in the SGC/CacyBP-siRNA cells were both markedly lower than those of the SGC/mU6 cells. Immunofluorescence staining showed weaker green fluorescence in the SGC/CacyBP-siRNA cells than the SGC/mU6 cells. MTT method showed that the growth of the SGC/CacyBP-siRNA cells was significantly faster than that of the SGC/mU6 cells (P < 0.01). Western blotting showed remarkable up-regulation of the protein expression of beta-catenin, COX-2, cyclin D1, rac1, and HSP 70 in the SGC/CacyBP-siRNA cells; and semi-quantitative RT-PCR showed remarkable up-regulation of the mRNA expression of COX-2 and cyclin D1 in the SGC/CacyBP-siRNA cells, however, the mRNA expression of HPS70, rac1, and beta-catenin showed no significant differences between these 2 groups. The size of tumor of the mice inoculated with SGC/CacyBP-siRNA cells was significantly larger than that of the mice inoculate with SGC/mU6 cells (P < 0.01). The survival times of the nude mice inoculated with SGC/CacyBP-siRNA1 and SGC/CacyBP-siRNA1 cells respectively were 60 d +/- 8 d and 50 d +/- 4 d, both significantly shorter than that of the control group (75 d +/- 9 d, both P < 0.01).. The down-regulation of CacyBP can promote the proliferation of gastric cancer cells and aggravate their malignant behavior.

Topics: Animals; beta Catenin; Blotting, Western; Calcium-Binding Proteins; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Cyclooxygenase 2; Gene Expression Regulation, Neoplastic; Genetic Vectors; Humans; Mice; Mice, Nude; Random Allocation; Reverse Transcriptase Polymerase Chain Reaction; RNA, Small Interfering; Stomach Neoplasms; Transfection; Xenograft Model Antitumor Assays

beta-Catenin nuclear translocation is frequently observed in different types of malignancies, including gastric cancer. In gastric cancer, however, the molecular mechanisms leading to accumulation of this protein in the nucleus remain unknown. In this setting, beta-catenin (CTNNB1) mutations have been reported, but studies of mutation frequency have yielded conflicting results. Mutations or silencing of other partners of beta-catenin (i.e., APC and AXIN) are also considered rare genetic events in gastric tumorigenesis. Gene amplification is a common mechanism of activation and/or overexpression of oncogenes in gastric and other cancers. In this study, we investigated whether gene amplification is a possible mechanism of beta-catenin activation in gastric cancer by determining its presence in 49 patients with gastric cancer and two gastric-derived cell lines (KATO III and ST2957). Using fluorescence in situ hybridization, we identified beta-catenin amplification in one of the tumor samples as well as in KATO III cells. beta-Catenin immunostaining revealed nuclear translocation of the protein in both cases. In the KATO III cells, beta-catenin overexpression was confirmed by quantitative real-time PCR and Western blot analyses and beta-catenin gene amplification by Southern blot analysis and multiplex ligation probe amplification. In the KATO III cell line, no correlation was found between beta-catenin nuclear translocation and increased expression of the WNT1 target gene CCND1 (cyclin D1). Our data suggest that gene amplification is a possible mechanism of beta-catenin overexpression in cancer.

Topics: beta Catenin; Blotting, Southern; Blotting, Western; Cell Nucleus; Cyclin D1; Cytoskeletal Proteins; DNA Mutational Analysis; Exons; Gene Amplification; Gene Deletion; Gene Expression Regulation, Neoplastic; Humans; In Situ Hybridization, Fluorescence; Intestinal Neoplasms; Mutation; Protein Transport; Reverse Transcriptase Polymerase Chain Reaction; Stomach Neoplasms; Trans-Activators; Tumor Cells, Cultured; Up-Regulation

To study the blocking effects of genistein on cell proliferation cycle in human gastric carcinoma cells (SGC-7901) and the possible mechanism.. MTT assay was applied in the detection of the inhibitory effects of genistein on cell proliferation. Flow cytometry was used to analyze the cell cycle distribution. Immunocytochemical technique and Western blotting were performed to detect the protein expression of cyclin D1, cyclin B1 and p21(waf1/cip1).. Genistein significantly inhibited the growth and proliferation of human gastric carcinoma cells (SGC-7901). Seven days after treatment with different concentrations of genistein (2.5, 5.0, 10.0, 20.0 microg/mL), the growth inhibitory rates were 11.2%, 28.8%, 55.3%, 84.7% respectively and cell cycles were arrested at the G(2)/ M phase. Genistein decreased cyclin D1 protein expression and enhanced cyclin B1 and p21(waf/cip1) protein expression in a concentration-dependent manner.. The growth and proliferation of SGC-7901 cells can be inhibited by genistein via blocking the cell cycle, with reduced expression of cyclin D1 and enhanced expression of cyclin B1 and p21(waf/cip1) protein in the concentration range of 0-20 microg/mL.

Topics: Antineoplastic Agents; Blotting, Western; Cell Cycle Proteins; Cell Division; Cell Line, Tumor; Cyclin B; Cyclin B1; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p21; Flow Cytometry; Genistein; Humans; Stomach Neoplasms

Abnormality of cell cycle regulation is an important cause of cell over-proliferation and oncogenesis. But the relationship between cell cycle regulators and gastric carcinoma is uncertain. This study was to investigate the expression and significance of cell cycle regulators, including P16(INK4), Cyclin D1, P21(WAF1), and P53, in gastric carcinoma.. The expressions of P16(INK4), Cyclin D1, P21(WAF1), and P53 in 53 specimens of gastric carcinoma were observed by SP immunohistochemistry. Multivariate Cox regression was used to analyze factors affecting prognosis.. Positive rate of P53 in gastric carcinoma was higher than that in adjacent tissues (60.4% vs. 0, P < 0.01); those in well, and poorly differentiated adenocarcinoma were significantly higher than that in mucoid carcinoma (65.4%, and 68.2% vs. 0, P < 0.01). Over-expression rate of Cyclin D1 in gastric carcinoma was higher than that in adjacent tissues (69.8% vs. 5.7%, P < 0.01). Positive rate of P16(INK4) in gastric carcinoma was lower than that in adjacent tissues (60.3% vs. 88.6%, P < 0.05). Positive rate of P21(WAF1) in gastric carcinoma was lower than that in adjacent tissues (26.4% vs. 56.6%, P < 0.01). Positive rate of P16(INK4) was significantly related with the depth of tumor invasion (P < 0.05), and lymph node metastasis (P < 0.01). Multivariate Cox regression analysis indicated that lymph node metastasis and the expression of P16(INK4) were independent prognostic factors of gastric carcinoma.. Down-regulation of P16(INK4) and P21(WAF1), and over-expression of Cyclin D1 and P53 are significantly related to genesis and progression of gastric carcinoma. Down-regulation of P16(INK4) may be correlated to infiltration, metastasis, and prognosis of gastric carcinoma.

Topics: Adenocarcinoma; Adenocarcinoma, Mucinous; Adult; Aged; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p16; Cyclin-Dependent Kinase Inhibitor p21; Female; Follow-Up Studies; Gastric Mucosa; Humans; Lymphatic Metastasis; Male; Middle Aged; Neoplasm Invasiveness; Neoplasm Staging; Prognosis; Proportional Hazards Models; Stomach Neoplasms; Tumor Suppressor Protein p53

The Ras-association domain family 1A (RASSF1A) tumour suppressor gene is inactivated in a variety of solid tumours, usually by epigenetic silencing of the promoter and/or allelic loss of its locus at 3p21.3. RASSF1A induces cell cycle arrest through inhibition of cyclin D1 accumulation. In this work, 62 endocrine tumours from different sites in the gut were investigated for methylation of the RASSF1A promoter using the polymerase chain reaction, the presence of 3p21.3 deletions by loss of heterozygosity analysis, and cyclin D1 expression by immunohistochemistry. Methylation was found in 20/62 (32%) cases and was restricted to foregut tumours; deletion at 3p21.3 was found in 15/58 (26%) informative cases and restricted to malignant foregut tumours; cyclin D1 hyper-expression was found in 31/58 (53%) cases and correlated with RASSF1A methylation. Our data suggest that RASSF1A is involved in the development of endocrine tumours derived from the foregut only, and that the presence of both RASSF1A methylation and 3p21.3 deletion is associated with malignancy. These results may provide a rationale for foregut-targeted therapy for aggressive endocrine carcinomas entailing the use of demethylating agents.

Topics: Adult; Aged; Aged, 80 and over; Appendiceal Neoplasms; Carcinoma, Neuroendocrine; Cyclin D1; Duodenal Neoplasms; Female; Gastrointestinal Neoplasms; Gene Expression Regulation, Neoplastic; Humans; Ileal Neoplasms; Intestinal Neoplasms; Loss of Heterozygosity; Male; Methylation; Middle Aged; Pancreatic Neoplasms; Promoter Regions, Genetic; Rectal Neoplasms; Stomach Neoplasms; Tumor Suppressor Proteins

Identification of precise prognostic marker and effective therapeutic target is pivotal in the treatment of gastric cancer. In the present study, we determined the level of RUNX3 expression in gastric cancer cells and gastric cancer specimens and the impact of its alteration on cancer biology and clinical outcome. There was a loss or substantial decrease of RUNX3 protein expression in 86 cases of gastric tumors as compared with that in normal gastric mucosa (P < 0.0001), which was significantly associated with inferior survival duration (P = 0.0005). In a Cox proportional hazards model, RUNX3 expression independently predicted better survival (P = 0.036). Moreover, various human gastric cancer cell lines also exhibited loss or drastic decrease of RUNX3 expression. Enforced restoration of RUNX3 expression led to down-regulation of cyclin D1 but to up-regulation of p27, caspase 3, 7, and 8 expression, cell cycle arrest, and apoptosis in vitro, and dramatic attenuation of tumor growth and abrogation of metastasis in animal models. Therefore, we offered both clinical and mechanistic evidence that RUNX3 was an independent prognostic factor and a potential therapeutic target for gastric cancer.

Topics: Apoptosis; Caspases; Cell Cycle; Cell Growth Processes; Core Binding Factor Alpha 3 Subunit; Cyclin D1; DNA-Binding Proteins; Down-Regulation; Female; Humans; Isoenzymes; Male; Middle Aged; Neoplasm Metastasis; Prognosis; Stomach Neoplasms; Transcription Factors

We investigated the prevalence of single nucleotide polymorphisms in the p16 gene (C540G) and the cyclin D1 gene (G870A), both known to regulate function in G1 arrest and therefore, may play an important role in carcinogenesis.. Using PCR based restriction fragment length polymorphism and single strand conformational polymorphism, we determined single nucleotide exchanges in the p16 and cyclin D1 genes among 56 esophageal adenocarcinomas (ADC) arising in Barrett's esophagus, 95 cardiac gastric ADC, and in 191 distal gastric ADC. The allelic frequencies were compared to a control group of 253 healthy blood donors.. The C/G genotype of p16 was identified in 10.4% of esophageal carcinomas, 13.3% of cardiac carcinomas, and in 14.1% of gastric carcinomas, compared to 17.4% in the healthy control group. All other cases showed the C/C wildtype, as no homozygous G/G nucleotide exchange was detected in the group of cancer patients or in the control group. In esophageal cancer, cyclin D1 G/G genotype was found 28.6%, A/G in 46.4%, and A/A in 25.0%. In cardiac carcinoma, frequency of cyclin D1 genotype was 27.4% for G/G, 57.9% for A/G, and 14.7% for AA. In distal gastric carcinoma, both homozygous genotypes (G/G and A/A) had a frequency of 15.2% each, while the heterozygous A/G genotype occurred in 69.6% of patients. The control group displayed 24.9% G/G, 53.8% A/G, and 21.3% A/A genotype.. Our results show that frequencies of p16 or cyclin D1 polymorphisms in gastric and esophageal ADC do not differ significantly from the healthy control group. Therefore, these polymorphisms are unlikely to be associated with risk of ADC of the upper gastrointestinal tract.

Topics: Adenocarcinoma; Adult; Aged; Aged, 80 and over; Alanine; Barrett Esophagus; Cardia; Case-Control Studies; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p16; Cysteine; DNA, Neoplasm; Esophageal Neoplasms; Female; Gene Frequency; Glycine; Homozygote; Humans; Male; Middle Aged; Polymerase Chain Reaction; Polymorphism, Genetic; Polymorphism, Restriction Fragment Length; Polymorphism, Single Nucleotide; Polymorphism, Single-Stranded Conformational; Stomach Neoplasms

The mechanism by which Epstein-Barr virus (EBV) contributes to the carcinogenesis of gastric mucosa remains unanswered. In this study, the role of cell-cycle regulators (p53, p21, p27, p16, cyclin D1, Rb), bcl-2 and NF-kappaB p65 (Rel A) was evaluated. Immunohistochemistry for these proteins was performed in EBV-positive (n=55) and EBV-negative gastric carcinomas (n=72). The bcl-2 protein by western blot and EBV transcripts using RT-PCR were studied in cell lines. The p27 loss, p16 loss, cyclin D1 expression and NF-kappaB nuclear positivity were more frequent in EBV-positive gastric carcinomas than those in EBV-negative gastric carcinomas, while p53 overexpression seldom occurred in EBV-positive carcinomas (p<0.001). EBV-positive gastric carcinoma showed unique p53 immunostaining (heterogeneous, weak to moderate, focal staining), and rare bcl-2 positivity (1 case). Western blot showed bcl-2 to be irrespective of EBV status in stomach cancer cell lines. However, bcl-2 was highly expressed in EBV-positive lymphoma or EBV-positive lymphoblastoid cell lines. The BARF1 transcript was confirmed in both EBV-positive stomach cancer and EBV-positive lymphoma, suggesting tissue type-specific bcl-2 activation by BARF1. The pathological tumor stage was the only independent prognostic factor. A small size of tumor, p16 preservation and NF-kappaB nuclear positivity were associated with a good prognosis in univariate analysis (p<0.05). p27, p16, cyclin D1 and NF-kappaB may be associated with oncogenesis in EBV-positive gastric carcinomas. EBV-positive gastric carcinomas showed infrequent p53 overexpression, wild-type p53 stabilization and rare bcl-2 involvement. The characteristic expression of proteins may relate to both EBV and tissue type.

Topics: Adolescent; Adult; Aged; Blotting, Western; Carcinoma; Cell Cycle; Cell Transformation, Neoplastic; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p16; Epstein-Barr Virus Infections; Female; Gene Expression Profiling; Herpesvirus 4, Human; Humans; Immunohistochemistry; Male; Middle Aged; Neoplasm Staging; NF-kappa B; Prognosis; Proto-Oncogene Proteins c-bcl-2; Reverse Transcriptase Polymerase Chain Reaction; Stomach Neoplasms; Tumor Cells, Cultured; Tumor Suppressor Protein p53; Up-Regulation

Changes in proliferation and apoptosis parameters of the gastric epithelium in patients with chronic Hp-associated gastritis were studied depending on the prevalence of the inflammatory process, presence of intestinal metaplasia and atrophic changes of the stomach glandular epithelium. The obtained results demonstrated a change in the cellular updating processes of the stomach epithelium depending on the localization, prevalence of the process, and more expressed - during the development of atrophic and dystrophic changes of the stomach mucous coat. Moderate amplification of apoptosis was recorded in focal atrophic gastritis, which was shown in the increased Iapopt and reduction of IPCNA and IcyclineD1 parameters. From then on, along with the distribution of the process, proliferation enhancement, occurrences of intestinal metaplasia and neoplasia centers, oppression of apoptosis destructions of stomach epitheliocytes was marked.

Topics: Adult; Aged; Apoptosis; Cell Proliferation; Cyclin D1; Female; Gastric Mucosa; Gastritis; Helicobacter; Humans; Male; Middle Aged; Precancerous Conditions; Proliferating Cell Nuclear Antigen; Stomach Neoplasms

Cyclins condition the course of a cell cycle through the activation of appropriate serine-threonine kinases. Any variation in the cyclins' expression result in pathologies of the cell division, including neoplastic proliferation. Activity of the complexes of cyclins D1 and E with appropriate cyclin-dependent kinases may be inhibited by protein P21 (WAF1/CIP1) which functions as a cell growth cycle inhibitor. As yet, there have been rather few reports on the prognostic value of this cyclin expression assessment in gastric cancer, the kind of neoplasm still characterized by very poor prognosis. The study aimed at the assessment of expression levels of cyclins D1 and E in surgically removed gastric cancers, including the analysis of this prognostic value parameter, and attempted to determine some correlations between the expression of the examined cyclins and selected histoclinical and molecular parameters such as: patients' age and gender, histological type according to the Lauren classification, cancer stage (TNM), degree of histological malignancy (G) and level of expression of the cell-cycle regulatory genes protein products--P53, P21, P27. Immunohistochemical analysis was performed on specimens obtained from radical stomach resections of 80 patients treated in the period 1992-1997 for gastric cancer stage I-IIIB (TNM-UICC) at the Department of Surgical Oncology, Medical University of Lodz. For immunohistochemical examinations, the LSAB system was used, designed for assessment of antigen expression. In statistical analysis, Fisher's exact test was applied to evaluate correlations between the analyzed variables and Mantel-Haenschel's test to evaluate their collinearity. For the evaluation of the effect of the analyzed variables on postoperation survival and recurrence-free survival the Cox regression model was used. When analyzing the prognostic value and survival period in association to the cyclins D1 and E expression levels, a statistically significant correlation was found only in relation to cyclin E expression: a survival period of minimum 5 year duration was significantly higher in the group displaying a negative, or only faintly positive, reaction to the presence of cyclin E, than in the group with a strongly positive response. Moreover, the analysis showed statistically significant non-linear dependence between the histological type of cancer in the Lauren classification as well as a degree of histological malignancy and the level of cyclin E exp

Topics: Cell Cycle; Cyclin D1; Cyclin E; Genes, Regulator; Humans; Immunohistochemistry; Prognosis; Stomach Neoplasms

This study was undertaken to determine whether selected risk factors for esophageal and gastric cancer are associated with tumors that overexpress cyclin D1. Archived tumor tissue was available for 630 esophageal and gastric cancer patients who participated in a population-based case-control study. Patients were categorized into case groups based on whether protein overexpression of the cyclin D1 gene, as assessed by immunohistochemistry, was present (cyclin D1+, n = 285) or not (cyclin D1-, n = 345) in the tumor. The distribution of risk factors in each of these case groups was then compared with the distribution among the 695 controls. Multivariate-adjusted odds ratios (OR) for esophageal adenocarcinoma were reduced in relation to use of aspirin and other nonsteroidal anti-inflammatory drug (NSAID) use but only among patients with cyclin D1+ tumors (0.45, 95% confidence interval [CI] = 0.26, 0.79) and not among those with cyclin D1- tumors (1.12, 95% CI = 0.67, 1.86). A similar pattern was observed for gastric cardia adenocarcinomas. In contrast, ORs for esophageal squamous cell carcinoma and noncardia gastric adenocarcinomas in relation to NSAID use were reduced, regardless of cyclin D1 status. ORs did not vary with cyclin D1 status in relation to alcohol, body size, or cigarette smoking, with the following exception; for noncardia gastric adenocarcinomas the cyclin D1- tumors showed a 2-fold elevation in the OR with ever smoking. These data suggest that the reduction in risk associated with NSAID use may be restricted to those esophageal and gastric cardia adenocarcinomas that overexpress cyclin D1.

Topics: Adenocarcinoma; Aged; Anti-Inflammatory Agents, Non-Steroidal; Confidence Intervals; Cyclin D1; Esophageal Neoplasms; Female; Humans; Life Style; Male; Middle Aged; Population Surveillance; Prevalence; Risk Factors; Stomach Neoplasms; Surveys and Questionnaires; United States

To examine the expression of nuclear factor kappaB (NF-kappaB) and its target genes in intestinal metaplasia (IM), dysplasia (DYS) and gastric carcinoma (GC) infected with Helicobacter pylori (H pylori) and to investigate the mechanism underlying H pylori cytotoxin associated gene A (cag A) infection leading to gastric adenocarcinoma.. Expressions of NF-kappaB/p65 and its target genes: c-myc, cyclinD1 and bcl-xl were immunohistochemically examined in 289 cases of gastric biopsy and resection specimens from patients with IM, DYS and GC infected with H pylori. H pylori in the above mentioned tissues was detected by Warthin-Starry stain and rapid urease tests. IgG antibody to cagA in sera of the patients was measured by ELISA.. The positive rates of NF-kappaB/p65 were significantly higher in groups with cagA of IMI-II(28/33), IM III(48/52), DYSI(27/31), DYS II-III(28/32), GC(35/40) than in groups without cagA of IMI-II(4/17), IMIII(3/20), DYSI(3/20), DYSII-III(6/21), GC(10/23). The expressions of c-myc, cyclinD1, and bcl-xl were significantly higher in groups with cagA of IM III(47/52, 49/52, 46/52), DYSII-III(29/32, 26/32, 25/32) than in groups without cagA of IM III(8/20, 7/20, 5/20), DYSII-III(10/21, 8/21, 3/21), which were in conformity with the expression of NF-kappaB in IM III, and DYSII-III. A significantly higher expression level of NF-kappaB/p65, c-myc, cyclinD1 and bcl-xl was detected in intestinal type GC(27/28, 18/28, 22/28, 24/28) than in diffuse type GC(8/12, 3/12, 3/12, 6/12), respectively.. There may be two different molecular mechanisms in the occurrence of intestinal and diffuse type gastric carcinomas. Intestinal type gastric carcinoma is strongly associated with high expression of c-myc, cyclinD1 and bcl-xl through NF-kappaB/p65 activated by H pylori cagA. Inhibiting the activity of NF-kappaB is an effective and promising way to prevent intestinal type gastric carcinoma.

Topics: Adenocarcinoma; Adult; Aged; Antigens, Bacterial; Bacterial Proteins; bcl-X Protein; Cyclin D1; Enzyme-Linked Immunosorbent Assay; Female; Helicobacter Infections; Helicobacter pylori; Humans; Immunohistochemistry; Male; Middle Aged; NF-kappa B; Precancerous Conditions; Proto-Oncogene Proteins c-bcl-2; Proto-Oncogene Proteins c-myc; Stomach Neoplasms; Transcription Factor RelA

Syndromic and sporadic fundic gland polyps are morphologically indistinguishable but may arise via different pathogenetic mechanisms involving mutations of the adenomatous polyposis coli (APC) and its downstream target beta-catenin genes. Although a higher frequency of dysplasia has been reported in syndromic forms, the risk of developing invasive carcinoma is exceedingly low. The current study was designed to investigate whether syndromic and sporadic fundic gland polyps differ in protein expression of a number of genes that are thought to be important in the control of neoplastic transformation. A total of 262 fundic gland polyps, including 155 syndromic polyps obtained from 35 patients with familial adenomatous polyposis or Gardner's syndrome and 107 sporadic polyps randomly selected from 45 patients with gastroesophageal reflux disease or Barrett's esophagus, were included in this study. Immunohistochemical evaluation showed that loss of immunoreactivity to the antibody against the carboxyl terminus of the APC protein, presumably resulting from APC gene mutations, was more frequent in syndromic than in sporadic cases (40% versus 6.7%, P<0.001). However, immunostaining failed to show aberrant nuclear localization of beta-catenin, a protein regulated by APC, in any of the polyps, irrespective of syndromic or sporadic types. Instead, positive membranous staining for beta-catenin was observed in all the cases. In addition, the expression characteristics of 2 other proteins, c-Myc and cyclin D1, whose genes have been reported to be transcriptionally regulated by the APC/beta-catenin pathway, were similar in these two types of polyps. Furthermore, all cases, including those harboring dysplasia, showed negative nuclear staining for p53 and positive nuclear staining for retinoblastoma (RB). Taken together, these data show a lack of dysregulation in the APC/beta-catenin signaling pathway and in the expression of p53 and RB in fundic gland polyps despite a high frequency of somatic mutations of the APC and beta-catenin genes reported in these polyps. These findings may explain at least in part why fundic gland polyps show a negligible malignant potential even in the presence of dysplasia.

Topics: Adenomatous Polyposis Coli Protein; Adolescent; Adult; Aged; beta Catenin; Biomarkers, Tumor; Cell Nucleus; Cyclin D1; Cytoskeletal Proteins; Female; Gastric Fundus; Humans; Immunoenzyme Techniques; Male; Middle Aged; Neoplasm Proteins; Polyps; Proto-Oncogene Proteins c-myc; Retinoblastoma Protein; Stomach Neoplasms; Syndrome; Trans-Activators; Tumor Suppressor Protein p53

Gastrin and its precursors promote proliferation in different gastrointestinal cells. Since mature, amidated gastrin (G-17) can induce cyclin D1, we determined whether G-17-mediated induction of cyclin D1 transcription involved Wnt signaling and CRE-binding protein (CREB) pathways. Our studies indicate that G-17 induces protein, mRNA expression and transcription of the G(1)-specific marker cyclin D1, in the gastric adenocarcinoma cell line AGSE (expressing the gastrin/cholecystokinin B receptor). This was associated with an increase in steady-state levels of total and nonphospho beta-catenin and its nuclear translocation, indicating the activation of the Wnt-signaling pathway. In addition, G-17-mediated increase in cyclin D1 transcription was significantly attenuated by axin or dominant-negative (dn) T-cell factor 4(TCF4), suggesting crosstalk of G-17 with the Wnt-signaling pathway. Mutational analysis indicated that this effect was mediated through the cyclic AMP response element (CRE) (predominantly) and the TCF sites in the cyclin D1 promoter, which was also inhibited by dnCREB. Furthermore, G-17 stimulation resulted in increased CRE-responsive reporter activity and CREB phosphorylation, indicating an activation of CREB. Chromatin immunoprecipitation studies revealed a G-17-mediated increase in the interaction of beta-catenin with cyclin D1 CRE, which was attenuated by dnTCF4 and dnCREB. These results indicate that G-17 induces cyclin D1 transcription, via the activation of beta-catenin and CREB pathways.

Topics: beta Catenin; Cyclic AMP Response Element-Binding Protein; Cyclin D1; Cytoskeletal Proteins; G1 Phase; Gastrins; Humans; Proto-Oncogene Proteins; S Phase; Signal Transduction; Stomach Neoplasms; Trans-Activators; Transcription, Genetic; Wnt Proteins; Zebrafish Proteins

DNA (cytosine-5-)-methyltransferase 1 (DNMT1) plays an important role in the maintenance of DNA methylation patterns via complicated networks including signaling pathways and transcriptional factors, relating to cell differentiation or carcinogenesis. In the present study, we designed an antisense oligodeoxynucleotide of DNMT1 (AS/MT: 5'-CGGTAC GCGCCGGCATCT-3') and demonstrated successful inhibition of DNMT1 expression by AS/MT at the protein level, using gastric cancer cell lines in vitro. E-cadherin protein expression was increased, and both cyclin D1 and PCNA were decreased by AS/MT treatment. AS/MT also induced suppression of cell growth as determined by BrDU uptake incorporation, in a dose-dependent manner, suggesting specificity of AS/MT. Simultaneously, morphological alterations were observed in both TMK-1 and MKN-45 cells after 24 h incubation with 2 micro M of AS/MT. The cells changed shape from their original forms to dispersed, fibroblast-like cells with neurite-like processes, accompanied by an increased adhesive potential of the cells. An in vivo model of peritoneal dissemination using the nude mouse system showed an increased malignant potential of AS/MT treated TMK-1 cells as demonstrated by a greater number of peritoneal tumor nodules in the AS/MT as compared to the NS/MT treated group, 34.8+/-4.3 vs. 22.4+/-3.0 nodules, respectively (p=0.0039). The total wet tumor weight in the AS/MT group (350+/-47.4 g) was significantly greater than that in the NS/MT group (248+/-41.5 g) (p=0.0065). In conclusion, the inhibition of DNA methylation by DNMT1 by an antisense oligodeoxynucleotide influences cell morphology and adhesion, as well as cell growth in gastric cancer cells in vitro. Moreover, these alterations in the characteristics of cancer cells resulted in an increased ability to attach onto the peritoneum in the nude mouse system in vivo, suggesting that strict clinical guidelines will be necessary to utilize such a DNA methylation inhibitor, since it does not always mean a therapeutic antitumor strategy.

Topics: Adenocarcinoma; Animals; Base Sequence; Blotting, Western; Bromodeoxyuridine; Cadherins; Cell Adhesion; Cell Division; Cell Line, Tumor; Cyclin D1; DNA (Cytosine-5-)-Methyltransferase 1; DNA (Cytosine-5-)-Methyltransferases; DNA Methylation; Dose-Response Relationship, Drug; Fibroblasts; Humans; Immunohistochemistry; Mice; Mice, Nude; Molecular Sequence Data; Neoplasm Invasiveness; Oligonucleotides, Antisense; Proliferating Cell Nuclear Antigen; Signal Transduction; Stomach Neoplasms; Time Factors

To detect the genetic alteration and abnormal expression of cyclin D1 in gastric carcinoma and investigate its clinicopathologic significance in advanced gastric carcinoma.. Proteins of cyclin D1 were detected by immunohistochemistry in 42 cases of advanced gastric carcinoma with their follow-up data available, 27 cases of early stage carcinoma, 21 cases of gastric adenoma, 22 cases of hyperplastic polyp and 20 cases of normal mucosa adjacent to adenocarcinomas. Genetic alteration of cyclin D1 was detected by Southern blot and expression of cyclin D1 mRNA was detected by PT-PCR in 42 cases of advanced gastric carcinoma.. Cyclin D1 protein was not expressed in normal mucosa, hyperplastic polyp and gastric adenoma, while it was only positively expressed in gastric carcinoma. The expression rate of cyclin D1 protein in early stage gastric carcinoma, advanced gastric carcinoma and lymph node metastasis was 48.1%, 47.4% and 50.0%, respectively. The amplification of cyclin D1 gene was detected in 16.6% of advanced gastric carcinomas. The overexpression of cyclin D1 mRNA was detected in 40.5% of the samples. There was no significant correlation between cyclin D1 protein expression and age, lymph-node metastasis and histological grading in patients with advanced gastric carcinoma (chi2 = 0.038, 0.059, 0.241, P>0.05). Significant correlation was observed between the expression of cyclin D1 protein and the 5-year survival rate (chi2 = 3.92, P<0.05).. Detection of cyclin D1 protein by immunohistochemistry may be useful in the diagnosis of early gastric carcinomas. Patients with positive expression of cyclin D1 protein tend to have a worse prognosis.

Topics: Adenocarcinoma; Cyclin D1; Humans; Immunohistochemistry; Lymphatic Metastasis; Prognosis; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Stomach Neoplasms

SIAH-1: is the mammalian homolog of Drosophila seven in absentia (sina) and has been identified as a p53-inducible gene. Siah-1 can induce cell cycle arrests, tumor suppression, and apoptosis through a novel beta-catenin degradation pathway. To determine whether genetic alterations of Siah-1 gene are involved in the development and/or progression of gastric cancer, we searched for mutation of the Siah-1 gene in 95 gastric cancers by single-strand conformational polymorphism and sequencing. The effect of Siah-1 on beta-catenin degradation was further examined in wild- and mutant-type Siah-1-transfected HEK 293T cells. We found two missense mutations of the Siah-1 gene. The cases with Siah-1 mutation showed nuclear translocation and cytoplasmic staining of beta-catenin. Interestingly, two mutants of Siah-1 stabilized cytoplasmic levels of beta-catenin, even after treatment of adriamycin. Furthermore, both mutants failed to suppress cyclin D1 expression and to induce apoptosis. These data suggest that inactivating mutations of the Siah-1 may contribute to the development of gastric cancer through beta-catenin stabilization and apoptosis block.

Topics: Apoptosis; beta Catenin; Cell Line, Tumor; Cyclin D1; Cytoskeletal Proteins; Gene Expression Regulation; Humans; Immunohistochemistry; Mutation; Nuclear Proteins; Protein Transport; Stomach Neoplasms; Trans-Activators; Tumor Suppressor Protein p53; Ubiquitin-Protein Ligases

To study the expression of NFkappaB p65 and its target genes in intestinal metaplasia (IM), dysplasia (Dys), gastric cancer (GC) infected with Helicobacter pylori (Hp) and explore the mechanism of infection by cytotoxin-associated antigen A expressing Hp (CagA(+)Hp) in the development of gastric cancer.. CagA antibody in blood sample of 289 patients was determined by ELISA. Hp was detected by rapid urease test and Warthin starry staining. Expression of NFkappaB p65 and its target genes in IM, Dys and GC was examined by immunohistochemistry.. In IMI approximately II, IMIII, DysI, DysII approximately III and GC, the expression of NFkappaB p65 was significantly higher in patients with CagA(+)Hp infection than those without CagA Hp infection. In IMIII and DysII approximately III, the expression of NFkappaB p65, c-myc, CyclinD(1) and bcl-xl was significantly higher in patients with CagA Hp infection than those without CagA Hp infection. In gastric cancer infected with CagA(+)Hp, the expression of NFkappaB p65, c-myc, CyclinD(1) and bcl-xl was significantly higher in intestinal type than in diffuse type.. There are different mechanisms in intestinal type and diffuse type in the development of gastric cancer. The occurrence of intestinal type gastric cancer is associated with CagA(+)Hp infection which by NFkappaB p65 upregulating the expression of c-myc, CyclinD(1),bcl-xl in patients with IMIII, DysII approximately III. It may be an effective method to prevent gastric cancer by inhibiting NFkappaB p65.

Topics: Adult; Aged; Antigens, Bacterial; Bacterial Proteins; bcl-X Protein; Cyclin D1; Female; Helicobacter Infections; Helicobacter pylori; Humans; Male; Middle Aged; Precancerous Conditions; Proto-Oncogene Proteins c-myc; Stomach Neoplasms; Transcription Factor RelA

Enterochromaffin-like (ECL) cell hyperplasia and then irreversible neoplasia can be generated in the African rodent Mastomys natalensis using the H2 receptor blocker, loxtidine, for 8-16 wk. We used a GeneChip approach complemented by standard technologies to identify gene expression alterations in the gastric mucosa during gastrin-mediated ECL cell transformation. Gastric mucosa (mucosal scrapping) and ECL cell-enriched fractions were obtained from untreated Mastomys (controls) and from animals treated with loxtidine for 8 wk (hyperplasia). Tumor ECL cells were obtained by hand-dissection of gastric ECL cell nodules from animals treated with loxtidine for >16 wk and from a spontaneously developed ECL cell tumor. RNA was isolated, examined on rat U34A GeneChips, and comparison analysis was performed to identify altered gene expression. Alterations in gene expressions were examined further by immunohistochemistry, quantitative RT-PCR (Q-RT-PCR), sequencing and Western blot. GeneSpring analysis demonstrated alterations in few genes (<20) in hyperplastic and tumor mucosa. The histamine H1 receptor was consistently increased in proliferating mucosa. This gene change was confirmed by Q-RT-PCR. Other genes showing alterations included neural-(chromogranin A and somatostatin), cell-cycle-, and AP-1-associated genes. Immunostaining confirmed alterations in neural markers. Cluster analysis of ECL cell-enriched samples demonstrated that c-fos and junD were differently regulated. Q-RT-PCR and Western blot in prospectively collected gastric mucosal samples confirmed the differential expression of Fos and Jun. The negative regulators of AP-1, JunD, and Menin were decreased in tumor mucosa. A missense of unknown function was noted in the menin gene. Hypergastrinemia in an animal model of gastric carcinoids differentially altered the histamine type 1 receptor and gene expression and protein composition of AP-1. These results suggest that expression of this receptor and an altered composition of AP-1 with a loss of inhibition play a role in ECL cell transformation.

Topics: Amino Acid Sequence; Animals; Blotting, Western; Cell Transformation, Neoplastic; Chromogranin A; Chromogranins; Cluster Analysis; Cyclin D1; DNA Primers; Enterochromaffin Cells; Gastric Mucosa; Histamine; Immunohistochemistry; Models, Biological; Molecular Sequence Data; Murinae; Mutation; Oligonucleotide Array Sequence Analysis; Rats; Receptors, Histamine H1; Reverse Transcriptase Polymerase Chain Reaction; RNA; Sequence Homology, Amino Acid; Software; Somatostatin; Stomach Neoplasms; Time Factors; Transcription Factor AP-1

Gastrin is a gastrointestinal (GI) peptide that possesses potent trophic effects on most of the normal and neoplastic mucosa of the GI tract. Despite abundant evidence for these properties, the mechanisms governing gastrin-induced proliferation are still largely unknown. To elucidate the mechanisms by which gastrin might influence mitogenesis in gastric adenocarcinoma, we analyzed its effects on the human cell line AGS-B. Amidated gastrin (G-17), one of the major circulating forms of gastrin, induced a concentration-dependent increase in [3H]thymidine incorporation of cells in culture, with the maximum effective concentration occurring with 20 nM G-17. This effect was significantly attenuated by the gastrin-specific receptor antagonist L-365260. In addition, we found that G-17 induced a significant increase in the levels of cyclin D1 transcripts, protein, and promoter activity. The results of these studies indicate that gastrin appears to exert its mitogenic effects on gastric adenocarcinoma, at least in part, through changes in cyclin D1 expression.

Topics: Adenocarcinoma; beta Catenin; Cell Division; Cyclin D1; Cytoskeletal Proteins; Dose-Response Relationship, Drug; Gastrins; Gene Expression Regulation, Neoplastic; Hormones; Humans; Promoter Regions, Genetic; RNA, Messenger; Stomach Neoplasms; Trans-Activators; Tumor Cells, Cultured

Our aim was to investigate the association of cyclin D1 (G870A) single nucleotide polymorphism with susceptibility to esophageal and cardiac carcinoma in a northern Chinese population. By polymerase chain reaction-single strand conformation polymorphism analysis, cyclin D1 (G870A) genotyping was carried out among 120 patients with esophageal squamous cell carcinoma (ESCC), 87 patients with gastric cardiac adenocarcinoma (CAC), and 183 age- and gender-matched controls. The cyclin D1 genotype distribution among ESCC patients was significantly different from that among healthy controls (chi(2) = 7.372, p = 0.025). The G/G genotype was significantly less frequent among ESCC patients (9.2%) than among healthy controls (20.8%) (chi(2) = 7.192, p = 0.007). The G/G genotype significantly reduced risk for the development of ESCC compared to the combination of G/A and A/A genotypes (adjusted odds ratio [OR] = 0.37, 95% confidence interval [CI] = 0.16-0.83). After stratification according to smoking status, the A/A frequency among smoking ESCC (34.3%) and CAC patients (35.7%) was significantly higher than that among smoking healthy controls (18.6%) (chi(2) = 5.426 and 5.599, p = 0.020 and 0.018, respectively). Smokers with the A/A genotype had an about 2-fold increased risk for both of ESCC and CAC compared to the G/A and G/G genotypes, with an adjusted OR of 2.26 in ESCC (95% CI = 1.14-4.49) and of 2.42 in CAC (95% CI = 1.17-4.98). No correlation between the cyclin D1 genotype and development of ESCC or CAC was found among nonsmokers. Determination of the cyclin D1 (G870A) single nucleotide polymorphism may be suitable to identify individuals with increased risk for ESCC or CAC in the northern Chinese population.

Topics: Adenocarcinoma; Asian People; Carcinoma, Squamous Cell; Cardia; Case-Control Studies; Cyclin D1; DNA; Esophageal Neoplasms; Esophagus; Female; Genetic Predisposition to Disease; Genotype; Humans; Male; Middle Aged; Polymerase Chain Reaction; Polymorphism, Single Nucleotide; Polymorphism, Single-Stranded Conformational; Risk Factors; Smoking; Stomach Neoplasms

Overexpression of cyclin D1 and disruption of cell cycle control in G(1) occur frequently in human esophageal cancer. Transgenic (TG) mice with cyclin D1 overexpression targeted to the oral-esophageal tissue by the EBV ED-L2 promoter showed increased severity in esophageal dysplasia without cancer development, after multiple doses of N-nitrosomethylbenzylamine (NMBA). Dietary zinc deficiency (ZD) in mice enhances cellular proliferation in esophagus/forestomach and susceptibility to NMBA-induced carcinogenesis. We investigated whether cyclin D1 overexpression in TG mice, together with ZD, might lead to unchecked cell proliferation and accelerated NMBA-induced tumorigenesis. Five-week-old TG and wild-type (WT) mice were fed a ZD- or -sufficient (ZS) diet, forming four groups: ZD:TG; ZS:TG; ZD:WT; and ZS:WT. After 4 weeks, animals were given a single intragastric NMBA dose and were sacrificed 25 and 77 days later. Without NMBA, cell proliferation was greatest in ZD:TG esophagus/forestomach, followed by ZD:WT, and then ZS:TG>/=ZS:WT. The high rate of cell proliferation was accompanied by overexpression of cell cycle progression and tumorigenesis biomarkers, including proliferating cell nuclear antigen, cyclin D1, cyclin-dependent kinase 4, p53, cytokeratin 14, epidermal growth factor receptor, and by a reduced rate of apoptosis. ZD substantially increased forestomach tumor incidence in TG mice: 85% of ZD:TG versus 14% of ZS:TG mice had forestomach tumors (P < 0.001), with progression to malignancy occurring only in ZD:TG tumors. Additionally, 14% of ZD:TG mice developed esophageal tumors and esophageal intestinal metaplasia at 77 days. Thus, cyclin D1 overexpression, in cooperation with ZD, decontrols cell proliferation, ensuring cell expansion, a prerequisite for cancer development.

Topics: Animals; Apoptosis; Cell Cycle; Cell Division; Cyclin D1; Disease Progression; Esophageal Neoplasms; Female; Male; Mice; Mice, Transgenic; Stomach Neoplasms; Zinc

To observe the effects of Helicobacter pylori (H. pylori) on growth and cell cycle progression of AGS gastric epithelial cells.. AGS cells and H. pylori were co-cultured for 1 - 4 days. Vital cell numbers were counted by heamatocounter. Apoptosis was detected by fluorescence stain of cell nucleus and DNA agarose electrophoresis. Cell cycle was analyzed by flow cytometry technique.. During co-culture of AGS cells and H. pylori, cell growth inhibition was observed. H. pylori induces apoptosis and cell cycle arrest from G1 to S phase accompanied by high expression of cyclinD1.. Exposure of gastric epithelial cells to H. pylori causes block of G1 to S progression of cell cycle and alters expression of cyclinD1. The cell cycle arrest and the associated induction of apoptosis are responsible for the growth inhibition of gastric epithelial cells caused by H. pylori.

Topics: Apoptosis; Cell Division; Cell Line, Tumor; Cyclin D1; Epithelial Cells; Flow Cytometry; G1 Phase; Gastric Mucosa; Helicobacter pylori; Humans; S Phase; Stomach Neoplasms

To investigate the association of Cyclin D1 (A870G) single nucleotide polymorphism (SNP) with the susceptibility to esophageal and cardiac cancer in northern Chinese population.. By polymerase chain reaction-single strand conformation polymorphism analysis (PCR-SSCP), the Cyclin D1 (A870G) genotyping was performed among 178 patients with esophageal or esophageal -gastric junction carcinoma (120 with esophageal squamous cell cancer and 58 with cardiac adenoma cancer) and 122 health controls.. There were no significant differences in Cyclin D1 (A870G) allele frequencies between cancer patients and health controls (P = 0.075). There is no genotype distribution difference was found between non-smoker patients and controls (P > 0.05). The risk for esophageal and cardiac cancer is 2.5 times higher in A/A genotype carried smokers than that in A/G or G/G genotype carried non-smokers, with the adjusted Odd Ratio of 2.57 (95% confidence interval is 1.19 approximately 5.57). The G/G genotype reduces the susceptibility to esophageal cancer, with the adjusted Odd Ratio of 0.39 and 95% confidence interval of 0.18 - 0.82. The A/A frequency in cardiac patients (34.48%) is higher than that in health controls (23.77%) but the difference does not reach significant (P = 0.212).. In northern Chinese population, the smoking individuals carrying Cyclin D1 (A870G) A/A genotype increase the susceptibility to esophageal and cardiac cancer. The G/G genotype probably plays a protecting role in the occurrence of esophageal cancer.

Topics: Adult; Aged; Cardia; Cyclin D1; Esophageal Neoplasms; Female; Genetic Predisposition to Disease; Genotype; Humans; Male; Middle Aged; Polymorphism, Genetic; Stomach Neoplasms

The retinoblastoma (Rb) pathway controls the G1-S checkpoint of the cell cycle. Inactivating mutations and deletions of p16 and Rb and up-regulation of cyclin D1 disrupt this pathway and occur in many cancers. However, the concurrent expression of these genes in primary and metastatic gastric cancer is unknown, and the prognostic value of their expression is unclear. In this study, the expression of cyclin D1, retinoblastoma protein (pRb), and p16 in 67 resected gastric adenocarcinomas, and of pRb and p16 in 40 associated lymph node metastases, was determined using a streptavidin-biotin-peroxidase immunohistochemical method. Relationships with clinical and pathological features were analyzed. Cyclin D1 overexpression (>/=5% expression) was seen in 55% of cancers; pRb loss (<20% expression), in 33%; p16 loss (<10% expression), in 49%; and at least 1 of these abnormalities, in 92.5%. Cyclin D1 overexpression was associated with poor differentiation (P = 0.027) and signet ring cell type (P = 0.029). pRb expression was lower in lymph node metastases than in the corresponding primary tumors (P <0.001). Univariate and multivariate survival analysis (minimum follow-up 72 months or until death) revealed that <20% pRb expression, <30% pRb expression, and International Union Against Cancer stage >2 were associated with worse overall survival. The results suggest that Rb pathway disturbances play an important role in gastric carcinogenesis. The poor prognosis of cancers with low pRb expression and the reduced pRb expression in lymph node metastases raise the possibility that Rb and related genes also influence progression.

Topics: Adenocarcinoma; Adult; Aged; Aged, 80 and over; Biomarkers, Tumor; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p16; Female; Gene Expression Regulation, Neoplastic; Humans; Immunohistochemistry; Lymphatic Metastasis; Male; Middle Aged; Prognosis; Retinoblastoma Protein; Stomach Neoplasms

Previous study showed that allitridi markedly suppresses cellular proliferation, blocks cell cycle at G(1) phase, and induces cell apoptosis of human gastric cancer BGC823 cell. During the investigation of its molecular mechanisms and target genes, the authors found that protein expression of cyclin D1 and p27(Kip1) play an important role in an allitridi-induced G(1) arrest. This study was designed to explore the effect of allitridi on the expression of cyclin D1 and p27(Kip1) in BGC823 cells.. After total RNA and total protein in allitridi-treated (25 microg/ml) and allitridi-untreated BGC823 cells were abstained, Western blot analysis was performed to determine the protein levels of cyclin D1 and p27(Kip1), and RT-PCR was performed to determine the mRNA levels of cyclin D1 and p27(Kip1).. After treated with 25 microg/ml allitridi for 24 hours, the protein levels of cyclin D1 of BGC823 cells were downregulated and the protein levels of p27(Kip1) were upregulated, and this changes were more obvious after 48 hours,while their mRNA levels remained unchanged.. Allitridi may influence the protein expression of cyclin D1 and p27(Kip1) in BGC823 cells, while do not influence their mRNA transcription.

Topics: Allyl Compounds; Antioxidants; Cell Cycle Proteins; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p27; Gene Expression Regulation, Neoplastic; Humans; RNA, Messenger; Stomach Neoplasms; Sulfides; Tumor Cells, Cultured; Tumor Suppressor Proteins

To investigate the effects of Cyclin D1 antisense oligodeoxyneucleotides (ASODN) on the growth, cell cycle progression and expression of G1 phase regulators in human gastric carcinoma cell lines SGC7901 and HS746T, phosphorothioate-modified Cyclin D1 ASODN were encapsulated by LipofectAMINE2000 and transfected into gastric carcinoma cells. Dose-dependent inhibitory effects were induced by Cyclin D1 ASODN in two gastric carcinoma cell lines. Treatment of gastric carcinoma cells with 0.2 micromol/L Cyclin D1 ASODN for 24 h could significantly inhibit their growth in vitro and in vivo, reduce expression of Cyclin D1 mRNA to 26.3% (SGC7901) and 17.3% (HS746T) respectively. The percentage of cells in G0/G1 phase was increased as revealed by flow cytometry. Immunohistochemical staining showed that the expression of p21 was increased and the expression of Cyclin D1 and pRb was decreased in the two cell lines; the expression of p27 was increased in HS746T, but unchanged in SGC7901. Cyclin D1 ASODN could inhibit the growth and the expression of Cyclin D1 mRNA in gastric carcinoma cells, influence the cell cycle and expression of its regulators.

Topics: Animals; Cell Cycle; Cell Division; Cell Line, Tumor; Cyclin D1; Dose-Response Relationship, Drug; G1 Phase; Humans; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Oligodeoxyribonucleotides, Antisense; RNA, Messenger; Stomach Neoplasms; Transfection

To clarify the role of these cyclins in human gastric cancer.. 38 gastric cancer patients, 29 first degree relatives of gastric cancer patients, as well as 18 healthy subjects were included. The mRNA expression of cyclins D1, D2, D3 and E in gastric biopsies was evaluated by RT-PCR analysis using specific primers. Histomorphological features such as intestinal metaplasia, atrophy, H. pylori infection and severity of gastritis were determined by the updated Sydney System.. Significant mRNA overexpression was found for cyclins D2, D3 and E compared with healthy normal specimen, but cyclin D1 expression was not different between tumor and normal tissues. In addition, cyclin D2 and D3 overexpression was significantly more frequent in first degree relatives than in healthy controls (P < 0.05). Among the various pathological findings, the overexpression of cyclins D2 and E was associated with intestinal metaplasia, and the overexpression of cyclin D3 was associated with intestinal metaplasia as well as atrophy. The overexpression of cyclins D2 and D3 was significantly correlated with H. pylori infection. No correlation was observed between the overexpression of cyclin D1 and any pathological variables.. The overexpression of cyclins D2, D3 and E is a frequent event in patients with gastric cancer and their first degree relatives and may be an early event in gastric carcinogenesis.

Topics: Adult; Aged; Aged, 80 and over; Cyclin D1; Cyclin D2; Cyclin D3; Cyclin E; Cyclins; Family Health; Gastric Mucosa; Gastritis; Gene Expression Regulation, Neoplastic; Helicobacter Infections; Helicobacter pylori; Humans; Middle Aged; RNA, Messenger; Stomach; Stomach Neoplasms

In order to study the inhibitory effects of genistein on the growth of human gastric carcinoma cells and to explore its possible mechanism, cell proliferation and DNA incorporation tests are applied. Immunocytochemistry is also applied in this study to detect the protein expression of cyclin D1 after the cell-line is exposed to genistein. The results showed that the growth of the cells and the synthesis of DNA is decreased in a marked dose-dependent manner after the treatment with genistein. Genistein also decreased the protein expression of cyclin D1. The above mentioned results indicate that genistein inhibits the growth of gastric carcinoma cells and the possible mechanism of this inhibition might be resulted from inhibiting the synthesis of DNA and the protein expression of cyclin D1.

Topics: Adenocarcinoma; Antineoplastic Agents; Cell Division; Cyclin D1; DNA, Neoplasm; Genistein; Humans; Stomach Neoplasms; Tumor Cells, Cultured

To determine the effect of cis -9, trans -11-conjugated linoleic acid (c9, t11-CLA) on the cell cycle of gastric cancer cells (SGC-7901) and its possible mechanism in inhibition cancer growth.. Using cell culture and immunocytochemical techniques, we examined the cell growth, DNA synthesis, expression of PCNA, cyclin A, B(1), D(1), p16(ink4a) and p21(cip/waf1) of SGC-7901 cells which were treated with various c9, t11-CLA concentrations (25, 50, 100 and 200 micromol.L(-1))of c 9, t 11-CLA for 24 and 48h, with a negative control (0.1% ethane).. The cell growth and DNA synthesis of SGC-7901 cells were inhibited by c9, t11-CLA.SGC-7901 cells. Eight day after treatment with various concentrations of c9, t11-CLA mentioned above, the inhibition rates were 5.92%, 20.15%, 75.61% and 82.44%, respectively and inhibitory effect of c9, t11-CLA on DNA synthesis (except for 25 micromol.L, 24h) showed significantly less (3)H-TdR incorporation than that in the negative controls (P<0.05 and P<0.01). Immunocytochemical staining demonstrated that SGC-7901 cells preincubated in media supplemented with different c9, t11-CLA concentrations at various times significantly decreased the expressions of PCNA (the expression rates were 7.2-3.0%, 24h and 9.1-0.9% at 48h, respectively), Cyclin A (11.0-2.3%, 24h and 8.5-0.5%,48h), B(1) (4.8-1.8% at 24h and 5.5-0.6% at 48h)and D(1) (3.6-1.4% at 24h and 3.7%-0 at 48h) as compared with those in the negative controls(the expressions of PCNA, Cyclin A, B(1) and D(1) were 6.5% at 24h and 9.0% at 48h, 4.2% at 24h and 5.1% at 48h, 9.5% at 24h and 6.0% at 48h,respectively)(P<0.01), whereas the expressions of P16(ink4a) and P21(cip/waf1), cyclin-dependent kinases inhibitors(CDKI), were increased.. The cell growth and proliferation of SGC-7901 cell is inhibited by c9, t11-CLA via blocking the cell cycle, with reduced expressions of cyclin A,B(1) and D(1) and enhanced expressions of CDKI(P16(ink4a) and p21(cip/waf1)).

Topics: Adenocarcinoma; Animals; Cell Cycle; Cell Division; Cyclin A; Cyclin B; Cyclin B1; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p16; Cyclin-Dependent Kinase Inhibitor p21; Cyclins; Enzyme Inhibitors; Humans; Immunohistochemistry; Linoleic Acids; Linoleic Acids, Conjugated; Proliferating Cell Nuclear Antigen; Stomach Neoplasms; Tumor Cells, Cultured

The aim of this study was to investigate the expression of D-type cyclins and cyclin E in gastric cancer patients (N = 34), in healthy first-degree relatives of gastric cancer patients (N = 29), and in control subjects (N = 18). Expression of cyclins D1, D2, D3, and E was determined by RT-PCR. Localization of cyclin expression was determined by immunohistochemistry. Expression of cyclins D2, D3, and E was more frequently detected in tumor tissue compared with tumor-free gastric mucosa (P < 0.05) and was associated with the presence of intestinal metaplasia. In contrast, cyclin D1 was frequently expressed in both tumor- and tumor-free tissue. Cyclin D3 expression was more frequently detected in the antrum mucosa of first-degree relatives compared to controls (P < 0.01) and was associated with the presence of Helicobacter pylori. Our data suggest that deregulation of G1 phase cyclins may play a role in gastric carcinogenesis, and may point to the presence of molecular alterations in individuals at an increased risk for gastric cancer.

Topics: Aged; Aged, 80 and over; Cyclin D1; Cyclin E; Female; G1 Phase; Gastric Mucosa; Humans; Immunohistochemistry; Male; Middle Aged; Stomach Neoplasms

Helicobacter pylori (H. pylori) infection is associated with changes in epithelial turnover, through their significance of these in gastric carcinogenesis is still controversial. The purpose of this study was to determine the influence of H. pylori infection on cell proliferation and the relation with the cell-cycle regulators, and finally to provide insights into the mechanism by which H. pylori may lead to gastric carcinogenesis. We investigated Ki-67, p53, p21(Waf1/Cip1), cyclin D1 expression in 55 patients with H. pylori gastritis, and compared the results with patients those of non-H. pylori gastritis patients (n=21), gastric adenocarcinoma patients (n=8) and samples with normal gastric mucosa (n=12). Gastric biopsies were histologically evaluated for inflammatory reaction, intestinal metaplasia and atrophy according to the Sydney system. Overexpression of Ki-67, p53, p21(Waf1/Cip1) and cyclin D1 was found in H. pylori gastritis patients (32.7%, 10.9%, 20.0% and 7.3%, respectively), whereas only scattered expression in cells in the neck region of the crypts, but no overexpression was found in gastric antral epithelial cells in biopsy specimens from patients with non-H. pylori gastritis and noninflammed mucosa. A significant relationship was found between the grade of H. pylori colonization and Ki-67, p53, p21(Waf1/Cip1) and cyclin D1 expression. Expression was significantly higher in patients with intestinal metaplasia with atrophy, whereas no overexpression was found in patients without intestinal metaplasia with atrophy (p=0.05). H. pylori infection is associated with increased cell proliferation, increased epithelial DNA damage, and atrophy, which might contribute to the development of gastric cancer. Even if the exact mechanism has not been elucidated yet, our results suggest that H. pylori infection acts as a cofactor in gastric carcinogenesis.

Topics: Adenocarcinoma; Biopsy; Cell Cycle; Cell Cycle Proteins; Cell Division; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p21; Cyclins; Gastric Mucosa; Gastritis; Helicobacter Infections; Helicobacter pylori; Humans; Ki-67 Antigen; Reference Values; Stomach Neoplasms; Tumor Suppressor Protein p53

To investigate tumorigenesis in the gastric hyperplastic polyp (HP), we evaluated 19 HPs with and 50 HPs without dysplasia (including carcinoma in situ), as compared with normal mucosa and fundic gland polyps. Helicobacter pylori density was highest in HPs without dysplasia. Apoptotic activity and Ki-67 and p53 expression also were higher in dysplasia in HPs than in normal mucosa, fundic gland polyps, or HPs themselves. The p21WAF1/CIP1 and cyclin D1 levels, in contrast, were highest in HPs. In HPs without dysplasia, size was correlated positively with the degree of stromal inflammation and with p53 and cyclin D1 expression. p53 and c-Ki-ras mutations were detected in 41% (8/19) and 5% (1/19) of dysplasia (including carcinoma in situ) in HPs. Our results demonstrate that the HP enlarges with enhanced cell turnover and overexpression of p53, p21WAF1/CIP1, and cyclin D1, associated with H pylori-related inflammation, and that p53 but not c-Ki-ras mutations may have an important role in dysplastic change in HPs.

Topics: Adult; Aged; Aged, 80 and over; Apoptosis; Carcinoma in Situ; Cell Transformation, Neoplastic; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p21; Cyclins; DNA, Neoplasm; Down-Regulation; Female; Helicobacter pylori; Humans; Hyperplasia; Immunoenzyme Techniques; Ki-67 Antigen; Male; Middle Aged; Mutation; Polymerase Chain Reaction; Polyps; Proto-Oncogene Proteins p21(ras); Stomach Neoplasms; Tumor Suppressor Protein p53

Helicobacter pylori induces cellular proliferation in host cells, but the mechanism remains unclear. Thus, we examined the effect of H. pylori on cyclin D1, an important regulator of the cell cycle, especially in relation to intracellular signaling pathways. In a Northern blot analysis, cyclin D1 transcription in gastric cancer (AGS) cells was enhanced by coculture with H. pylori strain TN2 in a time-dependent and multiplicity-of-infection-dependent manner. An isogenic mutant form of vacA also increased cyclin D1 transcription, but mutant forms of cagE or the entire cag pathogenicity island did not enhance cyclin D1 transcription. These effects were confirmed with a luciferase assay of the cyclin D1 promoter (pD1luc). Cyclin D1 promoter activation by H. pylori was inhibited by MEK inhibitors (U0126 and PD98059), indicating that the mitogen-activated protein kinase pathway may be involved in intracellular signal transduction. In contrast, transfection of a reporter plasmid having any point mutations of the NF-kappaB binding sites in the promoter (pD1-kappaB1M, pD1-kappaB2M, or pD1-kappaB1/2M) or cotransfection of dominant negative IkappaBalpha did not affect cyclin D1 activation by H. pylori. In conclusion, H. pylori activates cyclin D1 through the mitogen-activated protein kinase pathway and not through NF-kappaB activation in AGS cells. This activation of cyclin D1 is partly dependent on the cag pathogenicity island but not on vacA.

Topics: Cyclin D1; Helicobacter Infections; Helicobacter pylori; Humans; Mitogen-Activated Protein Kinases; NF-kappa B; Promoter Regions, Genetic; Stomach Neoplasms; Transcription, Genetic; Transcriptional Activation; Tumor Cells, Cultured; Virulence

The cyclin D1 protein is one of the cell cycle regulators required for cell cycle progression through G1 phase to S phase. The cyclin D1-cyclin-dependent kinase (CDK) system is thought to control the cell cycle through mediating extracellular signals from mitogens, such as epidermal growth factor (EGF). In this study, we attempted to examine the therapeutic effect of cyclin D1 antisense oligonucleotides (AS/D1) on cell proliferation and apoptosis of the gastric cancer cell line MKN-74, in the presence and absence of EGF-stimulation. Evaluation of cell survival and DNA synthesis revealed that enhanced cell growth following EGF-stimulation was completely inhibited by a 24 h pre-incubation with 100 nM AD/D1. This inhibition was down to 19.3% compared with maximal DNA synthesis after stimulation with 3 nM EGF alone. Western blotting demonstrated that while EGF-stimulation led to cyclin D1 over-expression, AS/D1 inhibited cyclin D1 protein expression. We also demonstrated the induction of apoptosis in MKN-74 cells by AS/D1. In conclusion, EGF-stimulated MKN-74 cell proliferation was inhibited by AS/D1, which could overcome EGF-induced cyclin D1 over-expression. AS/D1 also affected cell survival by inducing apoptosis through cell cycle arrest following cyclin D1 depletion. Thus, AS/D1 may be a candidate for use as a novel cancer therapy specifically targeted against the over-expression of cyclin D1 enhanced by EGF in malignant cells.

Topics: Apoptosis; Blotting, Western; Cell Division; Cell Survival; Cells, Cultured; Cyclin D1; DNA; Dose-Response Relationship, Drug; Epidermal Growth Factor; Humans; In Situ Nick-End Labeling; Oligonucleotides, Antisense; Stomach Neoplasms; Time Factors; Tumor Cells, Cultured

Wnt signaling pathway is important for development and carcinogenesis. Alterations of this pathway, such as mutations in adenomatous polyposis coli (APC) gene and activation mutations of beta-catenin, would result in stabilization of beta-catenin and subsequent translocation to nucleus where genes are transcribed. Recently, a receptor of Wnt, FzE3 was found to be up-regulated in esophageal carcinoma while a non-receptor antagonist of Wnt, secreted frizzled related protein (hsFRP) was found to be down-regulated in some cancer. These findings suggested that FzE3 is a potential oncogene while hsFRP is a potential tumor suppressor gene. We aimed to investigate whether FzE3 and hsFRP were altered in gastric cancer. Twelve cases of gastric cancer, including 7 cases of intestinal type, 4 cases of diffuse type and I case of mixed type, were studied. FzE3 and hsFRP mRNAs were expressed in most of the paired normal gastric tissues. FzE3 was over-expressed in 9 cases (75%) of gastric carcinoma tissues while hsFRP was down-regulated in 2 cases (16%). Beta-catenin nuclear staining was identified in 3 cases (27%) and cyclin D1 was expressed in 5 cases (41%) of cancer samples. All these cases were associated with either up-regulation of FzE3 or down-regulation of hsFRP. Our results suggested that alterations of FzE3 or hsFRP were frequent in gastric cancer. These provide alternative mechanisms leading to activation of Wnt signaling pathway in gastric carcinogenesis.

Topics: Adenocarcinoma; beta Catenin; Cyclin D1; Cytoskeletal Proteins; Down-Regulation; Female; Humans; Immunoenzyme Techniques; Male; Neoplasm Proteins; Proteins; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; RNA, Neoplasm; Signal Transduction; Stomach Neoplasms; Trans-Activators; Up-Regulation

To compare the effects of selenium-enriched garlic (Se-garlic), garlic, Na2SeO3, and garlic + Na2SeO3 on growth of human gastric carcinoma cells.. In vivo and in vitro assays were carried out in the cultured human gastric carcinoma cell line MGC803 transplanted in the nude mice by cell count, flow cytometry, Western blot and neoplasm volume measurement.. The inhibition effect of garlic was similar to that of Se-garlic, but Na2SeO3 was weaker than Se-garlic. Combination of garlic and Na2SeO3 was stronger than Se-garlic. In flow cytometry assay, the proportion of G1 phase was increased after 24 hour treatment of Se-garlic, garlic and Na2SeO3 in the non-synchronized cells. However, the proportion of S phase was increased in the synchronized cells. The proportion of G2 + M phase was increased both in non-synchronized and synchronized cells on treatment with the combination of garlic and Na2SeO3. The amount of Cdk2-CyclinE complex and Cdk4-CyclinD1 complex was decreased in all treated synchronized cells in immunoprecipitation and immunoblot assays. The growth of MGC803 tumor in male Balb/c nude mice was inhibited by administration of 1.67% of Se-garlic (Se 2 micrograms/g) in diet with an inhibition rate of 29.92% in tumor weight. Treatment of either 0.83% of Se-garlic or 1.67% of garlic or 4.38 micrograms/g of Na2SeO3 (Se 2 micrograms/g) could not appreciably inhibit the growth of tumor. Wrapping of a number of monocytes around the tumor was induced in 62.50% of tumors in 0.83% of the Se-garlic group.. In vitro, Se-garlic is able to inhibit the growth of MGC803 cell through action of garlic. In vivo, Segarlic is able to inhibit growth of MGC803 tumor in nude mice by being better than garlic and selenite.

Topics: Animals; CDC2-CDC28 Kinases; Cell Division; Cyclin D1; Cyclin E; Cyclin-Dependent Kinase 2; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinases; Garlic; Humans; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Neoplasms, Experimental; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins; Selenium; Selenium Compounds; Selenium Oxides; Stomach Neoplasms; Tumor Cells, Cultured

Cyclin D1 overexpression was examined in early gastric carcinomas and precursor lesions with the following aims; (1) to assess the chronology of cyclin D1 overexpression in various stages of gastric carcinogenesis, (2) to correlate cyclin D1 overexpression with the Lauren type, the grade of differentiation and the type of growth pattern of the tumours and (3) to correlate cyclin D1 overexpression with clinical parameters, in particular lymph node metastasis and overall prognosis.. Forty-five paraffin-embedded gastrectomy specimens from early carcinomas were examined for the presence of various precursor lesions. The Lauren type, the grade of differentiation and the type of growth pattern were reassessed for all early carcinomas. Cyclin D1 overexpression was examined using the monoclonal antibody DCS-6. Cyclin D1 overexpression was absent from all precursor lesions. Ten early carcinomas (22%) were cyclin D1 positive without significant differences when stratified according to Lauren type, grade of differentiation, type of growth pattern or lymph node status. Univariate analysis failed to show a significant difference in 5-year surival rate between cyclin D1 positive and negative early carcinomas (90% vs. 94%).. Cyclin D1 protein overexpression does not play a role in the progression from normal to neoplastic gastric mucosa and does not discriminate between intestinal and diffuse type early gastric carcinomas of Caucasian origin. Moreover, mechanisms other than cyclin D1 protein overexpression underlie the reported difference in biological behaviour of early gastric carcinomas with different types of growth pattern. Finally, although it appears that cyclin D1 does not have prognostic significance, studies on larger numbers, including advanced carcinomas, are warranted.

Topics: Cyclin D1; Follow-Up Studies; Gastric Mucosa; Humans; Immunohistochemistry; Stomach Neoplasms; Survival Rate

The tumor suppressor SMAD4, also known as DPC4, deleted in pancreatic cancer, is a central mediator of TGF-beta signaling. It was previously shown that mice homozygous for a null mutation of Smad4 (Smad4-/-) died prior to gastrulation displaying impaired extraembryonic membrane formation and endoderm differentiation. Here we show that Smad4+/- mice began to develop polyposis in the fundus and antrum when they were over 6 - 12 months old, and in the duodenum and cecum in older animals at a lower frequency. With increasing age, polyps in the antrum show sequential changes from hyperplasia, to dysplasia, in-situ carcinoma, and finally invasion. These alterations are initiated by a dramatic expansion of the gastric epithelium where Smad4 is expressed. However, loss of the remaining Smad4 wild-type allele was detected only in later stages of tumor progression, suggesting that haploinsufficiency of Smad4 is sufficient for tumor initiation. Our data also showed that overexpression of TGF-beta1 and Cyclin D1 was associated with increased proliferation of gastric polyps and tumors. These studies demonstrate that Smad4 functions as a tumor suppressor in the gastrointestinal tract and also provide a valuable model for screening factors that promote or prevent gastric tumorigenesis.

Topics: Age Factors; Animals; Cyclin D1; DNA-Binding Proteins; Genes, Tumor Suppressor; Haploidy; Loss of Heterozygosity; Mice; Polyps; Smad4 Protein; Stomach Neoplasms; Trans-Activators; Transforming Growth Factor beta

We performed the immunohistochemical staining for six G1 check point cell cycle proteins to study their expression patterns and roles in the gastric carcinogenesis. We studied 76 cases of paraffin blocks that included the sections of 18 tubular adenomas (TA), 38 early gastric carcinomas (EGC) (20 cases of mucosal type, nine cases of submucosal type with no nodal metastasis, nine cases of submucosal type with nodal metastasis), 20 advanced gastric carcinomas (AGC) (ten cases with no nodal metastasis, ten cases with nodal metastasis). We found that abnormal expression of p16 and p27 increased with the progression of tubular adenomas to advanced gastric cancers. Inverse relationship between pRb and p16 proteins was found in a small portion of the gastric tumors. Expressions of pRb and cdk4 were consistently high in benign and malignant gastric tumors. Expression of cyclin D1 and cyclin E rather decreased with the tumor progression. In conclusion, losses of p16 and p27 seem to play a significant role during the gastric carcinogenesis, and the G1 checkpoint cell cycle proteins such as pRb, cdk4, cyclin D1, and cyclin E variably participate in the gastric carcinogenesis and metastasis by the mechanisms which are yet unknown; thus, further studies need to be performed to elucidate the mechanisms.

Topics: Biomarkers, Tumor; Cell Cycle Proteins; Cyclin D1; Cyclin E; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase Inhibitor p16; Cyclin-Dependent Kinase Inhibitor p27; Cyclin-Dependent Kinases; Disease Progression; G1 Phase; Humans; Immunohistochemistry; Microtubule-Associated Proteins; Prognosis; Proto-Oncogene Proteins; Retinoblastoma Protein; Stomach Neoplasms; Tumor Suppressor Proteins

Cyclin D1 and E have been found to be deregulated and overexpressed in various types of cancers. In order to study the cell cycle regulatory mechanisms in gastric cancer, we have analyzed the protein expression of cyclin D1 and cyclin E in 76 tumor specimens from patients with primary gastric cancer, using immunohistochemistry. Overexpression of cyclin D1 was observed in 38 cases (50.0%). Overexpression of cyclin E was observed in 40 cases (52.6%). There was no significant difference between the expression of cyclin D1 and any clinicopathological factor. Cyclin E overexpression was correlated with a high incidence of lymph node metastasis, a low incidence of T1, and with Stage I. There was no significant difference in survival curves between cyclin D1 (+) and cyclin D1 (-). The survival curves of cyclin E (-) were significantly higher than those of cyclin E (+). These results suggested that in gastric carcinoma, cyclin E overexpression was useful as a prognostic indicator, but cyclin D1 was not.

Topics: Cyclin D1; Cyclin E; Humans; Immunohistochemistry; Prognosis; Stomach Neoplasms

p27Kip1 is an inhibitor of cyclin-dependent kinases and is speculated to be a potential prognostic indicator in numerous human cancers. We investigated expression of p27Kip1 along with cyclin D1 in gastric cancer to estimate the clinical utility of p27Kip1.. Immunohistochemical assay for p27Kip1 and cyclin D1 proteins was performed in 64 patients with primary gastric cancer. Correlation between p27Kip1 expression and clinical-biological parameters including patient survival was analyzed.. p27Kip1 expression was suppressed in 40 (62.5%) of 64 gastric cancer patients and cyclin D1 was overexpressed in 22 (34.4%) out of 64. Expression of p27Kip1 was significantly reduced in poorly differentiated cancers (82.1%, 23/28; P = 0.015) and was also reduced in the tumors with high S-phase fraction (86.7%, 26/30) compared with tumors showing low S-phase fraction (41.2%, 14/34; P = 0.0002). Expression of p27Kip1 and cyclin D1 was inversely correlated (P = 0.021). In univariate analysis, extent of the disease (P < 0.001), expression of cyclin D1 (P = 0.0001), and reduced expression of p27Kip1 (P = 0. 0006), were statistically significant to predict patient's outcome, but depth of invasion (P = 0.008) and pathologic stage (P = 0.009) emerged as significant prognostic indicators in multivariate analysis.. Expression of p27Kip1 is closely linked with cell proliferation and differentiation of human gastric cancer. p27Kip1 seems to have potential as a prognostic marker in the management of gastric cancer patients.

Topics: Adult; Aged; Cell Cycle Proteins; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p27; Enzyme Inhibitors; Female; Humans; Immunohistochemistry; Male; Microtubule-Associated Proteins; Middle Aged; Prognosis; Stomach Neoplasms; Survival Analysis; Survival Rate; Treatment Outcome; Tumor Suppressor Proteins

Increased expression of the cyclin D1 gene frequently occurs in human squamous carcinomas of the esophagus. However, the expression of cyclin D1 has not been previously examined in detail in adenocarcinomas of the esophagus or stomach. Therefore, we examined, in parallel, the expression of cyclin D1 in both squamous and adenocarcinomas of the esophagus and in adenocarcinomas of the stomach. The level of expression of the cyclin D1 protein was assessed by immunohistochemistry in 39 esophageal and 34 gastric carcinomas and correlated with clinical and pathology parameters. Within the esophagus, 71% of the squamous carcinomas and 64% of the adenocarcinomas were positive for increased cyclin D1 nuclear staining. For adenocarcinomas of the stomach, the overall positive rate was 47%; in the gastric cardia, the rate was 44%, and in other regions of the stomach, it was 50%. In esophageal and gastric adenocarcinomas of the intestinal type, increased expression of cyclin D1 was seen in 70% of the samples, whereas with the diffuse type only 13% were positive (P < .01). Tumors from patients older than the median age of 67 years were more frequently positive than tumors from patients younger than 67 years (74% v 42%, respectively) (P < .01). Positive staining was also seen more frequently in well and moderately differentiated tumors than in poorly differentiated tumors (74% v 49%, respectively) (P < .05). Cytoplasmic staining for cyclin D1 was noted in 22% of the tumors, of various types. Therefore, increased expression of cyclin D1 frequently occurs in both adenocarcinomas and squamous carcinomas of the esophagus, and in adenocarcinomas of the stomach. The increased expression in adenocarcinomas is especially frequent in the intestinal-type lesions.

Topics: Adenocarcinoma; Adult; Aged; Carcinoma, Squamous Cell; Cyclin D1; Esophageal Neoplasms; Female; Humans; Immunohistochemistry; Male; Middle Aged; Stomach Neoplasms

The expression and prognostic role of cyclin D1, cyclin E, and p21 (WAF1/CIP1) were immunohistochemically investigated in 413 curatively resected gastric carcinomas. p21 was expressed in 65.4 per cent (n=270), cyclin D1 in 23.7 per cent (n=98), and cyclin E in 13.6 per cent ( n=56) of the tumours. The expression of p21, cyclin D1, and cyclin E was positively associated with the papillary or tubular type of the WHO classification, as well as with the intestinal type according to the Lauren classification. No significant correlation could be found between the expression of p21, cyclin D1 and cyclin E and the parameters pT category, lymph node involvement, and blood vessel and lymphatic vessel invasion. Concerning survival, no prognostic impact of p21, cyclin D1, and cyclin E expression could be verified, even when different subgroups of patients were analysed separately according to the pT and pN category as well as to the Lauren classification. The present data suggest that neither cyclin D1, cyclin E nor their inhibitor p21 can predict the survival of gastric cancer patients, nor is their immunohistochemical detection a suitable tool for identifying subgroups of patients who may be at higher risk.

Topics: Adult; Aged; Aged, 80 and over; Biomarkers, Tumor; Cyclin D1; Cyclin E; Cyclin-Dependent Kinase Inhibitor p21; Cyclins; Female; Follow-Up Studies; Gastric Mucosa; Humans; Immunoenzyme Techniques; Male; Middle Aged; Neoplasm Proteins; Prognosis; Stomach Neoplasms; Survival Rate

Expression of cyclins D1 and D2, as well as cyclin-dependent kinase 4 (cdk4), was investigated by means of immunohistochemistry in 455 gastric cancer cases. Additional western blotting was performed for four breast cancer and four gastric cancer cell lines and 35 fresh frozen gastric cancer samples, to confirm the cyclin D1, D2, and cdk4 data. Cyclin D1 was restricted to the nucleus of cancer cells with a few exceptions, whereas cyclin D2 was present in both cell compartments, but predominantly in the cytoplasm. Cdk4 was intermediately expressed. Cyclin D1 was overexpressed in 93 cases (20.4 per cent) and cyclin D2 in 105 (23.0 per cent). In the cyclin D2 cases, this correlated with greater age (p=0.0004), better differentiation (p=0.0023), greater depth of cancer invasion (p=0. 003), the presence of lymph node metastasis (p=0.0014), vascular invasion by cancer cells (p< 0.0001), and poor prognosis (p< 0.0001), while cyclin D1 did not correlate with any of these except age (p=0.00193). Multivariate analysis revealed cyclin D2 overexpression to be an independent prognostic factor, in addition to depth of cancer invasion and lymph node status. Cdk4 overexpression was linked to cyclin D1, but not cyclin D2 overexpression. The results indicate that cyclin D2 up-regulation plays an important role in the progression and prognosis of gastric cancer independently of cdk4, whereas cyclin D1 overexpression does not.

Topics: Adult; Aged; Aged, 80 and over; Biomarkers, Tumor; Breast Neoplasms; Cyclin D1; Cyclin D2; Cyclins; Disease Progression; Female; Follow-Up Studies; Humans; Immunoenzyme Techniques; Male; Middle Aged; Neoplasm Invasiveness; Neoplasm Proteins; Prognosis; Stomach Neoplasms; Survival Rate; Tumor Cells, Cultured

Cyclin D1 is a G1 cyclin that controls the transition of the cell cycle from G1 phase to S phase, and its gene is located on chromosome 11q13. We evaluated the expression of cyclin D1 mRNA in surgically resected specimens of gastric and colorectal cancers using quantitative RT-PCR. In this method, cDNA derived from cyclin D1 mRNA was amplified in a tube together with an internal control. The expression of cyclin D1 mRNA was high in 8 of 36 gastric cancer tissues (22%) and 9 of 27 (33%) colorectal cancer tissues, compared to normal mucosal tissues. In gastric cancers, the rate of cyclin D1 mRNA expression (an index of the density of DNA bands) was significantly higher in patients with tumors invading beyond the submucosal layer, regional lymph nodes and lymphatic vessels (i.e., patients with stage III or IV). In colorectal cancers, the rate of cyclin D1 mRNA expression was significantly higher in patients with venous invasion. Moreover, in patients with colorectal cancer, the survival rate of high-expression group was significantly lower than in low-expression group. Our results suggested that overexpression of cyclin D1 mRNA reflected the severity of gastric cancer and poor prognosis of colorectal cancer.

Topics: Adult; Aged; Aged, 80 and over; Base Sequence; Cell Cycle; Colorectal Neoplasms; Cyclin D1; DNA Primers; Female; Gene Expression; Humans; Male; Middle Aged; Neoplasm Invasiveness; Prognosis; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; RNA, Neoplasm; Stomach Neoplasms

In order to clarify the relationship between cyclin D1 and D2 (CD1/CD2) overexpression and progression, 191 gastric cancer cases (81 early and 110 advanced cancers) were investigated using the 5D4 monoclonal antibody for both CD1/CD2 in immunohistochemistry. 5D4 immunoreactivity was noted in 68 (35.6%) cases, staining being restricted to the nucleus in 27 (14.1%) cases, the cytoplasm in 34 (17.8%) cases, and its presence in both the nucleus and cytoplasm in seven (3.7%). Cases demonstrating cytoplasmic positivity, including both positive cases, were significantly more frequent in advanced cancers (P = 0.010), those having lymph node metastasis (P = 0.004) and cases showing cancer invasion of vessels (P = 0.009), although no relation to histological malignant grading was apparent. In contrast, cases of nuclear positivity behaved no differently from 5D4-negative cases. Statistics showed a trend where survival in patients was worse in the cytoplasm-positive cases than the cytoplasm-negative group. However, multivariate analysis revealed no independent statistical significance in the cytoplasmic positivity of prognosis. Additional studies using DCS-6 antibody for CD1 and C-17 antibody for CD2, suggest that nuclear staining of 5D4 indicates the presence of CD1 but cytoplasmic staining is derived from an antigen that is related to CD2. In conclusion, the present results indicate that the accumulation of CD2 in the cytoplasm may play some role in the progression of gastric cancers but not prognosis; however, CD1 overexpression is not linked to either.

Topics: Cell Nucleus; Cyclin D1; Cyclin D2; Cyclins; Cytoplasm; Disease Progression; Female; Humans; Immunoenzyme Techniques; Male; Middle Aged; Multivariate Analysis; Stomach Neoplasms; Survival Rate

Cyclin D1 and cyclin E are the mammalian G1 cydins that are both required and rate limiting for entry into S phase. Alterations in cell cycle regulators and subsequent deregulation of the cell cycle are frequently involved in tumorigenesis and/or tumor progression. We investigated the expression of cyclin D1 and cyclin E protein in 84 gastric carcinoma by immunohistochemical staining and also the relevance of each cyclin expression to the clinical outcomes. Overexpression of cyclin D1 and cyclin E was noted in 21 of 84 (25.0%) and 34 of 84 (40.5%) gastric cancer tissues, respectively. There was a significant correlation between overexpression of cyclin E and lymph node metastasis (p=0.003), recurrence (p=0.043), disease free survival (p=0.0378) and overall survival (p=0.0319), but no correlation was noted between overexpression of cyclin D1 and other clinicopathologic variables. These findings suggest that overexpression of cyclin E and cyclin D1 is a frequent finding in gastric cancer and immunohistochemical analysis for cell cycle regulators, especially cyclin E might be a useful prognostic indicator in gastric cancer.

Topics: Adult; Cyclin D1; Cyclin E; Female; Humans; Male; Stomach Neoplasms

Cyclin D1 in cooperation with its major catalytic partners, cyclin-dependent kinases cdk4 and cdk6, facilitates progression through the G1 phase of the eukaryotic cell cycle, in part through phosphorylation of the retinoblastoma protein. Cyclin D1's oncogenic properties have been suggested by its cooperation with ras or adenovirus E1a to transform cultured cells, as well its overexpression in transgenic mice that leads to breast cancer. Activated by a number of different mechanisms in human cancers, the cyclin D1 gene is frequently amplified in squamous epithelial cancers derived from the head/neck and esophageal regions. In order to study the functional consequences of cyclin D1 overexpression in these squamous epithelial specific sites, we have linked the Epstein-Barr virus ED-L2 promoter to the human cyclin D1 cDNA and utilized this transgene to generate founder lines. This transgene is transcribed specifically in the tongue, esophagus and forestomach, all sharing a stratified squamous epithelium. The transgene protein product localizes to the basal and suprabasal compartments of these squamous epithelial tissues, and mice from different lines develop dysplasia, a prominent precursor to carcinoma, by 16 months of age in contrast to age-matched wild-type mice. This transgenic model is useful in demonstrating cyclin D1 may be a tumor initiating event in aero-upper digestive squamous epithelial tissues.

Topics: Animals; Blotting, Southern; Cell Transformation, Neoplastic; Cyclin D1; Cyclins; DNA, Complementary; Esophageal Neoplasms; Esophagus; Gastric Mucosa; Herpesvirus 4, Human; Humans; Mice; Mice, Transgenic; Oncogene Proteins; Phenotype; Precancerous Conditions; Promoter Regions, Genetic; Stomach; Stomach Neoplasms; Tongue; Tongue Neoplasms

We examined the expression of p53, p21, cyclin D1, E, and PCNA in 75 cases of gastric cancer by immunohistochemical study and the expression of p21 RNA in cases by in situ hybridization. The rate of stage III, IV cases of p53(+) p21(-) group was significantly higher than that of any other groups. The apportinately 3-year survival rate of p53(+) p21(-) group was significantly lower than either that of p21(+) p53(-) or p53(-) p21(-) group. The 3-year survival rates of positive cases were significantly lower than those of negative cases on both cyclin D1 and E. The positive rate of cyclin E of the p53(-) p21(+) group was significantly lower than that of the p53(+) p21(-) group. The average PCNA Labeling. Index (LI) of the p53(+) p21(-) group was significantly higher than that of the p53(-) p21(+) group. The 3-year survival rate of cases with expression of p21 RNA was higher than that of cases without p21 RNA. Average PCNA L1 of cases with expression of mutant-type p53 was high and the number of poor prognostic cases in cases with expression of mutant-type p53 was large. In contrast, the average PCNA LI of cases with expression of p21 was low and the number of good prognostic cases with expression of p21 was large. These results suggest that p21 suppresses synthesis of DNA via cyclin E and PCNA.

Topics: Cyclin D1; Cyclin-Dependent Kinase Inhibitor p21; Cyclins; Humans; Immunohistochemistry; In Situ Hybridization; Oncogene Proteins; Proliferating Cell Nuclear Antigen; RNA, Messenger; Stomach Neoplasms; Survival Rate; Tumor Suppressor Protein p53

We searched for genetic alterations of the cyclin D1 and cyclin E genes in 45 human gastric carcinoma tissues. Expression of cyclin E mRNA and protein was also analyzed in eight of them by Northern and Western blots and immunohistochemical staining. The cyclin E gene was amplified 3-10 fold in seven gastric cancer tissues (15.6%), of which six were advanced gastric cancers. All of the cases with the cyclin E gene amplification displayed lymph node metastasis. Moreover, the case with the gene amplification overexpressed the cyclin E mRNA and protein. One of eight gastric cancer cell lines, MKN-7, shared the cyclin E gene amplification, and all of the gastric cancer cell lines expressed high levels of the cyclin E mRNA and protein even without gene amplification. Amplification of the cyclin D1 gene was not observed in any of the gastric carcinoma tissues or gastric carcinoma cell lines. These results suggest that the gene amplification and overexpression of cyclin E play an important role in the abnormal growth and progression of gastric carcinoma.

Topics: Aged; Blotting, Northern; Blotting, Western; Cell Line; Cyclin D1; Cyclins; Female; Gene Amplification; Gene Expression; Humans; Lymphatic Metastasis; Male; Middle Aged; Neoplasm Invasiveness; Neoplasm Staging; Oncogene Proteins; Prognosis; RNA, Messenger; Stomach Neoplasms; Tumor Cells, Cultured

The morphology, phenotype, genotype and clinical behaviour of four cases of mantle cell lymphoma (centrocytic lymphoma) presenting primarily in mucosa (two gastric, one in large bowel and one tonsillar) are reviewed. Their relationship with the broader group of mantle cell and mucosa-associated lymphoid tissue (MALT) lymphomas is also discussed. All four tumours showed a monomorphic picture of mantle cells (centrocytes) arranged in a diffuse, or vaguely nodular, pattern. Scattered non-neoplastic germinal centres were entrapped within the tumour cells, although there was no follicular colonization. In two cases distinct epithelial infiltration by tumour cells was observed. All four tumours had a CD19, CD20, CD5, IgD, Leu8 immunophenotype, whereas KiM1P and CD10 expression were absent. DRC antibody showed loose aggregates of dendritic cells in three of four cases. Three cases showed PRAD-1/Cyclin D1 overexpression by Northern blot analysis. Although we were not able to detect bcl-1 rearrangement in the major translocation cluster (MTC) breakpoint, the possibility of bcl-1 rearrangement involving other cluster breakpoints cannot be ruled out. The four cases evolved as a disseminated disease, involving either peripheral lymph nodes, spleen or bone marrow. The biological behaviour of mantle cell lymphoma presenting in mucosa appears, irrespective of localization or macroscopic presentation, similar to that of nodal mantle cell lymphoma. Their tendency to dissemination contrasts with MALT lymphomas, which tend to remain localized, and from which mucosa mantle cell lymphoma must be distinguished. The presence of lymphoepithelial lesions does not seem to be a useful differential feature, since occasional epithelial infiltration was seen in two cases. Reactivity with CD5 appears to be especially useful in distinguishing these, since all four cases were clearly positive, in contrast with what is usually found in MALT lymphomas.

Topics: Aged; Antigens, Surface; Cyclin D1; Cyclins; Female; Humans; Intestinal Neoplasms; Lymphatic Metastasis; Lymphoma, B-Cell, Marginal Zone; Lymphoma, Non-Hodgkin; Male; Middle Aged; Oncogene Proteins; Stomach Neoplasms; Tonsillar Neoplasms

Resection specimens from 83 patients with primary gastric lymphoma (PGL) of B cell phenotype at stage IE and at stage IIE according to the Ann Arbor classification were investigated. Histologically, these lymphomas could be divided into four types: Type I lesions (n = 24) were entirely made up of MALT lymphoma; Type II lesions (n = 13) were predominantly MALT lymphoma containing one to a few foci of high-grade B cell lymphoma; Type III lesions (n = 22) consisted largely of high-grade lymphoma with small areas of low-grade MALT lymphoma; and Type IV lesions (n = 24) were pure high-grade B cell lymphoma, mostly of the large cell type. All patients had undergone primary gastric resection, and 14 received additional chemotherapy (n = 12), or both chemotherapy and radiotherapy (n = 2). The survival probability was significantly higher for Types I and II lymphomas than for Types III and IV tumors (P < 0.05 by the generalized Wilcoxon test). According to The General Rules for the Gastric Cancer Study by the Japanese Research Society for Gastric Cancer, the stage of disease showed a clear distinction between each of them (P < 0.01 by the generalized Wilcoxon test). This staging method seemed to serve well as a prognostic indicator. The histological typing of the PGL of the present series also seemed to correlate with the gross appearance, pathologic stage and prognosis. Furthermore, the expression of cyclin D1, bcl-2 and p53 protein, and PCNA was immunohistochemically investigated in 42 cases of the present series. Most of the low-grade PGL (Types I and II) had less than 60% PCNA-positive cells, whereas the high-grade PGL (Types III and IV) had more than 60% positive cells. In a study for cyclin D1 protein, no cases showed the nuclear staining pattern characteristic for mantle cell lymphoma, and the cytoplasmic staining frequently observed in the node-based large B cell lymphoma was seldom identified in the PGL. This discrepancy might suggest a lineage difference among the morphologically similar, but site-different, lymphomas. On the other hand, bcl-2 protein overexpression was almost equal in frequency between the gastric and node-based high-grade B cell lymphomas. This is in contrast to the reports from Western countries, in which the majority of high-grade gastric tumors were bcl-2 negative.

Topics: Adult; Aged; Cyclin D1; Cyclins; Female; Follow-Up Studies; Humans; Immunophenotyping; Japan; Lymph Nodes; Lymphoma, B-Cell; Lymphoma, B-Cell, Marginal Zone; Male; Middle Aged; Neoplasm Staging; Oncogene Proteins; Proliferating Cell Nuclear Antigen; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-bcl-2; Stomach Neoplasms; Tumor Suppressor Protein p53

The objective of this study was to quantify the changes in p53 and cyclin D1 protein levels in different stages of human esophageal and gastric cardia carcinogenesis in a high-risk population in Henan, China. Immunoreactivity of p53, cyclin D1 and proliferating-cell nuclear antigen (PCNA) was observed in the cell nuclei of esophageal and gastric cardia biopsies. The number of p53-immunostaining-positive cells was low in normal epithelia, slightly increased in basal-cell hyperplasia (BCH), markedly increased in dysplasia (DYS) (10-fold), and further increased in squamous-cell carcinoma (SCC) (40-fold). This pattern of change was similar to that of cell proliferation as indicated by PCNA immunostaining. On the other hand, the number of cyclin D1-immunostaining-positive cells did not increase from BCH to DYS, although a slight increase from DYS to SCC was noted. In the gastric cardia, again, the pattern of change of p53-positive cells in different stages of lesions paralleled the pattern of cell proliferation. The number of p53-positive cells was very low, much lower than that of PCNA-positive cells, in normal, chronic superficial gastritis (CSG) and chronic atrophic gastritis (CAG); therefore, the increase of p53-positive cells from CAG to DYS was more dramatic (100-fold). From DYS to adenocarcinoma (AC), the p53-positive and the PCNA-positive cells increased 4-fold. On the other hand, the number of cyclin D1-positive cells did not increase in pre-cancerous lesions, but increased slightly in AC. This study demonstrates that p53 protein accumulation increased with the progression of pre-cancerous lesions, especially in the genesis of dysplasia, both in the esophagus and in the gastric cardia. Our approach of quantitative immunohistochemistry sheds light on the mechanisms of genesis of esophageal and gastric-cardia cancers, which frequently occur together in many high-incidence areas.

Topics: Adenocarcinoma; Adult; Aged; Biomarkers, Tumor; Carcinoma, Squamous Cell; Cardia; Cell Division; Cell Transformation, Neoplastic; Chi-Square Distribution; Cyclin D1; Cyclins; Esophageal Neoplasms; Female; Humans; Hyperplasia; Immunoenzyme Techniques; Male; Middle Aged; Neoplasm Proteins; Neoplasm Staging; Oncogene Proteins; Precancerous Conditions; Proliferating Cell Nuclear Antigen; Stomach Neoplasms; Tumor Suppressor Protein p53

To study the involvement of the p16 tumor suppressor gene in esophageal cancer development, we examined homozygous deletion of the p16 gene in 13 human esophageal cancer cell lines and 9 gastric cancer cell lines, in which some of genetic alterations have already been characterized. By Southern blot analysis, homozygous deletion was observed in 12 out of the 13 esophageal cancer cell lines (92%), in 2 out of a total of 9 gastric cancer cell lines (22%). It was also found that the p16 gene loss, cyclin D1 amplification and p53 gene mutations occurred independently in these cell lines. These findings suggest that loss or mutations of the p16 gene are involved in most esophageal cancers and that mutation of this gene plays a critical role in the development of esophageal cancer.

Topics: Blotting, Southern; Carrier Proteins; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p16; Cyclins; Esophageal Neoplasms; Gene Deletion; Genes, p53; Homozygote; Humans; Mutation; Oncogene Proteins; Protein Kinase Inhibitors; Stomach Neoplasms; Tumor Cells, Cultured