epidermal-growth-factor and Stomach-Neoplasms

Previous studies suggested an association between the EGF +61 A>G polymorphism and susceptibility to gastric cancer, but the results have been inconsistent. To draw a more precise risk estimation of the association, we performed a meta-analysis of published studies. PubMed, EMBASE, Google Scholar and the Chinese Wanfang databases were systematically searched to identify relevant studies. There were 7 studies involving 1992 cases of gastric cancer and 3202 controls in this meta-analysis. Our study showed that, overall, the EGF +61 A>G polymorphism was significantly associated with the increased risk of gastric cancer in allele model (G vs. A: OR=1.18, 95% CI=1.00-1.39), dominant model (GG + GA vs. AA: OR=1.28, 95% CI=1.05-1.55), homozygous model (GG vs. AA: OR=1.31, 95% CI=1.06-1.63) and heterozygous model (GA vs. AA: OR=1.25, 95% CI=1.01-1.53). The stratified analysis by ethnicity revealed a significant association between EGF +61 A>G polymorphism and gastric cancer risks in Asians. This meta-analysis indicates that EGF +61 A>G polymorphism may increase the risk of gastric cancer, especially in Asians. Large-sized, well-designed studies involving different ethnic groups should be conducted to confirm this association.

Topics: Asian People; EGF Family of Proteins; Epidermal Growth Factor; Genetic Association Studies; Genetic Predisposition to Disease; Humans; Polymorphism, Single Nucleotide; Regression Analysis; Stomach Neoplasms

Alterations in the structure and function of oncogenes and tumor suppressor genes, as well as genetic instability at several other genetic foci may be responsible for stomach carcinogenesis. The particular combination of multiple gene changes found in gastric cancer differs depending on the two histological types, strongly indicating that different genetic pathways exist for well differentiated or intestinal type and poorly differentiated or diffuse type gastric cancers. In general, genetic instability, telomerase activity, CD44 abnormal transcripts, and p53 mutation, all of which are common events of two types of gastric cancer, may be involved mainly in the early stage of stomach carcinogenesis, whereas activation of oncogenes and overexpression of the epidermal growth factor-related growth factor system may chiefly confer progression on gastric cancer. A new strategy of molecular diagnosis of gastrointestinal cancer, which has been implemented as a routine service in the Hiroshima University Clinical Laboratory, may provide new opportunities for early cancer diagnosis and more accurate evaluation of prognosis or grade of malignancy.

Topics: Disease Progression; Epidermal Growth Factor; Gene Expression Regulation, Neoplastic; Genes, p53; Genes, Tumor Suppressor; Humans; Hyaluronan Receptors; Molecular Biology; Mutation; Oncogenes; Prognosis; Stomach Neoplasms; Telomerase; Transcription, Genetic

The EGF stimulation system for growth regulation is implicated in normal and neoplastic cell proliferation. The role of EGF, the EGF receptor, and c-erbB-2 in human gastric cancer is reviewed on the basis of several reports, which have been mainly oriented toward their clinical significance. EGF has been shown immunohistochemically to be present in 26% of gastric cancers (n = 395). The presence of EGF in gastric cancer is correlated with the degree of gastric wall invasion and lymph node metastasis. The 5-year survival of patients with EGF-positive tumors is worse than that of patients with EGF-negative tumors. The presence of EGF in human gastric cancer may therefore represent a higher malignant potential. Fifteen percent of gastric cancers (n = 352) were also shown to be positive for both EGF and the EGF receptor immunohistochemically, and the simultaneous occurrence of EGF and the EGF receptor suggests that these tumors grow in an autocrine fashion. Tumors exhibiting EGF and the EGF receptor simultaneously show a greater degree of local invasion and lymph node metastasis. Increased expression of EGF receptor protein in gastric cancer appears to be related to biologic aggressiveness, although gene amplification has occurred only to a small extent. Twelve percent of gastric cancers (n = 486) were found to be positive for c-erbB-2. This type of tumor has a frequent metastasis, and patients with c-erbB-2-positive cancer have a poorer prognosis than those with c-erbB-2-negative tumors. Selective blockade of the EGF receptor and c-erbB-2 from their ligands with monoclonal antibodies (MoAbs) inhibits the growth of human gastric cancer xenografts. These MoAbs may therefore be effective antitumor agents against gastric cancer showing overexpression of EGF receptors or c-erbB-2.

Topics: Epidermal Growth Factor; ErbB Receptors; Gene Expression; Humans; Lymphatic Metastasis; Prognosis; Receptor, ErbB-2; Stomach Neoplasms

To review genetic alterations in precancerous lesions and adenocarcinoma of the stomach.. Telomere reduction, tpr-met oncogenic rearrangement, overexpression of cripto, p53 mutations, adenomatous polyposis coli gene mutations and K-ras mutations, which are frequently associated with the well differentiated or intestinal type of stomach cancer, were found in intestinal metaplasia and adenoma of the stomach.. Among these genetic alterations, reduction of telomere repeat arrays might be the initial step in the genetic instability of stomach carcinogenesis. Some of the well differentiated type stomach cancers may develop by an accumulation of multiple gene changes similar to those of colorectal cancer.

Topics: Base Sequence; Biomarkers, Tumor; Epidermal Growth Factor; Gene Expression; Genes, Tumor Suppressor; GPI-Linked Proteins; Humans; Immunohistochemistry; Intercellular Signaling Peptides and Proteins; Intestines; Membrane Glycoproteins; Metaplasia; Molecular Sequence Data; Neoplasm Proteins; Oncogenes; Precancerous Conditions; Stomach Neoplasms; Telomere

Topics: Cytokines; Drug Therapy; Epidermal Growth Factor; Factor XIII; Fibroblast Growth Factor 2; Humans; Insulin-Like Growth Factor I; Nutritional Physiological Phenomena; Stomach Neoplasms; Wound Healing

Topics: Adenocarcinoma; Chromosome Deletion; Cytokines; Epidermal Growth Factor; Genes, Tumor Suppressor; Humans; Neoplasm Staging; Oncogenes; Stomach Neoplasms; Transforming Growth Factor alpha; Transforming Growth Factor beta

Human esophageal and gastric carcinomas express multi-autocrine growth factors and hormones including epidermal growth factor (EGF), transforming growth factor (TGF)-alpha and beta, platelet-derived growth factor (PDGF), insulin-like growth factor (IGF) and sex hormones. Overexpression of EGF, TGF-alpha and EGF receptor (EGFR) by tumor cells is closely correlated with the tumor invasion and patient prognosis. This is substantiated by the facts that EGF and TGF-alpha act as autocrine growth factors and then induce the expression of mRNAs for multi-growth factors and their receptors (EGF, TGF-alpha, EGFR, ERBB2, PDGF). Moreover, they stimulate the expression of metalloproteinase genes suggesting that EGF and TGF-alpha successively evoke cascade phenomena which are most convenient for tumor progression, invasion and metastasis. On the other hand, multiple oncogene alterations take place in the process of tumor progression. HST-1 and INT-2 genes which is a member of fibroblast growth factor gene family, are amplified in approximately 50% of primary tumors and all the metastatic tumors of esophageal carcinomas. The amplification of ERBB2 gene in metastatic gastric carcinomas is detected more frequently than in primary carcinomas. Overexpression of multi-growth factor-receptor systems might lead to genetical alterations. Scirrhous gastric carcinoma has vast fibrous stroma with rapid and extensive growth and exhibits high malignancy. Its fibrous stroma may account for synchronous overexpression of EGF, TGF-alpha, PDGF, IGF and TGF-beta by tumor cells. Most of well differentiated adenocarcinomas show overexpression of p 185ERBB2 and coexpression of p 185ERBB2, and EGFR evidently correlates with high malignancy. In conclusion, the accumulation and interaction of several growth factors produced by tumor cells are necessary for the progression of human esophageal and gastric carcinomas. They may be attributed to genetic changes including activation of oncogenes, inactivation and deletion of anti-oncogenes and transcriptional regulatory sequences.

Topics: Epidermal Growth Factor; ErbB Receptors; Esophageal Neoplasms; Female; Gene Expression Regulation, Neoplastic; Growth Substances; Humans; Male; Neoplasm Invasiveness; Stomach Neoplasms; Transforming Growth Factor alpha; Tumor Cells, Cultured

Topics: Biomarkers, Tumor; Carcinoembryonic Antigen; Epidermal Growth Factor; ErbB Receptors; Estradiol; Humans; Receptors, Estrogen; Stomach Neoplasms

Topics: 8-Bromo Cyclic Adenosine Monophosphate; Antineoplastic Agents; Cell Division; Depression, Chemical; Epidermal Growth Factor; ErbB Receptors; Gene Amplification; Gene Expression Regulation, Neoplastic; Growth Substances; Humans; Receptors, Estrogen; Stomach Neoplasms; Transforming Growth Factors; Tumor Cells, Cultured

Topics: Bombesin; Cholecystokinin; Cimetidine; Epidermal Growth Factor; Gastric Inhibitory Polypeptide; Gastrins; Gastrointestinal Hormones; Humans; Motilin; Nerve Tissue; Pancreas; Pancreatic Polypeptide; Pituitary Gland; Secretin; Somatostatin; Stomach Neoplasms; Vasoactive Intestinal Peptide; Zollinger-Ellison Syndrome

There is evidence of a relationship between epidermal growth factor (EGF) and tumor cell proliferation, such as the overexpression of EGF receptor (EGF-R) in different human tumors, which makes this system an interesting target for cancer treatment. Up to now, passive immunotherapy with monoclonal antibodies against the EGF-R has been assayed in clinics. Our approach consists of active immunotherapy with human EGF (hu-EGF). We conducted a pilot clinical trial to define the safety, toxicity and immunogenicity of vaccination with hu-EGF coupled to a carrier protein.. Ten patients with histologically-proven malignant carcinomas (colon, lung, stomach and prostate) in advanced clinical stages were enrolled. Patients were immunized twice (on days 0 and 15) with hu-EGF linked to either tetanic toxoid (TT, five patients) or P64K Neisseria Meningitidis recombinant protein (P64k, five patients), intradermically, using aluminium hydroxyde as adjuvant.. In both groups 60% of patients developed anti-EGF antibody titers without evidence of toxicity. Secondary reactions were very mild, limited to erythema and itching at the site of injection, which disappeared without medication.. We conclude that the proposed vaccination with hu-EGF was well tolerated and that antibody titers against self EGF were developed. The results of this trial may be useful in the design of new clinical trials with higher dose immunization protocols and using more effective adjuvants.

Topics: Aged; Cancer Vaccines; Carcinoma; Carrier Proteins; Colonic Neoplasms; Epidermal Growth Factor; Female; Humans; Immunotherapy; Lung Neoplasms; Male; Middle Aged; Pilot Projects; Prostatic Neoplasms; Stomach Neoplasms; Treatment Outcome

Topics: Animals; Antineoplastic Agents; Bombyx; Carboxypeptidases; Cell Proliferation; Epidermal Growth Factor; ErbB Receptors; Humans; Molecular Docking Simulation; Signal Transduction; Stomach Neoplasms

This report aims to explore how LINC00691 regulates the proliferation and invasion of gastric cancer (GC). Clinical tissue and serum samples, as well as specimens in the Cancer Genome Atlas (TCGA) database, were used to analyse the expression of LINC00691 in GC. Our data indicated that the expression of LINC00691 in GC was significantly higher than that in healthy controls and was associated with clinicopathological features and survival time. In the GC cell lines MKN-45 and HGC-27, the knockdown of LINC00691 suppressed proliferation, colony formation, migration, and invasion. Bioinformatics analysis and luciferase reporter gene experiments showed that LINC00691 activated Lin28 transcription. Western blot analysis indicated that the knockdown of LINC00691 contributed to the decreased expression of p-JAK2 and p-STAT3 in GC cells. The Janus kinase/signal transducer and activator of transcription (JAK/STAT) signalling pathway inhibitor ruxolitinib effectively suppressed the effects of LINC00691. In addition, both LINC00691 and Lin28 promoted the expression of epidermal growth factor (EGF). Therefore, our study clarified that LINC00691 is highly expressed in GC and is a potential biomarker for GC diagnosis and prognosis. LINC00691 promotes the proliferation and invasion of GC cells by activating Lin28 transcription and facilitating EGF expression through the JAK/STAT signalling pathway, which provides new ideas for targeted therapy of GC.

Topics: Animals; Biomarkers, Tumor; Cell Line, Tumor; Cell Movement; Cell Proliferation; Epidermal Growth Factor; Female; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Humans; In Situ Hybridization, Fluorescence; Janus Kinase 2; Janus Kinases; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Middle Aged; Nitriles; Prognosis; Pyrazoles; Pyrimidines; RNA-Binding Proteins; RNA, Long Noncoding; Signal Transduction; STAT3 Transcription Factor; Stomach Neoplasms; Xenograft Model Antitumor Assays

For gastric cancer (GC) control, metastasis and chemoresistance are the major challenges, accompanied with various stresses. Ataxin-2-like (ATXN2L) was discovered as a novel regulator of stress granules, yet its function in cancers remained unknown. Hence, we wanted to explore the functions of ATXN2L to see whether it participates in stress-related cancer malignant activities. Clinical follow-up was performed to see the impact of ATXN2L on GC patient survival. As a result, ATXN2L expression was upregulated in GC tissue and indicated adverse prognosis for overall survival and recurrence. In GC cells, ATXN2L expression was knocked down and functional experiments were performed. ATXN2L promoted GC cell migration and invasion via epithelial to mesenchymal transition, yet no influence on proliferation was detected by ATXN2L interference. When adding the chemotherapeutic agent oxaliplatin to induce stress, silencing ATXN2L sensitized GC cells to oxaliplatin. Interestingly, oxaliplatin was found to in turn promote ATXN2L expression and stress granule assembly. Then, two acquired oxaliplatin-resistant strains were generated by long-term oxaliplatin induction. The oxaliplatin-resistant strains presented with elevated ATXN2L levels, while silencing ATXN2L in the strains reversed the oxaliplatin resistance by increasing reactive oxygen species production and apoptosis. These results suggested that ATXN2L was responsible for not only intrinsic but also acquired oxaliplatin chemoresistance. Finally, ATXN2L-related signaling was screened using bioinformatic methods, and epidermal growth factor (EGF) was verified to promote ATXN2L expression via PI3K/Akt signaling activation. Blocking EGFR/ATXN2L signaling reversed GC cell oxaliplatin resistance and inhibited migration. In conclusion, ATXN2L promotes cell invasiveness and oxaliplatin resistance and can be upregulated by EGF via PI3K/Akt signaling. ATXN2L may be an indicator and therapeutic target in GC, especially for oxaliplatin-based chemotherapy.

Topics: Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cell Movement; Cell Proliferation; Computational Biology; Disease Progression; Drug Resistance, Neoplasm; Epidermal Growth Factor; Epithelial-Mesenchymal Transition; Gene Expression Regulation, Neoplastic; Humans; Neoplasm Recurrence, Local; Nerve Tissue Proteins; Oxaliplatin; Phosphatidylinositol 3-Kinases; Prognosis; Proto-Oncogene Proteins c-akt; Signal Transduction; Stomach Neoplasms; Up-Regulation

Epithelial-to-mesenchymal transition (EMT) plays important roles in the migration, invasion, and metastasis of cancer cells. However, the role of Src in epidermal growth factor (EGF)-induced EMT and migration in gastric cancer cells remains to be clarified. In the current study, the effect of Src on EGF-stimulated EMT and migration was explored in gastric cancer cells. EGF induced EMT in gastric cancer cells and increased their migratory ability, which was accompanied by the phosphorylation of Src. PP2, the Src inhibitor, markedly suppressed EGF-mediated EMT and migration in gastric cancer cells. Additionally, EGF-stimulated upregulation of zinc finger E-box binding homeobox 1 (ZEB1) and zinc finger E-box binding homeobox 2 (ZEB2) was significantly repressed by PP2. Further analysis showed that EGF-stimulated phosphorylation of protein kinase B (AKT) was almost completely abolished by PP2, whereas that of extracellular signal-regulated kinase (ERK), signal transducer and activator of transcription 3 (STAT3) was only mildly suppressed. Moreover, LY294002, the AKT inhibitor, significantly inhibited EGF-induced upregulation of ZEB1 and ZEB2 as well as EMT and migration stimulated by EGF in gastric cancer cells. However, neither ERK inhibitor nor STAT3 inhibitor repressed EGF-induced EMT-related changes. Taken together, these results suggest that Src promotes EGF-stimulated EMT and migration by upregulation of ZEB1 and ZEB2 through AKT signaling pathway in gastric cancer cells.

Topics: Cell Line, Tumor; Cell Movement; Epidermal Growth Factor; Epithelial-Mesenchymal Transition; Humans; MicroRNAs; Neoplasm Invasiveness; Proto-Oncogene Proteins c-akt; Recombinant Proteins; Signal Transduction; src-Family Kinases; Stomach Neoplasms; Transcriptional Activation; Up-Regulation; Zinc Finger E-box Binding Homeobox 2; Zinc Finger E-box-Binding Homeobox 1

Epidermal growth factor receptor (EGFR) plays an important role in gastric cancer (GC) progression. Our previous data demonstrated that type II cGMP-dependent protein kinase (PKG II) could block the EGF-EGFR axis as well as down-stream signaling pathways, for example, MAPK, PI3 K, and PLC in GC cells. However, the exact mechanisms of PKG II against cancer remain unclear. Therefore, the present work was to address the above question. Human GC cell line AGS was infected with adenoviral construct encoding cDNA of PKG II (Ad-PKG II) to up-regulate PKG II and then treated with 8-pCPT-cGMP. Two-dimensional electrophoresis (2-DE) was used to analyze the changes of protein expression in the cells. The results showed that 17 proteins had more than twofold changes in EGF-treated group compared with control. However, Ad-PKG II could effectively reversed the changes. Furthermore, far upstream element-binding protein 1 (FUBP1) and MarvelD3 were chosen and PKG II activation reversed EGF/EGFR-induced up-regulation of FUBP1 and downregulation of MarvelD3, respectively. MarvelD3 silence effectively abolished the inhibitory effect of PKG II on EGF-triggered migration. These data indicated that the inhibitory effect of PKG II partially was associated with MarvelD3.

Topics: Cell Line, Tumor; Cyclic GMP; Cyclic GMP-Dependent Protein Kinase Type II; DNA Helicases; DNA-Binding Proteins; Electrophoresis, Gel, Two-Dimensional; Epidermal Growth Factor; ErbB Receptors; HEK293 Cells; Humans; Membrane Proteins; Phosphorylation; RNA-Binding Proteins; Signal Transduction; Stomach Neoplasms; Thionucleotides; Transcriptional Activation

Previous studies revealed that type II cGMP-dependent protein kinase G (PKG II) could inhibit the activation of epidermal growth factor receptor (EGFR) which is a widely investigated RTK. PDGFR belongs to family of receptor tyrosine kinases (RTKs) too. However, the effect of PKG II on PDGFR activation is not clear yet. This study investigated potential regulatory effect of PKG II on activation of PDGFRβ and the downstream signaling transductions in gastric cancer. The results from CCK8 assay and Transwell assay indicated that PDGF-BB induced cell proliferation and migration. Activated PKG II reversed the above variations caused by PDGF-BB. Immunoprecipitation and Western blotting results showed that PKG II combined with PDGFRβ and phosphorylated this receptor, and thereby inhibited PDGF-BB induced activation of PDGFRβ, and MAPK/ERK and PI3K/Akt mediated signal transduction pathways. Based on the prediction by phosphorylation site software, Ser643 and Ser712 were mutated to alanine respectively which prevented phosphorylation at these sites. Mutation at Ser712 abolished the inhibitory function of PKG II on PDGFRβ activation but mutation of Ser643 had no such an effect, indicating that Ser712 was PKG II-specific phosphorylating site of PDGFRβ. In conclusion, PKG II inhibited PDGFRβ activation in gastric cancer via phosphorylating Ser712 of this RTK.

Topics: Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclic GMP-Dependent Protein Kinase Type II; Epidermal Growth Factor; ErbB Receptors; Humans; Phosphorylation; Platelet-Derived Growth Factor; Proto-Oncogene Proteins c-sis; Receptor, Platelet-Derived Growth Factor beta; Receptors, Platelet-Derived Growth Factor; Signal Transduction; Stomach Neoplasms

Epidermal growth factor (EGF) signaling has been shown to induce epithelial to mesenchymal transition (EMT) in many types of cancer cells. However, the molecular mechanism of EGF-induced EMT in gastric cancer remains largely unknown. In the present study, we found that human gastric cancer cell lines SGC-7901 and BGC-823 underwent EMT phenotypic changes upon exposure to EGF. The induction of EMT was consistent with aggressive characteristics such as increased cell migration, invasion and clonogenic growth. Additionally, EGF stimulation also led to the upregulation of urokinase plasminogen activator receptor (uPAR) both at mRNA and protein levels. Knockdown of uPAR by siRNA significantly attenuated EMT induction by EGF in SGC-7901 and BGC-823 cells. Furthermore, EGF increased ERK1/2 activity and blocking ERK1/2 signaling with its inhibitor, U0126, markedly inhibited EGF-induced uPAR expression and consequently EMT. Collectively, the present study demonstrated that EGF induced aggressiveness of gastric cancer cells by activating EMT, which involved the activation of the ERK1/2 pathway and, subsequently, uPAR expression.

Topics: Cell Line, Tumor; Cell Movement; Epidermal Growth Factor; Epithelial-Mesenchymal Transition; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Humans; MAP Kinase Signaling System; Neoplasm Invasiveness; Receptors, Urokinase Plasminogen Activator; RNA, Small Interfering; Stomach Neoplasms

CMTM3 (CKLF-like MARVEL transmembrane domain containing 3), a tumor suppressor gene, is involved in multiple types of malignancies. CMTM3 knockdown promotes metastasis of gastric cancer via the STAT3/Twist1/EMT signaling pathway. Strong epidermal growth factor receptor1 (EGFR) expression is significantly associated with tumor metastasis and poor outcomes of gastric cancer patients. In this paper, we show that CMTM3 suppresses epidermal growth factor (EGF)-mediated migration and STAT3 signaling, downregulates EGFR expression via accelerating EGFR degradation in gastric cancer cells. CMTM3 colocalizes with early endosome markers Rab5 and EEA1. Co-immunoprecipitation (Co-IP) assay further confirms that CMTM3 interacts with Rab5. More importantly, CMTM3 markedly increases Rab5 activity. The suppressive effects of CMTM3 on EGFR expression and EGF-mediated migration can be abrogated by the siRNA against Rab5. Finally, we found that the C-terminal region of CMTM3 plays more important roles in the tumor suppressive effects of CMTM3. Overall, this study demonstrates that CMTM3 decreases EGFR expression, facilitates EGFR degradation, and inhibits the EGF-mediated tumorigenicity of gastric cancer cells via enhancing Rab5 activity.

Topics: Cell Movement; Chemokines; Down-Regulation; Endosomes; Epidermal Growth Factor; ErbB Receptors; Gene Expression Regulation, Neoplastic; HeLa Cells; Humans; MARVEL Domain-Containing Proteins; Neoplasm Invasiveness; Protein Interaction Domains and Motifs; Proteolysis; rab5 GTP-Binding Proteins; RNA Interference; Signal Transduction; STAT3 Transcription Factor; Stomach Neoplasms; Time Factors; Transfection; Vesicular Transport Proteins

Gastric cancer remains a major health concern, and improvement of the therapeutic options is crucial. Treatment with targeted therapeutics such as the EGFR-targeting antibody cetuximab or the HER2-targeting antibody trastuzumab is either ineffective or moderately effective in this disease, respectively. In this study, we analysed the involvement of the HER receptor ligands amphiregulin (AREG), epidermal growth factor (EGF), heparin-binding epidermal growth factor (HB-EGF) and transforming growth factor alpha (TGFα) in the responsiveness of gastric cancer cell lines to cetuximab and trastuzumab.. A panel of 11 gastric cancer cell lines was characterized for cetuximab and trastuzumab sensitivity, ligand secretion and expression and activation of the HER receptors using WST-1 cell proliferation assays, ELISAs and Western blot analyses. We further investigated the effects of an exogenous ligand application on the cetuximab and trastuzumab sensitivity.. We found no correlation between TGFα secretion and the sensitivity to cetuximab or trastuzumab. For AREG, we confirmed previous results indicating that this ligand is a positive predictor of cetuximab sensitivity. Exogenous HB-EGF was effective in rescuing sensitive cell lines from inhibition of cell proliferation by both, cetuximab and trastuzumab.. Our data indicate that HB-EGF may be a useful marker for the prediction of trastuzumab sensitivity in gastric cancer.

Topics: Amphiregulin; Antineoplastic Agents; Cell Division; Cell Line, Tumor; Cetuximab; Epidermal Growth Factor; Heparin-binding EGF-like Growth Factor; Humans; Ligands; Prognosis; Receptor, ErbB-2; Stomach Neoplasms; Transforming Growth Factor alpha; Trastuzumab

Our previous study demonstrated that type II cyclic guanosine monophosphate (cGMP)-dependent protein kinase (PKG II) inhibited epidermal growth factor (EGF)-induced phosphorylation/activation of epidermal growth factor receptor (EGFR). Since human epidermal growth factor receptor 2 (HER2) has a similar molecular structure to EGFR, the present study was designed to investigate whether PKG II also inhibits HER2 activation. The human gastric cancer cell line HGC‑27 was infected with an adenoviral construct encoding cDNA of PKG II (Ad‑PKG II) to increase the expression of PKG II and treated with 8‑(4‑chlorophenylthio)guanosine‑3',5'‑cyclic monophosphate (8‑pCPT‑cGMP) to activate the kinase. Western blotting was performed to detect the tyrosine and serine/threonine phosphorylation of HER2. Co‑immunoprecipitation was performed in order to determine the binding between PKG II and HER2. In addition, a QuikChange Lightning Site‑Directed Mutagenesis kit was used to mutate threonine 686 of HER2 to glutamic acid or alanine. The results demonstrated that EGF treatment increased the tyrosine phosphorylation (activation) of HER2. Increasing the PKG II activity of HGC‑27 cells through infection with Ad‑PKG II and stimulation with 8‑pCPT‑cGMP inhibited the EGF‑induced tyrosine phosphorylation/activation of HER2. PKG II bound directly with HER2 and caused phosphorylation of threonine 686. When threonine 686 of HER2 was mutated to alanine, which could not be phosphorylated by PKG II, the inhibitory effect of PKG II on the activation of HER2 was eradicated. When threonine 686 of HER2 was mutated to glutamic acid, which mimicked the phosphorylation of this site, treatment with EGF had no stimulating effect on tyrosine phosphorylation/activation of the mutant HER2. The results suggested that PKG II inhibits EGF‑induced activation of HER2 through binding with and causing threonine 686 phosphorylation of this oncogenic protein.

Topics: Cell Line, Tumor; Cyclic GMP-Dependent Protein Kinase Type II; Epidermal Growth Factor; Humans; Phosphorylation; Phosphoserine; Phosphothreonine; Protein Binding; Receptor, ErbB-2; Stomach Neoplasms

CD24, a mucin-like membrane glycoprotein, plays a critical role in carcinogenesis, but its role in human gastric cancer and the underlying mechanism remains undefined.. The contents of CD24 and epidermal growth factor receptor (EGFR) in gastric cancer cells (SGC-7901 and BGC-823) and non-malignant gastric epithelial cells (GES-1) were evaluated by Western blotting assay. Cellular EGFR staining was examined by immunofluorescence assay. Cell migration rate was measured by wound healing assay. The effects of depletion/overexperssion of CD24 on EGFR expression and activation of EGF/EGFR singaling pathways were evaluated by immunofluorescence, qPCR, Western blotting and flow cytometry techniques. RhoA activity was assessed by pulldown assay. CD24 and EGFR expression patterns in human gastric tumor samples were also investigated by immunohistochemistry staining.. CD24 was overexpressed in human gastric cancer cells. Ectopic expression of CD24 in gastric epithelial cells augmented the expression of EGFR, while knockdown of CD24 in gastric cancer cells decreased the level of EGFR and cell migration velocity. To further explore the mechanisms, we investigated the effect of CD24 expression on EGF/EGFR signaling. We noticed that this effect of CD24 on EGFR expression was dependent on promoting EGFR internalization and degradation. Lower ERK and Akt phosphorylations in response to EGF stimulation were observed in CD24-depleted cells. In addition, we noticed that the effect of CD24 on EGFR stability was mediated by RhoA activity in SGC-7901 gastric cancer cells. Analysis of gastric cancer specimens revealed a positive correlation between CD24 and EGFR levels and an association between CD24 expression and worse prognosis.. Thus, these findings suggest for the first time that CD24 regulates EGFR signaling by inhibiting EGFR internalization and degradation in a RhoA-dependent manner in gastric cancer cells.

Topics: CD24 Antigen; Cell Differentiation; Cell Line, Tumor; Cell Movement; Down-Regulation; Endocytosis; Epidermal Growth Factor; ErbB Receptors; Gene Knockdown Techniques; Humans; Proteolysis; rhoA GTP-Binding Protein; RNA, Small Interfering; Signal Transduction; Stomach Neoplasms

To investigate levels of epidermal growth factor (EGF) and prostaglandin E2 (PGE2) in Han Chinese patients with Helicobacter pylori-positive gastric low-grade intraepithelial neoplasia (LGIN).. In this prospective, observational study, gastric specimens from patients with LGIN were collected by gastroscopy with consecutive biopsy. EGF and PGE2 concentrations in serum and gastric juice from patients with LGIN were measured by enzyme-linked immunosorbent assay. Presence of H. pylori infection was assessed in patients with LGIN and healthy controls.. Out of 5 638 patients and 548 controls, H. pylori infection in patients with chronic gastritis was associated with disease type (endoscopic classification) and disease severity. Patients with H. pylori-positive LGIN had significantly higher concentrations of serum EGF and lower concentrations of serum PGE2 versus patients with H. pylori-negative LGIN. Serum EGF and PGE2 levels in patients with LGIN were not significantly associated with disease type, but were significantly associated with disease severity.. H. pylori infection was associated with chronic gastritis type (endoscopic classification) and disease severity. Abnormal EGF and PGE2 levels may be associated with H. pylori-positive LGIN in Han Chinese patients in central China.

Topics: Adult; Aged; Aged, 80 and over; Carcinoma in Situ; Case-Control Studies; China; Dinoprostone; Epidermal Growth Factor; Female; Gastric Juice; Gastric Mucosa; Gastritis; Gastroscopy; Gene Expression; Helicobacter Infections; Helicobacter pylori; Humans; Male; Middle Aged; Neoplasm Grading; Prospective Studies; 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

Dopamine (DA), an important neurotransmitter, has been reported to play a negative role in tumor progression. DA acts its role via dopamine receptors (DRs), which can be divided into five receptor subtypes (D1R-D5R). Among these receptor subtypes, D2R has been found to inhibit IGF-I-induced gastric cancer cell growth. However, the functions of D2R in gastric cancer cell invasion remain elusive. Here, we found that D2R expression was decreased in gastric cancer cells. DA treatment dose-dependently inhibited EGF-mediated gastric cancer cell invasion and migration via D2R. Furthermore, D2R decreased EGF-mediated MMP-13 production, and attenuated EGFR and AKT activation. Together with the results that EGF promoted gastric cancer cell invasion and migration via EGFR/AKT pathway, these data indicate that DA treatment, acting via D2R, suppresses gastric cancer cell invasion and migration via inhibition of EGFR/AKT/MMP-13 pathway. Thus, our findings suggest that use of D2R agonist may have a potential therapeutic effect on gastric cancer.

Topics: Antineoplastic Agents; Carcinogenesis; Cell Line, Tumor; Cell Movement; Cell Proliferation; Dopamine; Epidermal Growth Factor; ErbB Receptors; Gene Expression Regulation, Neoplastic; Humans; Matrix Metalloproteinase 13; Oncogene Protein v-akt; Receptors, Dopamine D2; Signal Transduction; Stomach Neoplasms

Tetraspanins are cell-surface glycoproteins and have received attention recently as both suppressors and promoters of metastasis. CO-029 is a member of the tetraspanin family and is implicated to be a metastasis-promoting tetraspanin in some cancers. However, the role of CO-029 in gastric cancer remains unexplored. The present study aimed to investigate the expression of CO-029 in gastric cancer tissues and to determine whether CO-029 is involved in the effects of epidermal growth factor (EGF) on gastric cancer cell proliferation and invasion. We collected clinical samples and found that the expression of CO-029 was increased both at the mRNA level and protein level in gastric cancer tissues in comparison to normal and tumor-adjacent tissues, as demonstrated by RT-qPCR and western blot analysis, respectively. Furthermore, we performed an in vitro experiment using AGS cells and observed that EGF promoted AGS cell proliferation and enhanced the invasion ability of the AGS cells, as shown by MTT assay and cell invasion assay, respectively. To the best of our knowledge, our results reveal for the first time, that CO-029 expression was affected by EGF in a concentration- time-dependent manner. The knockdown of CO-029 attenuated the effects of EGF on gastric cancer cell proliferation and invasion. These findings suggest that CO-029 is an oncogene in human gastric cancer and that CO-029 at least partially mediates the effects of EGF on gastric cancer cell proliferation and invasion. Our data may provide a novel target for therapeutic intervention in human gastric cancer.

Topics: Cell Line, Tumor; Cell Movement; Cell Proliferation; Epidermal Growth Factor; Gene Expression; Humans; RNA, Messenger; Stomach Neoplasms; Tetraspanins

Wnt5a, a ligand for activating the non-canonical Wnt signaling pathway, is commonly associated with Epithelial-to-mesenchymal transition (EMT) in cancer cell metastasis. Here, we show that downregulation of Wnt5a mRNA and protein by EGF is necessary for EGF-induced EMT in gastric cancer SGC-7901 cells. To further explore the mechanisms, we investigated the effect of EGF signaling on Wnt5a expression. EGF increased Arf6 and ERK activity, while blockade of Arf6 activation repressed ERK activity, up-regulated Wnt5a expression and repressed EMT in response to EGF. We also demonstrate that EGF inactivated Wnt5a transcription by direct recruitment of ERK to the Wnt5a promoter. On the other hand, inhibition of ERK phosphorylation resulted in decreased movement of ERK from the cytoplasm to the nucleus, following rescued Wnt5a mRNA and protein expression and favored an epithelial phenotype of SGC-7901 cells. In addition, we notice that kinase-dead, nuclear-localised ERK has inhibitory effect on Wnt5a transcription. Analysis of gastric cancer specimens revealed an inverse correlation between P-ERK and Wnt5a protein levels and an association between Wnt5a expression and better prognosis. These findings indicate that Wnt5a is a potential suppressor of EMT and identify a novel Arf6/ERK signaling pathway for EGF-regulated Wnt5a expression at transcriptional level of gastric cancer cells.

Topics: ADP-Ribosylation Factor 6; ADP-Ribosylation Factors; Base Sequence; Cell Differentiation; Cell Line, Tumor; Cell Movement; Epidermal Growth Factor; Epithelial-Mesenchymal Transition; Extracellular Signal-Regulated MAP Kinases; Gene Expression Profiling; Gene Expression Regulation; Humans; Molecular Sequence Data; Neoplasm Metastasis; Phosphorylation; Prognosis; Proto-Oncogene Proteins; Signal Transduction; Stomach Neoplasms; Wnt Proteins; Wnt-5a Protein

Epidermal growth factor (EGF) induces various biological signaling pathways, including proliferation and differentiation and it is the natural ligand of the epidermal growth factor receptor (EGFR) which is a member of tyrosine kinase transmembrane receptor family. EGF and EGFR control important processes in carcinogenesis and several differences in this signaling pathway are very common in certain types of cancers. In present study, we examined EGF A61G gene polymorphism as a marker of risk and progression in gastric cancer.. A total of 84 patients with gastric cancer and 146 control individuals were enrolled in the current study. EGF A61G gene variation was genotyped by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis.. The distribution of EGF A61G genotypes were different between patients with gastric cancer and controls (p=0.039). Serum EGF levels in gastric cancer cases were significantly lower than those in controls (p=0.012). There were no correlations between the serum EGF levels according to EGF A61G genotype and allelic distributions in patients with gastric cancer.. Our findings suggested that EGF A61G gene variations and EGF serum levels might be associated with the risk of gastric cancer.

Topics: Adult; Aged; Alleles; Epidermal Growth Factor; Female; Genetic Predisposition to Disease; Genotype; Humans; Male; Middle Aged; Polymorphism, Single Nucleotide; Risk Factors; Stomach Neoplasms

Circulating factors in patients with gastric/gastroesophageal junction (GEJ) cancers may promote tumor progression and metastasis and may be targeted for therapy.. Serum levels of ligands-vascular endothelial growth factor A (VEGF-A), fibroblast growth factor 2 (FGF2), epidermal growth factor (EGF), hepatocyte growth factor (HGF)-from four targetable pathways were measured before surgery, and levels were correlated to clinicopathologic characteristics and overall survival (OS).. In 147 patients who underwent potentially curative resection for gastric/GEJ adenocarcinoma, VEGF-A levels were higher in patients with R1 versus R0 resection (p = 0.037). High EGF levels were associated with poorly differentiated tumors (p = 0.02). Elevated FGF2 levels were found in Lauren diffuse-type tumors (p = 0.017) and tumors with seven or more metastatic nodes (N3) (p < 0.042). Patients with advanced-staged tumors had higher HGF levels (p = 0.012). At a median follow-up of 35 months, 46 patients (31 %) had died. Increased VEGF and HGF levels were correlated with decreased OS (p = 0.009 and 0.005). An adjusted total value (ATV) of all factors was better than any single factor in stratifying patients into good and poor prognosis groups (5-year OS 84.1 vs. 53.9 %, p = 0.005). By multivariate analysis, serum VEGF-A and ATV were significant independent prognostic factors (along with T and N category) for OS (p = 0.028 and 0.013, respectively).. In patients undergoing resection for gastric and GEJ cancer, high levels of angiogenic and growth factors are associated with unfavorable tumor characteristics and poorer overall survival. Thus levels of these factors can help delineate tumor biology and stratify prognosis.

Topics: Adenocarcinoma; Adult; Aged; Aged, 80 and over; Biomarkers, Tumor; Enzyme-Linked Immunosorbent Assay; Epidermal Growth Factor; Esophageal Neoplasms; Esophagogastric Junction; Female; Fibroblast Growth Factor 2; Follow-Up Studies; Hepatocyte Growth Factor; Humans; Lymphatic Metastasis; Male; Middle Aged; Neoplasm Staging; Prognosis; Retrospective Studies; Stomach Neoplasms; Survival Rate; Vascular Endothelial Growth Factor A

Our previous data demonstrated that type II cGMP‑dependent protein kinase (PKG II) inhibited epidermal growth factor (EGF)-induced MAPK/ERK/JNK‑mediated signal transduction through inhibiting the phosphorylation/activation of the epidermal growth factor receptor (EGFR). Since the EGFR also binds with several other ligands as well as EGF, the present study was designed to investigate whether PKG II inhibited transforming growth factor-α (TGF-α), betacellulin (BTC) and epiregulin (EPR) induced phosphorylation/activation of the EGFR and consequent MAPK/ERK‑mediated signaling. The human gastric cancer cell line AGS, was infected with adenoviral constructs encoding cDNA of PKG II (Ad-PKG II) to increase the expression of PKG II and was treated with 8-pCPT-cGMP to activate the kinase. Western blotting was applied to detect the phosphorylation of EGFR and MAPK/ERK. The results demonstrated that treatment with EGF (100 ng/ml, 5 min), TGF-α (100 ng/ml, 5 min), BTC (100 ng/ml, 5 min) and EPR (100 ng/ml, 5 min) increased the tyrosine (tyr) 1068 phosphorylation of the EGFR and the threonine (thr) 202/tyr 204 phosphorylation of MAPK/ERK. Infecting the cells with Ad-PKG II and stimulating the kinase with 8-pCPT-cGMP efficiently inhibited the phosphorylation of the EGFR and MAPK/ERK induced by EGF, TGF-α, BTC and EPR. The results indicated that PKG II also inhibits the activation of the EGFR caused by diverse ligands of the receptor.

Topics: Betacellulin; Cell Line, Tumor; Cyclic GMP-Dependent Protein Kinase Type II; Enzyme Activation; Epidermal Growth Factor; Epiregulin; ErbB Receptors; Extracellular Signal-Regulated MAP Kinases; Humans; Intercellular Signaling Peptides and Proteins; Ligands; Phosphorylation; Phosphotyrosine; Stomach Neoplasms; Transforming Growth Factor alpha

Growth and inflammatory factors are associated with poor prognosis in gastric adenocarcinoma (GA); however, the additive effects of growth and inflammatory factors in GA remain unclear. In this study, we investigated the ability of epidermal growth factor (EGF) and interleukin (IL-1β) to activate extracellular signal-regulated kinase (ERK)1/2 in GA cells, and correlated the relationships between their roles with the metastatic potential both in GA cells and GA tissues. The effects of EGF, IL-1β and EGF plus IL-1β in AGS and MKN-45 GA cells were examined using western blotting, Transwell migration and invasion assays, immunocytochemical staining and an activator protein (AP)-1 luciferase reporter gene assay, and was further characterized in GA tissues by immunohistochemistry. The results exhibited that EGF and IL-1β additively activated ERK1/2, increased migration and invasion than either EGF or IL-1β alone in AGS and MKN-45 cells. The mechanisms were involved in upregulating MMP-9 expression through increasing AP-1 transcriptional activity via ERK1/2 pathway; these effects were dose-dependently inhibited by silencing ERK1/2 or using U0126. In vivo data also confirmed that the overexpression of p-ERK1/2 in GA tissues correlated well with the EGF, IL-1β, EGF plus IL-1β, and was associated with metastasis, which was well correlation with the expression of MMP-9 and c-fos (AP-1). The results demonstrate that growth and inflammatory factors play an important role in metastasis of GA by additively activating ERK-1/2 and AP-1, and upregulating MMP-9. As both cytokines contribute to the migration and invasion of GA cells, EGF/IL-1β/ERK1/2 pathways may be key pathways closely associated with GA progression.

Topics: Adenocarcinoma; Butadienes; Cell Line, Tumor; Cell Movement; Enzyme Inhibitors; Epidermal Growth Factor; Female; Humans; Interleukin-1beta; Male; MAP Kinase Signaling System; Matrix Metalloproteinase 9; Middle Aged; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Neoplasm Invasiveness; Nitriles; Phosphorylation; Stomach Neoplasms; Transcription Factor AP-1

Increased expression of epidermal growth factor (EGF), its receptor (EGFR), and c-erb-B2 protein, which is homological with the EGF receptor, in gastric mucosa, may play a role in gastric carcinogenesis. We assessed if the infection and eradication of Helicobacter pylori (H. pylori) affects the gastric expression of growth factors and serum gastrin concentrations.. We examined immunohistochemically gastric EGF and both receptors' expression in: gastric cancer (GC; n=29), chronic gastritis with H. pylori infection (GHp+; n=40) before and after eradication and in patients without H. pylori infection (GHp-; n=42).. Before the eradication therapy, gastric mucosal EGF and both receptor's expressions in GHp+ patients were increased compared to GHp- (p<0.05), but were similar to GC. After eradication, EGF and the receptor's expression significantly decreased in the gastric body. Both EGFR and c-erb-B2 expression in the antrum were still higher than in GHp- (p<0.05), and remained comparable to GC.. In patients with H. pylori infection the gastric mucosal EGF, EGFR, and c-erb-B2 expressions are similar to those observed in gastric cancer. The persistence of the antral expression of receptors after eradication, at a level comparable to the gastric cancer group, suggests their eventual role in the progression of changes initiated by H. pylori toward carcinogenesis.

Topics: Aged; Anti-Bacterial Agents; Drug Therapy, Combination; Epidermal Growth Factor; ErbB Receptors; Gastric Mucosa; Gastritis; Gene Expression Regulation; Gene Expression Regulation, Neoplastic; Helicobacter Infections; Helicobacter pylori; Host-Pathogen Interactions; Humans; Male; Middle Aged; Receptor, ErbB-2; Stomach Neoplasms

The molecular pathway regulating gastric carcinoma (GC) invasiveness and metastasis remains elusive. Here, we detected significant increase in the phosphorylated epidermal growth factor receptor (pEGFR), MMP7, and MMP13 in the resected GC, compared with the adjacent normal tissue, in patients. Moreover, strong positive correlation was detected between pEGFR and MMP7, and between pEGFR and MMP13 in GC. To examine whether a causal link exists, we used two human GC lines, SNU-5 and AGS, to study the cross talk between EGFR signaling activation, and expression of MMP7 and MMP13. We found that EGF-induced EGFR phosphorylation activated both MMP7 and MMP13, and consequently cancer invasiveness. EGF-induced activation of MMP7 and MMP13 can be both inhibited by use of an inhibitor for EGFR. EGF-induced activation of MMP7 can be also significantly inhibited by use of an inhibitor for Akt, but not an inhibitor for ERK1/2, while EGF-induced activation of MMP13 can be significantly inhibited by use of an inhibitor for ERK1/2, but not by an inhibitor for Akt. These data suggest that EGF-induced activation of MMP7 and MMP13 in GC is through phosphatidylinositol 3-kinase (PI3K) and extracellular-related kinase/mitogen-activated protein kinase (ERK/MAPK) signaling pathway, respectively. Our study thus highlights EGFR signaling regulated MMP7 and MMP13 activation as molecular basis for metastasis of GC, and further demonstrate that different signaling pathway cascades are involved in the downstream signaling transduction.

Topics: Blotting, Western; Cell Movement; Down-Regulation; Enzyme Inhibitors; Epidermal Growth Factor; ErbB Receptors; Humans; Matrix Metalloproteinase 13; Matrix Metalloproteinase 7; Mitogen-Activated Protein Kinases; Phosphorylation; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Signal Transduction; Stomach Neoplasms; Tumor Cells, Cultured

Although HER2-targeting antibody trastuzumab confers a substantial benefit for patients with HER2-overexpressing breast and gastric cancer, overcoming trastuzumab resistance remains a large unmet need. In this study, we revealed a STAT3-centered positive feedback loop that mediates the resistance of trastuzumab. Mechanistically, chronic exposure of trastuzumab causes the upregulation of fibronection (FN), EGF and IL-6 in parental trastuzumab-sensitive breast and gastric cells and convergently leads to STAT3 hyperactivation. Activated STAT3 enhances the expression of FN, EGF and IL-6, thus constituting a positive feedback loop which amplifies and maintains the STAT3 signal; furthermore, hyperactivated STAT3 signal promotes the expression of MUC1 and MUC4, consequently mediating trastuzumab resistance via maintenance of persistent HER2 activation and masking of trastuzumab binding to HER2 respectively. Genetic or pharmacological inhibition of STAT3 disrupted STAT3-dependent positive feedback loop and recovered the trastuzumab sensitivity partially due to increased apoptosis induction. Combined trastuzumab with STAT3 inhibition synergistically suppressed the growth of the trastuzumab-resistant tumor xenografts in vivo. Taken together, our results suggest that feedback activation of STAT3 constitutes a key node mediating trastuzumab resistance. Combinatorial targeting on both HER2 and STAT3 may enhance the efficacy of trastuzumab or other HER2-targeting agents in HER2-positive breast and gastric cancer.

Topics: Aminosalicylic Acids; Animals; Antibodies, Monoclonal, Humanized; Antineoplastic Agents; Benzenesulfonates; Breast Neoplasms; Cell Line, Tumor; Cell Proliferation; Dose-Response Relationship, Drug; Drug Resistance, Neoplasm; Epidermal Growth Factor; Feedback, Physiological; Female; Fibronectins; Gene Knockdown Techniques; Humans; Interleukin-6; Mice, Nude; Mucin-1; Mucin-4; Phosphorylation; Signal Transduction; STAT3 Transcription Factor; Stomach Neoplasms; Time Factors; Trastuzumab; Tumor Burden; Up-Regulation

Our previous research results showed that Type II cGMP dependent protein kinase (PKG II) could block the activation of epidermal growth factor receptor (EGFR) and consequently inhibit the proliferation and the related MAPK/ERK-mediated signal transduction of gastric cancer cell line BGC-823, suggesting that PKG II might inhibit other EGFR-triggered signal transduction pathways and related biological activities of gastric cancer cells. This paper was designed to investigate the potential inhibition of PKG II on EGF/EGFR-induced migration activity and the related signal transduction pathways.. In gastric cancer cell line AGS, expression and activity of PKG II were increased by infecting the cells with adenoviral construct encoding PKG II cDNA (Ad-PKG II) and treating the cells with cGMP analogue 8-pCPT-cGMP. Phosphorylation of proteins was detected by Western Blotting and active small G protein Ras and Rac1 was measured by "Pull-down" method. Cell migration activity was detected with trans-well equipment. Binding between PKG II and EGFR was detected with Co-IP. The results showed EGF stimulated migration of AGS cell and the effect was related to PLCγ1 and ERK-mediated signal transduction pathways. PKG II inhibited EGF-induced migration activity and blocked EGF-initiated signal transduction of PLCγ1 and MAPK/ERK-mediated pathways through preventing EGF-induced Tyr 992 and Tyr 1068 phosphorylation of EGFR. PKG II bound with EGFR and caused threonine phosphorylation of it.. Our results systemically confirms the inhibition of PKG II on EGF-induced migration and related signal transduction of PLCγ1 and MAPK/ERK-mediated pathways, indicating that PKG II has a fargoing inhibition on EGF/EGFR related signal transduction and biological activities of gastric cancer cells through phosphorylating EGFR and blocking the activation of it.

Topics: Cell Line; Cell Line, Tumor; Cell Movement; Cyclic GMP; Cyclic GMP-Dependent Protein Kinase Type II; Epidermal Growth Factor; ErbB Receptors; Humans; Phosphorylation; Signal Transduction; Stomach Neoplasms; Thionucleotides

EGFR activation and PKM2 expression are instrumental in tumorigenesis. EGFR activation regulates PKM2 functions in a subcellular compartment-dependent manner and promotes gene transcription and tumor growth. In addition, PKM2 is upregulated in EGFR-induced pathways in glioma malignancies. However, we found that PKM2 could also regulate the activity of the EGF/EGFR signaling pathway in gastric cancer cells. We aimed to define the biological mechanisms for PKM2 in regulating the cell motility and invasion.. We employed stable transfection with short hairpin RNA to stably silence the expression of PKM2 in the BGC823, SGC7901 and AGS gastric cancer cell lines. The effects of PKM2 in vitro were determined by assessing cell migration and invasion. Immunohistochemical analysis was used to explore the relationship among PKM2 and other proteins.. Our results indicate that the knockdown of PKM2 decreased the activity of E-cadherin and enhanced the EGF/EGFR signaling pathway in the gastric cell lines BGC823 and SGC7901 that were positive for E-cadherin expression. However, in the undifferentiated gastric carcinoma cell line AGS, which lacks E-cadherin expression, PKM2 promoted cell migration and invasion. Immunohistochemical analyses showed that the levels of E-cadherin expression, ERK1/2 phosphorylation, and cytoplasmic PKM2 expression were correlated with each other.. PKM2 may play different roles in differently differentiated gastric cancer cell types, and this finding would be consistent with the previous clinical research. The results of our study reveal an important link between PKM2 and E-cadherin during EGFR-stimulated gastric cancer cell motility and invasion.

Topics: Cadherins; Carrier Proteins; Cell Line, Tumor; Cell Movement; Epidermal Growth Factor; ErbB Receptors; Humans; MAP Kinase Signaling System; Membrane Proteins; Neoplasm Invasiveness; Phosphorylation; Signal Transduction; Stomach Neoplasms; Thyroid Hormone-Binding Proteins; Thyroid Hormones

In this study, we aimed to determine EGF, c-erbB-2 and EGFR expression in 25 specimens of intestinal gastric adenocarcinomas by standardized immunohistochemistry and to establish correlations with the major clinico-morphological parameters of these patients. We observed EGF reactivity in 22 (88%) cases, a c-erbB-2 protein expression in eight (32%) cases and an EGFR reactivity in 13 (46.42%) cases. The EGF expression was significantly correlated with the tumor degree of differentiation, but not with other investigated clinico-morphological parameters and nor with c-erbB-2 and EGFR1 expression. However, we noticed the existence of a dependence between c-erbB-2 and EGFR1 expression in the main tumor mass. Such immunoprofile suggests the possible intervention of autocrine and paracrine loops in the developing of intestinal variant of gastric adenocarcinomas.

Topics: Adenocarcinoma; Epidermal Growth Factor; ErbB Receptors; Humans; Immunohistochemistry; Receptor, ErbB-2; Stomach Neoplasms

Downregulation of HLA class I expression may contribute to a poor prognosis in cancer patients. There is limited information about epigenetic and oncogenic regulation of HLA class I, and multiple mechanisms may be involved. In the current study, we examined the relationship between the HER2-signaling pathway (MAPK and PI3K-Akt) and the expression of HLA class I and Ag-processing machinery (APM) components. A panel of gastric and esophageal cancer cell lines was treated with wortmannin as an Akt-signal inhibitor; the MAPK signal inhibitor PD98059; lapatinib, which inhibits both the epidermal growth factor receptor and HER2 tyrosine kinase; or siRNA for MAPK. The levels of HER2-signaling molecules, APM components, and HLA class I were evaluated by Western blot, quantitative PCR, and flow cytometry. Resected gastric tumor tissues (n = 102) were analyzed for p-Erk and HLA class I expression by immunohistochemistry. As a result, inhibition of the MAPK pathway induced upregulation of HLA-A02 and HLA-A24 expression in parallel with an increase in APM components and enhanced target sensitivity to tumor Ag-specific CTL lysis. HLA-A expression was predominantly regulated by the MAPK pathway, but it was also influenced, in part, by the Akt pathway. There was a strong inverse correlation between p-Erk expression and HLA class I expression in clinical tumor samples. In conclusion, HLA-A expression is predominantly regulated by the MAPK pathway in gastric and esophageal cancer.

Topics: Androstadienes; Antigen Presentation; Antigens, Neoplasm; Cell Line, Tumor; Epidermal Growth Factor; ErbB Receptors; Esophageal Neoplasms; Extracellular Signal-Regulated MAP Kinases; Flavonoids; Gene Expression Regulation, Neoplastic; Genes, MHC Class I; HLA-A Antigens; Humans; Lapatinib; MAP Kinase Signaling System; Neoplasm Proteins; Phosphorylation; Protein Kinase Inhibitors; Protein Processing, Post-Translational; Proto-Oncogene Proteins c-akt; Quinazolines; Receptor, ErbB-2; RNA, Small Interfering; Signal Transduction; Stomach Neoplasms; Wortmannin

Our previous study found that Type II cGMP-dependent protein kinase (PKG II) is expressed at lower levels in human gastric cancer tissues and cell lines and increasing the expression and activity of PKG II inhibited the proliferation of cancer cell line BGC-823. However, the mechanism through which PKG II inhibits proliferation of gastric cancer cells is still not clear. Herein, we show that PKG II can inhibit EGF-induced MAPK signal transduction. In the gastric cancer cell line BGC-823, the expression and activity of PKG II were increased by infecting the cells with adenoviral construct encoding PKG II cDNA and treating the cells with the cGMP analogue 8-pCPT-cGMP. We found that PKG II inhibited the EGF-induced dual phosphorylation of ERK, a key component of the MAPK signal transduction pathway. Upstream of ERK, PKG II inhibited the phosphorylation of MEK1/2, the phosphorylation/activation of Raf-1, the activation of Ras, and the binding between adaptor protein Grb2 and GTP exchange factor Sos1 induced by EGF. Of note, PKG II inhibited the tyrosine phosphorylation of EGFR induced by EGF. Downstream of ERK, the EGF-induced nuclear translocation of phospho-ERK was also inhibited by PKG II. The results suggest that PKG II inhibits the proliferation of gastric cancer cells through blocking EGF-triggered MAPK signal transduction and the key blocking point is the tyrosine phosphorylation of the EGF receptor.

Topics: Cell Line, Tumor; Cell Nucleus; Cyclic GMP-Dependent Protein Kinases; Epidermal Growth Factor; ErbB Receptors; Extracellular Signal-Regulated MAP Kinases; GRB2 Adaptor Protein; Humans; MAP Kinase Signaling System; Oncogene Protein p21(ras); Phosphorylation; Protein Binding; Protein Transport; Proto-Oncogene Proteins c-raf; SOS1 Protein; Stomach Neoplasms; Thymidine; Tyrosine

Vasodilator-stimulated phosphoprotein (VASP) has been implicated in the establishment of cancerous phenotypes. However, the role of VASP in gastric cancer progression and metastasis remains poorly understood. Here, we demonstrated that VASP was upregulated by epidermal growth factor (EGF) and promoted the migration and invasion of gastric cancer cells. Then we explored the regulatory mechanisms responsible for high expression of VASP in gastric cancer. Based on miRNA expression profiling of the paired gastric cancer tissues and their adjacent non-tumour gastric tissues 18 miRNAs were identified including microRNA-610 (miR-610) which were down-regulated in gastric cancer. Next, we observed an inverse correlation between VASP and miR-610 expression levels in gastric cancer cells after EGF stimulation. Then we performed bioinformatics analysis, Western blot and reverse transcription polymerase chain reaction (RT-PCR) analysis and luciferase assay to establish that miR-610 directly targets VASP 3'-UTR and inhibits its expression. Functionally, we demonstrated that miR610-mediated inhibition of VASP expression resulted in a significant reduction in the migration and invasion properties of gastric cancer cells. The identification of miR-610 as a novel miRNA regulated by EGF that targets VASP in gastric cancer cells suggests that EGF-miR610-VASP axis may be exploited for therapeutic intervention to inhibit gastric cancer progression and metastasis.

Topics: Base Sequence; Cell Adhesion Molecules; Cell Line, Tumor; Cell Movement; Disease Progression; Epidermal Growth Factor; Gene Expression Profiling; Gene Knockdown Techniques; Humans; Microfilament Proteins; MicroRNAs; Neoplasm Invasiveness; Phosphoproteins; Stomach Neoplasms; Up-Regulation

Epiregulin (EREG) induces cell growth by binding to the epidermal growth factor receptor (EGFR). Expression of EREG affects sensitivity to cetuximab a chimeric monoclonal antibody that inhibits the EGFR signaling pathway. The mechanism through which EREG is regulated is largely unknown, but a methyl-array study previously performed by our group revealed that EREG is methylated in gastric cancer cells. In this study, we found that EREG gene expression was low in 7 out of 11 gastric cancer cells and this downregulation was mediated by aberrant CpG methylation of the EREG promoter. Treatment with 5-aza-CdR restored EREG expression and demethylated CpG sites in the EREG promoter. Compared with DNA methyltransferase 1 (DNMT1), knock-down of DNA methyltransferase 3b (DNMT3b) significantly increased the expression of EREG and led to the demethylation of specific CpG sites in the EREG promoter, suggesting that DNMT3b primarily regulates CpG methylation and silencing of the EREG gene. EREG methylation was observed in 30% (4/13) of human primary gastric tumor tissues we evaluated. In addition to DNA methylation, results from a chromatin immunoprecipitation assay demonstrated that transcriptional levels of EREG were associated with the enrichment of active histone marks (H3K4me3 and AcH3) and of a repressive mark (H3K27me2). Treatment with 5-aza-CdR dynamically increased the low occupancy of H3K4me3 and AcH3, while decreasing the high enrichment of H3K27me2, indicating that dynamic histone modifications contribute to EREG regulation in addition to DNA methylation. Finally, the combination of 5-aza-CdR and cetuximab exerted a synergistic anti-proliferative effect on gastric cancer cells. Taken together, the results of our study showed for the first time that EREG is epigenetically silenced in gastric cancer cells by aberrant DNA methylation and histone modification.

Topics: Animals; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Azacitidine; Cell Line, Tumor; Cetuximab; CpG Islands; Decitabine; DNA (Cytosine-5-)-Methyltransferase 1; DNA (Cytosine-5-)-Methyltransferases; DNA Methylation; DNA Methyltransferase 3B; Epidermal Growth Factor; Epigenesis, Genetic; Epiregulin; ErbB Receptors; Gene Knockdown Techniques; Gene Silencing; Histones; Humans; Mice; Mice, Inbred BALB C; Mice, Nude; Promoter Regions, Genetic; RNA, Messenger; RNA, Neoplasm; RNA, Small Interfering; Stomach Neoplasms; Xenograft Model Antitumor Assays

The therapeutic activity of the epidermal growth factor receptor (EGFR)-directed monoclonal antibody cetuximab in gastric cancer is currently being investigated in clinical studies. Reliable biomarkers for the identification of patients who are likely to benefit from this treatment are not available. In this study, we assessed the activity of cetuximab in five gastric cancer cell lines (AGS, AZ521, Hs746T, LMSU and MKN1). The viability of two of these cell lines, AZ521 and MKN1, was significantly reduced by cetuximab treatment. High expression and secretion levels of the EGFR-binding ligand, amphiregulin (AREG), were associated with cetuximab responsiveness. MET activation and mutations in Kirsten-Ras gene (KRAS) were associated with cetuximab resistance. By introducing a hierarchy between these markers, we established a model that facilitated the correct classification of all five gastric cancer cell lines as cetuximab responsive or non-responsive. The highest priority was allocated to activating KRAS mutations, followed by MET activation and finally by the levels of secreted AREG. In order to validate these results, we used three additional human gastric cancer cell lines (KATOIII, MKN28 and MKN45). In conclusion, we propose that our model allows the response of gastric cancer cell lines to cetuximab treatment to be predicted.

Topics: Amphiregulin; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Antineoplastic Agents; Biomarkers, Tumor; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cetuximab; DNA Mutational Analysis; Drug Resistance, Neoplasm; EGF Family of Proteins; Enzyme Activation; Epidermal Growth Factor; ErbB Receptors; Glycoproteins; Humans; Intercellular Signaling Peptides and Proteins; Mutation; Phosphorylation; Protein Processing, Post-Translational; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-met; Proto-Oncogene Proteins p21(ras); ras Proteins; Stomach Neoplasms

Gastric cancer (GC) is one of the most common malignancies worldwide. The epidermal growth factor receptor (EGFR) molecule is very important in GC progression. To examine the correlation between EGFR and GC-related genes, we analyzed gene expression profiles of HT-29 cells treated with EGFR ligands and identified six genes upregulated by epidermal growth factor (EGF) and transforming growth factor (TGF)-α treatment. Among these, we focused on cadherin 17 (CDH17) encoding liver-intestine cadherin (LI-cadherin). Expression of LI-cadherin was induced by both EGF and TGF-α, as detected by quantitative RT-PCR and Western blot analysis. A luciferase assay showed that LI-cadherin promoter activity was enhanced by EGF or TGF-α in both HT-29 cells and MKN-74 GC cells. Immunohistochemical analysis of 152 GC cases showed that out of 58 LI-cadherin-positive cases, 24 (41%) cases were also positive for EGFR, whereas out of 94 LI-cadherin-negative cases, only 9 (10%) cases were positive for EGFR (P < 0.0001). Double-immunofluorescence staining revealed that EGFR and LI-cadherin were coexpressed. Significant correlation was found between LI-cadherin expression and advanced T grade and N grade. Both EGFR and LI-cadherin expression were more frequently found in GC cases with an intestinal mucin phenotype than in cases with a gastric mucin phenotype. These results indicate that, in addition to the known intestinal transcription factor caudal type homeobox 2, EGFR activation induces LI-cadherin expression and participates in intestinal differentiation of GC.

Topics: Cadherins; Epidermal Growth Factor; ErbB Receptors; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; HT29 Cells; Humans; Intestinal Mucosa; Intestines; Ligands; Liver; Neoplasm Staging; Stomach Neoplasms; Transforming Growth Factor alpha

A previous study has shown that type II cGMP‑dependent protein kinase (PKG II) inhibits the proliferation of gastric cancer cells through blocking EGF-triggered MAPK/ERK signal transduction, indicating that the kinase may be a potential anticancer factor. In the present study, the role of PKG II in the EGF-induced activation of transcription factors in the MAPK/ERK signal transduction pathway was investigated. BGC-823 human gastric cancer cells were infected with adenoviral constructs encoding the cDNA of PKG II (pAd‑PKG II) to increase the expression of PKG II and treated with 8-pCPT‑cGMP to activate the enzyme. Using luciferase reporter assays, it was revealed that PKG II markedly suppressed the EGF-induced transcriptional activities of AP-1 and Elk1. Consistent with the inhibitory effect of PKG II on AP-1 activity, the expression levels of c-Jun and c-Fos, components of AP-1, were also inhibited. Co-immunoprecipitation analysis demonstrated that EGF treatment increased the AP-1 content through inducing the formation of p-c-Jun-c-Jun homodimers and p-c-Jun-c-Fos heterodimers. However, this combination was efficiently blocked by activated PKG II. While pretreatments with MAPK inhibitors suppressed the EGF-induced transcriptional activities of AP-1 and Elk1, PKG II prevented the EGF-induced phosphorylation/activation of ERK and JNK, but not the phosphorylation of p38MAPK induced by EGF. These data suggest that PKG II inhibits the EGF-triggered proliferation of gastric cancer cells through suppressing ERK-/JNK-, but not p38MAPK, -mediated AP-1 and Elk1 transactivation.

Topics: Cell Line, Tumor; Cyclic GMP-Dependent Protein Kinase Type II; Epidermal Growth Factor; ets-Domain Protein Elk-1; Extracellular Signal-Regulated MAP Kinases; Humans; Immunoprecipitation; JNK Mitogen-Activated Protein Kinases; Phosphorylation; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-fos; Proto-Oncogene Proteins c-jun; Signal Transduction; Stomach Neoplasms; Transcription Factor AP-1; Transcription Factors; Transcriptional Activation

Altered cell motility is considered to be a key factor in determining tumor invasion and metastasis. Epidermal growth factor (EGF) signaling has been implicated in this process by affecting cytoskeletal organization and dynamics in multiple ways. To sort the temporal and spatial regulation of EGF-dependent cytoskeletal re-organization in relation to a cell's motile behavior time-lapse microscopy was performed on EGF-responsive gastric carcinoma-derived MKN1 cells co-expressing different fluorescently labeled cytoskeletal filaments and focal adhesion components in various combinations. The experiments showed that EGF almost instantaneously induces a considerable increase in membrane ruffling and lamellipodial activity that can be inhibited by Cetuximab EGF receptor antibodies and is not elicited in non-responsive gastric carcinoma Hs746T cells. The transient cell extensions are rich in actin but lack microtubules and keratin intermediate filaments. We show that this EGF-induced increase in membrane motility can be measured by a simple image processing routine. Microtubule plus-ends subsequently invade growing cell extensions, which start to accumulate focal complexes at the lamellipodium-lamellum junction. Such paxillin-positive complexes mature into focal adhesions by tyrosine phosphorylation and recruitment of zyxin. These adhesions then serve as nucleation sites for keratin filaments which are used to enlarge the neighboring peripheral keratin network. Focal adhesions are either disassembled or give rise to stable zyxin-rich fibrillar adhesions which disassemble in the presence of EGF to support formation of new focal adhesion sites in the cell periphery. Taken together the results serve as a basis for modeling the early cytoskeletal EGF response as a tightly coordinated and step-wise process which is relevant for the prediction of the effectiveness of anti-EGF receptor-based tumor therapy.

Topics: Actins; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Antineoplastic Agents; Carcinoma; Cell Movement; Cetuximab; Epidermal Growth Factor; ErbB Receptors; Focal Adhesions; Gene Expression; Humans; Keratins; Microtubules; Paxillin; Phosphorylation; Pseudopodia; Signal Transduction; Stomach Neoplasms; Time Factors; Time-Lapse Imaging; Tumor Cells, Cultured; Zyxin

Cyclooxygenase-2 (COX-2) plays an important role in tumorigenesis through prostaglandin E(2) (PGE(2)) biosynthesis. It has been shown by in vitro studies that PGE(2) signaling transactivates epidermal growth factor receptor (EGFR) through an intracellular mechanism. However, the mechanisms underlying PGE(2)-induced EGFR activation in in vivo tumors are still not fully understood. We previously constructed transgenic mice that develop gastric tumors caused by oncogenic activation and PGE(2) pathway induction. Importantly, expression of EGFR ligands, epiregulin, amphiregulin, heparin-binding EGF-like growth factor, and betacellulin, as well as a disintegrin and metalloproteinases (ADAMs), ADAM8, ADAM9, ADAM10, and ADAM17 were significantly increased in the mouse gastric tumors in a PGE(2) pathway-dependent manner. These ADAMs can activate EGFR by ectodomain shedding of EGFR ligands. Notably, the extensive induction of EGFR ligands and ADAMs was suppressed by inhibition of the PGE(2) receptor EP4. Moreover, EP4 signaling induced expression of amphiregulin and epiregulin in activated macrophages, whereas EP4 pathway was required for basal expression of epiregulin in gastric epithelial cells. In contrast, ADAMs were not induced directly by PGE(2) in these cells, suggesting indirect mechanism possibly through PGE(2)-associated inflammatory responses. These results suggest that PGE(2) signaling through EP4 activates EGFR in gastric tumors through global induction of EGFR ligands and ADAMs in several cell types either by direct or indirect mechanism. Importantly, gastric tumorigenesis of the transgenic mice was significantly suppressed by combination treatment with EGFR and COX-2 inhibitors. Therefore, it is possible that inhibition of both COX-2/PGE(2) and EGFR pathways represents an effective strategy for preventing gastric cancer.

Topics: ADAM Proteins; Amphiregulin; Animals; Antigens, CD; Betacellulin; Biomarkers, Tumor; Blotting, Western; Cell Proliferation; Cells, Cultured; Cyclooxygenase 2; Cytoskeletal Proteins; Dinoprostone; Disease Models, Animal; Disintegrins; EGF Family of Proteins; Enzyme-Linked Immunosorbent Assay; Epidermal Growth Factor; Epiregulin; ErbB Receptors; Gene Expression Profiling; Glycoproteins; Immunoenzyme Techniques; Immunoprecipitation; Intercellular Signaling Peptides and Proteins; Macrophages; Membrane Proteins; Mice; Mice, Transgenic; Oligonucleotide Array Sequence Analysis; Receptors, Prostaglandin E; Receptors, Prostaglandin E, EP4 Subtype; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Signal Transduction; Stomach Neoplasms

To investigate the association between epidermal growth factor (EGF) +61A/G polymorphism and susceptibility to gastric cancer, through a cross-sectional study.. Polymerase chain reaction restriction fragment length polymorphism analyses were used to genotype EGF +61 in 207 patients with gastric lesions (162 patients with gastric adenocarcinomas, 45 with atrophy or intestinal metaplasia) and 984 controls. All subjects were Caucasian.. Genotype distribution was 23.5% for GG and 76.5% for GA/AA in the control group, 18.4% for GG and 68.6% for GA/AA in the entire group with gastric lesions and 17.9% for GG and 82.1% for GA/AA in the group with gastric adenocarcinoma. No statistically significant associations were found between EGF +61 variants and risk for developing gastric cancer [odds ratios (OR) = 1.41, 95% confidence intervals (CI): 0.90-2.21, P = 0.116]. However, the stratification of individuals by gender revealed that males carrying A alleles (EGF +61A/G or AA) had an increased risk for developing gastric cancer as compared to GG homozygous males (OR = 1.55, 95% CI: 1.05-2.28, P = 0.021).. In summary, we found that males who were A carriers for EGF +61 had an increased risk for developing gastric cancer. This result may be explained by the suggestion that women secrete less gastric acid than men.

Topics: Cross-Sectional Studies; Epidermal Growth Factor; Female; Genetic Predisposition to Disease; Genotype; Humans; Male; Polymorphism, Single Nucleotide; Risk Factors; Stomach Neoplasms; White People

To explore the relationship between Cripto-1 (CR-1) and tyrosine phosphorylation STAT3 (p-STAT3) expressions in gastric cancer (GC) and gastric carcinogensis and metastasis.. The PV9000 immunohistochemical method was used to detect the expression of CR-1 and p-STAT3 in 178 cases of GC, 95 matched normal gastric mucosa, 40 chronic atrophic gastritis (CAG), 48 intestinal metaplasia (IM) and 25 dysplasia (DYS).. The positive rates of CR-1 and p-STAT3 expression were significantly higher in CAG (65.0% and 60.0%), in IM (83.3% and 77.1%), DYS (80.0% and 68%) and GC (71.3% and 60.1%) than in normal gastric mucosa (43.2% and 41.1%, P < 0.05), respectively. The expressions of CR-1 and p-STAT3 (78.3% and 66.7%) were significantly higher in GC with lymph node metastasis than in those without metastasis (53.1% and 42.9%, P < 0.05). CR-1 expression was also related to histological and Lauren's types of GC (P < 0.001). Furthermore, there was positive relationship between CR-1 and p-STAT3 expressions in GC (r(k) = 0.189, P = 0.002).. The up-regulation of CR-1 and p-STAT3 may play important roles in gastric carcinogenesis and lymph node metastasis. CR-1 and p-STAT3 expression in GC was positively correlated, and the relevant molecular mechanism requires further investigations.

Topics: Animals; Epidermal Growth Factor; Female; Gastric Mucosa; GPI-Linked Proteins; Humans; Intercellular Signaling Peptides and Proteins; Lymphatic Metastasis; Male; Membrane Glycoproteins; Middle Aged; Neoplasm Proteins; Precancerous Conditions; STAT3 Transcription Factor; Stomach Neoplasms; Tissue Array Analysis

Aquaporins (AQPs) are expressed in many different tumor cell types in human. New evidence for the involvement of AQPs in cell migration and proliferation adds AQPs to an expanding list of effectors in tumor biology.. The aim of this study was to investigate whether AQP3 expression in the human gastric carcinoma cell lines, AGS and SGC7901, enhances cell migration and proliferation.. Here, we showed that AQP3 is expressed in the human gastric cancer cell lines, AGS and SGC7901. The hEGF induced AQP3 expression in a time- and dose-dependent manner and increased gastric cancer cell migration and proliferation. AQP3 knockdown by siRNA inhibited hEGF-induced AQP3 expression and thus cell migration and proliferation. Furthermore, a mitogen-activated protein kinase (MEK)/extracellular signal-regulated kinase (ERK) inhibitor U0126 inhibited hEGF-induced AQP3 expression and cell migration or proliferation.. Cultured AGS or SGC7901 cells were treated with human epidermal growth factor (hEGF) and subjected to cell migration assay and cell proliferation assay. The expression or activation level of proteins was analyzed by western blot. AQP3 knockdown was obtained by small interfering (si)RNA.. Collectively, our findings provide for the first time that AQP3 plays a critical role in hEGF-induced cancer cell migration and proliferation and that hEGF induces AQP3 expression via ERK signal transduction pathways. These finds provide evidence for a novel role of AQP3 in human gastric carcinoma as a potentially important determinant of tumor growth and spread.

Topics: Adenocarcinoma; Aquaporin 3; Cell Line, Tumor; Cell Movement; Cell Proliferation; Epidermal Growth Factor; Humans; MAP Kinase Signaling System; Stomach Neoplasms

ErbB receptors and their cognate ligands are implicated in cancer progression. Their expression in gastrointestinal cancer, however, has not been systemically studied.. The expression of four ErbB receptors and a panel of ErbB ligands were determined by reverse transcription-PCR in two gastric (TMK1, MKN-45) and two colon (SW1116, HT-29) cancer cell lines. Cell proliferation was measured by MTT assay while gene knockdown was achieved by RNA interference.. ErbB1, ErbB2 and ErbB3 receptors and five known or putative ErbB ligands, namely, epiregulin, epidermal growth factor (EGF), heparin-binding EGF, transforming growth factor alpha (TGFalpha) and neuroglycan-C were expressed in all four cell lines. Knockdown of neuroglycan-C, however, did not affect cell proliferation.. This study profiles the expression of ErbB receptors and their cognate ligands in gastric and colon cancer cells. These findings might lay the basis for the development of ErbB pathway-directed therapeutics for gastrointestinal cancer.

Topics: Adenocarcinoma; Cell Growth Processes; Cell Line, Tumor; Chondroitin Sulfate Proteoglycans; Colonic Neoplasms; Epidermal Growth Factor; Epiregulin; Heparin-binding EGF-like Growth Factor; HT29 Cells; Humans; Intercellular Signaling Peptides and Proteins; Ligands; Neuregulins; Oncogene Proteins v-erbB; Stomach Neoplasms

Adenovirus early region 4 open reading frame 4 (E4orf4) protein is a novel cell death factor that selectively induces apoptosis in cancer cells. This study evaluated tumor inhibitory effects of a protein made by fusion E4orf4 and human epidermal growth factor (EGF). EGF was used to ensure the selective targeting of EGF receptor (EGFR)-overexpressing tumor cells. Results showed that EGF-E4orf4 stimulated EGFR phosphorylation in a time- and dose-dependent manner. Confocal microscopy analysis showed both EGF-E4orf4 and EGF could be internalized via EGFR but they had different intercellular trafficking pathways. In vitro study showed that EGF-E4orf4 significantly inhibited the proliferation of BGC823 and in vivo study showed EGF-E4orf4 suppressed tumor growth in a dose-dependent fashion with an inhibition rate of 79% for MDA-MB-231 and 49% for BGC 823 (p < 0.05). No toxic effects were observed in the nude mice with a dose as high as 10 mg/kg of EGF-E4orf4. These results indicated that EGF-E4orf4 could be a potential drug for cancer therapy.

Topics: Adenocarcinoma; Animals; Breast Neoplasms; Cell Proliferation; Colony-Forming Units Assay; Epidermal Growth Factor; ErbB Receptors; Female; Flow Cytometry; Humans; Immunoblotting; Immunoprecipitation; Mice; Mice, Inbred BALB C; Mice, Nude; Phosphorylation; Recombinant Fusion Proteins; Stomach Neoplasms; Viral Proteins; Xenograft Model Antitumor Assays

Breast cancer resistance protein (BCRP)/ABCG2 is a drug efflux pump responsible for multidrug resistance in cancer cells. We report that dephosphorylation of extracellular signal-regulated kinase (ERK) by treatment with mitogen-activated protein kinase/ERK kinase (MEK) inhibitors causes two opposing effects, transcriptional upregulation and prompted protein degradation of endogenous BCRP in breast cancer MCF-7 cells. Endogenous BCRP was eventually found to be upregulated. Conversely, treatment with epidermal growth factor was associated with its downregulation in the cells. MEK inhibitors also caused prompted degradation of exogenous BCRP in MCF-7 and gastric cancer NCI-N87 cells that express exogenous BCRP without affecting its transcriptional levels, and potentiated anticancer agents in the cells. A lysosomal inhibitor abolished this prompted degradation of exogenous BCRP, but a proteasome inhibitor did not. Inhibition of p90 ribosomal protein S6 kinase (RSK), one of the downstream effectors of ERK, resulted in transcriptional upregulation of endogenous BCRP but did not affect the protein degradation of exogenous BCRP. The data suggest that BCRP expression is differentially regulated downstream of the MEK-ERK pathway, transcriptionally upregulated through the inhibition of the MEK-ERK-RSK pathway, and posttranscriptionally downregulated through the inhibition of the MEK-ERK-non-RSK pathway. Although the immediate downstream effector of ERK remains to be elucidated, the data provide new insights into regulatory mechanisms of BCRP activity and may assist the development of BCRP-specific expression modulators.

Topics: Antineoplastic Agents; ATP Binding Cassette Transporter, Subfamily G, Member 2; ATP-Binding Cassette Transporters; Breast Neoplasms; Butadienes; Cell Line, Tumor; DNA Primers; Enzyme Inhibitors; Epidermal Growth Factor; Extracellular Signal-Regulated MAP Kinases; Female; Gene Expression Regulation, Neoplastic; Genes, myc; Humans; Neoplasm Proteins; Nitriles; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Stomach Neoplasms; Up-Regulation

The family of epidermal growth factor (EGF, EGFR, c-erbB-2) plays a pivotal role in gastric cancer progression, invasion and metastasizing. Helicobacter pylori infection is known to contribute significantly to the formation and progression of gastric cancer. However, the mechanisms responsible for this process have not been yet elucidated. We analysed the relationship between H. pylori infection and expression of proteins belonging to the family of epidermal growth factor (EGF, EGFR, c-erbB-2). Fifty-five patients with gastric cancer were analysed for Helicobacter pylori infection. The expressions of EGF, EGFR, c-erbB-2 proteins were determined using an immunohistochemical method. No statistically significant correlation was found between the degree of H. pylori infection and the expressions of EGF, EGFR and c-erbB-2 in gastric cancer. However, c-erbB-2 expression in the main mass of tumour correlated with tumour expression of EGF and EGFR and with c-erbB-2 expression in local lymph nodes. The expression of c-erbB-2 in lymph nodes was statistically significantly related to the expressions of EGF and EGFR both in the main mass of tumour and in lymph nodes. The expression of EGF was found to correlate with EGFR in the main mass of tumour and the expression of EGF in lymph nodes was related to lymph node EGFR level. Our study did not confirm the relationship between H. pylori infection and the expression of epidermal growth factor in gastric cancer.

Topics: Carcinoma; Disease Progression; Epidermal Growth Factor; ErbB Receptors; Helicobacter Infections; Helicobacter pylori; Humans; Immunohistochemistry; Receptor, ErbB-2; Stomach Neoplasms

The c-erbB-2 (HER-2/neu), EGF and EGFR (erbB-1) proteins, members of the epidermal growth factor receptor family, play a role in cell growth by binding to cell membrane receptors. The aim of the current study was to evaluate the expression of c-erbB-2, EGF and EGFR in advanced gastric carcinoma and to analyze its relationship with chosen anatomo-clinical parameters and prognosis. Standard avidin-biotin-peroxidase was used for c-erbB-2, EGF and EGFR immuno-histochemical staining (Novostain Super ABC Kit Universal); anti-human c-erbB-2 protein monoclonal antibody NCL-cerbB-2-316, anti-Epidermal Growth Factor monoclonal antibody (clone EGF-10) and EGFR goat polyclonal IgG (p-EGFR). A statistically significant correlation was found between c-erbB-2, EGF, EGRF expressions in the main mass of tumor and lymph node metastasis (p=0.000; p=0.000; p=0.00001, respectively). Also an association was observed between c-erbB-2 expression and Bormann's and Lauren's classifications (p=0.05; p=0.006, respectively). Similarly, the expression of EGFR in main mass of tumor was correlated with the depth of invasion (p=0.007) and histological differentiation (p=0.04). Moreover, the expression of c-erbB-2 in the main mass of tumor and lymph node metastasis was associated with the age of the patients (p=0.03; p=0.0002 respectively). Strong association was found between the expression of EGRF in lymph node metastasis and histological differentiation (p=0.04). Positive expression of c-erbB-2 in lymph node metastasis was correlated with lymph node involvement (p=0.04). Positive expression of c-erbB-2 in the main mass of tumor and in lymph node metastasis was strongly correlated with postoperative survival (p=0.00001; p=0.003 respectively). We also found a relationship between EGF expression in gastric tumor and survival time (p=0.003). No association was noted between the expression of EGFR in the main mass of tumor and in lymph node metastasis and between the expression of EGF in lymph node metastasis and survival time. Our results suggest that the expression of c-erbB-2 and EGF protein can help predict the postoperative survival time.

Topics: Adult; Aged; Epidermal Growth Factor; ErbB Receptors; Female; Humans; Lymphatic Metastasis; Male; Middle Aged; Postoperative Period; Receptor, ErbB-2; Stomach Neoplasms; Survival Rate

Overexpression of epidermal growth factor (EGF) and urokinase plasminogen activator receptor (uPAR) have been observed in human gastric cancers. However, the interaction between EGF and uPAR in gastric cancer has not been well elucidated. In this study, we investigated the effect of EGF on uPAR expression and the underlying signal pathways in human gastric cancer AGS cells. EGF induced uPAR mRNA expression in a time- and concentration-dependent manner. EGF also induced uPAR promoter activity. In addition, EGF induced the activation of extracellular signal regulated kinase-1/2 (ERK-1/2) and P38 mitogen-activated protein kinase (MAPK) but not the activation of c-Jun amino terminal kinase. A specific inhibitor of MEK-1 (an upstream effector of ERK-1/2) and a dominant negative MEK-1 were able to suppress the EGF-induced uPAR promoter activity. Site-directed mutagenesis and electrophoretic mobility shift assays demonstrated that the binding sites of transcription factors, activator protein-1 (AP-1) and nuclear factor (NF)-kappaB, are involved in the EGF-induced uPAR transcription. Suppression of the EGF-induced uPAR promoter activity by the AP-1 decoy oligonuclotide, as well as expression vectors encoding mutated-type NF-kappaB-inducting kinase and I-kappaB, confirmed that the activation of AP-1 and NF-kappaB are essential for the EGF-induced uPAR upregulation. The AGS cells pretreated with EGF showed a remarkably enhanced invasiveness and this effect was partially abrogated by uPAR neutralizing antibodies and by the inhibitors of ERK-1/2, AP-1, and NF-kappaB. The above results suggest that EGF induces uPAR expression via ERK-1/2, AP-1, and NF-kappaB signaling pathways and, in turn, stimulates cell invasiveness in human gastric cancer AGS cells.

Topics: Carcinoma; Epidermal Growth Factor; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Neoplastic; Humans; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Neoplasm Invasiveness; NF-kappa B; Oligonucleotides; Promoter Regions, Genetic; Receptors, Urokinase Plasminogen Activator; Signal Transduction; Stomach Neoplasms; Transcription Factor AP-1

Mutations of the tumor suppressor E-cadherin and overexpression of the receptor tyrosine kinase epidermal growth factor receptor (EGFR) are among the most frequent genetic alterations associated with diffuse-type gastric carcinoma. Accumulating evidence suggests a functional relationship between E-cadherin and EGFR that regulates both proteins. We report that somatic mutation of E-cadherin is associated with increased activation of EGFR followed by enhanced recruitment of the downstream acting signaling components growth factor receptor binding protein 2 and Shc, and activation of Ras. Reduced complex formation of mutant E-cadherin - with an in frame deletion of exon 8 in the extracellular domain resulting in reduced adhesion and increased motility - with EGFR was observed compared with wild-type E-cadherin. We conclude that reduced binding of mutant E-cadherin to EGFR in a multicomponent complex or reduced stability of the complex may enhance EGFR surface motility, thereby facilitating EGFR dimerization and activation. Furthermore, reduced surface localization due to enhanced internalization of mutant E-cadherin compared with the wild-type protein was observed. The internalization of EGFR was decreased in response to epidermal growth factor stimulation in cells expressing mutant E-cadherin, suggesting that mutation of E-cadherin also influences the endocytosis of EGFR. Moreover, we show increased activation of EGFR in gastric carcinoma samples with mutant E-cadherin lacking exons 8 or 9. In summary, we describe activation of EGFR by mutant E-cadherin as a novel mechanism in tumor cells that explains the enhanced motility of tumor cells in the presence of an extracellular mutation of E-cadherin.

Topics: Animals; Breast Neoplasms; Cadherins; Carcinoma, Ductal; Cell Line, Tumor; Endocytosis; Enzyme Activation; Epidermal Growth Factor; ErbB Receptors; Exons; Gene Deletion; Humans; Mice; Phosphorylation; ras Proteins; Signal Transduction; Stomach Neoplasms; Transfection

Cripto-1 may be capable of up-regulating signalling molecules associated with epithelial-to-mesenchymal transition (EMT), an important event characterized by loss of E-cadherin during malignant tumour progression and metastasis. The aim was to investigate the expression of Cripto-1 and E-cadherin in relation to clinicopathological features and patient prognosis of gastric cancer.. The expression of Cripto-1 and E-cadherin was studied by immunohistochemistry in 118 gastric cancer cases. Up-regulated Cripto-1 (CR+) was found in 54% (64/118) of cases, whereas down-regulated E-cadherin (E-cad-) was found in 70% (83/118) of cases. Either CR+ or E-cad- was associated with lymph node metastasis, liver metastasis and late TNM stage (P < 0.05). Patients with either CR- or E-cad+ showed higher 5-year survival rates than those with CR+ or E-cad- (P = 0.0012 and P = 0.0017, respectively). When combined, evaluation of these two proteins, simultaneous CR+ and E-cad- (CR+/E-cad-) in cancer was strongly associated with the above three aggressive clinicopathological features (P < 0.001) and indicated the worst patient survival (P = 0.0001). Multivariate analysis revealed that CR+/E-cad- was an independent prognostic factor in gastric cancer.. Combined analysis of Cripto-1 and E-cadherin has significant value in evaluating the metastatic potential of gastric cancer and predicting patient prognosis.

Topics: Adenocarcinoma; Adult; Aged; Aged, 80 and over; Cadherins; Disease Progression; Down-Regulation; Epidermal Growth Factor; Female; Gastrectomy; GPI-Linked Proteins; Humans; Immunoenzyme Techniques; Intercellular Signaling Peptides and Proteins; Lymph Nodes; Male; Membrane Glycoproteins; Middle Aged; Neoplasm Proteins; Neoplasm Staging; Prognosis; Stomach Neoplasms; Survival Rate; Up-Regulation

Oncogenic signaling through activation of epidermal growth factor receptor (EGFR), HER-2, and hypoxia inducible-factor-1alpha (HIF-1alpha) has been implicated in gastric cancer growth and angiogenesis through up-regulation of vascular endothelial growth factor (VEGF). Recently, heat shock protein 90 (Hsp90) has been identified as a critical regulator of oncogenic protein stability, including EGFR, HER-2, and HIF-1alpha. We hypothesized that inhibition of Hsp90 impairs EGF- and hypoxia-mediated angiogenic signaling in gastric cancer cells and consequently inhibits angiogenesis and tumor growth. In vitro, the geldanamycin derivate 17-allylamino-17-demethoxygeldanamycin (17-AAG) led to marked reduction in constitutive and inducible activation of extracellular signal-regulated kinase 1/2, Akt, and signal transducer and activator of transcription 3 and decreased nuclear HIF-1alpha protein. In addition, EGFR and HER-2 were down-regulated after Hsp90 inhibition. With respect to regulation of angiogenic molecules, 17-AAG significantly reduced EGF-mediated VEGF secretion. Phosphorylation of focal adhesion kinase and paxillin were both abrogated by 17-AAG, which resulted in significant impairment of cancer cell motility. Interestingly, cytotoxic effects of 17-AAG in vitro were higher on cancer cells and gastric fibroblasts than on pericytes. In vivo, the water-soluble compound 17-dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG; 25 mg/kg, thrice per week) significantly reduced s.c. xenografted tumor growth. By immunohistochemistry, 17-DMAG significantly reduced vessel area and numbers of proliferating tumor cells in sections. Furthermore, similar significant growth-inhibitory effects of 17-DMAG were achieved when administered as low-dose therapy (5 mg/kg, thrice per week). In conclusion, blocking Hsp90 disrupts multiple proangiogenic signaling pathways in gastric cancer cells and inhibits xenografted tumor growth in vivo. Hence, gastric cancer harbors attractive molecular targets for therapy with Hsp90 inhibitors, which could lead to improved efficacy of antineoplastic therapy regimens.

Topics: Angiogenesis Inhibitors; Animals; Benzoquinones; Blood Vessels; Cell Hypoxia; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cyclic AMP Response Element-Binding Protein; Enzyme-Linked Immunosorbent Assay; Epidermal Growth Factor; ErbB Receptors; Extracellular Signal-Regulated MAP Kinases; Fibroblasts; HSP90 Heat-Shock Proteins; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Lactams, Macrocyclic; Male; Mice; Mice, Inbred BALB C; Mitogen-Activated Protein Kinases; Muscle, Smooth, Vascular; Neovascularization, Pathologic; Pericytes; Proto-Oncogene Proteins c-akt; Receptor, ErbB-2; Signal Transduction; Stomach Neoplasms; Vascular Endothelial Growth Factor A

Epidermal growth factor (EGF), a ligand of the EGF receptor, plays a critical role in the development of gastric cancer. Genetic variants in its promoter region may influence transcription activity and contribute to gastric cancer predisposition. To test this hypothesis, we genotyped three EGF promoter polymorphisms (G61A, G-1380A, and A-1744G) in a case-control study of 675 gastric cancer cases and 704 cancer-free controls. We found that the variant genotypes of EGF 61GA/AA were associated with a significantly decreased risk of gastric cancer (OR = 0.77, 95% CI = 0.61-0.95), when compared with wild-type homozygote 61GG. In the combined analysis with all three loci of EGF, subjects carrying one or more variant loci had a significantly decreased risk of gastric cancer in a dose-response manner (adjusted OR = 0.58, 95% CI = 0.42-0.80 for subjects carrying one variant locus and OR = 0.46, 95% CI = 0.32-0.66 for those carrying two to three variant loci, respectively; trend test: chi(2) = 16.14, P < 0.001). Compared with the most common haplotype GGA, haplotypes AGA, GGG and GAA (each containing one variant allele) were associated with 33%, 29% and 34% significantly decreased risk of gastric cancer (adjusted OR = 0.67, 95% CI = 0.55-0.82 for AGA; OR = 0.71, 95% CI = 0.57-0.88 for GGG and OR = 0.66, 95% CI = 0.52-0.84 for GAA, respectively). Our findings indicate that variant genotypes and haplotypes of EGF promoter might play a role in gastric carcinogenesis.

Topics: Adult; Aged; Aged, 80 and over; Alcohol Drinking; Asian People; Case-Control Studies; China; Epidermal Growth Factor; Female; Gene Frequency; Genotype; Haplotypes; Humans; Male; Middle Aged; Polymorphism, Genetic; Promoter Regions, Genetic; Regression Analysis; Risk Factors; Smoking; Stomach Neoplasms

Epidermal growth factor (EGF) is involved in cancer development and proliferation. We measured preoperative serum EGF, and serologically investigated the clinical significance of EGF expression in gastric cancer. We also performed immunohistological staining at the same time, and investigated its relationship with serum EGF.. There were 79 patients who underwent surgery for gastric cancer. For the measurement, one-step sandwich EIA was performed. Of 79 cases of gastric cancer in which the serum EGF level was measured, EGF immunostaining was performed in 50 cases.. In Serology, the EGF level was 345.6 +/- 260.6 pg/mL in m-sm cases, and 212.2 +/- 170.4 pg/mL in mp-si cases (p < 0.05). The EGF level was 294.4 +/- 236.0 pg/mL in ly0 cases, and 194.2 +/- 142.5 pg/mL in ly1-3 cases (p < 0.05). The EGF level was 323.5 +/- 233.4 pg/mL in cases staged IA-IB, and 202.8 +/- 176.8 pg/mL in cases staged II-IV (p < 0.05). In immunohistology the EGF positivity rate was 36.4% in the differentiated types, and 67.9% in the poorly differentiated types (p < 0.05). The EGF positivity rate was 25.0% in m-sm cases, and 63.1% in mp-si cases (p < 0.05).. The above findings suggest that EGF uptake by cancer cells increases when cancer cells are poorly differentiated, and that invasion in the surrounding tissue is severe.

Topics: Carcinoma; Epidermal Growth Factor; Female; Humans; Immunohistochemistry; Male; Stomach Neoplasms

The coexistence of gastrointestinal stromal tumors (GISTs) and pregnancy is very rare. We are the first to add to the literature a case report of GIST occurring during pregnancy with immunohistochemical staining for epidermal growth factor receptor (EGFR) and progesterone receptor (PgR). A role of PgR and EGFR in tumor growth should not be excluded, and these findings indicate that the expression of these receptors could provide pertinent biological information required to determine adequate therapeutic regimens. In conclusion, considering that GIST occurring during pregnancy is a rare event, with frequent delay in diagnosis, it is important to consider this diagnosis for early recognition, correct diagnosis, and a better outcome.

Topics: Adult; Epidermal Growth Factor; ErbB Receptors; Female; Gastrointestinal Stromal Tumors; Humans; Immunohistochemistry; Pregnancy; Pregnancy Complications, Neoplastic; Progesterone; Receptors, Progesterone; Stomach Neoplasms

Both gastrin and Helicobacter pylori have been shown capable of up-regulating gene expression and protein shedding of heparin-binding epidermal growth factor (HB-EGF). Furthermore, the bacteria have previously been shown to induce serum hypergastrinemia in infected individuals. The aim of this work was to assess the extent to which the ability of H. pylori to up-regulate expression of HB-EGF can be attributed to its effect on gastrin. Gastric cells, transfected with either gastrin small interfering RNA or antisense plasmid or the gastrin/cholecystokinin-2 receptor (CCK-2R), were cultured for 24 hours with H. pylori(+/-), a CCK-2R antagonist. Gene expression levels were measured using reverse transcription-PCR, whereas protein changes were measured using ELISA, Western blotting, and immunofluorescence. H. pylori induced significantly higher levels of HB-EGF gene expression and ectodomain shedding in the CCK-2R-transfected cells than the vector control (P < 0.01). Addition of the CCK-2R inhibitor significantly decreased gene and shedding up-regulation. Gastrin down-regulation reduced the effect of the bacteria on HB-EGF gene and protein expression levels. Endogenous gastrin and CCK-2R expression were also found to be significantly up-regulated in all cell lines as a result of exposure to H. pylori (P < 0.02). Gastric mucosal tissue from H. pylori-infected individuals had significantly higher CCK-2R expression levels than noninfected (P < 0.003), and in hypergastrinemic mice, there was an increase in HB-EGF-expressing cells in the gastric mucosa and colocalization of HB-EGF with CCK-2R-positive enterochromaffin-like cells. In conclusion, gastrin and the CCK-2R play significant roles in the induction of HB-EGF gene and protein expression and ectodomain shedding by H. pylori.

Topics: Adenocarcinoma; Animals; Cell Line, Tumor; Disease Models, Animal; DNA, Antisense; Enterochromaffin Cells; Epidermal Growth Factor; Gastrins; Helicobacter Infections; Helicobacter pylori; Heparin-binding EGF-like Growth Factor; Humans; Intercellular Signaling Peptides and Proteins; Mice; Plasmids; Receptor, Cholecystokinin B; Reverse Transcriptase Polymerase Chain Reaction; RNA, Small Interfering; Stomach Neoplasms; Transfection; Up-Regulation

We investigated the survival signals of epidermal growth factor (EGF) in human gastric adenocarcinoma cell line TMK-1. Treatment of TMK-1 cells with adriamycin (ADR) caused apoptosis and apoptosis-related reactions such as the release of cytochrome c from mitochondria and the activation of caspase 9. However, EGF treatment greatly reduced the ADR-induced apoptosis as well as these reactions. We previously reported that hepatocyte growth factor transmitted protective signals against ADR-induced apoptosis by causing activation of the phosphatidylinositol-3'-OH kinase (PtdIns3-K)/Akt signaling pathway in human epithelial cell line MKN74 [Takeuchi K & Ito F (2004) J Biol Chem279, 892-900]. However, PtdIns3-K/Akt signaling did not mediate the antiapoptotic action of EGF in TMK-1 cells. EGF increased the expression of the Bcl-X(L) protein, an antiapoptotic member of the Bcl-2 family, but not that of other anti (Bcl-2) or proapoptotic (Bad and Bax) protein members. Expression of the c-Fos and c-Jun, components of activator protein 1 (AP1), which are known to regulate bcl-X(L) gene transcription, were increased in response to EGF. Pretreatment of the cells with PD98059, an inhibitor of MAP kinase kinase, inhibited the EGF-induced c-Fos and c-Jun expression, AP1 DNA binding, Bcl-X(L) expression, and the resistance against ADR-induced apoptosis, suggesting that EGF transmitted the antiapoptotic signal in such a way that it activated AP1 via a MAP kinase signaling pathway. TMK-1 cells stably transfected with TAM67, c-Jun dominant-negative mutant, did not display EGF-induced Bcl-X(L) expression or resistance against ADR-induced apoptosis. These results indicate that AP1-mediated upregulation of Bcl-X(L) expression is critical for protection of TMK-1 cells against ADR-induced apoptosis.

Topics: Adenocarcinoma; Animals; Antibiotics, Antineoplastic; Apoptosis; Cell Line, Tumor; Cell Survival; Cells, Cultured; DNA Damage; Doxorubicin; Epidermal Growth Factor; Humans; Mice; Stomach Neoplasms; Transcription Factor AP-1

The recently cloned epidermal growth factor receptor related protein (ERRP) has been proposed to be a negative regulator of the epidermal growth factor receptor (EGFR). Because of the causal involvement of EGFR and its ligands in gastric cancer growth, we investigated expression of ERRP and cell proliferation in human gastric cancer.. We examined ERRP expression and localisation in surgical specimens of gastric cancers from 47 patients versus non-malignant gastric mucosa and determined their relationship to cell proliferation and differentiation. We also examined expression of ERRP by western blotting in three different gastric cancer cell lines. To further determine the functional properties of ERRP, we examined the effect of ERRP on epidermal growth factor (EGF) induced EGFR phosphorylation essential for its activation in MKN-28 gastric cancer cells.. ERRP expression was dramatically reduced in gastric cancers (34% of all specimens positive) compared with non-malignant gastric mucosa (66% of specimens positive). Expression of ERRP in cancer cells inversely correlated with cell proliferation and grade of malignancy. Cell lines derived from metastatic gastric cancers had reduced ERRP expression compared with cell lines derived from a non-metastatic cancer. Exogenous ERRP protein markedly inhibited EGF induced EGFR phosphorylation in gastric cancer cells providing a novel molecular mechanism of its action.. Our data indicate that downregulation of ERRP could play an important role in gastric cancer differentiation and progression. ERRP is a negative regulator of tumour cell proliferation and may exert its inhibitory effect, in part, by attenuating EGFR activation.

Topics: Adult; Aged; Amino Acid Sequence; Cell Differentiation; Cell Division; Disease Progression; Epidermal Growth Factor; ErbB Receptors; Female; Gastric Mucosa; Glycoproteins; Humans; Male; Middle Aged; Molecular Sequence Data; Neoplasm Proteins; Phosphorylation; Precancerous Conditions; Stomach Neoplasms; Tumor Cells, Cultured

Epidermal growth factor receptor (EGFR) and its ligands are involved in tumor growth, metastasis, angiogenesis, and resistance to chemotherapy. In the experiments described here using AGS gastric cancer cells, SN38 (the active metabolite of CPT-11) induced tyrosine phosphorylation of EGFR within 5 min, and this was followed by the induction of transcripts and/or proteins of heparin-binding EGF-like growth factor, amphiregulin, transforming growth factor-alpha, and interlukin-8 (IL-8). SN38 also activates nuclear factor-kappaB and activator protein-1, both of which are critical for the transcription of the IL-8 gene. However, the blocking of EGFR activation by gefitinib (Iressa, ZD1839), an EGFR-TKI (tyrosine kinase inhibitor), abrogates all the above reactions. The SN38-triggered mechanisms include the generation of reactive oxygen species (ROS) and the activation of protein kinase C (PKC), followed by metalloproteinase activation and the sequential ectodomain shedding of EGFR ligands. These findings suggest that EGF signaling is enhanced by CPT-11 and point to the potential benefit of the use of a combination of CPT-11 with gefitinib in the treatment of certain gastric cancers.

Topics: Amphiregulin; Antineoplastic Agents; Camptothecin; Cell Line, Tumor; Drug Screening Assays, Antitumor; EGF Family of Proteins; Epidermal Growth Factor; ErbB Receptors; Gefitinib; Glycoproteins; Heparin-binding EGF-like Growth Factor; Humans; Intercellular Signaling Peptides and Proteins; Interleukin-8; Irinotecan; Phosphorylation; Quinazolines; Reactive Oxygen Species; Signal Transduction; Stomach Neoplasms; Transforming Growth Factor alpha; Tyrosine

Epidermal growth factor (EGF) has many biological functions and plays an important role in the progression of various tumors including gastric cancer. An A-G single nucleotide polymorphism (SNP) at position 61 in the 5'-untranslated region (UTR) of the EGF gene has recently been reported to be associated with different levels of EGF production. We examined whether this polymorphism is correlated with the development and malignant phenotypes of gastric cancer.. The study population included 200 gastric cancer patients and 230 healthy control subjects. The SNP in the 5'-UTR of the EGF gene was analyzed by polymerase chain reaction-restriction fragment length polymorphism.. The A allele was significantly less frequent in patients than in controls (p = 0.01). Individuals with the A/A or A/G genotype showed a significantly lower risk of gastric cancer than those with the G/G genotype [adjusted odds ratio (OR) = 0.56], whereas the same genotypes were associated with malignant progression of this cancer, e.g. deeper tumor invasion, increased lymph node metastasis and advanced clinical stage, and histological classification in gastric cancer patients (adjusted OR = 1.80, 1.98, 2.26 and 1.89, respectively).. Our findings suggest that the A-G polymorphism of EGF is involved not only in the occurrence but also in the malignant progression of gastric cancer.

Topics: 5' Flanking Region; Adult; Aged; Alleles; Disease Progression; DNA, Neoplasm; Epidermal Growth Factor; Female; Gene Frequency; Genotype; Humans; Male; Middle Aged; Neoplasm Staging; Polymerase Chain Reaction; Polymorphism, Restriction Fragment Length; Polymorphism, Single Nucleotide; Risk Factors; Stomach Neoplasms

Tight junctions are commonly disrupted in cancer cells, including gastric cancer. Various growth factors have been reported to affect the localization of tight junction-associated proteins such as ZO-1 and occludin. We investigated the effect of epidermal growth factor (EGF), a growth factor that is often overexpressed in gastric cancer, and fetal bovine serum (FBS) on the localization of ZO-1 and occludin in a gastric cancer cell line. In the poorly differentiated gastric cancer cell line TMK-1, immunohistochemistry demonstrated that ZO-1 and occludin were predominantly localized to the cytoplasm, although there was some weak expression at the cell-cell contact. When the medium was replaced with fresh medium containing 10% FBS, ZO-1 and occludin were rapidly translocated from the cytosol to the cell-cell contact. A similar effect was seen in EGF exposure. These effects induced by FBS or EGF were attenuated in the presence of protein kinase C (PKC) inhibitors calphostin C and bisindolylmaleimide I, but not another PKC inhibitor Gö6976, PD98059 (MAPK inhibitor), LY294002 (PI3 kinase inhibitor) or KT5720 (protein kinase A inhibitor). These results suggest that serum-derived factors, including EGF, can rapidly alter the localization of ZO-1 and occludin via a protein kinase C signaling pathway in TMK-1 gastric cancer cells.

Topics: Animals; Cattle; Cell Communication; Cell Line, Tumor; Culture Media; Cytoplasm; Epidermal Growth Factor; Humans; Immunohistochemistry; Membrane Proteins; Occludin; Phosphoproteins; Protein Kinase C; Stomach Neoplasms; Tight Junctions; Zonula Occludens-1 Protein

The etiology of gastric cancer is not well-understood. Epidermal growth factor (EGF) transduces growth signals to mitogen-activated protein kinase via RAS and BRAF, and EGF/EGF receptor interaction is important for tumor growth and progression. Previous studies have reported that the EGF +61 (A/G) single nucleotide polymorphism in the 5'-untranslated region of the EGF gene is functional, and is associated with gastric cancer and various malignancy. Individuals with the EGF A/A genotype produce less EGF than individuals with G/G or G/A. We investigated a single nucleotide polymorphism at exon 1 of EGF, named rs4444903 in NCI dbSNP, in 454 Japanese subjects undergoing a health checkup and 202 patients with gastric cancer. Genotype was determined by PCR with confronting two-pair primers. Results showed that EGF polymorphism was not associated with gastric cancer but that the EGF A/A genotype showed a protective effect (odds ratios, 0.58; 95% confidence interval, 0.29-1.17 relative to G/G). Furthermore, when we divided cases into two groups, a differentiated type and an undifferentiated type, the A/A and G/A combined was found to be lower frequency in the latter type than in the former type without significance (OR, 0.81; 95% confidence interval, 0.44-1.49 relative to G/G). As is the case with any malignancy, other factors are involved, including environmental and host factors. The present results show that although EGF is necessary for cancer, it is not sufficient. We also found ethnic heterogeneity in the functional EGF polymorphism. Because the relationship between EGF polymorphism and malignancy remains inconsistent, confirmation of the role of EGF polymorphism in gastric cancer requires a much larger study.

Topics: Adult; Aged; Aged, 80 and over; Epidermal Growth Factor; Female; Genotype; Humans; Male; Middle Aged; Polymorphism, Genetic; Stomach Neoplasms

CD97EGF is a member of the EGF-TM7 family of class II seven-transmembrane (7TM), and its cellular ligand CD55 (also known as decay accelerating factor; DAF) protects host cells from complement attack. To determine whether the expression levels of these two molecules are correlated with the clinicopathological features of gastric carcinomas, a total of 35 gastric carcinomas and their corresponding margins and normal specimens were investigated by RT-PCR, Western blot analysis and immunohistochemistry. Transcript levels of CD97EGFand CD55 were higher in tumors than those in the margin and normal epithelial mucous tissues (P<0.05). However, the expression levels of CD97EGF and CD55 mRNA had no correlation with the clinicopathological features of gastric carcinoma patients. All three groups of specimens were immunoreactive for CD97EGF and the CD55 protein. Strong and specific immunoreactivities of CD97EGF were located in the mucosal epithelia of the marginal basal membrane. Expression of CD97(EGF) in the margins showed a marked difference between the depth of tumor invasion T1 and T2, 3 and 4, and stages I and II/III/IV of gastric carcinomas (P<0.05). The expression of CD55 protein was highly correlated with CD97EGF (R=0.6483, P<0.001). Western blot analysis confirmed the expression and distribution patterns of CD97EGF and CD55. Our findings suggest that CD97EGF may play a role in the development and invasion of gastric carcinomas by binding its cellular ligand CD55. Detection of the CD97EGF expression in the tumor margin could be referred to as the molecular edge of gastric carcinomas.

Topics: Antigens, CD; Blotting, Western; CD55 Antigens; Epidermal Growth Factor; Epithelium; Female; Gene Expression Regulation, Neoplastic; Humans; Immunohistochemistry; Lung; Male; Membrane Glycoproteins; Neoplasm Invasiveness; Neoplasm Staging; Receptors, G-Protein-Coupled; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Stomach Neoplasms

The epidermal growth factor receptor (EGF-R) pathway plays a pivotal role in the progression of human gastric cancer. The angiogenic factor vascular endothelial growth factor (VEGF) has been shown to be induced by EGF in various cancer cell lines. Neuropilin-1 (NRP-1) acts as a coreceptor for VEGF-165 and increases its affinity for VEGF receptor 2 (VEGFR-2) in endothelial cells. Furthermore, NRP-1 has been found to be expressed by tumour cells and has been shown to enhance tumour angiogenesis and growth in preclinical models. We examined the expression of NRP-1 mRNA and EGF-R protein in seven human gastric cancer cell lines. NRP-1 expression was expressed in five of seven cell lines, and EGF-R expression closely mirrored NRP-1 expression. Moreover, in EGF-R-positive NCI-N87 and ST-2 cells, EGF induced both NRP-1 and VEGF mRNA expression. C225, a monoclonal antibody to EGF-R, blocked EGF-induced NRP-1 and VEGF expression in NCI-N87 cells in a dose-dependent manner. The treatment of NCI-N87 cells with EGF resulted in increases in phosphorylation of Erk1/2, Akt, and P38. Blockade of the Erk, phosphatidylinositol-3 kinase/Akt, or P38 pathways in this cell line prevented EGF induction of NRP-1 and VEGF. These results suggest that regulation of NRP-1 expression in human gastric cancer is intimately associated with the EGF/EGF-R system. Activation of EGF-R might contribute to gastric cancer angiogenesis by a mechanism that involves upregulation of VEGF and NRP-1 expression via multiple signalling pathways.

Topics: Base Sequence; Blotting, Northern; Blotting, Western; DNA Primers; Endothelial Growth Factors; Epidermal Growth Factor; Gene Expression Regulation, Neoplastic; Humans; Immunohistochemistry; Intercellular Signaling Peptides and Proteins; Lymphokines; Neuropilin-1; Phosphorylation; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Signal Transduction; Stomach Neoplasms; Tumor Cells, Cultured; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors

Nur77 is an orphan receptor. Although Nur77 affects cell proliferation and apoptosis through its capability of binding to a variety of response elements and regulating their transactivation activities, the intrinsic function of Nur77 is not yet fully understood; in particular, its regulation of apoptosis and proliferation has been characterized as cell type-dependent and agent context-dependent. In this study, Nur77 can be seen to regulate apoptosis via its expression and translocation, rather than its transactivation activity in gastric cancer cells. Nur77 was constitutively expressed in BGC-823 cells. The tetradecanoylphorbol-1,3-acetate (TPA) treatment not only resulted in up-regulation of the Nur77 mRNA level, but also led to translocation of Nur77 protein from the nucleus to the mitochondria, and caused the release of cytochrome c. This TPA-induced translocation of Nur77 was in association with the initiation of apoptosis in gastric cancer cells. Although all-trans retinoic acid (ATRA) could not induce apoptosis in BGC-823 cells due to failure of stimulating Nur77 translocation, expression of Nur77 in the nucleus was required for cell growth inhibition by ATRA. Transfection of antisense Nur77 receptor into BGC-823 cells resulted in resistance of cell growth against ATRA inhibition, and the cells were still arrested in the S phase. Furthermore, the action of Nur77 in TPA-induced apoptosis was mediated through a protein kinase C signaling pathway, while mitogen-activated protein kinase and phosphatidylinositol 3-kinase signaling pathways were responsible for the regulation of Nur77 mRNA expression. Taken together, the data revealed the dual functioning mechanisms of Nur77 in gastric cancer cells in response to TPA and ATRA.

Topics: Apoptosis; Cell Cycle; Cycloheximide; DNA-Binding Proteins; Epidermal Growth Factor; Genetic Vectors; Humans; Nuclear Receptor Subfamily 4, Group A, Member 1; Receptors, Cytoplasmic and Nuclear; Receptors, Steroid; Recombinant Proteins; Stomach Neoplasms; Tetradecanoylphorbol Acetate; Transcription Factors; Transfection; Tretinoin; Tumor Cells, Cultured

CD97 expression is related closely to the dedifferentiation and tumor stage in thyroid carcinomas. We systematically examined the role of CD97 and its closest relative, EMR2, in normal and malignant gastric, esophageal, and pancreatic tissue. The normal tissues were EMR2-, whereas CD97 was expressed slightly in the parietal cells of gastric mucosa and in exocrine pancreatic cells. Interestingly, intralobular and interlobular pancreatic ducts were CD97+. All tumors were EMR2-. CD97 was expressed by 44 of 50 gastric, 14 of 18 pancreatic, and 10 of 13 esophageal carcinomas. Of the 44 gastric cancers, 27 showed disseminated or scattered tumor cells at the invasion front with stronger CD97 expression than tumor cells located in solid tumor formations. There was no correlation between CD97 levels in the tumors or soluble CD97 in the serum samples and the clinicopathologic features of the patients. Taken together, significant numbers of gastric, esophageal, and pancreatic carcinomas are CD97+, whereas its homolog, EMR2, does not have any role in such tumors.

Topics: Aged; Antigens, CD; Biomarkers, Tumor; Carcinoma; Epidermal Growth Factor; Esophageal Neoplasms; Female; Humans; Immunohistochemistry; Male; Membrane Glycoproteins; Middle Aged; Pancreatic Neoplasms; Receptors, G-Protein-Coupled; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; RNA, Neoplasm; Stomach Neoplasms; Tumor Cells, Cultured

Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is a member of the EGF family. Juxtacrine activity of proHB-EGF (the membrane-anchored form of HB-EGF) has been shown to be significantly potentiated when it is coexpressed with CD9 in vitro. The purpose of our study was to investigate the issue of whether proHB-EGF and CD9 are coexpressed in gastric cancer. HB-EGF gene expression and protein production in human gastric cancers was investigated, and EGF receptor and CD9 expressions were also evaluated. HB-EGF mRNA levels in gastric cancers were elevated, compared with normal gastric tissues, especially in the intestinal type. ProHB-EGF immunoreactivity was detected primarily in the cytoplasm and plasma membrane of gastric cancer cells. Of 66 patients, 40 (60.6%) exhibited proHB-EGF immunoreactivity and the level of its expression was significantly associated with tumor status (p < 0.01) and histological differentiation (p < 0.001). In addition, proHB-EGF mRNA was detected at high levels in the intestinal type by in situ hybridization. CD9 immunoreactivity was found to be preserved in 26 of 36 patients (72.2%) and CD9 protein expression was inversely associated with lymph node status (p < 0.05). A significant correlation between its expression and histological differentiation (p < 0.01) was found, and the association of CD9 with proHB-EGF was increased in the intestinal type, as evidenced by an immunoprecipitation method. These results indicate that the coexpression of proHB-EGF and CD9 may be involved in the tumorigenesis and/or proliferation of gastric cancers in a juxtacrine manner.

Topics: Adult; Aged; Aged, 80 and over; Antigens, CD; Blotting, Western; Epidermal Growth Factor; ErbB Receptors; Female; Gene Expression Regulation, Neoplastic; Heparin-binding EGF-like Growth Factor; Humans; Immunohistochemistry; In Situ Hybridization; Intercellular Signaling Peptides and Proteins; Male; Membrane Glycoproteins; Middle Aged; RNA, Messenger; Stomach Neoplasms; Tetraspanin 29

The ErbB1 and ErbB2 receptor tyrosine kinases (RTKs) play important roles in the development of numerous types of human cancer and, as such, have been pursued as anticancer targets. To understand the mechanisms contributing to the response of tumor cells to receptor-directed therapeutics, the sensitivity of the ErbB receptor-overexpressing tumor cell lines BT474 and MKN7 to specific inhibitors has been examined. The inhibitors used included monoclonal antibody (mAb) 4D5, which targets ErbB2, and the small molecular weight kinase inhibitors CGP59326 and PKI166, which block the activity of ErbB1 or both ErbB1 and ErbB2, respectively. We had reported previously that although both BT474 and MKN7 cells overexpress ErbB2, only BT474 cells show an antiproliferative response to mAb 4D5 treatment. Here, we show that MKN7 cells, which also overexpress ErbB1, are sensitive to CGP59326, displaying a 60% decrease in their proliferation after treatment with this inhibitor. Most carcinomas express multiple ErbB receptors as well as EGF-related ligands, a situation favoring activation of numerous combinations of ligand-activated receptors. Considering this, the sensitivity of MKN7 and BT474 cells to CGP59326 and mAb 4D5, respectively, was also tested in the presence of exogenous ligands. Treatment of MKN7 cells with CGP59326 in the presence of heregulin (HRG), which activates ErbB2/ErbB3, attenuated the antiproliferative effect of CGP59326 by 50%; MKN7 cells engineered to overexpress ErbB3 were completely rescued from CGP59326 by HRG. Likewise, BT474 cells treated with mAb 4D5 in the presence of epidermal growth factor, betacellulin, and HRG were rescued from its antiproliferative effects by 57, 84, and 90%, respectively. In both MKN7 and BT474 tumor cells, the degree of ligand-induced rescue from the inhibitors correlated with the potency of ErbB receptor activation and stimulation of the PI3K and MAPK intracellular signaling pathways. In comparison with the monospecific agents, treatment with the bispecific ErbB1/ErbB2 kinase inhibitor PKI166 almost completely prevented the EGF-related ligand-induced bypass of the proliferation block in the MKN7 and BT474 cells. These data suggest that the efficacy of anticancer drugs that block a single ErbB receptor may be compromised by the presence of exogenous epidermal growth factor-related ligands, a phenomenon that could be averted by simultaneously blocking multiple ErbB receptors.

Topics: Antibodies, Monoclonal; Antineoplastic Agents; Betacellulin; Breast Neoplasms; Cell Division; Drug Interactions; Enzyme Inhibitors; Epidermal Growth Factor; ErbB Receptors; G1 Phase; Growth Substances; Humans; Intercellular Signaling Peptides and Proteins; Ligands; Neuregulin-1; Phosphorylation; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-akt; Pyrimidines; Pyrroles; Receptor, ErbB-2; Signal Transduction; Stomach Neoplasms; Substrate Specificity; Tumor Cells, Cultured

Epidermal growth factor (EGF) plays an important role in the regulation of gastrointestinal tissue growth and development, and it can stimulate epithelial proliferation, cell differentiation and growth. It has been established that the EGF can promote gastric cytoprotection and ulcer healing. But the potential ability of EGF to regulate the gastric cancer growth is unknown. This study is to investigate the influence of EGF on human gastric cancer cell and the implanted tumor growth of nude mice.. The cell growth rates of human gastric adenocarcinoma cell lines MKN-28, MKN-45, SGC-7901 and normal human gastric epithelial cells 3T3 were assessed when incubated with recombinant human EGF (rhEGF, 0.05, 0.1, 0.5, 1.0, 10, 50, 100 mg.L(-1)) using MTT method. The cells of MKN-28, MKN-45, SGC-7901 (gastric cancer tissue 1.5mm(3)) were implanted in the BALB/cA nude mice for 10 days. The EGF was given intraperitoneally (15, 30, 60 microg.kg(-1)) for 3 weeks. The body weights of the tumor-bearing animals and their tumor mass were measured afterwards to assess the mitogenic effect of rhEGF in the nude mice.. Within the concentration range of 0.05-100mg.L(-1), rhEGF could increase the cell growth of normal 3T3 cells (cell growth rate 100% vs 102.8%, P<0.05), but partially restrain the gastric cancer cell growth. The latter effect was related to cell differentiation. In 15-60 microg/kg rhEGF groups, the mean implanted tumor mass of MKN-28 cell were 1.75 g, 1.91 g, 2.08 g/NS group 1.97 g (P>0.05), the mean tumor mass of SGC-7901 cell were 1.53 g, 1.07 g, 1.20 g/NS group 1.07 g (P>0.05), and for MKN-45 cell, the tumor mass were respectively 1.92 g, 1.29 g, 1.77 /NS group 1.82 g (P>0.05). So rhEGF had no obvious effect on implanted MKN-28, SGC-7901 and MKN-45 tumor growth.. EGF has no stimulating effect on the human gastric cancer cell growth neither in vitro nor in vivo.

Topics: Animals; Cell Division; Epidermal Growth Factor; Humans; Male; Mice; Mice, Nude; Neoplasm Transplantation; Recombinant Proteins; Stomach Neoplasms; Transplantation, Heterologous; Tumor Cells, Cultured

Helicobacter pylori has a major aetiological role in human gastric carcinogenesis but the cellular and molecular pathways by which infection promotes transformation remain to be resolved. This study demonstrates that H. pylori exposure to MKN-1, ST42, and MKN-28 gastric epithelial tumour cells results in the activation of HB-EGF gene expression and EGFR tyrosine phosphorylation. These cell responses are induced by both cagPAI positive and cagPAI negative H. pylori strains and are dependent on cell surface expression of the HB-EGF precursor. The induction of HB-EGF gene transcription by H. pylori requires metalloprotease-, EGFR-, and Mek1-activities, indicating the involvement of the "triple membrane passing signal" (TMPS) for EGFR transactivation. Moreover, the release of the inflammatory cytokine IL-8 by cells exposed to H. pylori is significantly impaired by inhibitors of TMPS pathway elements. Our findings support a model in which H. pylori triggers constitutive EGFR signal activation, which enhances IL-8 production, and initiates neoplastic transformation of gastric epithelial cells.

Topics: Blotting, Northern; Blotting, Western; Cell Line; Cell Membrane; Cells, Cultured; Coculture Techniques; Enzyme Inhibitors; Enzyme-Linked Immunosorbent Assay; Epidermal Growth Factor; Epithelium; ErbB Receptors; Helicobacter pylori; Heparin-binding EGF-like Growth Factor; Humans; Intercellular Signaling Peptides and Proteins; Interleukin-8; Metalloendopeptidases; Phosphorylation; RNA, Messenger; Signal Transduction; Stomach; Stomach Neoplasms; Time Factors; Transcriptional Activation; Tyrosine

The present investigation aims at defining the functional status of several gastric cancer cell lines in order to assess their usefulness as adequate cellular models to study the regulation of gastric digestive functions. Compared to AGS, Hs746t and KATO-III cells, NCI-N87 exhibited an unique differentiation status. They formed coherent monolayers expressing E-cadherin and ZO-1 junctional proteins; their integrity and epithelial morphology were maintained at post-confluency for up to 10 days. All cell lines synthesized PAS-reactive (mucous-type) glycoconjugates. However, only NCI-N87 cells expressed MUC6 glycoprotein suggesting a mucopeptic phenotype. Immunostaining, enzymatic assays, Western blotting and Reverse Transcriptase polymerase chain reaction (RT-PCR) revealed that all cell lines contained varying levels of pepsinogen (Pg5) and human gastric lipase (HGL). Only NCI-N87 cells were able to express zymogens at higher levels, in granule-like structures, and to efficiently secrete both HGL and Pg5. The addition of epidermal growth factor (EGF) to post-confluent NCI-N87 cells, which exhibit an abundant membrane staining for EGF-receptors, modulated HGL activity without affecting Pg5. In conclusion, this investigation enlightens the potential usefulness of the gastric cell line NCI-N87 as a model for elucidating the cellular and molecular mechanisms involved in the regulation of human gastric epithelial functions.

Topics: Blotting, Western; Cadherins; Cell Differentiation; Cell Division; Digestion; Electrophoresis, Polyacrylamide Gel; Epidermal Growth Factor; Fluorescent Antibody Technique, Indirect; Humans; Lipase; Membrane Proteins; Microscopy, Fluorescence; Mucin-6; Mucins; Pepsin A; Pepsinogen A; Phenotype; Phosphoproteins; Reverse Transcriptase Polymerase Chain Reaction; Stomach; Stomach Neoplasms; Time Factors; Tumor Cells, Cultured; Zonula Occludens-1 Protein

Overexpression of the HER2 (neu/c-erbB-2) oncogene frequently coincides with an aggressive clinical course of certain human adenocarcinomas. Expression and secretion of aberrant HER2 splice variants has been reported in various cell lines and tissues and can interfere with the oncogenic HER2 activity. Here we demonstrate, using two different approaches, that expression of a truncated 100 kDa HER2 variant which encodes the extracellular domain of HER2 (HER-ECD) inhibits growth factor-mediated tumour cell proliferation. A HER2-ECD cDNA encoding the truncated variant was overexpressed in MCF7 breast cancer cells. HER2-ECD overexpression decreased spontaneous proliferation of MCF7 cells as well as heregulin-mediated soft agar colony formation. Concomitantly, heregulin-induced phosphorylation of HER4 as well as downstream activation of p44/p42 MAP-kinases was decreased. To confirm these data, ribozymes were targeted to the 3'-untranslated region of the 2.3 kb HER2-ECD mRNA which is spontaneously expressed in MKN7 gastric cancer cells. HER2-ECD-targeted ribozymes downregulated HER2-ECD expression and enhanced EGF-mediated soft agar colony formation of MKN7 cells. In parallel, EGF-induced activation of p44/p42 MAP-kinases and activation of c-Fos expression were increased in ribozyme-transfected MKN7 cells. Finally, in RT-PCR we found a trend towards a progressive loss of 2.3 kb HER2-ECD mRNA expression in more advanced gastric tumours. These data show that the HER2-ECD variant inhibits growth factor-mediated tumour cell proliferation suggesting an important role during the progression of human cancer.

Topics: Alternative Splicing; Base Sequence; Breast Neoplasms; Cell Division; DNA, Complementary; Down-Regulation; Doxycycline; Epidermal Growth Factor; Genes, erbB-2; Growth Inhibitors; Humans; MAP Kinase Signaling System; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Mitogen-Activated Protein Kinases; Molecular Sequence Data; Neuregulin-1; Protein Structure, Tertiary; Receptor, ErbB-2; RNA, Catalytic; RNA, Messenger; Stomach Neoplasms; Transfection; Tumor Cells, Cultured

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

The expression of epidermal growth factor (EGF), epidermal growth factor receptor (EGFR), transforming growth factor alpha (TGF alpha), and of c-erbB-2 was immunohistochemically investigated in resected gastric carcinoma (in 39 cases of superspreading type and in 11 cases of penetrating type), to understand the differential biological features of these two types of gastric carcinoma. EGF, EGFR and c-erbB-2 positive cases were preferentially found in penetrating type rather than in superspreading type (p < 0.05, p < 0.01, and p < 0.05, respectively). The positive rates of EGFR and c-erbB-2 were significantly higher in submucosal gastric carcinoma than in intramucosal gastric carcinoma (p < 0.01, p < 0.05, respectively). These results suggested that the autocrine mechanism of the growth factors and the expression of c-erbB-2 were correlated to the degree of gastric wall invasion.

Topics: Adult; Aged; Epidermal Growth Factor; ErbB Receptors; Female; Humans; Immunohistochemistry; Male; Middle Aged; Receptor, ErbB-2; Stomach Neoplasms; Transforming Growth Factor alpha

Hypergastrinemia occurs frequently in association with acid suppression and Helicobacter infection, but its role in the progression to gastric atrophy and gastric cancer has not been well defined.. The effects of hypergastrinemia, and possible synergy with Helicobacter felis infection, were investigated in insulin-gastrin (INS-GAS) transgenic mice.. INS-GAS mice initially showed mild hypergastrinemia, increased maximal gastric acid secretion, and increased parietal cell number but later progressed to decreased parietal cell number and hypochlorhydria. Development of gastric atrophy was associated with increased expression of growth factors, heparin-binding epidermal growth factor and transforming growth factor alpha. At 20 months of age, INS-GAS mice showed no evidence of increased enterochromaffin-like cell number, but instead exhibited gastric metaplasia, dysplasia, carcinoma in situ, and gastric cancer with vascular invasion. Invasive gastric carcinoma was observed in 6 of 8 INS-GAS mice that were >20 months old. Helicobacter felis infection of INS-GAS mice led to accelerated (< or = 8 mo) development of intramucosal carcinoma (85%), with submucosal invasion (54%) and intravascular invasion (46%; P < or = 0.05).. These findings support the unexpected conclusion that chronic hypergastrinemia in mice can synergize with Helicobacter infection and contribute to eventual parietal cell loss and progression to gastric cancer.

Topics: Animals; Cell Count; Epidermal Growth Factor; Epithelial Cells; Gastric Acid; Gastrins; Gastritis, Atrophic; Helicobacter Infections; Heparin; Heparin-binding EGF-like Growth Factor; Hyperplasia; Hypertrophy; Intercellular Signaling Peptides and Proteins; Metaplasia; Mice; Mice, Transgenic; Stomach Neoplasms; Transforming Growth Factor alpha

We studied the expression of cell cycle regulators and growth factor-receptor systems in gastric carcinoma in young adults and tried to clarify the specific alterations associated with H. pylori. We studied 33 young patients (18-29 years old, mean age 26.4) with gastric carcinoma. The patients were classified into two groups according to the degree of atrophic gastritis. Then we examined the expression of p53, cripto, cyclin-E, c-met, c-erbB2 and TGF-alpha immunohistochemically and compared the results between the two groups. The results were compared with 66 sex-, tumor histology-, and depth-matched elder controls (36-86 years old, mean age 64.0). H. pylori was judged by Giemsa staining. Seventeen patients had atrophic changes in the corpus (Group A), while 16 showed superficial gastritis or normal mucosa (Group S). All 17 patients of Group A showed H. pylori infection, while the 3 of the 16 members of Group S did not have H. pylori. p53 overexpression was observed more frequently in Group S (88%) than in Group A (41%, p<0.05). In the 3 patients without H. pylori infection, all carcinoma specimens showed p53 overexpression. Overexpression of cyclin-E was detected in 4 patients from Group S. On the other hand, cripto was observed more frequently in Group A than in Group S. No obvious differences were observed in c-erbB2, TGF-alpha and c-met expression. Overall, p53 overexpression was detected more frequently in younger than in older patients, whereas cripto expression was less detected. These results suggest that p53 and cyclin-E may act in an H. pylori-independent or -adjunctive manner for gastric carcinogenesis. Cripto expression might be correlated tightly with H. pylori infection.

Topics: Adolescent; Adult; Cell Cycle Proteins; Cyclin E; Epidermal Growth Factor; Female; GPI-Linked Proteins; Growth Substances; Helicobacter Infections; Humans; Immunohistochemistry; Intercellular Signaling Peptides and Proteins; Male; Membrane Glycoproteins; Neoplasm Proteins; Proto-Oncogene Proteins c-met; Receptor, ErbB-2; Receptors, Growth Factor; Stomach Neoplasms; Transforming Growth Factor alpha; Tumor Suppressor Protein p53

Recent evidence suggests that both estrogens and growth factors play an important role in the growth of gastrointestinal tumors. The expression of estrogen receptors (ER) and epidermal growth factor receptors (EGFR) in the gastrointestinal tract might therefore result in functional cross-talk between estrogens and EGF. The aim of the present study was to evaluate in vitro the effects of 17beta-estradiol and EGF administration on cell proliferation of a human gastric adenocarcinoma cell line (AGS) and investigate whether any interaction of these compounds may play a role in regulating gastric cancer cell proliferation.. Estrogen and EGFRs were detected by enzyme immunoassay. Cell proliferation was assessed with the MTT test.. Exposure of AGS cells to increasing concentrations of 17beta-estradiol showed an anti-proliferative action at concentrations of 2 microM or higher. The addition of increasing concentrations of EGF stimulated cell growth, with a maximal response at 50 ng/ml EGF. The effect of increasing 17beta-estradiol concentrations combined with 50 ng/ml EGF was to increase cell growth at the lower estradiol concentrations. At the highest estradiol concentration the EGF proliferative effect was suppressed, and a decrease in proliferation rates occurred. Moreover, a significant negative correlation was found between 17beta-estradiol concentrations and EGFR expression.. These findings suggest that growth of cultured gastric cancer cells (AGS) might be modulated by sex steroid hormones through interaction with EGF.

Topics: Adenocarcinoma; Cell Division; Epidermal Growth Factor; ErbB Receptors; Estradiol; Humans; Receptors, Estrogen; Stomach Neoplasms; Tumor Cells, Cultured

EGF stimulates gene expression through a variety of signal transduction pathways that include the ras-Erk pathway. We have shown previously that EGF receptor activation stimulates gastrin gene expression through a GC-rich element called gERE. This element binds Sp1 family members and raises the possibility that the ras-Erk signal transduction cascade may target this novel EGF responsive element. Moreover, it is known that Erk 2 is capable of phosphorylating other mitogen-inducible transcription factors, e.g., Elk, Sap suggesting that Erk may also inducibly phosphorylate Sp1. To test this hypothesis directly using cotransfection experiments, we show that ras and Erk 2 activation indeed target the gERE element. The Mek 1 kinase inhibitor, PD98059, blocks 50% of EGF-inducible gastrin promoter activity. Pretreatment of the extracts with recombinant Erk2 stimulated Sp1 binding; whereas dephosphorylation reduced but did not eliminate Sp1 binding. Together, these studies demonstrate the novel finding that inducible binding of Sp1 is regulated by its state of phosphorylation. Further, gastrin promoter activation is mediated in part by the ras-Erk signaling cascade that targets Sp1.

Topics: Adenocarcinoma; Base Sequence; Binding Sites; Calcium-Calmodulin-Dependent Protein Kinases; Enzyme Inhibitors; Epidermal Growth Factor; Flavonoids; Gastrins; Gene Expression Regulation, Neoplastic; Genes, ras; Humans; Mitogen-Activated Protein Kinase 1; Oligodeoxyribonucleotides; Phosphorylation; Promoter Regions, Genetic; Signal Transduction; Sp1 Transcription Factor; Stomach Neoplasms; Transcription Factors; Tumor Cells, Cultured

Cigarette smoking has been shown to aggravate ulceration and delay ulcer healing. Smokers had a lower level of mucus in their stomachs. In the present study, we examined whether cigarette smoke or its extract reduced mucus production through the suppression of epidermal growth factor (EGF) associated with the reduction of polyamine biosynthesis both in vivo and in vitro. Ornithine decarboxylase (ODC) activities and mucus synthesis were determined in rat gastric mucosa and in human MKN-28 cells. Incubation of MKN-28 cells with EGF (0.01-1.00 ng/mL) significantly increased mucus synthesis in vitro, which was accompanied by an increase of ODC activity. Removal of salivary glands decreased the circulated EGF level and induced a significant reduction of mucus-secreting layer thickness in the gastric mucosa. Cigarette smoke or its extract markedly decreased mucus synthesis in vivo and in vitro, both of which could be completely reversed by intravenous administration of EGF (20 microg/kg) in rats or co-incubation with EGF (1 and 2 ng/mL) in MKN-28 cells. However, ODC activities, which were suppressed by cigarette smoke or its extract, were unaffected by intravenous administration of EGF in rats, or only partially reversed by co-incubation with EGF in MKN-28 cells. These findings indicate that both EGF and ODC activity represent two different entities in the modulation of cigarette smoking on gastric mucus synthesis. The action of EGF on mucus synthesis may only be partially if not dependent on ODC activity in the stomach.

Topics: Adenocarcinoma; Animals; Epidermal Growth Factor; Gastric Mucosa; Humans; Male; Mucus; Nicotiana; Ornithine Decarboxylase; Plants, Toxic; Rats; Rats, Sprague-Dawley; Salivary Glands; Smoke; Stomach Neoplasms; Tumor Cells, Cultured

Interleukin (IL)-8 is a multifunctional cytokine that can stimulate the division of endothelial cells. We examined the expression of IL-8 mRNA using Northern blot analysis and in situ mRNA hybridization (ISH) and protein production using enzyme-linked immunosorbent assay and immunohistochemistry in 8 human gastric carcinoma cell lines and 39 gastric carcinomas and corresponding normal mucosa (34 surgical specimens and 5 biopsy specimens). Of the 8 human gastric carcinoma cell lines, 6 expressed 1.8-kb IL-8 mRNA and secreted various levels of IL-8 protein. The expression of IL-8 by TMK-1 cells was induced by exposure to IL-1 alpha, epidermal growth factor, and transforming growth factor-alpha, shown previously to be autocrine growth stimulators for human gastric carcinoma cells. In tumor tissues, most of the tumors (28 of 34 surgical specimens and 4 of 5 biopsy specimens) expressed IL-8 at higher levels than the corresponding normal mucosa. ISH and immunohistochemical analyses revealed that IL-8 mRNA and protein were localized in the cytoplasm of tumor cells. The number of blood vessels in the gastric carcinomas was determined by using antibodies against CD34. The level of IL-8 mRNA in the neoplasms strongly correlated with vascularization (Spearman correlation, r = 0.812; P = 0.001). The data suggest that IL-8 produced by tumor cells may regulate neovascularization and, hence, the growth and spread of human gastric carcinoma.

Topics: Adult; Aged; Blood Vessels; Carcinoma; Cell Division; Epidermal Growth Factor; Female; Humans; Interleukin-1; Interleukin-8; Male; Middle Aged; RNA, Messenger; Stomach Neoplasms; Tissue Distribution; Transforming Growth Factor alpha; Tumor Cells, Cultured

Epidermal growth factor (EGF) has a wide variety of biological activities in the protection of gastric mucosa against acute injury and the healing of gastric ulcer. However, the molecular basis of the EGF action remains unknown. EGF-induced activation of ornithine decarboxylase (ODC) was examined, because ODC is a key enzyme for the cell proliferation.. The effects of epidermal growth factor (EGF) and indomethacin on ornithine decarboxylase (ODC) mRNA and enzyme activity were examined in gastric cancer derived KATO-III cells.. EGF induced both ODC mRNA expression and enzyme activation in a biphasic manner with the peaks at 0.5 and 3 h for mRNA and at 5 and 9 h for enzyme activity, respectively. Indomethacin pretreatment significantly reduced EGF-induced ODC activation and was completely abolished for the first 5 h.. Since it has been reported that both EGF and ODC are involved in cell migration and proliferation, two actions of EGF for gastric mucosal healing may be through, at least in part, this biphasic activation of ODC. Indomethacin suppresses and changes the response of ODC induced by EGF.

Topics: Adenocarcinoma; Anti-Inflammatory Agents, Non-Steroidal; Cell Division; Cell Movement; Enzyme Activation; Epidermal Growth Factor; ErbB Receptors; Gastric Mucosa; Gene Expression Regulation, Neoplastic; Humans; Indomethacin; Ornithine Decarboxylase; RNA, Messenger; RNA, Neoplasm; Stomach Neoplasms; Time Factors; Tumor Cells, Cultured

Acute exposure to Helicobacter pylori causes cell damage and impairs the processes of cell migration and proliferation in cultured gastric mucosal cells in vitro. EGF-related growth factors play a major role in protecting gastric mucosa against injury, and are involved in the process of gastric mucosal healing. We therefore studied the acute effect of H. pylori on expression of EGF-related growth factors and the proliferative response to these factors in gastric mucosal cells (MKN 28) derived from gastric adenocarcinoma. Exposure of MKN 28 cells to H. pylori suspensions or broth culture filtrates upregulated mRNA expression of amphiregulin (AR) and heparin-binding EGF-like growth factor (HB-EGF), but not TGFalpha. This effect was specifically related to H. pylori since it was not observed with E. coli, and was independent of VacA, CagA, PicA, PicB, or ammonia. Moreover, H. pylori broth culture filtrates stimulated extracellular release of AR and HB-EGF protein by MKN 28 cells. AR and HB-EGF dose-dependently and significantly stimulated proliferation of MKN 28 cells in the absence of H. pylori filtrate, but had no effect in the presence of H. pylori broth culture filtrates. Inhibition of AR- or HB-EGF- induced stimulation of cell growth was not mediated by downregulation of the EGF receptor since EGF receptor protein levels, EGF binding affinity, number of specific binding sites for EGF, or HB-EGF- or AR-dependent tyrosine phosphorylation of the EGF receptor were not significantly altered by incubation with H. pylori broth culture filtrates. Increased expression of AR and HB-EGF were mediated by an H. pylori factor > 12 kD in size, whereas antiproliferative effects were mediated by both VacA and a factor < 12 kD in size. We conclude that H. pylori increases mucosal generation of EGF-related peptides, but in this acute experimental model, this event is not able to counteract the inhibitory effect of H. pylori on cell growth. The inhibitory effect of H. pylori on the reparative events mediated by EGF-related growth factors might play a role in the pathogenesis of H. pylori-induced gastroduodenal injury.

Topics: Adenocarcinoma; Amphiregulin; Cell Division; Cell Line; EGF Family of Proteins; Epidermal Growth Factor; ErbB Receptors; Gastric Mucosa; Gastritis; Glycoproteins; Growth Substances; Helicobacter Infections; Helicobacter pylori; Heparin; Heparin-binding EGF-like Growth Factor; Humans; Intercellular Signaling Peptides and Proteins; Peptic Ulcer; Recombinant Proteins; RNA, Messenger; Stomach Neoplasms; Transforming Growth Factor alpha; Up-Regulation; Virulence

Epidermal growth factor (EGF) induced the disruption and scattering of colonies of TMK-1, a cell line derived from a human gastric carcinoma. A stimulatory action of EGF on cell migration was also observed as determined by a wound assay. However, these actions of EGF were inhibited if the cells were pretreated with dexamethasone, a synthetic glucocorticoid. Dexamethasone increased cell adhesion to collagen type IV and laminin, but not to poly-L-lysine and fibronectin. In contrast, EGF did not affect cell adhesion to these extracellular matrices whether dexamethasone was present or not. Dexamethasone enhanced the protein levels of both alpha1 and beta1 integrin subunits, and that of the alpha1 beta1 heterodimer. Further, flow cytometric analysis revealed that dexamethasone increased the expression of beta1 and alpha1 integrin subunits at the cell surface, whereas EGF increased expression of beta1 and alpha2 subunits at the cell surface. Antibodies against alpha1 and beta1 integrin subunits inhibited the increased cell adhesion seen in the presence of dexamethasone. An immunofluorescence study indicated that dexamethasone increased the formation of focal adhesions along the entire edges of cell colonies. In contrast, EGF led to the formation of focal adhesions preferentially at the cell front, and this EGF-induced preferential formation was not observed if the cells were pretreated with dexamethasone. These results suggest that glucocorticoid increased cell adhesion to the extracellular matrix via alpha1 beta1 integrin, and thereby antagonized EGF-induced cell migration.

Topics: Cadherins; Cell Adhesion; Cell Adhesion Molecules; Cell Movement; Collagen; Dexamethasone; Epidermal Growth Factor; Extracellular Matrix; Flow Cytometry; Glucocorticoids; Humans; Immunohistochemistry; Integrins; Laminin; Phosphotyrosine; Stomach Neoplasms; Tumor Cells, Cultured

Vascular endothelial growth factor (VEGF), also known as vascular permeability factor, is a secreted protein which may play a pivotal role in tumor-associated microvascular angiogenesis and hyperpermeability. The expression of mRNA for VEGF was examined in eight gastric carcinoma cell lines and 30 gastric carcinoma tissues as well as corresponding normal mucosa. All the cell lines expressed VEGF mRNA at various levels that correlated well with the amounts of VEGF secreted into the condition medium. The expression of VEGF mRNA by TMK-1 cells was increased by the treatment of epidermal growth factor (EGF) or interleukin-1alpha (IL-1alpha), whereas it was decreased by the treatment of interferon-beta (IFN-beta). In gastric carcinoma tissues, the level of VEGF mRNA in primary tumors was higher than that in the corresponding normal mucosas in six (46%) of 13 well-differentiated adenocarcinomas and in two (12%) of 17 poorly differentiated adenocarcinomas, respectively. Vessel counts in well-differentiated adenocarcinomas had a tendency to be higher than those in poorly differentiated adenocarcinomas. In well-differentiated adenocarcinomas, the levels of VEGF mRNA expression tended to be higher in carcinomas of advanced stage than in early stage carcinomas. Both in situ mRNA hybridization and immunohistochemistry demonstrated the presence of VEGF expression within the tumor cells. These results suggest that VEGF may confer angiogenesis and progression of human gastric carcinomas, especially of the well-differentiated type.

Topics: Adenocarcinoma; Adult; Aged; Blood Vessels; Blotting, Northern; DNA Probes; DNA, Neoplasm; Endothelial Growth Factors; Epidermal Growth Factor; Female; Humans; In Situ Hybridization; Interferon-beta; Interleukin-1; Lymphokines; Male; Middle Aged; RNA; Stomach Neoplasms; Tumor Cells, Cultured; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors

To understand the role of NM23/NDPK in the transmembrane signal transduction proccess in tumor metastasis.. The NDPK activity, IP3 contents, the invasive potentials of the cells of mouse forestomach carcinoma(MFC) substrains with different metastatic potentials and the effect of LN and EGF were observed.. Both the NDPK activity and the contents of IP3 of the cells of the subclone with lower metastatic potential was higher than that with higher metastatic potential. Also, the cells with lower metastatic potential had lower invasive potential and higher responsibility to the challenge of EGF compared with that higher metastatic potential. However, no different effect of LN on the cells of those subclones was found.. NDPK might regulate the metastasis of FMC cells by impacting the G protein efficacy with the selection of exotic signal ligands.

Topics: Animals; Epidermal Growth Factor; Inositol 1,4,5-Trisphosphate; Mice; Neoplasm Metastasis; Neoplasm Transplantation; Nucleoside-Diphosphate Kinase; Signal Transduction; Stomach Neoplasms; Tumor Cells, Cultured

Epidemiological studies have consistently shown an association between infection of Helicobacter pylori (Hp) and duodenal ulcer (DU) and gastric cancer. The mechanism of the ulcerogenic effect of Hp has been related to excessive gastrin release, gastric acid hypersecretion and gastric metaplasia in duodenum. The implication of Hp in gastric carcinogenesis has not been explained. In this study, mucosal expression of EGF and TGF alpha and luminal release of EGF as well as basal and pentagastrin-stimulated acid secretion and plasma gastrin levels have been determined in healthy subjects, gastric carcinoma and DU patients. It was found that Hp positive DU patients show excessive gastrin release and gastric acid secretion combined with increased expression and luminal release of EGF and TGF alpha. These changes returned to normal values two years after the eradication of Hp. Gastric cancer patients also showed increased expression of EGF and TGF alpha and highly increased plasma gastrin but their gastric acid secretion was markedly reduced possibly due to atrophy of oxyntic mucosa. This study indicates that overexpression of growth factors in gastric mucosa may be implicated in the pathogenesis of both duodenal ulcer and gastric cancer and that Hp positive hypochlorhydric and hypergastrinemic patients may be predisposed to development of gastric cancer.

Topics: Adult; Aged; Carcinoma; Duodenal Ulcer; Epidermal Growth Factor; Gastric Acid; Gastric Juice; Gastric Mucosa; Helicobacter Infections; Helicobacter pylori; Humans; Immunochemistry; Middle Aged; Pentagastrin; Stomach Neoplasms; Transforming Growth Factor alpha

To examine the IP3 amounts, invasive potentials, and response to LN and EGF of the substrains with high or low metastatic ability from two kinds of carcinoma cell lines (MFC and CNZ-2Z).. Radio-ligand binding assay and matrigel invasive assay.. The low metastatic substrains from the two lines had higher amounts of IP3 and stronger response to EGF than their responsive high ones, but high metastatic substrains from CNZ-2Z had stronger response to LN than the low ones while MFC substrains had not significant difference in response to LN.. There is internal difference in signal transduction between the high and low metastatic cancer cells, and it is significant to study the difference in detail.

Topics: Animals; Epidermal Growth Factor; Humans; Inositol 1,4,5-Trisphosphate; Laminin; Mice; Nasopharyngeal Neoplasms; Neoplasm Metastasis; Signal Transduction; Stomach Neoplasms; Tumor Cells, Cultured

Hepatocyte growth factor (HGF) stimulated cell migration of human gastric carcinoma cell lines MKN1, MKN7, and MKN28. Epidermal growth factor (EGF) also stimulated the cell migration of these three cell lines. In MKN7 cells, HGF-stimulated cell migration was rather reduced in the presence of EGF, whereas such an observation was not made with MKN1 and MKN28 cells. Therefore, we compared the effect of EGF on HGF-stimulated HGF receptor phosphorylation in these cell lines. HGF induced a rapid tyrosine phosphorylation of the HGF receptor in all these cell lines. In MKN7 cells, the increased phosphorylation was further enhanced by EGF, although EGF alone did not affect tyrosine phosphorylation of the HGF receptor. In MKN1 and MKN28 cells, EGF did not influence tyrosine phosphorylation of the HGF receptor, whether HGF was present or not. The data presented here suggest that EGF negatively modulates the cellular response to HGF by increasing tyrosine phosphorylation of the HGF receptor in certain types of epithelial cells, e.g., MKN7 cells.

Topics: Carcinoma; Cell Movement; Epidermal Growth Factor; Hepatocyte Growth Factor; Humans; Phosphorylation; Proto-Oncogene Proteins c-met; Receptor Protein-Tyrosine Kinases; Stomach Neoplasms; Tumor Cells, Cultured; Tyrosine

Blockading the putative epidermal growth factor (EGF), transforming growth factor-alpha (TGF-alpha)/EGF receptor autocrine pathway with anti-EGF receptor monoclonal antibody (MoAb) might prevent the growth of tumor.. The present study was designed to examine the effect of MoAb 528 on the growth of an EGF receptor which was hyperproducing human gastric cancer cells in vitro and in vivo.. Treatment with MoAb 528 inhibited the growth of cultured cells in a dose-dependent manner. Twenty micrograms of MoAb 528 given intraperitoneally after inoculation of 1 x 10(6) cells and 200 micrograms of the MoAb 528 given after inoculation of 1 x 10(7) cells to athymic mice inhibited the growth of the xenograft. Twenty micrograms of MoAb 528 from a miniosmotic pump, which releases its contents over 2 weeks, also prevented the growth of the xenograft when the treatment was started on the day after tumor inoculation. However, no inhibitory effect was observed when the treatment was started 3 weeks after inoculation. The binding capacity of 125I-EGF on the MoAb treated tumors was diminished in comparison with control tumors.. The results suggest that MoAb 528 blocks the EGF or TGF-alpha/EGF receptor signal pathway, resulting in the inhibition of cancer cell growth. This MoAb 528 may therefore be an effective antitumor agent against human gastric cancer that shows expression of the EGF receptor.

Topics: Animals; Antibodies, Monoclonal; Cell Division; Epidermal Growth Factor; ErbB Receptors; Humans; Immunohistochemistry; Iodine Radioisotopes; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Neoplasm Transplantation; Radioligand Assay; Stomach Neoplasms; Transplantation, Heterologous; Tumor Cells, Cultured

Heparin-binding epidermal growth factor (EGF)-like growth factor (HB-EGF) is a member of the EGF family of polypeptide growth factors, which includes EGF, transforming growth factor alpha(TGF-alpha), amphiregulin (AR) and betacellulin (BTC). To assess the potential role of HB-EGF in human gastric carcinomas, the expression of HB-EGF and EGF receptor (EGF-R) was examined in normal and cancerous gastric tissues and cultured gastric cancer cell lines. By Northern blot analysis, there was a 4.7-fold increase in HB-EGF mRNA levels in human gastric cancers compared with normal gastric tissues. There was a concomitant 3.9-fold increase in EGF-R mRNA levels in these cancers. Immunostaining revealed co-localization in 72% of the cancer cells of HB-EGF and EGF-R. AR and BTC moieties were not evident by Northern blot analysis. However, using PCR, both AR and BTC mRNA species were demonstrated in normal and cancerous gastric tissues. By Northern blot analysis, HB-EGF, TGF-alpha, AR, BTC and EGF-R mRNA moieties were co-expressed in KATO III and NCI-N87 gastric cancer cell lines. Furthermore, HB-EGF, EGF and TGF-alpha enhanced the growth of both cell lines in a dose-dependent manner. Our findings suggest that HB-EGF is relatively abundant in human gastric cancers and that co-expression of the EGF ligand family may lead to excessive activation of EGF-R in this disorder.

Topics: Adenocarcinoma; Adult; Aged; Base Sequence; Blotting, Northern; Blotting, Southern; Cell Line; DNA Primers; Epidermal Growth Factor; ErbB Receptors; Female; Gene Expression; Heparin; Heparin-binding EGF-like Growth Factor; Humans; Intercellular Signaling Peptides and Proteins; Male; Middle Aged; Molecular Sequence Data; Polymerase Chain Reaction; RNA, Messenger; RNA, Neoplasm; Stomach Neoplasms; Transcription, Genetic; Tumor Cells, Cultured

A case of synchronous squamous cell carcinomas in the soft palate, larynx and esophagus is reported, along with findings of molecular-pathological analysis. A biopsy sample from the aryngeal carcinoma revealed well differentiated squamous cell carcinoma harboring two point mutations at codons 144 and 148 of the p53 gene but not at codon 299, and more than 50% of the cancer cells showed accumulation of p53 protein immunohistochemically. The esophageal tumor, which was moderately differentiated squamous cell carcinoma, showed immunoreactivity for p53 within the nuclei of 25-50% of cancer cells with a missense mutation at codon 299 but not at codon 144 or 148. This cancer also showed immunoreactivity for transforming growth factor alpha. On the other hand, the poorly differentiated squamous cell carcinoma in the soft palate showed negative immunoreactivity for p53 and no point mutation in exons 5 to 8 of the gene. These results suggest that the three synchronous squamous cell carcinomas arose as independent events.

Topics: Aged; Carcinoma, Squamous Cell; Epidermal Growth Factor; ErbB Receptors; Esophageal Neoplasms; Genes, p53; Humans; Immunohistochemistry; Laryngeal Neoplasms; Male; Mutation; Neoplasms, Multiple Primary; Palatal Neoplasms; Palate, Soft; Polymerase Chain Reaction; Stomach Neoplasms; Transforming Growth Factor alpha; Tumor Suppressor Protein p53

Gastric carcinoids evolved from enterochromaffin-like (ECL) cell hyperplasia are usually associated with high pH and hypergastrinemia. The Mastomys species exhibits a genetic propensity to gastric carcinoid formation that can be accelerated by acid inhibition-induced hypergastrinemia. Although gastrin is critical in the initiation of the ECL cell transformation, the role of other growth factors involved in the evolution of the tumor autonomy has not been established. The aim of this study was to evaluate the role of transforming growth factor (TGF) alpha in the regulation of ECL cell transformation.. Mastomys were orally administered an irreversible H2-receptor antagonist loxtidine for 0, 8, and 16 weeks, and ECL cell transformation was monitored by assessing gastrin levels, mucosal histamine content, and chromogranin immunoreactivity. The ECL cells were purified, and cell proliferation at each stage in response to gastrin and TGF alpha was measured by bromodeoxyuridine uptake. TGF-alpha expression was evaluated by radioimmunoassay and Northern blot, and epidermal growth factor (EGF) receptor expression was determined by Western blot, immunoprecipitation, and immunocytochemistry.. Although the response to gastrin decreased during hypergastrinemia, the proliferative effect of TGF-alpha on ECL cells was specifically amplified during the development of hyperplasia. TGF-alpha and EGF receptor expression increased steadily in the transformed cells.. During low acid-induced hypergastrinemia, the expression of TGF-alpha and EGF receptor may constitute an autocrine regulatory mechanism in ECL cell tumor transformation.

Topics: Animals; Carcinoid Tumor; Cell Division; Cell Transformation, Neoplastic; Cells, Cultured; Enterochromaffin Cells; Epidermal Growth Factor; ErbB Receptors; Gastrins; Histamine; Muridae; Stomach Neoplasms; Transforming Growth Factor alpha

We previously reported a new laminin variant containing laminin gamma 2 (or B2t) chain, ladsin, which exerted prominent cell-scattering, cell-adhesion, and cell-migration activities. In the present study, this laminin was further characterized, and gene expression of its three subunits in various human tissues and cancer cell lines was examined by Northern blotting. cDNA cloning of the largest subunit of ladsin and partial amino acid sequencing of its beta (or B1) subunit revealed that ladsin was identical to laminin-5 (kalinin/epiligrin/ nicein). Among various human tissues, placenta, lung, and fetal kidney expressed high levels of mRNAs for the three subunits of laminin-5 (laminin alpha 3EPA, beta 3, and gamma 2 chains). Most gastric and squamous carcinoma cell lines constitutively expressed all of the three subunit mRNAs, while other types of carcinoma cell lines expressed one or two of them. The tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) and epidermal growth factor (EGF) strongly enhanced the gene expression of the three subunits, increasing 2 to 8-fold the secretion of laminin-5 from carcinoma cells into culture medium. However, TPA treatment did not increase the secretion of laminin beta 1 chain, a subunit of laminins-1, -3, and -6. The unique properties and inducibility by TPA and EGF of laminin-5 suggest that it is associated with growth and migration of cancer cells.

Topics: Blotting, Northern; Cell Adhesion; Cell Adhesion Molecules; Epidermal Growth Factor; Gene Expression Regulation, Neoplastic; Humans; Kalinin; Molecular Sequence Data; Platelet-Derived Growth Factor; Protein Conformation; RNA, Messenger; Stomach Neoplasms; Tetradecanoylphorbol Acetate; Transforming Growth Factor beta; Tumor Cells, Cultured; Up-Regulation

To examine the suggested biological difference between Japanese and British gastric cancers, immunohistochemistry was used to demonstrate eight markers of biological activity in a matched series of 40 Japanese and 33 British cases. There were no differences in the proportions of Japanese and British tumours positive to epidermal growth factor, epidermal growth factor receptor, transforming growth factor alpha, cripto or p53. A significantly greater proportion of British tumours were positive to c-erbB-2 whilst a significantly greater proportion of Japanese tumours were positive to nm23. British tumours had a significantly greater mean proliferating cell nuclear antigen proliferation index than Japanese tumours. These differences could be clinically significant.

Topics: Adult; Aged; Aged, 80 and over; Epidermal Growth Factor; ErbB Receptors; Europe; Humans; Immunohistochemistry; Japan; Middle Aged; Monomeric GTP-Binding Proteins; NM23 Nucleoside Diphosphate Kinases; Nucleoside-Diphosphate Kinase; Proliferating Cell Nuclear Antigen; Receptor, ErbB-2; Stomach Neoplasms; Transcription Factors

Determination of the differences between cell lines which are derived from a primary tumour and a disseminated metastatic lesion from the same patient may aid in elucidating the factors associated with disseminated metastases. We report on the establishment and characterisation of two new scirrhous gastric cancer cell lines, designated OCUM-2M and OCUM-2D, derived from a 49-year-old female. OCUM-2M was derived from a primary gastric tumour, and OCUM-2D was derived from a sample of disseminated metastasis. The two cell lines were derived from the same patient. We investigated biological differences between the two cell lines to study mechanisms involved in disseminated metastasis. The growth activity of OCUM-2D cells as determined by doubling time and tumorigenicity was greater than that of OCUM-2M cells. The level of epidermal growth factor receptor (EGFR) expression in OCUM-2D cells was about twice that of OCUM-2M cells and the growth of OCUM-2D cells was stimulated more by epidermal growth factor (EGF) than that of OCUM-2M cells. The invasive activity of OCUM-2D cells was higher than that of OCUM-2M cells and was increased after addition of transforming growth factor-beta 1 (TGF-beta 1). An increase in the number of attached and spreading cells was found following the addition of 10 ng ml-1 TGF-beta 1. These findings suggest that high growth and invasive activity may play an important role in disseminated metastasis and that EGF and TGF-beta 1, which affect the growth and invasive activity of OCUM-2D cells, might be factors associated with metastasis in scirrhous gastric carcinoma. The two cell lines OCUM-2M and OCUM-2D should be beneficial for analysing mechanisms of tumour progression.

Topics: Adenocarcinoma, Scirrhous; Aneuploidy; Antigens, Neoplasm; Cell Division; Chromosome Aberrations; DNA, Neoplasm; Epidermal Growth Factor; ErbB Receptors; Female; Humans; Karyotyping; Middle Aged; Neoplasm Invasiveness; Neoplasm Proteins; Stomach Neoplasms; Transforming Growth Factor beta; Tumor Cells, Cultured

The effect of local administration of epidermal growth factor (EGF) on 9,10-dimethyl-1,2-benzanthracene (DMBA)-induced tumour formation was investigated in a hamster cheek pouch carcinogenesis model. DMBA-treated hamsters underwent either sialoadenectomy (groups 1 and 2) or a sham operation (groups 3 and 4). Thereafter, EGF (groups 1 and 3) or vehicle (groups 2 and 4) was applied to the cheek pouches for 6 weeks. Fourteen weeks after the beginning of the experiment, the number of cheek pouch tumours was significantly greater in EGF-treated hamsters than in vehicle-treated hamsters, irrespective of whether the submandibular glands had been removed. The number of forestomach tumours, induced by DMBA application to the cheek pouches, was also increased by EGF. These results suggest that EGF applied from the luminal side of the mucosa stimulates tumour formation in the hamster cheek pouch and forestomach.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Administration, Topical; Animals; Cheek; Cricetinae; Drug Synergism; Epidermal Growth Factor; Male; Mesocricetus; Mouth Mucosa; Mouth Neoplasms; Salivary Glands; Stomach Neoplasms

Topics: Abdominal Neoplasms; Adenocarcinoma, Scirrhous; Adult; Carcinoembryonic Antigen; Epidermal Growth Factor; ErbB Receptors; Fatal Outcome; Humans; Male; Skin Neoplasms; Stomach Neoplasms; Umbilicus

Epidermal growth factor (EGF), its related peptide transforming growth factor (TGF-alpha) and their common receptor (EGFR) have been implicated in the control of cell proliferation and differentiation in the gastrointestinal epithelium and may play an important role in gastric carcinogenesis. We compared the immunohistochemical expression and topographic distribution of these peptides using Western blot analysis in gastric carcinoma precursor lesions and in non-cancer tissue. We observed: (i) increased and extended expression of TGF-alpha in normal mucosa and hyperplasia in carcinoma fields compared with non-cancer controls; (ii) increased expression of EGFR in intestinal metaplasia (IM) from carcinoma fields compared with controls; (iii) EGF expression was not detected in normal mucosa and only weakly in IM; (iv) coexpression of TGF-alpha/EGFR and EGF/EGFR was higher in intestinal metaplasia in carcinoma fields than in non-cancer controls. We conclude that altered expression of TGF-alpha/EGFR is associated with morphological changes during gastric carcinogenesis. In this regard increased expression of TGF-alpha is a very early event which is subsequently followed by up-regulation of EGFR and this has important biological and clinical implications.

Topics: Epidermal Growth Factor; ErbB Receptors; Humans; Immunohistochemistry; Precancerous Conditions; Stomach Neoplasms; Transforming Growth Factor alpha

A human signet ring gastric carcinoma cell line TSGH9201 was established in vitro. The cells grew in vitro as a monolayer with polygonal morphology and had a population doubling time of 34 hours. The cells secreted tumor markers CEA and CA 125. They were, however, not tumorigenic in athymic nude mice. Karyotypic analysis demonstrated a near tetraploidy with a modal chromosome number of 98. Northern blotting and immunocytochemical analysis revealed the expression of both transforming growth factor alpha and high levels of epidermal growth factor receptor. Cell growth was inhibited by the epidermal growth factor in vitro. The cell line may be a useful tool to study autocrine growth regulation through the epidermal growth factor receptor.

Topics: Animals; Blotting, Northern; Carcinoma, Signet Ring Cell; Cell Division; DNA, Neoplasm; Epidermal Growth Factor; ErbB Receptors; Gene Expression Regulation, Neoplastic; Humans; Mice; Mice, Nude; Polyploidy; RNA, Neoplasm; Stomach Neoplasms; Transforming Growth Factor alpha; Tumor Cells, Cultured

Nude mice bearing xenografts of the gastrin-responsive human gastric carcinoma MKN45 cell line were treated for 4 to 5 weeks with bombesin/gastrin-releasing-peptide(GRP) antagonist (RC-3095), somatostatin analogues RC-160 and SMS 201-995, or the combination of RC-3095 and RC-160. Tumor volumes and weights were reduced significantly to a similar extent by RC-160 and SMS 201-995, administered by daily s.c. injections at a dose of 100 micrograms/day. Bombesin/GRP antagonist RC-3095, given s.c. at a dose of 20 micrograms/day, had the greatest inhibitory effect on tumor growth. The combination of RC-3095 with RC-160 did not further potentiate the suppression of tumor growth. Histologically, the number of mitotic cels decreased significantly in the groups treated with RC-160 or the combination of RC-3095 with RC-160. Serum gastrin levels were significantly diminished in all treated groups. Therapy with RC-160 or the combination also significantly decreased levels of serum growth hormone. Receptor assays on tumor membranes showed that bombesin was bound to 2 classes of receptor sites, one with high affinity and low capacity, the other with low affinity and high capacity. Binding sites for epidermal growth factor (EGF) were down-regulated in tumor cells after treatment with RC-3095, RC-160 or the combination of RC-3095 with RC-160. In studies in vitro, both RC-160 and RC-3095 significantly inhibited the proliferation of MKN45 cells in culture as measured by cell number. These data demonstrate, for the first time, that the growth of human gastric cancer in nude mice can be inhibited not only by somatostatin analogues, but also by administration of modern bombesin/GRP antagonists, such as RC-3095.

Topics: Adenocarcinoma; Amino Acid Sequence; Animals; Antineoplastic Agents; Binding Sites; Body Weight; Bombesin; Cell Division; Epidermal Growth Factor; Female; Humans; Insulin-Like Growth Factor I; Male; Mice; Mice, Nude; Middle Aged; Molecular Sequence Data; Neoplasm Transplantation; Octreotide; Peptide Fragments; Somatostatin; Stomach Neoplasms; Transplantation, Heterologous; Tumor Cells, Cultured

We recently established epidermal growth factor (EGF) receptor-hyperproducing human gastric cancer xenografts in nude mice. The present study was designed to examine whether the growth of a xenograft having 1,098 +/- 276 fmol/mg protein of EGF receptor would either be stimulated by the administration of EGF or inhibited by the removal of the submandibular glands (sialoadenectomy) which contain a large amount of EGF. A miniosmotic pump containing 2 micrograms or 20 micrograms of EGF was implanted on the back of the animals in the EGF stimulation experiments. The tumor growth was stimulated by the administration of EGF (P < 0.01), and the doubling time of the tumor was reduced relative to the controls (P < 0.01). Both the mitotic indices and the bromodeoxyuridine (BrdU)-labeling indices of the tumor were higher than those of the controls (P < 0.01). Tumor growth inhibited by the sialoadenectomy (P < 0.05) while the tumor doubling time was prolonged compared with the sham-operated mice (P < 0.05). These results suggest that the growth of a human gastric cancer xenograft may be modulated by EGF.

Topics: Adenocarcinoma; Animals; Cell Cycle; Epidermal Growth Factor; ErbB Receptors; Growth; Humans; Immunohistochemistry; Mice; Mice, Nude; Neoplasm Transplantation; Stimulation, Chemical; Stomach Neoplasms; Submandibular Gland; Transplantation, Heterologous; Tumor Cells, Cultured

We detect the expression of epidermal growth factor (EGF) and epidermal growth factor receptor (EGFR) in 104 specimens of gastric cancer by avidin biotin-peroxides complex technique (ABC). The positive rates of EGF, EGFR and synchronous EGF and EGFR were 35.6%, 42.3%, 30.8% respectively. The positive expression of EGF and EGFR to gastric cancer tissue was inclined to occur in patients who were in advanced stages, of poorly-differentiated types, Borrmann III, IV types, scirrhous type, seroinvasive type or lymph node metastasic types. The survival rates at 1, 3, 5 years after gastrectomy in the patients with expression of EGF were significantly lower than the survival rates of the patients with negative expression (P < 0.05). The patients with synchronous expression of EGF and EGFR had the worst prognosis. After gastrectomy, all of them died within 4 years. It is indicated that EGF and EGFR could serve as biological indicators of gastric cancer malignancy and an index for evaluating, the prognosis of the patients with gastric cancer.

Topics: Adenocarcinoma; Epidermal Growth Factor; ErbB Receptors; Humans; Prognosis; Stomach Neoplasms; Survival Rate

A cell line designated TSG6 was established from a signet-ring cell gastric carcinoma developed in a 57-year-old female patient. The TSG6 cells had well preserved the features of signet-ring cell carcinoma based on morphology. The cells exhibited both epidermal growth factor (EGF) and epidermal growth factor receptor (EGFR) immunoreactivities, and also secreted EGF. Moreover, the growth of TSG6 cells was stimulated in the presence of exogenous EGF. These results suggest that the possible presence of an EGF/EGFR autocrine growth mechanism is expressed in the TSG6 cells. The simultaneous treatment with EGF and 5-fluorouracil (5-FU) produced a nearly 2.4-fold enhancement of 5-FU cytotoxicity against TSG6 cells. A bromodeoxyuridine/DNA flow cytometry analysis revealed that EGF augmented 5-FU cytotoxicity by inducing the accumulation of S phase cells which might be more susceptible to 5-FU. Moreover, we found that the incorporation of 5-FU into the TSG6 cells was increased with the addition of EGF. These data indicate that EGF may be a potent agent as a biological response modifier for 5-FU against the tumors which express the EGF/EGFR autocrine mechanism, and that the TSG6 cell line is useful in furthering our understanding of the interaction between anticancer drugs and EGF.

Topics: Carcinoma, Signet Ring Cell; Cell Division; Cell Line; Cell Survival; Dose-Response Relationship, Drug; Drug Synergism; Epidermal Growth Factor; Female; Flow Cytometry; Fluorouracil; Humans; Lymphatic Metastasis; Middle Aged; Stomach Neoplasms; Tumor Cells, Cultured

Prostaglandins may inhibit or promote tumor cell replication, depending on the cell system that is investigated. In our laboratory, we have established and characterized four different specific human cancer cell lines. The objectives of this study were to examine and compare the prostaglandin endoperoxide synthase (PG synthase, EC 1.14.99.1) activity of these cell lines by measuring the conversion of arachidonate to 3H-PGE2 and 3H-PGF2 alpha. We found that the oral epidermal carcinoma cell line (OEC-M1) had a moderate degree of PG synthase activity. Enzyme activity could be partially blocked (statistically significant) by the addition of epidermal growth factor (EGF) at 20 ng/mL and almost completely inhibited by platelet-derived growth factor at (PDGF) 20 mU/mL. By contrast, we discovered that the human breast adenocarcinoma cell line (BC-M1) did not contain significant PG synthase, and enzyme activity could be significantly activated by the addition of epidermal growth factor at 20 ng/mL and platelet-derived growth factor at 20 mU/mL. We also found that the human stomach adenocarcinoma cell line (SCM-1) had a significant amount of PG synthase activity, and these PG synthase activities were not activated or inhibited by EGF at 20 ng/mL or PDGF at 20 mU/mL. Furthermore, the human fibrosarcoma (FS-M1) cell line also contained a moderate degree of PG synthase activity, which could be significantly inhibited by PDGF at 20 mU/mL but was not inhibited by EGF at 20 ng/mL. The results suggest that EGF and PDGF may be involved in the regulation of the PG synthase activities of human oral, breast, stomach, and fibrosarcoma cancer cells.

Topics: Adenocarcinoma; Breast Neoplasms; Buttocks; Carcinoma, Squamous Cell; Chromatography, Thin Layer; Cyclooxygenase Inhibitors; Dinoprost; Dinoprostone; Enzyme Activation; Epidermal Growth Factor; Female; Fibrosarcoma; Gingival Neoplasms; Humans; Organ Specificity; Platelet-Derived Growth Factor; Prostaglandin-Endoperoxide Synthases; Stomach Neoplasms; Tumor Cells, Cultured

In 68 cases of surgically resected gastric carcinomas, expression of human epidermal growth factor (EGF) and its receptor (EGFR) were examined immunohistologically using the Avidin-Biotin Peroxidase Complex Method, and their relation with DNA contents and nuclear protein synthesis in the tumor progression were studied by measuring DNA ploidy patterns and nucleolar organizer regions (NORs), respectively with cytofluorometry and AgNO3 stain method. EGF and EGFR expression were respectively found only in 2 (7%) and 1 (4%) in 28 early cancers, and significantly increased in advanced cancers, 25 (63%) and 9 (23%) out of 40 cases. The ratio of aneuploid tumor and the NORs numbers per tumor cell also increased in advanced cancers, compared with in early cancers. EGF and EGFR respectively expressed in 19 (51%) and 9 (23%) in 37 aneuploid cancers, significantly more frequent than 8 (26%) and 1 (3%) in 31 diploid cancers. In the EGF-positive tumors, the NORs numbers showed 4.11 +/- 0.72, significantly higher than 2.68 +/- 0.61 in the EGF-negative tumors. These results suggested that expression of EGF and EGFR in the gastric carcinomas increases during the tumor progression from the early to advanced stage, stimulates synthesis of DNA and nuclear protein, and consequently enhances (strengthens, heightens, or intensifies) the proliferative activity of the tumors.

Topics: DNA, Neoplasm; Epidermal Growth Factor; ErbB Receptors; Flow Cytometry; Humans; Immunohistochemistry; Nucleolus Organizer Region; Ploidies; Stomach Neoplasms

Effect of epidermal growth factor (EGF) on ornithine decarboxylase (ODC) was examined in human gastric cancer-derived KATO-III cells, because 125I-EGF binding studies indicated a presence of specific binding sites for EGF on these cells. Upon stimulation with EGF, both ODC mRNA expression and ODC enzyme activity were significantly increased in KATO-III cells. However, unlike in other cellular systems, both EGF-induced ODC mRNA expression and ODC enzyme activation were biphasic with the peaks at 15 +/- 10 min and 2.1 +/- 1.5 hrs (mean +/- SE) for mRNA, and 3.1 +/- 1.5 and 7.7 +/- 1.8 hrs (mean +/- SE) for enzyme activity, respectively. Therefore, KATO-III cell line may provide a unique model for the biochemical analysis of EGF action on ODC activation.

Topics: Cell Line; DNA Primers; Enzyme Induction; Epidermal Growth Factor; ErbB Receptors; Gene Expression; Humans; Kinetics; Molecular Sequence Data; Ornithine Decarboxylase; RNA, Messenger; Stomach; Stomach Neoplasms; Time Factors; Tumor Cells, Cultured

Expression of EGF, EGFR, TGF alpha, and PCNA in resected gastric carcinomas (15 cases of superspreading type and 25 cases of penetrating type) was immunohistochemically studied to understand biological features of these two types of gastric carcinomas. EGF, EGFR, and TGF alpha positive cases were preferentially found in the penetrating type rather than in the superspreading type (p < 0.05). Incidence of PCNA high expression cases in the penetrating type was significantly higher than that in superspreading type. Nineteen cases (76%) of the penetrating type and 1 case of the superspreading type (6.7%) were diffusely PCNA (+), and the incidence of in the former type was significantly higher than that of the latter type (p < 0.001). One case of the superspreading type and 13 cases of the penetrating type were either EGF (+) or TGF alpha (+), and EGFR (+), and the incidence in the latter type was significantly higher than that in the former type (p < 0.05), suggesting that growth and invasion of carcinoma cells, especially in the penetrating type, may depend on "autocrine mechanism". Incidence of the growth factors (+) and PCNA (+) cells in classical type of signet ring cells was lower than that in other types of singnet ring cells.

Topics: Carcinoma, Signet Ring Cell; Epidermal Growth Factor; ErbB Receptors; Humans; Immunohistochemistry; Neoplasm Invasiveness; Nuclear Proteins; Proliferating Cell Nuclear Antigen; Stomach Neoplasms; Transforming Growth Factor alpha

Immunohistochemical staining for EGF, EGFR, c-erbB-2, p53, K-ras and PCNA was performed on the formalin-fixed, paraffin embedded sections of resected gastric carcinomas. A relatively high positive rate was observed for EGFR and c-erbB-2 in the well-differentiated adenocarcinomas and p53 in the poorly-differentiated adenocarcinomas. The positive rate of these factor was higher in the advanced cases than in the early cases, and also in the deep invasive area than the superficial area. According to the PCNA staining, a relatively high positive rate was observed in the well-differentiated adenocarcinomas compared with the early cases of poorly-differentiated adenocarcinomas, but the positive rate was markedly higher in the advanced cases of the latter. Typical signet-ring cell carcinomas showed the lowest positivity rate compared with the other histological types of gastric carcinomas.

Topics: Adenocarcinoma; Adenocarcinoma, Mucinous; Epidermal Growth Factor; ErbB Receptors; Genes, p53; Genes, ras; Humans; Immunohistochemistry; Nuclear Proteins; Proliferating Cell Nuclear Antigen; Stomach Neoplasms

Hepatocyte growth factor (HGF), a protein with pleiotropic biological activity affecting cell growth and motility, was found to markedly activate prostaglandin production in human gastric carcinoma TMK-1 cells. HPLC analysis revealed that HGF stimulated the production of prostaglandin E2 (PGE2), which is the major prostaglandin produced in these cells. HGF maximally stimulated PGE2 production at a concentration of 10 ng/ml, and it was a more potent stimulator of PGE2 production than epidermal growth factor (EGF), which is known to stimulate prostaglandin production in various cell lines. The simultaneous addition of HGF and EGF caused no further stimulation of the PGE2 production observed in HGF-treated cells. We showed also that HGF increased the arachidonate release from TMK-1 cells, which release was completely suppressed by the addition of phospholipase A2 (PLA2) inhibitors. Further studies in vitro showed that HGF enhanced cellular activities of cytosolic PLA2 and cyclooxygenase 1.5-fold each. These results indicate that HGF stimulates prostaglandin production through increases in both cytosolic PLA2 and cyclooxygenase activities.

Topics: Chromatography, High Pressure Liquid; Dinoprostone; Epidermal Growth Factor; Hepatocyte Growth Factor; Humans; Phospholipases A; Phospholipases A2; Prostaglandin-Endoperoxide Synthases; Stomach Neoplasms; Tumor Cells, Cultured

Epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha) are polypeptides which bind to the EGF receptor (EGFr) and may play a role in cell growth and carcinogenesis. Our study investigated the content of EGF, TGF-alpha, and EGFr in tumors of the stomach and the colon in comparison with the surrounding mucosa. EGF was detected in half of the stomach specimens with concentrations between 1 and 9 ng/g weight irrespective of histology. In the colon no EGF was found in the tumor or normal mucosa. In the stomach normal mucosa contained higher TGF-alpha concentrations (mean 22.4 ng/g) than the tumors (mean 11.8 ng/g), but the difference was not statistically significant because of a wide variation in mucosal values. By contrast, the colon mucosa displayed significantly higher TGF-alpha concentrations than the tumor tissues (33 ng/g versus 12 ng/g; P < 0.01). EGFr content in the gastric mucosa was lower compared to gastric carcinoma (48 fmol/g versus 75 fmol/g) yet not significantly different. In contrast, colorectal tumor specimens disclosed significantly higher concentrations than the mucosal tissues (mean of 155 fmol/g versus 80 fmol/g; P < 0.01). In conclusion, TGF-alpha should not be considered a tumorigenic but a physiological growth factor in the stomach and colon. An elevated EGFr content in colorectal tumors in comparison with the normal mucosa could lead to a growth advantage by an autostimulating mechanism.

Topics: Colonic Neoplasms; Epidermal Growth Factor; ErbB Receptors; Gastric Mucosa; Humans; Intestinal Mucosa; Reference Values; Stomach Neoplasms; Transforming Growth Factor alpha

Immunohistochemical study for epidermal growth factor (EGF) and epidermal growth factor receptor (EGFR) was performed on paraffin-embedded tissue specimens from 39 colorectal and 24 gastric carcinomas. The carcinomas were placed in one of the following 3 groups: group 1, neither EGF nor EGFR was stained (11 gastric and 21 colorectal carcinomas); group 2, either EGF or EGFR was stained (4 gastric and 4 colorectal carcinomas); and group 3, both EGF and EGFR were stained (9 gastric and 14 colorectal carcinomas). Compared with the carcinomas in groups 1 and 2, those in group 3 had significantly higher rates of lymph node spread and serosal invasion of the gastrointestinal wall. In contrast, no significant differences were found between the EGF and/or EGFR expression and histological differentiation of carcinomas. These results suggest that gastrointestinal carcinomas expressing both EGF and EGFR display pathological features of more aggressive disease. Furthermore, the synchronous expression of EGF and EGFR indicates that these carcinomas may regulate their growth by an autocrine and/or paracrine mechanism.

Topics: Adenocarcinoma; Cell Differentiation; Colorectal Neoplasms; Epidermal Growth Factor; ErbB Receptors; Humans; Immunoenzyme Techniques; Lymphatic Metastasis; Neoplasm Invasiveness; Retrospective Studies; Stomach Neoplasms

The expression and effect of interleukin 1 alpha (IL-1 alpha) were examined in human gastric carcinoma cell lines to determine if IL-1 alpha acts as a growth stimulator for these cells. Six of 8 gastric carcinoma cell lines expressed IL-1 alpha mRNA at various levels. Among them, TMK-1 and MKN-7 cells secreted IL-1 alpha into the culture fluid, in an especially large amount by MKN-7 cells. Scatchard plot analysis of IL-1 alpha binding revealed that TMK-1 cells had only one type of high-affinity receptors, whereas MKN-7 cells had high- and low-affinity receptors. Cell growth and DNA synthesis of TMK-1 and MKN-7 cells were stimulated by IL-1 alpha, and those of MKN-7 were inhibited by addition of anti-IL-1 alpha antibody or IL-1 receptor antagonist. The expression of IL-1 alpha mRNA by these cell lines was induced by either IL-1 alpha, epidermal growth factor, or transforming growth factor alpha. On the other hand, IL-1 alpha increased the mRNA expression for transforming growth factor alpha and epidermal growth factor receptor. These findings indicate that IL-1 alpha is an autocrine growth stimulator for gastric carcinoma cells and the interaction with epidermal growth factor/transforming growth factor alpha/receptor system should be involved in the growth modulation by IL-1 alpha.

Topics: Cell Division; DNA, Neoplasm; Epidermal Growth Factor; ErbB Receptors; Humans; Interleukin-1; RNA, Messenger; Stomach Neoplasms; Transforming Growth Factor alpha; Transforming Growth Factor beta; Tumor Cells, Cultured

We have established a human gastric scirrhous carcinoma cell line (designated as HSC-43) in a serum-free chemically defined medium (CDM) without any polypeptide growth factor, from a primary tumor of a 56-year-old male patient. HSC-43 cells grew in vitro in adherence with a population doubling time of 55 hr, and had the cytological properties of mucinous epithelial tumor cells. Cytogenetic analysis of the cells revealed pseudotetraploidy, with structural abnormalities of deletion at chromosome Iq25 and with 3 marker chromosomes. Some cells had retained features of signet-ring cells and caused fibroblastic proliferation when transplanted into athymic nude mice. The possible involvement of transforming growth factor-alpha (TGF-alpha), and its receptor, the epidermal-growth-factor receptor (EGFR), on the growth of HSC-43 cells was studied. Synthesis and secretion of TGF-alpha by HSC-43 cells were confirmed by biological assay and enzyme-linked immunosorbent assay. Radioreceptor analysis showed the presence of receptors for EGF in HSC-43 cells. Proliferation of HSC-43 cells was inhibited by antibodies against TGF-alpha and/or the EGFR. However, neither TGF-alpha nor epidermal growth factor (EGF) was effective in stimulating the cell growth of HSC-43 cells, irrespective of the cell density when supplemented exogenously. Our data suggest that TGF-alpha and EGFR play a role in the autocrine growth of HSC-43 cells. This may be another example of growth regulation of gastric carcinoma.

Topics: Adenocarcinoma, Scirrhous; Animals; Antigens, Tumor-Associated, Carbohydrate; Cell Division; Culture Media; DNA, Neoplasm; Epidermal Growth Factor; ErbB Receptors; Gene Amplification; Humans; Karyotyping; Male; Mice; Mice, Nude; Neoplasm Transplantation; Oncogenes; Stomach Neoplasms; Transforming Growth Factor alpha; Transplantation, Heterologous; Tumor Cells, Cultured

The expression of mRNA for amphiregulin (AR), a novel gene of the epidermal growth factor family, was examined in 8 human gastric carcinoma cell lines and 32 gastric carcinoma tissues as well as corresponding normal mucosa. Of the 8 gastric carcinoma cell lines, 7 expressed 1.4 kb AR mRNA at various levels. The expression of AR mRNA by TMK-1 and MKN-28 cells was increased by treatment with epidermal growth factor or transforming growth factor a. In surgical cases, all the gastric carcinoma tissues and their adjacent normal mucosa expressed AR mRNA. Interestingly, 20 (62.5%) out of 32 tumors expressed AR mRNA at higher levels than their corresponding normal mucosas (tumor/normal > or = 1.2). No obvious correlation was observed between the AR mRNA levels and the histological types or tumor staging of gastric carcinoma. Immunohistochemically, AR protein was localized to the cytoplasm and/or nucleus in tumor cells. These results suggest that AR produced by tumor cells may be involved in the pathogenesis and/or progression of human gastric carcinoma.

Topics: Adult; Aged; Amphiregulin; Blotting, Northern; EGF Family of Proteins; Epidermal Growth Factor; Female; Gene Expression; Glycoproteins; Growth Substances; Humans; Immunohistochemistry; Intercellular Signaling Peptides and Proteins; Male; Middle Aged; RNA, Messenger; Stomach Neoplasms; Transforming Growth Factor alpha; Tumor Cells, Cultured

A novel cell line called Trioma, which can proliferate and secrete a human monoclonal antibody in the basal medium, was established. Trioma was generated by somatic cell hybridization with human x human hybridoma and A431c, which is a cell line able to grow autonomously in the basal medium. A Trioma called TriH8 has been kept growing in the DMEM/F-12 medium for over 1 year and stably producing stomach cancer-reactive human IgM into culture medium at 10 micrograms/ml. TriH8 has a characteristic cytological phenotype, that is, to diminish cell growth in the presence of epidermal growth factor.

Topics: Antibodies, Monoclonal; Antibodies, Neoplasm; Cell Division; Cell Line; Cost Control; Culture Media, Serum-Free; Culture Techniques; DNA; Epidermal Growth Factor; Humans; Hybrid Cells; Hybridomas; Immunoglobulin M; Stomach Neoplasms

Forty fresh gastric cancer specimens were examined by immunohistological staining using anti-BrdU monoclonal antibody, and simultaneously the specimens were studied by DNA ploidy pattern, EGF with flowcytometer and the immunohistological staining. For EGF study, the same 40 gastric cancer formalin fixed specimens were used. The results of flowcytometric measurement were divided into diploid and aneuploid patterns. BrdU positive stained cancer cells were observed in growing border area than in the center of tumor, and histologically in P(+), n(+), ps(+), INF gamma, and in scirrhous type, deep spread type and advanced stage. This data suggested that the BrdU labeling index seemed to be related to invasion, proliferation, and metastasis of cancer cells. However the positive rates of EGF were higher in ps(+), deep spread type and BrdU positive type but not in P(+), n(+), and EGF was considered to related to invasion but not to be related to metastasis. Although aneuploid pattern cancer showed high BrdU labeling index in ps(+), diploid pattern didn't indicate such tendency. High BrdU positive rate aneuploid cancer were seemed to grow quickly, advance in short period and own worse character. Further investigation would be necessary.

Topics: Adult; Aged; Aged, 80 and over; Antibodies, Monoclonal; Bromodeoxyuridine; Cell Cycle; DNA, Neoplasm; Epidermal Growth Factor; Female; Flow Cytometry; Humans; Lymphatic Metastasis; Male; Middle Aged; Ploidies; Stomach Neoplasms

In 19 patients with advanced gastric cancer the expression of epidermal growth factor receptor and epidermal growth factor (EGF) were studied using immunohistochemical techniques. There were 12 males and the mean age of the group was 54.8 years. Most cases belonged in Borrmann's types III or IV. Tumoral cells were positive for EGF receptor in 9 patients (47%), with a strong reaction in 6. Thirteen of 18 subjects were positive for EGF. The reaction for EGF receptor was positive in 20% of 12 patients with intestinal type tumors and in 67% of 7 patients with diffuse tumors. Reaction for EGF was positive in 80% of intestinal type tumors and 64% of diffuse tumors. Simultaneous positive reactions for both antigens was observed in 5 of 18 patients, all with diffuse type tumors. Signet ring cell tumors showed less positivity than less differentiated ones. Thus, the expression of EGF and EGF receptor was higher in our patients with advanced gastric cancer than reported elsewhere.

Topics: Adult; Aged; Aged, 80 and over; Antibodies, Monoclonal; Biomarkers, Tumor; Carcinoma; Epidermal Growth Factor; ErbB Receptors; Female; Humans; Immunohistochemistry; Male; Middle Aged; Stomach Neoplasms

The effects of human recombinant epidermal growth factor (EGF) on the growth of MKN-28 human gastric carcinoma, transplanted into nude mice were studied. Modulation of tissue cAMP and EGF receptor levels by EGF was also studied to reveal the mechanism of the growth inhibitory effects of EGF. EGF exhibited a dose-dependent growth inhibitory effect on MKN-28 human gastric carcinoma transplanted into nude mice. Local injection of 2 ng of EGF moderately inhibited the growth of MKN-28 gastric carcinoma, while injections of 20 ng, 200 ng and 2 micrograms of EGF significantly inhibited tumour growth. EGF decreased tissue cAMP levels in a dose-dependent manner within 24 h after EGF injection. On the other hand, EGF increased the EGF receptor levels up to two or three fold within 24 h after EGF injection. Conversely, the EGF receptor affinity for EGF decreased according to the increase in EGF receptor levels.

Topics: Aged; Animals; Cyclic AMP; Dose-Response Relationship, Drug; Epidermal Growth Factor; ErbB Receptors; Female; Humans; Mice; Mice, Nude; Neoplasm Transplantation; Recombinant Proteins; Stomach Neoplasms; Time Factors

A human adenocarcinoma cell line designated as GAC-1, was established from ascites of the 56-year old male patient with rapidly progressive gastric cancer. The doubling time was about 18.5 hours in vitro, and cell cycle analysis using flow cytometry showed marked increase of S phase (46.1%). Immunohistochemical demonstration of GAC-1 cells revealed positive staining of TGF-alpha, EGF, EGF-R, FN-R, laminin and negative staining of fibronectin. Histogram of them indicated aneuploidy with modal number 57 and they formed tumors in nude mice.

Topics: Adenocarcinoma; Animals; Cell Cycle; Cell Division; Epidermal Growth Factor; ErbB Receptors; Humans; Karyotyping; Laminin; Male; Mice; Middle Aged; Receptors, Fibronectin; Stomach Neoplasms; Tumor Cells, Cultured

In this study, 3 human pancreatic adenocarcinoma cell lines (PC-1, PC-2 and PC-3) and 3 other human cancer cell lines (adenocarcinoma of lung, LETP; gastric carcinoma, SGL7901; and breast carcinoma, BCP37) were investigated by adding EGF, anti-EGF antiserum and anti-EGFR monoclonal antibody into culture medium. EGF was found to exert a mild stimulating effect on the growth of PC-1 and LETP cells, but had no effect on the other 4 cell lines. Anti-EGF and anti-EGFR antibodies inhibited the proliferation of PC-1, LETP and SGL7901 cells. No significant effect on the other 3 cell lines was seen. By using the Northern blot technique, expression of EGFR mRNA was identified in all 6 cell lines. There were 3 bands (10.5 kb, 5.8 kb and 2.8 kb) of EGFR mRNA in all cell lines except for LETP, in which the 10.5 kb band was absent. The results indicate that the effect of EGF on the growth of cancer cells is very complicated and may involve an unknown regulatory mechanism of cancer cell growth. EGF may exert stimulating or inhibiting effects on cancer cell proliferation, or it may have no effect at all, even though the EGFR gene was expressed in these cell lines.

Topics: Adenocarcinoma; Antibodies, Monoclonal; Cell Division; Epidermal Growth Factor; ErbB Receptors; Humans; Immune Sera; Lung Neoplasms; Pancreatic Neoplasms; RNA, Messenger; Stomach Neoplasms; Tumor Cells, Cultured

Seven human gastric cancer xenografts with different concentrations of EGF receptor were established in nude mice. The expression of EGF receptor in the tumors was demonstrated by Western blotting with anti-EGF receptor antibody, binding assay with 125I-EGF and immunohistochemistry with anti-EGF receptor antibody. Western blotting revealed EGF receptor doublet bands at molecular masses of 150 KDa and 170 KDa in all of the samples. The concentration of 125I-EGF binding activity in the tumors ranged from 36.0 to 11,000 fmol/mg protein, with a mean of 345 fmol/mg protein. EGF receptor was also demonstrated immunohistochemically on the apical border of the glands and the cell membrane of the tumor cells. There seemed to be a close correlation between the concentration of 125I-EGF binding activity and the doubling time of these tumors in nude mice (gamma = -0.68). However, no definite correlation was observed between EGF ligand binding and histological features of intestinal type or diffuse type. The expression of EGF receptor appears to facilitate the growth of human gastric cancer xenografts in nude mice.

Topics: Animals; Blotting, Western; Epidermal Growth Factor; ErbB Receptors; Immunohistochemistry; Male; Mice; Mice, Nude; Neoplasm Transplantation; Stomach Neoplasms; Transplantation, Heterologous

We report that the penetrating type of early gastric cancer (PEN) is a specific type of early gastric cancer and that the poorly differentiated PEN type could be considered an initial lesion of linitis plastica-type cancer. We performed an immunohistochemical study to clarify the role of growth factors (epidermal growth factor [EGF] and transforming growth factor-beta [TGF-beta]) in the PEN type of early gastric cancer. The results indicated that the PEN type of early gastric cancer has a high growth capacity. Moreover, it was suggested that EGF was involved in its specific infiltrative growth and that both EGF and TGF-beta were involved in its specific scirrhous growth. From these findings, it was assumed that the immunohistochemical staining of EGF and TGF-beta in endoscopic biopsy specimens was useful for the diagnosis of the PEN type of gastric cancer and also for the diagnosis of the initial lesion of linitis plastica-type gastric cancer.

Topics: Epidermal Growth Factor; Humans; Immunoenzyme Techniques; Neoplasm Invasiveness; Stomach Neoplasms; Transforming Growth Factor beta

To investigate the mechanisms underlying contraction of the stomach wall in cases of gastric scirrhous carcinoma, we have developed an in vitro model for gastric cancer, in which both fibroblasts and gastric carcinoma cells are embedded within a collagen matrix. Gastric carcinoma cells of the scirrhous type (KATO-III) but not the nonscirrhous type (MKN-28) markedly enhanced the ability of human intestine, human lip, and mouse kidney fibroblasts to contract collagen gels. KATO-III cells released transforming growth factor-beta (TGF-beta) into culture media in an activated form, whereas the MKN-28 cells produced a latent form. The role of TGF-beta produced by gastric cancer cells from the scirrhous type was clarified by adding TGF-beta (receptor grade) into collagen gels embedded with fibroblasts, contraction being enhanced. Other growth factors tested, including transforming growth factor-alpha and epidermal growth factor, did not enhance the contraction of collagen gels containing embedded human and rodent fibroblasts. These results suggest that the activated form of TGF-beta released from gastric scirrhous carcinoma cells stimulates fibroblasts to contract the collagenous stroma of the stomach wall, which leads to the so-called "linitis plastica" stomach condition.

Topics: Adenocarcinoma, Scirrhous; Collagen; Culture Media; Epidermal Growth Factor; Extracellular Matrix; Fibroblasts; Gels; Humans; In Vitro Techniques; Stomach Neoplasms; Transforming Growth Factor beta; Tumor Cells, Cultured

Topics: Colonic Neoplasms; Epidermal Growth Factor; ErbB Receptors; Gastrointestinal Neoplasms; Humans; Neoplasm Invasiveness; Platelet-Derived Growth Factor; Receptors, Cell Surface; Receptors, Platelet-Derived Growth Factor; Stomach Neoplasms; Transforming Growth Factor beta

An immunohistological study of epidermal growth factor (EGF) and epidermal growth factor receptor (EGFR) was made with 157 specimens of stomach cancer. EGF stained positively in 70 specimens (45%), and EGFR in 53 specimens (34%). The cancers were classified into three groups; Group 1 with neither EGF nor EGFR staining positively (67 tumors); Group 2 with either EGF or EGFR staining positively (57 tumors); and Group 3 with both EGF and EGFR staining positively (33 tumors). The incidence rates of tumors of macroscopically infiltrative, poorly differentiated, deep invading and node-positive types were significantly higher for Group 3 than for Groups 1 and 2. The bromodeoxyuridine labeling indices (BrdU LIs) were significantly higher for Group 3 (median: 15.1%) than for Group 1 (median: 10.7%) or Group 2 (median: 11.4%). Patients with synchronous expression of EGF and EGFR (Group 3) had the poorest prognosis. From the results, it may be concluded that tumors with synchronous expression of EGF and EGFR have the highest malignant potentials and this phenomenon may cause autocrine secretion for self-replication.

Topics: Adult; Animals; Antibodies, Monoclonal; Biomarkers, Tumor; Bromodeoxyuridine; Cell Line; Combined Modality Therapy; Epidermal Growth Factor; ErbB Receptors; Follow-Up Studies; Humans; Immunohistochemistry; Lymph Node Excision; Mice; Mice, Nude; Prognosis; S Phase; Stomach Neoplasms; Submandibular Gland; Transplantation, Heterologous

The effect of tyrosine kinase inhibitor, erbstatin, on cell growth and mRNA expression of growth-factor/receptor system was examined in 6 human gastric-carcinoma cell lines. Erbstatin inhibited both EGF-induced and serum-stimulated cell growth of all 6 cell lines (TMK-1, MKN-1, -7, -28, -45, -74) in a dose-dependent manner. 3H-thymidine incorporation by TMK-1 cells was also suppressed by erbstatin. Erbstatin inhibited protein kinase activity of EGF receptor, p185ERBB2 and pp60c-src in TMK-1 cells. The expression of mRNA of EGF receptor gene and ERBB-2 by TMK-1 cells was not changed by erbstatin treatment, whereas that of c-src was slightly decreased. Interestingly, erbstatin decreased membrane-bound TGF-alpha precursor as measured by anti-TGF-alpha antibody-binding assay, although mRNA expression for TGF-alpha was not altered by erbstatin. Our findings suggest that erbstatin may act as a growth inhibitor for human gastric-carcinoma cells and may not only inhibit tyrosine kinase activities but also negatively modulate the post-transcriptional step of TGF-alpha expression.

Topics: Cell Division; Cell Line; Culture Media; DNA Replication; Epidermal Growth Factor; ErbB Receptors; Gene Expression; Humans; Hydroquinones; Kinetics; Protein-Tyrosine Kinases; Proto-Oncogenes; RNA, Messenger; Stomach Neoplasms; Transcription, Genetic; Transforming Growth Factor alpha

Topics: Epidermal Growth Factor; Helicobacter Infections; Helicobacter pylori; Humans; Stomach Neoplasms

The expression of mRNA for cripto gene, a novel transforming gene of the epidermal growth factor family, was examined in 20 alimentary tract carcinoma cell lines, 60 surgically resected tumor tissues and their adjacent normal mucosas. Although the cripto mRNA was not detected in esophageal carcinomas or in normal mucosas, it was detected in gastric and colorectal carcinomas. In gastric carcinomas, 2.2 kb cripto mRNA was detected in one cell line, all the gastric carcinoma tissues and their adjacent normal mucosas. Of 23 gastric tumor tissues 8 (34.8%) exhibited a higher mRNA level than normal gastric mucosas. cripto mRNA was detected in 2 out of 6 colorectal carcinoma cell lines. Interestingly, 18 (81.8%) out of 22 colorectal carcinoma specimens expressed a higher level of cripto mRNA than that in normal mucosas. The level of the expression was higher than that in gastric carcinoma tissues. The expression was also correlated to tumor stage of colorectal carcinomas.

Topics: Adult; Aged; Aged, 80 and over; Colorectal Neoplasms; Epidermal Growth Factor; Esophageal Neoplasms; Female; Gastric Mucosa; Gastrointestinal Neoplasms; Gene Expression; Humans; Intestinal Mucosa; Male; Middle Aged; RNA, Messenger; Stomach Neoplasms

Topics: Epidermal Growth Factor; ErbB Receptors; Humans; Retrospective Studies; Stomach Neoplasms

Hematopoietic growth factors have recently been well characterized by complementary DNA cloning. For human epidermal growth factor, granulocyte-macrophage colony-stimulating factor recombinant proteins have been expressed in Escherichia coli. To reduce the toxic side effects of chemotherapy on the bone marrow, recombinant human granulocyte-macrophage colony-stimulating factor and recombinant human interleukin 3 were applied to patients suffering of gastrointestinal cancers. To determine the influence of recombinant human granulocyte-macrophage colony-stimulating factor and recombinant human interleukin 3 on human pancreas and gastric cancer cell cells in vitro, a sensitive microculture test system was established that allows precise quantification of proliferation. A more than twofold enhancement of proliferation was observed by interleukin 3 and granulocyte-macrophage colony-stimulating factor in two of two cell cultures derived from gastric carcinoma cells, while two of nine cultures from pancreas carcinoma cells have shown enhanced cell growth in the presence of recombinant human interleukin 3 or recombinant human granulocyte-macrophage colony-stimulating factor. In comparison, recombinant human epidermal growth factor increased cell growth in two of two gastric and in five of nine pancreas carcinoma cultures. In general, 1-10 ng/mL of the growth factors yielded the highest growth rate, but even 1-pg amounts produced increased cell growth. Expression of messenger RNA for granulocyte-macrophage colony-stimulating factor, interleukin 3, and the oncogene HER2/neu remained undetectable in all of the tested cell lines, while the various abundance of messenger RNA for the epidermal growth factor receptor was different in each cell line. The reported results imply that the hematopoietic growth factors interleukin 3 and granulocyte-macrophage colony-stimulating factor influence cellular growth of pancreas and gastric carcinoma cells by a paracrine mechanism and may possess a more general regulatory function than originally anticipated.

Topics: Animals; Cell Division; Epidermal Growth Factor; Granulocyte-Macrophage Colony-Stimulating Factor; Interleukin-3; Mice; Pancreatic Neoplasms; RNA, Messenger; Stomach Neoplasms; Tumor Cells, Cultured

Expression of human epidermal growth factor (EGF) was examined immunohistologically in 93 surgically resected gastric carcinomas, using Biotin-StreptAvidin method pretreated by protease, and its relation with cancer progression and DNA ploidy pattern was studied. DNA ploidy pattern was determined by cytofluorometric measurement. The gastric cancers were divided into two basic ploidy patterns; a diploid mode and an aneuploid mode. EGF expressions were found in 5 out of 20 cases (25%) in intramucosal carcinomas and, the more deeply the carcinomas invaded into the gastric wall, the greater the frequency of EGF expressions did not always become. In the carcinomas with the aneuploid pattern, EGF expression was found only in 2 out of 12 cases (17%) in early cancers and significantly increased in advanced cancers, 15 out of 22 cases (68%). On the other hand, in the carcinomas with the diploid pattern, EGF was expressed in 9 out of 31 cases (29%) in advanced cancers, not significantly different in early cancers, 11 out of 28 cases (39%). Consequently, in advanced cancers, EGF was found more frequently in the aneuploid tumors than in the diploid tumors. These results suggested that EGF expression in the gastric carcinomas is closely correlated with the progression to the advanced cancer with DNA aneuploidy.

Topics: Aged; Aneuploidy; Cell Nucleus; Diploidy; DNA, Neoplasm; Epidermal Growth Factor; Female; Flow Cytometry; Humans; Immunohistochemistry; Neoplasm Invasiveness; Ploidies; Stomach Neoplasms

Thirty-two surgical specimens and three cell lines of human gastric cancers were used for subcutaneous transplantation into nude mice, resulting in the establishment of eight (25%) xenografts from the surgical specimens and two (67%) from the cell lines. The localization of epidermal growth factor (EGF) in the surgical specimens and cell lines of the gastric cancers and their xenografts in nude mice was then investigated immunohistochemically. Epidermal growth factor was stained in the cytoplasm of the cancer cells, being detected in 16 (50%) of the 32 surgical specimens and in all of the cell lines. Seven (44%) of the sixteen EGF-positive surgical specimens and one (6%) of the 16 EGF-negative ones were tumorigenic in nude mice. All of the xenografts in nude mice were positive for EGF. The tumorigenicity of human gastric cancer xenografts in nude mice may, therefore, be correlated with the presence of EGF in cancer cells.

Topics: Adenocarcinoma; Adolescent; Adult; Aged; Animals; Carcinoma, Renal Cell; Epidermal Growth Factor; Female; Humans; Kidney Neoplasms; Male; Mice; Mice, Nude; Middle Aged; Neoplasm Metastasis; Neoplasm Transplantation; Staining and Labeling; Stomach Neoplasms; Tumor Cells, Cultured; Wilms Tumor

The DNA ploidy pattern and amplification of ERBB and ERBB2 genes were examined in paraffin-embedded tissue from gastric carcinomas using flow cytometry and a slot-blot hybridization technique. The incidence of aneuploidy in well differentiated adenocarcinomas (56%) was significantly higher (p less than 0.05) than that in poorly differentiated adenocarcinomas (21%). The DNA ploidy pattern was not remarkably different between the primary tumors and metastatic deposits in lymph nodes. Of the nine specimens having an aneuploid stem cell line in the primary tumor and/or in metastases, three showed ERBB2 gene amplification and one showed ERBB gene amplification. The incidence of epidermal growth factor (EGF) immunoreactivity in tumor cells showed no difference between diploid and aneuploid tumors. These findings indicate that aneuploidy is frequently associated with amplification of ERBB and ERBB2 genes.

Topics: DNA, Neoplasm; Epidermal Growth Factor; Flow Cytometry; Gene Amplification; Humans; Immunoblotting; Immunohistochemistry; Ploidies; Retrospective Studies; Stomach Neoplasms

The expressions of mRNA for epidermal growth factor (EGF), transforming growth factor-alpha (TGF-alpha) and EGF receptor (EGFR) genes were examined in 7 human gastric carcinoma cell lines and 15 gastric carcinoma tissues and the corresponding normal mucosas. All of the gastric carcinoma cell lines expressed mRNA for EGFR and TGF-alpha genes. TMK-1 and MKN-28 cells also expressed EGF mRNA. Production of EGF, TGF-alpha and EGFR protein by gastric carcinoma cell lines was also confirmed by EGF and TGF-alpha specific monoclonal antibody binding. As for surgical specimens, EGFR and TGF-alpha mRNA were detected at high levels in all the tumor tissues. Interestingly, EGF mRNA was detected in 5 (33.3%) of the 15 gastric carcinomas but it was not detected in normal tissues. Moreover, anti-EGF and anti-TGF-alpha monoclonal antibodies inhibited the spontaneous 3H-TdR uptake by gastric carcinoma cells. These results suggest that EGF and/or TGF-alpha produced by tumor cells act as autocrine growth factors for gastric carcinomas.

Topics: Antibodies, Monoclonal; DNA, Neoplasm; Epidermal Growth Factor; ErbB Receptors; Gene Expression; Humans; Immunoassay; RNA, Messenger; Stomach Neoplasms; Transforming Growth Factors; Tumor Cells, Cultured

We observed that human epidermal growth factor (hEGF) alone prolonged the survival time of mice bearing various murine syngeneic tumors as well as athymic nude mice bearing human xenografts. No changes in the subcutaneous solid tumor mass volume were observed. Prolongation of survival time by hEGF was observed in mice bearing murine epidermoid carcinoma (BSC) and human gastric carcinoma (KATO III), but not in murine epidermoid carcinoma (KLN205) or human epidermoid carcinoma (A431). Human tumor cells such as A431, KATO III, and murine tumor cells, KLN205, BSC had roughly 2 X 10(6), 3 X 10(4), 1.3 X 10(3) and 1 X 10(3) EGF receptors/cell, respectively. Although KLN205 and BSC tumor cells maintained nearly the same number of EGF receptors, the effects of hEGF were very different. Although A431 tumor cells had nearly 100 times more receptors than KATO III cells, the prolongation of survival time of mice bearing A431 by hEGF was no better than that of mice bearing KATO III. Accordingly, it appears that this prolongation of survival time by hEGF is independent of the number of EGF receptors on tumor cells. In addition, hEGF was shown to inhibit experimental pulmonary metastasis of murine BSC tumor, but was ineffective with murine KLN205 tumor. These results suggest that prolongation of survival time by hEGF may result from the inhibition of tumor cell metastasis and EGF may play a role in preventing the metastasis of certain malignant neoplasms unrelated to its effects through the EGF receptor on tumor cells.

Topics: Adenocarcinoma; Animals; Carcinoma, Squamous Cell; Colonic Neoplasms; Epidermal Growth Factor; Humans; Lung Neoplasms; Male; Mice; Mice, Inbred C57BL; Stomach Neoplasms; Time Factors

We examined the effects of epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha) on EGF receptor (EGFR) phosphorylation and the expression of mRNAs for oncogenes, growth factors, their receptors and metalloproteinase genes by MKN-28 gastric carcinoma cells which express EGF, TGF-alpha and EGFR genes. Both EGF and TGF-alpha stimulated EGFR phosphorylation, EGF and TGF-alpha induced FOS, MYC and ERBB-2 oncogene expression. Interestingly, EGF increased the expression of mRNAs for TGF-alpha and EGFR. On the other hand, TGF-alpha increased TGF-alpha mRNA but decreased the expression of mRNAs for EGFR and TGF-beta. Furthermore, mRNAs for interstitial collagenase, stromelysin and procollagen type I genes were also enhanced after treatment with EGF and TGF-alpha. These results indicate that EGF and TGF-alpha successively evoke cascade phenomena which favor tumor progression, invasion and extracellular matrix formation, acting as autocrine growth regulators for gastric carcinomas.

Topics: Carcinogens; Carcinoma; Epidermal Growth Factor; ErbB Receptors; Gene Expression Regulation, Neoplastic; Humans; Matrix Metalloproteinase 3; Metalloendopeptidases; Microbial Collagenase; Phosphorylation; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-fos; RNA, Messenger; Stomach Neoplasms; Transforming Growth Factors; Tumor Cells, Cultured

We examined the localization of epidermal growth factor (EGF) in 185 specimens of primary human gastric cancer using the avidin-biotin peroxidase complex immunohistochemical method on formalin-fixed paraffin-embedded sections. Thirty-four per cent of the gastric cancer specimens were positive for EGF, which was mainly located in the cytoplasm of the cancer cells and occasionally in the stromal cells, but was not detected in non-cancerous gastric epithelium. Moreover, the presence of EGF in gastric cancer was correlated with gastric wall invasion and lymph node metastasis. EGF was found more often in advanced cancers than in early ones (p less than 0.01), and also more often in cancers with lymph node metastasis than in those without (p less than 0.05). The five-year survival of patients with EGF-positive tumors was worse than that of patients with EGF-negative tumors (p less than 0.05). The presence of EGF in human gastric cancer may thus represent higher malignant potential.

Topics: Epidermal Growth Factor; Humans; Immunoenzyme Techniques; Lymphatic Metastasis; Neoplasm Invasiveness; Stomach Neoplasms; Survival Rate

Specific type of early gastric cancer based on the cancer surface area and the degree of invasion were studied by measuring digital values of the cancer surface area in early gastric cancer patients. The results indicated that the pen and super type of early gastric cancer had many clinicopathological characteristics as compared with common type of early gastric cancer. An immunohistochemical study also revealed that the pen type of early gastric cancer had a high growth activity. Moreover, it was suggested that EGF was involved in its specific invasion and growth, and that EGF and TGF-beta affected its scirrhous growth. The possibility that the poorly differentiated pen type is an early lesion of linitis plastica type gastric cancer was also considered. From these findings, it was assumed that the immunological staining of EGF and TGF-beta in biopsy specimens might be useful in the diagnosis of the pen type of early gastric cancer and also in diagnosis of early lesion of linitis plastica type gastric cancer.

Topics: Epidermal Growth Factor; Humans; Immunohistochemistry; Neoplasm Invasiveness; Stomach Neoplasms; Transforming Growth Factor beta

The epidermal growth factor and the homologous alpha-tumor growth factor are mitogenic polypeptides that act by binding to the epidermal growth factor receptor. The present study investigated whether increased production of epidermal growth factor/alpha-tumor growth factor or increased density of epidermal growth factor receptors may occur in gastric carcinomas as compared with normal mucosa from the same individuals. Epidermal growth factor receptors were measurable by (125I)EGF-binding assays in 13 of 15 normal mucosas and in 15 of 15 carcinomas. The epidermal growth factor-binding capacity was significantly higher in carcinomas than in mucosa. A comparison of pairs of mucosa and carcinomas showed an increase of epidermal growth factor receptors in 9 of 15 carcinomas, no change in 3, and a decrease in 2 carcinomas. One mucinous adenocarcinoma contained extreme numbers of epidermal growth factor receptors (2445 fmol/mg protein) corresponding to a 320-fold increase over normal mucosa. Epidermal growth factor-like activity was increased in 2 of 22 carcinomas compared with mucosa. We conclude that relative overexpression of epidermal growth factor receptors occurs in a fraction of gastric carcinomas. Whether increased expression of epidermal growth factor receptors is associated with particular patterns of tumor progression needs to be investigated.

Topics: Adult; Aged; Aged, 80 and over; Carcinoma; Epidermal Growth Factor; ErbB Receptors; Female; Gastric Mucosa; Humans; Male; Middle Aged; Radioligand Assay; Stomach Neoplasms; Transforming Growth Factors

The effect of epidermal growth factor (EGF) on rat stomach carcinogenesis induced by N-methyl-N'-nitro-N-nitro-soguanidine (MNNG) was studied. Male Wistar rats given MNNG for 30 weeks in drinking water (80 micrograms/ml) were treated with s.c. injections of human EGF (10 micrograms/kg, once daily) at various stages of the carcinogenesis. Four (30.8%) out of 13 rats treated with EGF immediately after cessation of the MNNG treatment had stomach tumors including one adenocarcinoma, one adenoma and two carcinoids. No stomach tumor was found in rats treated with MNNG alone or in those treated with MNNG and EGF for different periods such as synchronously for 10 weeks, for 30 weeks or throughout the experiment. These findings suggest a possible enhancing effect of EGF on stomach carcinogenesis in rats.

Topics: Animals; Drug Interactions; Epidermal Growth Factor; Male; Methylnitronitrosoguanidine; Rats; Rats, Inbred Strains; Stomach Neoplasms

To ascertain the possible autocrine pathway in the growth promotion of gastric carcinomas, a study was made on the effects of exogenous human epidermal growth factor (hEGF) on the expression of mRNA for EGF, transforming growth factor-a (TGF-a), EGF receptor, FOS and MYC genes by TMK-1 cells. Exogenous hEGF increased FOS and MYC mRNA levels 30 min and 1 h after the treatment, respectively. TMK-1 cells accumulated the mRNA for EGF receptor about 7- to 8-fold by 3 h after treatment. Expressions of mRNA for EGF and TGF-a genes were detected, but the amounts of the mRNA of these genes in TMK-1 cells were not altered after the treatment.

Topics: Cell Line; Epidermal Growth Factor; ErbB Receptors; Gene Expression Regulation, Neoplastic; Genes; Humans; Kinetics; Proto-Oncogenes; RNA, Messenger; Stomach Neoplasms; Transcription, Genetic; Transforming Growth Factors; Tumor Cells, Cultured

Topics: Adenocarcinoma; Adenocarcinoma, Mucinous; Cell Division; Cell Line; Cell Survival; Drug Screening Assays, Antitumor; Drug Synergism; Epidermal Growth Factor; ErbB Receptors; Fluorouracil; Humans; Stomach Neoplasms; Tumor Cells, Cultured

The binding of epidermal growth factor (EGF) and insulin-like growth factor I (IGF-I) to cell membranes was determined in 14 renal cancers and in 13 normal kidney tissues adjacent to the tumors. The soluble 34K IGF binding protein (34K IGF-BP) content and the phosphotyrosyl-protein phosphatase activity in renal cancer tissue and adjacent normal tissue were also determined. The specific EGF receptor binding in renal cancers was 12.7 +/- 2.5% (mean +/- SEM) as compared to 2.6 +/- 0.2% (mean +/- SEM) in normal tissues (p less than 0.01). Phosphotyrosyl-protein phosphatase activity in renal cancer tissue was less than half of that observed in normal renal tissue (p less than 0.01). The highest IGF-I binding was observed in 5 renal cancers although no consistent differences between IGF-I binding to tumor and normal tissues were observed. Both EGF and IGF binding to kidney tissue were higher than binding to gastro-intestinal tissue irrespective of whether normal or malignant tissues were compared. All normal kidney tissues and 7 of 8 kidney tumors contained measurable amounts of 34K IGF-BP as determined by RIA and the cross-linking technique. In 2 tumor tissue samples the 34K IGF-BP content was increased 8- and 15-fold over that seen in adjacent normal kidney tissue, whereas in the 6 other renal cancers the 34K IGF-BP was similar to that observed in normal kidney tissue.

Topics: Adenocarcinoma; Aged; Colorectal Neoplasms; Epidermal Growth Factor; ErbB Receptors; Female; Humans; Insulin-Like Growth Factor I; Kidney; Kidney Neoplasms; Male; Middle Aged; Phosphoprotein Phosphatases; Protein Binding; Protein Tyrosine Phosphatases; Receptors, Cell Surface; Receptors, Somatomedin; Solubility; Somatomedins; Stomach Neoplasms

Topics: Adolescent; Adult; Child; Epidermal Growth Factor; Female; Humans; Male; Middle Aged; Reference Values; Sex Factors; Stomach Neoplasms

Immunohistochemical study for epidermal growth factor (EGF) and epidermal growth factor receptor (EGFR) was performed on 222 specimens of gastric carcinoma. The authors placed each carcinoma into one of the following three groups: group 1, neither EGF nor EGFR was stained (123 cases); group 2, either EGF or EGFR was stained (64 cases); and group 3, both EGF and EGFR were stained (35 cases). Compared with the carcinomas in groups 1 and 2, those in group 3 had significantly higher rates of infiltrative gross type, microscopically infiltrative type, poorly differentiated type, scirrhous type, and deep invading type. These results suggest that carcinomas in group 3 may have more proliferative and invasive activity and thus may have an autocrine mechanism, that is, the ability of cancer cells to produce and respond to their own growth factor.

Topics: Adenocarcinoma; Carcinoma; Epidermal Growth Factor; ErbB Receptors; Humans; Immunoenzyme Techniques; Lymphatic Metastasis; Neoplasm Invasiveness; Stomach Neoplasms

A high false negative rate from endoscopic forceps biopsy is well-known in gastric carcinoma. The initial aim of the present study was to determine whether possible thickening of adjacent nontumorous mucosa by nonspecific or specific trophic factors could contribute to this observation; 167 gastrectomy specimens (77 carcinomas, 14 lymphomas, 76 gastric ulcers) were examined and mucosal thickness measured. Mean thickness of uninvolved mucosa near carcinoma (1.4 +/- 0.08 mm, mean +/- SEM) and near lymphoma (1.5 +/- 0.1 mm) was in each case significantly greater than mucosal thickness near ulcer (1.14 +/- 0.05 mm) or at a distance in the same specimen (P less than 0.01 for each comparison). A subset of specimens representing 20% of carcinomas, showed marked mucosal thickening (2.01 +/- 0.05 mm) above the control mean. Immunohistochemical evaluation for intratumoral epidermal growth factor content (EGF) correlated with mucosal thickness in all groups examined (R = 0.67). Immunostaining for EGF receptor showed similar patterns of expression to those of EGF. EGF and EGF receptor contents were also correlated with depth of invasion when possible. In conclusion, the mucosal thickening adjacent to gastric malignancy may well contribute to the insensitivity of endoscopic forceps biopsy. More importantly, the higher tumor EGF and EGF-receptor contents seen in these lesions may prove to be a useful marker of biologic behavior and predictor of prognosis in these tumors.

Topics: Biomarkers, Tumor; Carcinoma; Epidermal Growth Factor; ErbB Receptors; False Negative Reactions; Female; Gastrectomy; Gastric Mucosa; Humans; Lymphoma; Male; Stomach Neoplasms

The expression of epidermal growth factor (EGF) receptor was examined immunohistochemically in a total of 122 gastric and 61 colonic carcinomas, out of which 16 gastric and 8 colonic carcinomas were also examined by 125I-labeled EGF binding analysis and Western blotting. The values of EGF binding were 12.68 +/- 1.98 (SE; n = 16) fmol/mg protein in gastric carcinomas and 5.72 +/- 2.15 (n = 8) fmol/mg protein in nonneoplastic gastric mucosa, the difference being significant (P less than 0.01). In the colonic tissue, the binding capacities in carcinomas and nonneoplastic mucosa were 13.29 +/- 4.17 (n = 8) and 10.68 +/- 0.41 (n = 3) fmol/mg protein, respectively. Scatchard analysis of 125I-labeled EGF binding indicated a single class of receptors in gastric and colonic carcinomas with an apparent Kd value of from 111 to 277 (n = 4) and from 87.4 to 341 fM (n = 5), respectively, except for one gastric carcinoma having two classes of receptors (Kd = 15.9 and 896 fM). In Western blotting using monoclonal anti-EGF receptor antibody, various levels of EGF receptor expression were detected in 12 (85.7%) of the 14 gastric carcinomas and in 7 (87.5%) of the 8 colonic carcinomas. Immunohistochemically, EGF receptor immunoreactivity was detected in one (3.8%) of the 26 early gastric carcinomas, while it was observed in 33 (34.4%) of the 96 advanced gastric carcinomas, the incidence between the two being significantly different (P less than 0.01). In the colonic carcinomas, 47 (77.1%) of the 61 cases showed positive immunoreactivity to EGF receptor, which did not differ by histological type.

Topics: Carcinoma; Colonic Neoplasms; Epidermal Growth Factor; ErbB Receptors; Humans; Immunohistochemistry; Iodine Radioisotopes; Staining and Labeling; Stomach Neoplasms

The expressions of epidermal growth factor (EGF) and its receptor were studied immunohistochemically in a total of 156 gastric carcinomas; 26 early and 130 advanced. No EGF immunoreactivity was found in early carcinomas, while EGF-positive tumor cells were detected in 38 (29.2%) of the 130 advanced carcinomas. EGF receptor immunoreactivity was detected in one (3.8%) of the 26 early carcinomas and in 44 (33.8%) of the 130 advanced carcinomas, the incidence being significantly different (p less than 0.01). Out of the 130 advanced carcinomas, 17 (13.1%) had synchronous expression of EGF and its receptor and most of the tumors with strong expression of EGF were positive to EGF receptor. A significant correlation was observed between the depth of tumor invasion and EGF or its receptor immunoreactivity in tumor cells (p less than 0.05). Furthermore, a good correlation was demonstrated between the synchronous expression of EGF and its receptor and the depth of tumor invasion or the tumor staging. The incidence of cases with EGF in metastatic tumors was significantly higher than that in primary tumors (p less than 0.05). Patients with synchronous expression of EGF and its receptor had a far poorer prognosis than those without EGF and receptor.

Topics: Adenocarcinoma; Epidermal Growth Factor; ErbB Receptors; Humans; Neoplasm Staging; Protein-Tyrosine Kinases; Stomach Neoplasms; Time Factors

Recent in vivo and in vitro evidence suggests that EGF-related growth factors and TGF beta derived from tumor cells mutually act not only on tumor cells themselves but also on fibroblasts surrounding the tumor, resulting in extensive progression and fibrosis of gastric scirrhous carcinoma. There are two mechanisms involved in such extensive fibrosis. One is collagen production by fibroblasts upon stimulation by tumor-derived growth factors, and the other is collagen synthesis by the tumor cells themselves. However, the expressions of the EGF-related growth factors, TGF beta and procollagen, in tumor cells are not specific for gastric scirrhous carcinoma. Future elucidation of the function and structure of the sam gene may shed light on the developmental mechanism of gastric scirrhous carcinoma.

Topics: Adenocarcinoma, Scirrhous; Epidermal Growth Factor; ErbB Receptors; Growth Substances; Humans; Peptides; Procollagen; Stomach Neoplasms; Transforming Growth Factors

The effect of human epidermal growth factor (hEGF) on the growth of various histological types of six human gastric carcinoma cell lines was examined. The cell lines had relatively high affinity EGF receptors (dissociation constant Kd = 10(-9) to 10(-10) M). One gastric cancer cell line, MKN-74 (well differentiated adenocarcinoma) showed no response to hEGF, in cell growth, DNA synthesis or 125I-hEGF cell binding. There were no apparent correlations between histological type and cell growth, DNA synthesis or number of EGF receptors in these cells. The number of EGF receptors and the Kd value of the gastric carcinoma cell lines varied with their internal and external environments. hEGF concentrations corresponding to maximum stimulation in DNA synthesis varied between cell lines. The results suggest some gastric carcinoma cells to have EGF receptors and their growth seemingly to be stimulated by EGF in vitro. There are, however, no obvious correlations between the effect of hEGF on the growth of human gastric carcinoma cell lines or their histological type.

Topics: Adenocarcinoma; Cell Division; Cell Line; DNA Replication; Dose-Response Relationship, Drug; Epidermal Growth Factor; ErbB Receptors; Humans; Kinetics; Stomach Neoplasms; Temperature; Time Factors

Topics: Epidermal Growth Factor; ErbB Receptors; Humans; Stomach Neoplasms

Topics: Alkaline Phosphatase; Animals; Cell Line; Epidermal Growth Factor; Fibroblasts; Graft Survival; Humans; Mice; Mice, Inbred BALB C; Mice, Nude; Neoplasm Transplantation; Stomach Neoplasms

Topics: Adenocarcinoma; Adolescent; Adult; Aged; Alkaline Phosphatase; Animals; Cell Division; Epidermal Growth Factor; Female; Humans; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Middle Aged; Neoplasm Transplantation; Stomach Neoplasms

Two hundred and twenty one gastric carcinomas were immunohistochemically stained for h-EGF and we examined the correlation between h-EGF immunoreactivities and histologic findings. Regarding macroscopic and histologic types, incidence of h-EGF immunoreactivities in infiltrating type and in poorly differentiated type was significantly higher than those in localized type and in differentiated type, respectively. In addition, h-EGF producing carcinomas showed high positive rate in prognostic serosal involvement and scirrhous type in stroma. Prognosis in patients with h-EGF producing tumors was poorer than that in those with h-EGF non-producing tumors, especially in stages II and III. These results suggest that h-EGF immunoreactivities serves as a biological marker of high malignancy.

Topics: Adenocarcinoma; Biomarkers, Tumor; Epidermal Growth Factor; Female; Humans; Immunohistochemistry; Male; Neoplasm Invasiveness; Neoplasm Metastasis; Neoplasm Staging; Prognosis; Stomach Neoplasms

c-myc protein p62 in human gastric carcinomas was studied by immunohistochemistry using an antiserum raised against the C-terminal portion of the human c-myc gene protein. No immunoreactivity of c-myc p62 was detected in tumor cells of 27 early carcinomas, while c-myc p62-positive tumor cells were observed in 51 (36.4%) of the 140 advanced carcinomas. Many stromal cells including macrophages and fibroblasts around the tumors showed various degrees of c-myc p62 immunoreactivity. Localization of c-myc p62 was predominant in the cytoplasm of tumor cells and stromal cells. The prognosis of patients with p62-positive stromal cells was significantly better than that of patients with p62-negative stromal cells.

Topics: Epidermal Growth Factor; Humans; Immunohistochemistry; Interferons; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-myc; Stomach; Stomach Neoplasms; Tetradecanoylphorbol Acetate

We have extended our recent observation that human gastric cancer cells (MKN-45) synthesize and secrete an hEGF-like immunoreactive factor (designated as EGF-LI) by characterization of EGF-LI produced by five human gastric cancer cell lines in culture. Two cell lines (MKN-45 and KATO-III) derived from poorly differentiated adenocarcinoma synthesized and secreted a much larger amount of EGF-LI than three cell lines (MKN-1, MKN-28, and MKN-74) derived from well-differentiated adenocarcinoma. Treatment of MKN-45 cells by retinoic acid reduced significantly synthesis and secretion of EGF-LI, suggesting that production of EGF-LI is dependent on differentiational state of gastric cancer cells.

Topics: Animals; Cell Differentiation; Cell Line; Cells, Cultured; Culture Media; DNA Replication; Epidermal Growth Factor; Humans; Immunoenzyme Techniques; Mice; Mice, Inbred BALB C; Stomach Neoplasms

The c-erbB-2 gene was first identified by virtue of its cross-hybridization with v-erbB. Nucleotide sequence analysis of complementary DNA clones suggested that the c-erbB-2 gene encodes a growth factor receptor similar to that for EGF. Antibodies against the carboxyl terminal sequence of the c-erbB-2 protein immunoprecipitated a 185-kDa glycoprotein which showed protein-tyrosine kinase activity in vitro. Despite the extensive similarity between the c-erbB-2 protein and EGF receptor, neither EGF nor TGF-alpha bound to the c-erbB-2 protein. Phosphorylation of the c-erbB-2 protein was stimulated by TPA via protein kinase C in vivo. EGF also induced phosphorylation of the c-erbB-2 protein. This phosphorylation occurred not only on serine and threonine residues but also on tyrosine residues. Preliminary data suggested that the latter was mediated by the kinase activity of the EGF receptor. Southern blot analysis of DNAs from primary tumors revealed that the c-erbB-2 gene tends to be amplified in adenocarcinomas, mostly of the stomach and the breast. By screening both human genomic and cDNA libraries using v-yes DNA as a probe, we obtained DNA clones of the c-yes gene, the pseudogene of c-yes, c-fgr gene and c-src gene and two novel yes-related genes, fyn and lyn. Complete nucleotide sequence analysis of the cDNA clones of c-yes, fyn and lyn revealed that these genes encode proteins similar to p60src both in size and sequence.

Topics: Adenocarcinoma; Amino Acid Sequence; Breast Neoplasms; Carcinoma, Squamous Cell; Epidermal Growth Factor; ErbB Receptors; Humans; Protein-Tyrosine Kinases; Proto-Oncogenes; Stomach Neoplasms; Transcription, Genetic

EGF is reported to have a potent protective effect on peptic ulcer formation in rats. In this study, we measured the IR-hEGF concentrations in the saliva of normal human subjects and patients with peptic ulcer disease or non-peptic ulcer gastroduodenal disease. In normal subjects, the level of salivary IR-hEGF was highest in the early morning, and the values in individuals on different days showed small variations. There were no sex differences or age-related changes in the salivary IR-hEGF levels. The concentrations of the peptide were lower in patients in the active (0.96 +/- 26 ng/ml, mean +/- SE, n = 4) and healing stages (1.06 +/- 0.24 ng/ml, n = 8) of peptic ulcer disease as compared with those in normal subjects (3.19 +/- 0.46 ng/ml, n = 47). No significant differences in salivary IR-hEGF levels were observed between normal subjects and patients in the scaring stage of peptic ulcer disease (2.40 +/- 0.42 ng/ml, n = 21), or those with gastric cancer (2.44 +/- 0.27 ng/ml, n = 21) and atrophic or superficial gastritis (2.31 +/- 0.34 ng/ml, n = 28). Although the pathophysiological significance of these lower salivary IR-hEGF levels in patients with peptic ulcer disease is unclear, it is possible that the low level of hEGF in saliva may decrease the resistance of the mucosa to physicochemical stress, and thus participate in the development of the diseases.

Topics: Circadian Rhythm; Epidermal Growth Factor; Female; Gastritis; Humans; Male; Peptic Ulcer; Radioimmunoassay; Saliva; Stomach Neoplasms

A large amount of an immunoreactive factor was detected in the medium conditioned by human gastric cancer cells, strain MKN-45, by our enzyme immunoassay system for human epidermal growth factor (hEGF) based on hEGF isolated from urine. However, the dose-response curve of the immunoreactive factor (designated as MKN-45 EGF) was not parallel with the standard curve of hEGF. The molecular weight of MKN-45 EGF was slightly larger than that of hEGF and was estimated to be 7,000-8,000 by gel filtration on Sephadex G-50. On isoelectric focusing analysis, MKN-45 EGF gave a major peak at pH 5.0 and a minor one at pH 4.3. These results demonstrate that MKN-45 cells synthesize and secrete into the culture medium a polypeptide immunologically related to hEGF.

Topics: Chromatography, Gel; Culture Media; Epidermal Growth Factor; Humans; Isoelectric Focusing; Molecular Weight; Peptides; Stomach Neoplasms; Tumor Cells, Cultured

The presence of human epidermal growth factor (hEGF) was studied in a total of 210 gastric carcinomas comprising 52 early carcinomas, 113 advanced carcinomas and 45 scirrhous carcinomas. An immunohistochemical study revealed no hEGF-immunoreactivity in early gastric carcinomas, while hEGF-positive tumor cells were detected in 24 (21.2%) of the 113 advanced carcinomas and in 15 (33.3%) of the 45 scirrhous carcinomas. The incidence of hEGF-immunoreactivity in well-differentiated adenocarcinomas was significantly higher than that in poorly differentiated adenocarcinomas (P less than 0.05). Moreover, hEGF-immunoreactive tumor cells were observed in 13 (30.4%) of the 42 scirrhous poorly differentiated adenocarcinomas, the incidence being significantly higher than that in non-scirrhous poorly differentiated adenocarcinomas (P less than 0.05). The average hEGF content in the tumor tissue estimated by radioimmunoassay was 3.77 +/- 0.61 (mean +/- SE) ng/g wet weight in immunohistochemical hEGF-positive tumors and 2.19 +/- 0.18 ng/g wet weight in hEGF-negative tumors, the difference being significant (P less than 0.05). Patients with hEGF-positive carcinomas (excluding scirrhous carcinomas) had much worse prognosis than those with hEGF-negative carcinomas. These results suggest that EGF produced by tumor cells plays an important role in the invasive growth and productive fibrosis of gastric carcinoma and also serves as a biologic marker of high malignancy in patients with gastric cancers.

Topics: Adenocarcinoma; Adenocarcinoma, Scirrhous; Aged; Carcinoma; Epidermal Growth Factor; ErbB Receptors; Female; Histocytochemistry; Humans; Male; Middle Aged; Prognosis; Receptors, Cell Surface; Staining and Labeling; Stomach Neoplasms

c-Ha-ras oncogene product in human gastric carcinomas was examined by Western blotting and immunohistochemistry using anti-Ha-ras p21 antibody. In Western blotting, high levels of c-Ha-ras p21s were found in gastric carcinomas. Immunohistochemically, c-Ha-ras p21 was detected in 3 (11.1%) of 27 early carcinomas and in 63 (43.8%) of 144 advanced carcinomas. In advanced carcinomas, c-Ha-ras p21-immunoreactivity was correlated with the depth of tumor invasion and was stronger in metastatic tumors than in primary tumors. Patients with c-Ha-ras p21-positive carcinomas had a significantly worse prognosis than those with p21-negative carcinomas.

Topics: Amino Acid Sequence; Carcinoma; Epidermal Growth Factor; Histocytochemistry; Humans; Neoplasm Invasiveness; Neoplasm Metastasis; Oncogenes; Prognosis; Proto-Oncogene Proteins; Stomach Neoplasms