epidermal-growth-factor and Carcinogenesis

Previously, we showed that knockout mice homozygous for deficiency of the mercapturic acid pathway (MAP) transporter protein, RLIP (RLIP

Topics: Acetylcysteine; Adipokines; Animals; Carcinogenesis; Carcinogens; Carrier Proteins; Clathrin; Cytokines; Epidermal Growth Factor; GTPase-Activating Proteins; Humans; Infant; Insulins; Male; Mice; Neoplasms; Obesity; Oxidative Stress; Peptide Hormones; Transforming Growth Factor beta; Tumor Suppressor Protein p53

The pursual of novel anticancer molecules from natural sources has gained worthwhile appreciation, and a significant fraction of conceptual knowledge has revolutionized our understanding about heterogeneous nature of cancer. Betulinic acid has fascinated interdisciplinary researchers due to its tremendous pharmacological properties. Ground-breaking discoveries have unraveled previously unprecedented empirical proof-of-concept about momentous chemopreventive role of betulinic acid against carcinogenesis and metastasis. Deregulation of cell signaling pathways has been reported to play a linchpin role in cancer progression and colonization of metastatically competent cancer cells to the distant organs for the development of secondary tumors. Importantly, betulinic acid has demonstrated unique properties to mechanistically modulate oncogenic transduction cascades. In this mini-review, we have attempted to provide a sophisticated compendium of regulatory role of betulinic acid in cancer chemoprevention. We have partitioned this multi-component review into different sections in which we summarized landmark research-works which highlighted betulinic acid mediated regulation of JAK/STAT, VEGF, EGF/EGFR, TRAIL/TRAIL-R, AKT/mTOR and ubiquitination pathways in the inhibition of cancer. In parallel, betulinic acid mediated regulation of signaling cascades and non-coding RNAs will be critically analyzed in cell culture and animal model studies. Better comprehension of the pharmaceutical features of betulinic acid and mapping of the existing knowledge gaps will be valuable in the translatability of preclinical studies into rationally designed clinical trials.

Topics: Animals; Antineoplastic Agents; Betulinic Acid; Carcinogenesis; Epidermal Growth Factor; ErbB Receptors; Neoplasms; Proto-Oncogene Proteins c-akt; TOR Serine-Threonine Kinases; Vascular Endothelial Growth Factor A

Colorectal cancer (CRC) is a heterogeneous disease that includes both hereditary and sporadic types of tumors. Tumor initiation and growth is driven by mutational or epigenetic changes that alter the function or expression of multiple genes. The genes predominantly encode components of various intracellular signaling cascades. In this review, we present mouse intestinal cancer models that include alterations in the Wnt, Hippo, p53, epidermal growth factor (EGF), and transforming growth factor β (TGFβ) pathways; models of impaired DNA mismatch repair and chemically induced tumorigenesis are included. Based on their molecular biology characteristics and mutational and epigenetic status, human colorectal carcinomas were divided into four so-called consensus molecular subtype (CMS) groups. It was shown subsequently that the CMS classification system could be applied to various cell lines derived from intestinal tumors and tumor-derived organoids. Although the CMS system facilitates characterization of human CRC, individual mouse models were not assigned to some of the CMS groups. Thus, we also indicate the possible assignment of described animal models to the CMS group. This might be helpful for selection of a suitable mouse strain to study a particular type of CRC.

Topics: Animals; Carcinogenesis; Cell Transformation, Neoplastic; Colonic Neoplasms; Colorectal Neoplasms; Disease Models, Animal; DNA Mismatch Repair; Epidermal Growth Factor; Gene Expression Regulation, Neoplastic; Genes, p53; Hippo Signaling Pathway; Humans; Mice; Protein Serine-Threonine Kinases; Transforming Growth Factor beta; Wnt Signaling Pathway

Mammographic density reflects variation in breast tissue composition as detected on mammogram. It is associated with a number of well-known breast cancer risk factors and itself is considered one of the strongest risk factors for breast cancer. If the expression of several proteins and genes within the breast tissue influences mammographic density in the same way as it influences breast cancer risk, then mammographic density might serve as an intermediate biomarker in future epidemiological studies on breast cancer. This has the potential to provide a quick means for predicting the effect of changes in the breast microenvironment on breast cancer risk without having to wait for an eventual development of breast cancer. In this review, the expression of several proteins and genes (growth factors, enzymes, proteoglycans and pro-inflammatory markers) within the breast tissue is shown to be associated with mammographic density. These proteins and genes are suspected to play a role in breast carcinogenesis. More studies assessing differential expression of proteins and genes in mammary epithelium and stroma and their association with mammographic density among premenopausal and postmenopausal women are required. Identification of proteins and genes influencing mammographic density may provide further insight on the molecular causes of breast cancer.

Topics: Biomarkers, Tumor; Body Mass Index; Breast Density; Breast Neoplasms; Carcinogenesis; Epidermal Growth Factor; Female; Gene Expression; Humans; Inflammation; Insulin-Like Growth Factor I; Mammary Glands, Human; Proteoglycans; Receptors, Estrogen; Receptors, Progesterone; Risk Factors

It is now widely accepted that therapeutic antibodies targeting epidermal growth factor receptor (EGFR) can have efficacy in KRAS wild-type advanced colorectal cancer (CRC) patients. What remains to be ascertained is whether a subgroup of KRAS-mutated CRC patients might not also derive benefit from EGFR inhibitors. Metalloproteinase inhibitor 1 (TIMP-1) is a pleiotropic factor predictive of survival outcome of CRC patients. Levels of TIMP-1 were measured in pre-treatment plasma samples (n = 426) of metastatic CRC patients randomized to Nordic FLOX (5-fluorouracil and oxaliplatin) +/- cetuximab (NORDIC VII study). Multivariate analysis demonstrated a significant interaction between plasma TIMP-1 protein levels, KRAS status and treatment with patients bearing KRAS mutated tumors and high TIMP-1 plasma level (> 3rd quartile) showing a significantly longer overall survival if treated with cetuximab (HR, 0.48; 95% CI, 0.25 to 0.93). To gain mechanistic insights into this association we analyzed a set of five different CRC cell lines. We show here that EGFR signaling induces TIMP-1 expression in CRC cells, and that TIMP-1 promotes a more aggressive behavior, specifically in KRAS mutated cells. The two sets of data, clinical and in vitro, are complementary and support each other, lending strength to our contention that TIMP- 1 plasma levels can identify a subset of patients with KRAS-mutated metastatic CRC that will have benefit from EGFR-inhibition therapy.

Topics: Aged; Antineoplastic Combined Chemotherapy Protocols; Carcinogenesis; Cell Line, Tumor; Cell Movement; Cetuximab; Colorectal Neoplasms; Epidermal Growth Factor; Female; Fluorouracil; Humans; Male; Mutation; Neoplasm Metastasis; Organoplatinum Compounds; Oxaliplatin; Phenotype; Proto-Oncogene Proteins p21(ras); Signal Transduction; Survival Analysis; Tissue Inhibitor of Metalloproteinase-1

Growth factors secreted by stromal fibroblasts regulate the intestinal epithelium. Stroma-derived epidermal growth factor (EGF) family ligands are implicated in epithelial regeneration and tumorigenesis, but their specific contributions and associated mechanisms remain unclear. Here, we use primary intestinal organoids modeling homeostatic, injured and tumorigenic epithelia to assess how the fibroblast-derived EGF family ligands neuregulin 1 (NRG1) and epiregulin (EREG) regulate the intestinal epithelium. NRG1 was expressed exclusively in the stroma, robustly increased crypt budding and protected intestinal epithelial organoids from radiation-induced damage. NRG1 also induced regenerative features in the epithelium, including a fetal-like transcriptome, suppression of the Lgr5+ stem cell pool and remodeling of the epithelial actin cytoskeleton. Intriguingly, unlike EGF and EREG, NRG1 failed to support the growth of pre-tumorigenic intestinal organoids lacking the tumor suppressor Apc, commonly mutated in human colorectal cancer (CRC). Interestingly, high expression of stromal NRG1 was associated with improved survival in CRC cohorts, suggesting a tumor-suppressive function. Our results highlight the power of stromal NRG1 in transcriptional reprogramming and protection of the intestinal epithelium from radiation injury without promoting tumorigenesis.

Topics: Carcinogenesis; Cellular Reprogramming; Epidermal Growth Factor; Fibroblasts; Humans; Intestinal Mucosa; Ligands; Neuregulin-1

Crystalline silica-induced inflammation possibly facilitates carcinogenesis. Here, we investigated its effect on lung epithelium damage. We prepared conditioned media of immortalized human bronchial epithelial cell lines (hereinafter bronchial cell lines) NL20, BEAS-2B, and 16HBE14o- pre-exposed to crystalline silica (autocrine crystalline silica conditioned medium), a phorbol myristate acetate-differentiated THP-1 macrophage line, and VA13 fibroblast line pre-exposed to crystalline silica (paracrine crystalline silica conditioned medium). As cigarette smoking imposes a combined effect on crystalline silica-induced carcinogenesis, a conditioned medium was also prepared using the tobacco carcinogen benzo[a]pyrene diol epoxide. Crystalline silica-exposed and growth-suppressed bronchial cell lines exhibited enhanced anchorage-independent growth in autocrine crystalline silica and benzo[a]pyrene diol epoxide conditioned medium compared with that in unexposed control conditioned medium. Crystalline silica-exposed nonadherent bronchial cell lines in autocrine crystalline silica and benzo[a]pyrene diol epoxide conditioned medium showed increased expression of cyclin A2, cdc2, and c-Myc, and of epigenetic regulators and enhancers, BRD4 and EZH2. Paracrine crystalline silica and benzo[a]pyrene diol epoxide conditioned medium also accelerated the growth of crystalline silica-exposed nonadherent bronchial cell lines. Culture supernatants of nonadherent NL20 and BEAS-2B in crystalline silica and benzo[a]pyrene diol epoxide conditioned medium had higher EGF concentrations, whereas those of nonadherent 16HBE14o- had higher TNF-α levels. Recombinant human EGF and TNF-α promoted anchorage-independent growth in all lines. Treatment with EGF and TNF-α neutralizing antibodies inhibited cell growth in crystalline silica conditioned medium. Recombinant human TNF-α induced BRD4 and EZH2 expression in nonadherent 16HBE14o-. The expression of γH2AX occasionally increased despite PARP1 upregulation in crystalline silica-exposed nonadherent lines with crystalline silica and benzo[a]pyrene diol epoxide conditioned medium. Collectively, crystalline silica- and benzo[a]pyrene diol epoxide-induced inflammatory microenvironments comprising upregulated EGF or TNF-α expression may promote crystalline silica-damaged nonadherent bronchial cell proliferation and oncogenic protein expression despite occasional γH2AX upregulation. Thus, carcinogenesis may be cooperatively aggravated by crysta

Topics: 7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide; Benzo(a)pyrene; Carcinogenesis; Culture Media, Conditioned; Enhancer of Zeste Homolog 2 Protein; Epidermal Growth Factor; Epithelial Cells; Epoxy Compounds; Humans; Lung; Nuclear Proteins; Transcription Factors; Tumor Microenvironment; Tumor Necrosis Factor-alpha

Circular RNA (circRNA) is a covalently closed endogenous RNA that participates in disease progression. However, its role in lung cancer is largely undetermined. In the present study, we found an onctogenic circRNA in lung cancer, FAT atypical cadherin 3 (FAT3) circRNA (circ-FAT3) was remarkably upregulated in lung cancer in comparison to paired normal tissues. High circ-FAT3 was closely linked to larger tumour size, lymph node metastasis, later clinical stage, as well as dismal outcome. Stable knockdown of circ-FAT3 inhibited cell proliferation and metastasis both in vitro and in vivo. RNA binding protein ELAV like RNA binding protein 1 (HuR) was found to bind to introns flanking circ-FAT3, promoting the cyclization and generation of circ-FAT3. Further, circ-FAT3 was able to sponge miR-136-5p by acting as a competing endogenous RNA (ceRNA), alleviating the repressive effect of miR-136-5p on HuR mRNA at the transcriptional and post-transcriptional levels. Moreover, circ-FAT3 expression in lung cancer tissues was strongly positively and negatively correlated with HuR and miR-136-5p expression, respectively. Overall, our data reveal the previously uncharacterized regulatory loop of circ-FAT3/miR-136-5p/HuR in lung cancer and provide novel evidence for the importance of circRNA as a ceRNA in tumorigenesis.

Topics: Cadherins; Carcinogenesis; Cell Line, Tumor; Cell Proliferation; ELAV-Like Protein 1; Epidermal Growth Factor; Gene Expression Regulation, Neoplastic; Humans; Lung Neoplasms; MicroRNAs; RNA-Binding Proteins; RNA, Circular

Cr(VI) is broadly applied in industry. Cr(VI) exposure places a big burden on public health, thereby increasing the risk of lung squamous cell carcinoma (LUSC). The mechanisms underlying Cr(VI)-induced LUSC remain largely elusive. Here, we report that the cancer stem cell (CSC)/tumour-initiating cell (TIC)-like subgroup within Cr(VI)-transformed bronchial epithelial cells (CrT) promotes lung cancer tumourigenesis. Mechanistically, Cr(VI) exposure specifically increases the expression levels of aldehyde dehydrogenase 1A1 (ALDH1A1), a CSC marker, through KLF4-mediated transcription. ALDH1A1 maintains self-renewal of CrT/TICs and facilitates the expression and secretion of EGF from CrT/TICs, which subsequently promotes the activation of EGFR signalling in differentiated cancer cells and tumour growth of LUSC. In addition, the ALDH1A1 inhibitor A37 and gemcitabine synergistically suppress LUSC progression. Importantly, high ALDH1A1 expression levels are positively correlated with advanced clinical stages and predict poor survival in LUSC patients. These findings elucidate how ALDH1A1 modulates EGF secretion from TICs to facilitate LUSC tumourigenesis, highlighting new therapeutic strategies for malignant lung cancers.

Topics: Aldehyde Dehydrogenase; Aldehyde Dehydrogenase 1 Family; Carcinogenesis; Carcinoma, Non-Small-Cell Lung; Carcinoma, Squamous Cell; Cell Transformation, Neoplastic; Epidermal Growth Factor; Humans; Lung; Lung Neoplasms; Neoplastic Processes; Retinal Dehydrogenase; Tics

Colorectal cancer and other adult solid cancers pose a significant challenge for successful treatment because the tumor microenvironment both hinders the action of conventional therapeutics and suppresses the immune activities of infiltrating leukocytes. The immune suppression is largely the effect of enhanced local mediators such as purine nucleosides and eicosanoids. Genetic approaches have the promise of interfering with these mechanisms of local immunosuppression to allow both intrinsic and therapeutic immunological anticancer processes. Bacterial phages offer a novel means of enabling access into tissues for therapeutic genetic manipulations.. We generated spheroids of fibroblastic and CRC cancer cells to model the 3-dimensional stromal and parenchymal components of colorectal tumours. We used these to examine the access and effects of both wildtype (WT) and epidermal growth factor (EGF)-presenting bacteriophage λ (WT- λ and EGF-λ) as a means of delivery of targeted genetic interventions in solid cancers. We used both confocal microscopy of spheroids exposed to AF488-tagged phages, and the recovery of viable phages as measured by plaque-forming assays to evaluate access; and measures of mitochondrial enzyme activity and cellular ATP to evaluate the outcome on the constituent cells.. Using flourescence-tagged derivatives of these bacteriophages (AF488-WT-λ and AF488-EGF-λ) we showed that phage entry into these tumour microenvironments was possible and that the EGF ligand enabled efficient and persistent uptake into the cancer cell mass. EGF-λ became localized in the intracellular portion of cancer cells and was subjected to subsequent cellular processing. The targeted λ phage had no independent effect upon mature tumour spheroids, but interfered with the early formation and growth of cancer tissues without the need for addition of a toxic payload, suggesting that it might have beneficial effects by itself in addition to any genetic intervention delivered to the tumour. Interference with spheroid formation persisted over the duration of culture.. We conclude that targeted phage technology is a feasible strategy to facilitate delivery into colorectal cancer tumour tissue (and by extension other solid carcinomas) and provides an appropriate delivery vehicle for a gene therapeutic that can reduce local immunosuppression and/or deliver an additional direct anticancer activity.

Topics: Bacteriophage lambda; Carcinogenesis; Colorectal Neoplasms; Epidermal Growth Factor; ErbB Receptors; Humans; Tumor Microenvironment

Many metabolic phenotypes in cancer cells are also characteristic of proliferating nontransformed mammalian cells, and attempts to distinguish between phenotypes resulting from oncogenic perturbation from those associated with increased proliferation are limited. Here, we examined the extent to which metabolic changes corresponding to oncogenic KRAS expression differed from those corresponding to epidermal growth factor (EGF)-driven proliferation in human mammary epithelial cells (HMECs). Removal of EGF from culture medium reduced growth rates and glucose/glutamine consumption in control HMECs despite limited changes in respiration and fatty acid synthesis, while the relative contribution of branched-chain amino acids to the TCA cycle and lipogenesis increased in the near-quiescent conditions. Most metabolic phenotypes measured in HMECs expressing mutant KRAS were similar to those observed in EGF-stimulated control HMECs that were growing at comparable rates. However, glucose and glutamine consumption as well as lactate and glutamate production were lower in KRAS-expressing cells cultured in media without added EGF, and these changes correlated with reduced sensitivity to GLUT1 inhibitor and phenformin treatment. Our results demonstrate the strong dependence of metabolic behavior on growth rate and provide a model to distinguish the metabolic influences of oncogenic mutations and nononcogenic growth.

Topics: Animals; Breast; Breast Neoplasms; Carcinogenesis; Cell Proliferation; Epidermal Growth Factor; Epithelial Cells; Female; Gene Expression Regulation, Neoplastic; Glucose; Glucose Transporter Type 1; Glutamic Acid; Glutamine; Humans; Lactic Acid; Mammary Glands, Human; Proto-Oncogene Proteins p21(ras); Tumor Cells, Cultured

Esophageal squamous cell carcinoma (ESCC) presents with lymph node metastasis in the early stages, limiting the opportunities for curative local resection, including endoscopic submucosal dissection (ESD). ESD is regarded as the standard treatment for early-stage ESCCs. However, radical surgery is recommended when lymph node metastasis risk exists. More efforts are needed to find the markers for early prediction and clarify the molecular mechanism underlying the pathogenesis of lymph node metastasis. Recently, aberrant regulation of gene expression by histone methylation modifiers has emerged as an important mechanism for cancer metastasis. Herein, we demonstrated that mixed-lineage leukemia 2 (MLL2) positively regulates gene expression programs associated with ESCC cell migration. MLL2 interacts with RelA in the nucleus to enhance transcription of stanniocalcin-1 (STC1) and to facilitate cancer metastasis. Meanwhile, MLL2 knockdown resulted in a significant decrease in the migration of ESCC cells. Clinically, high level of MLL2 was significantly associated with early-stage ESCC lymph node metastasis. In summary, these findings discovered a previously unidentified molecular pathway underlying the coordinated regulation of metastasis-related STC-1 expression by MLL2 and RelA and highlighted the critical role of MLL2 in ESCC.

Topics: Animals; Carcinogenesis; Cell Line, Tumor; Cell Movement; DNA-Binding Proteins; Epidermal Growth Factor; Esophageal Squamous Cell Carcinoma; Extracellular Signal-Regulated MAP Kinases; Gene Silencing; Glycoproteins; Humans; Lymphatic Metastasis; Male; Mice, Nude; Neoplasm Invasiveness; Neoplasm Proteins; Promoter Regions, Genetic; Protein Binding; Transcription Factor RelA; Transcription, Genetic; Tumor Stem Cell Assay

Activating mutations in RAS are present in ~ 30% of human tumors, and the resulting aberrations in ERK/MAPK signaling play a central role in oncogenesis. However, the form of these signaling changes is uncertain, with activating RAS mutants linked to both increased and decreased ERK activation in vivo. Rationally targeting the kinase activity of this pathway requires clarification of the quantitative effects of RAS mutations. Here, we use live-cell imaging in cells expressing only one RAS isoform to quantify ERK activity with a new level of accuracy. We find that despite large differences in their biochemical activity, mutant KRAS isoforms within cells have similar ranges of ERK output. We identify roles for pathway-level effects, including variation in feedback strength and feedforward modulation of phosphatase activity, that act to rescale pathway sensitivity, ultimately resisting changes in the dynamic range of ERK activity while preserving responsiveness to growth factor stimuli. Our results reconcile seemingly inconsistent reports within the literature and imply that the signaling changes induced by RAS mutations early in oncogenesis are subtle.

Topics: Animals; Carcinogenesis; Epidermal Growth Factor; Feedback, Physiological; Fluorescence Resonance Energy Transfer; Fluorescent Antibody Technique; Genes, ras; Image Processing, Computer-Assisted; Kinetics; MAP Kinase Signaling System; Mice; Mutation; Phosphoric Monoester Hydrolases; Phosphorylation; Protein Isoforms; ras Proteins; Single-Cell Analysis

Neural progenitor cells (NPCs) are self-renewing cells that give rise to the major cells in the nervous system and are considered to be the possible cell of origin of glioblastoma. The gap junction protein connexin43 (Cx43) is expressed by NPCs, exerting channel-dependent and -independent roles. We focused on one property of Cx43-its ability to inhibit Src, a key protein in brain development and oncogenesis. Because Src inhibition is carried out by the sequence 266-283 of the intracellular C terminus in Cx43, we used a cell-penetrating peptide containing this sequence, TAT-Cx43

Topics: Animals; Astrocytes; beta Catenin; Carcinogenesis; Cell Differentiation; Cell Line, Tumor; Cell Proliferation; Cell-Penetrating Peptides; Connexin 43; Disease Models, Animal; Epidermal Growth Factor; Fibroblast Growth Factor 2; Gene Expression Regulation, Neoplastic; Glioblastoma; Humans; Neoplastic Stem Cells; Neural Stem Cells; Rats; src-Family Kinases; Stem Cells

Many adenocarcinomas, including colorectal cancer (CRC), overexpress the MUC13 cell surface mucin, but the functional significance and mechanisms are unknown. Here, we report the roles of MUC13 in colonic tumorigenesis and tumor progression. High-MUC13 expression is associated with poor survival in two independent patient cohorts. In a comprehensive series of in vivo experiments, we identified a critical role for MUC13 in the development of this malignancy, by promoting survival and proliferation of tumor-initiating cells and driving an immunosuppressive environment that protects tumors from checkpoint inhibitor immunotherapy. In Muc13-deficient mice, fewer tumors are generated after exposure to carcinogens and inflammation, they have markedly reduced β-catenin signaling, have more tumor-infiltrating CD103

Topics: Animals; Antigens, Surface; Apoptosis; beta Catenin; Biomarkers, Tumor; Carcinogenesis; Cell Proliferation; Cohort Studies; Colitis; Colorectal Neoplasms; Epidermal Growth Factor; Gene Expression Regulation, Neoplastic; Humans; Mice; Mice, Inbred C57BL; Mice, Knockout; Mucins; Neoplastic Stem Cells; Prognosis; Survival Rate; Tumor Cells, Cultured

Individuals with a single functional copy of the BRCA2 tumor suppressor have elevated risks for breast, ovarian, and other solid tumor malignancies. The exact mechanisms of carcinogenesis due to BRCA2 haploinsufficiency remain unclear, but one possibility is that at-risk cells are subject to acute periods of decreased BRCA2 availability and function ("BRCA2-crisis"), which may contribute to disease. Here, we establish an in vitro model for BRCA2-crisis that demonstrates chromatin remodeling and activation of an NF-κB survival pathway in response to transient BRCA2 depletion. Mechanistically, we identify BRCA2 chromatin binding, histone acetylation, and associated transcriptional activity as critical determinants of the epigenetic response to BRCA2-crisis. These chromatin alterations are reflected in transcriptional profiles of pre-malignant tissues from BRCA2 carriers and, therefore, may reflect natural steps in human disease. By modeling BRCA2-crisis in vitro, we have derived insights into pre-neoplastic molecular alterations that may enhance the development of preventative therapies.

Topics: Animals; BRCA2 Protein; Carcinogenesis; Cell Line; Cell Proliferation; Chromatin; Chromatin Assembly and Disassembly; Epidermal Growth Factor; Female; Gene Deletion; Gene Expression Regulation; Humans; Mice; Mutation; NF-kappa B; Signal Transduction; Transcription, Genetic; Transcriptome

Topics: Carcinogenesis; Cell Proliferation; Epidermal Growth Factor; ErbB Receptors; Female; HeLa Cells; Humans; Interleukin-6; Phosphorylation; Phytotherapy; Plant Extracts; Signal Transduction; STAT3 Transcription Factor; Uterine Cervical Neoplasms; Zingiberaceae

Aberrant glycosylation is recognized as a cancer hallmark that is associated with cancer development and progression. In this study, the clinical relevance and significance of terminal fucose (TFG), by fucosyltransferase-1 (FUT1) in carcinogenesis and progression of cholangiocarcinoma (CCA) were demonstrated. TFG expression in human and hamster CCA tissues were determined using Ulex europaeus agglutinin-I (UEA-I) histochemistry. Normal bile ducts rarely expressed TFG while 47% of CCA human tissues had high TFG expression and was correlated with shorter survival of patients. In the CCA-hamster model, TFG was elevated in hyperproliferative bile ducts and gradually increased until CCA was developed. This evidence indicates the involvement of TFG in carcinogenesis and progression of CCA. The mechanistic insight was performed in 2 CCA cell lines. Suppression of TFG expression using siFUT1 or neutralizing the surface TFG with UEA-I significantly reduced migration, invasion and adhesion of CCA cells in correlation with the reduction of Akt/Erk signaling and epithelial-mesenchymal transition. A short pulse of EGF could stimulate Akt/Erk signaling via activation of EGF-EGFR cascade, however, decreasing TFG using siFUT1 or UEA-I treatment reduced the EGF-EGFR activation and Akt/Erk signaling. This evidence provides important insight into the relevant role and molecular mechanism of TFG in progression of CCA.

Topics: Adult; Aged; Bile Duct Neoplasms; Bile Ducts, Intrahepatic; Carcinogenesis; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cholangiocarcinoma; Disease Progression; Epidermal Growth Factor; Epithelial-Mesenchymal Transition; ErbB Receptors; Female; Fucose; Fucosyltransferases; Galactoside 2-alpha-L-fucosyltransferase; Humans; Male; MAP Kinase Signaling System; Middle Aged; Proto-Oncogene Proteins c-akt; Signal Transduction; Transcriptome

Tumor microenvironments expose cancer cells to heterogeneous, dynamic environments by shifting availability of nutrients, growth factors, and metabolites. Cells integrate various inputs to generate cellular memory that determines trajectories of subsequent phenotypes. Here we report that short-term exposure of triple-negative breast cancer cells to growth factors or targeted inhibitors regulates subsequent tumor initiation. Using breast cancer cells with different driver mutations, we conditioned cells lines with various stimuli for 4 hours before implanting these cells as tumor xenografts and quantifying tumor progression by means of bioluminescence imaging. In the orthotopic model, conditioning a low number of cancer cells with fetal bovine serum led to enhancement of tumor-initiating potential, tumor volume, and liver metastases. Epidermal growth factor and the mTORC1 inhibitor ridaforolimus produced similar but relatively reduced effects on tumorigenic potential. These data show that a short-term stimulus increases tumorigenic phenotypes based on cellular memory. Conditioning regimens failed to alter proliferation or adhesion of cancer cells in vitro or kinase signaling through Akt and ERK measured by multiphoton microscopy in vivo, suggesting that other mechanisms enhanced tumorigenesis. Given the dynamic nature of the tumor environment and time-varying concentrations of small-molecule drugs, this work highlights how variable conditions in tumor environments shape tumor formation, metastasis, and response to therapy.

Topics: Animals; Carcinogenesis; Cell Adhesion; Cell Count; Cell Line, Tumor; Cell Proliferation; Disease Models, Animal; Disease Progression; Epidermal Growth Factor; Extracellular Signal-Regulated MAP Kinases; Female; Humans; Luminescent Measurements; Mechanistic Target of Rapamycin Complex 1; Neoplasm Metastasis; Proto-Oncogene Proteins c-akt; Serum Albumin, Bovine; Sirolimus; Triple Negative Breast Neoplasms; Tumor Microenvironment

Hypoxia-inducible factor 1α (HIF-1α) functions importantly in the development of colorectal cancer. HIF-1α is induced by some cytokines and growth factors and is also regulated by another kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathways. Meanwhile, inhibiting HIF-1α expression can inhibit the development of colorectal cancer. The aim of this study was to explore the effect of epidermal growth factor (EGF) on the activation of signal transducer and activator of transcription 3 (STAT3) in human colorectal cancer cells SW480. In addition, the underlying mechanism of the STAT3 signaling pathway in regulating HIF-1α and further affecting tumorigenesis and metastasis was investigated.. Immunofluorescence and Western blotting were used to detect the activation of STAT3 by EGF in human colorectal cancer cells SW480. SW480 cells were transfected with STAT3 siRNA or treated with STAT3 inhibitor Niclosamide, and then stimulated with EGF to change the expressions of STAT3 and p-STAT3. The expression level of HIF-1α mRNA in SW480 cells was detected by Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR). In addition, transwell assay and tumor formation experiments were performed to validate whether STAT3 and HIF-1α affected SW480 through EGF.. STAT3 was not activated in SW480 cells in vitro. EGF induced STAT3 activation and enhanced its phosphorylation level, so that it shuttled into the nucleus. Phosphorylated activation of STAT3 was a necessary condition for EGF to induce HIF-1α up-regulation. Both HIF-1α and EGF-induced phosphorylation of STAT3 could significantly promote the proliferation and metastasis of SW480, and enhance tumorigenesis.. In SW480 cells, EGF regulated HIF-1α through the STAT3 phosphorylation pathway, eventually promoting the occurrence and metastasis of colorectal cancer.

Topics: Carcinogenesis; Cell Line, Tumor; Cell Movement; Cell Proliferation; Epidermal Growth Factor; Gene Expression Regulation, Neoplastic; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Niclosamide; Phosphorylation; RNA, Small Interfering; Signal Transduction; STAT3 Transcription Factor; Up-Regulation

The triple-negative breast cancer is the most malignant type of breast cancer. Its pathogenesis and prognosis remain poor despite the significant advances in breast cancer diagnosis and therapy. Meanwhile, long noncoding RNAs (LncRNAs) play a pivotal role in the progression of malignant tumors. In this study, we found that LncRNA-ZEB2-AS1 was dramatically up-regulated in our breast cancer specimens and cells (MDA231), especially in metastatic tumor specimens and highly invasive cells, and high lncRNA-ZEB2-AS1 expression is associated with clinicopathologic features and short survival of breast cancer patients. LncRNA-ZEB2-AS1 promotes the proliferation and metastasis of MDA231 cells in SCID mice. Thus, it is regarded as an oncogene in triple-negative breast cancer. It is mainly endo-nuclear and situated near ZEB2, positively regulating ZEB2 expression and activating the epithelial mesenchymal transition via the PI3K/Akt/GSK3β/Zeb2 signaling pathway. Meanwhile, EGF-induced F-actin polymerization in MDA231 cells can be suppressed by reducing lncRNA-ZEB2-AS1 expression. The migration and invasion of triple-negative breast cancer can be altered through cytoskeleton rearrangement. In summary, we demonstrated that lncRNA-ZEB2-AS1 is an important factor affecting the development of triple-negative breast cancer and thus a potential oncogene target.

Topics: Actins; Animals; Carcinogenesis; Cell Line, Tumor; Cell Proliferation; Down-Regulation; Epidermal Growth Factor; Epigenesis, Genetic; Epithelial-Mesenchymal Transition; Female; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Glycogen Synthase Kinase 3 beta; Humans; Mice, SCID; Middle Aged; Neoplasm Invasiveness; Neoplasm Metastasis; Phosphatidylinositol 3-Kinases; Polymerization; Proto-Oncogene Proteins c-akt; RNA, Long Noncoding; Signal Transduction; Survival Analysis; Triple Negative Breast Neoplasms; Up-Regulation; Zinc Finger E-box Binding Homeobox 2

Homeobox A5 (HOXA5), a member of the HOX family, plays an important role in tumor development and morphogenesis, although opposite effects on tumorigenesis have been observed, depending on the tissue type. In this study, we aimed to investigate the role of a novel transcript from the HOXA6-HOXA5 locus in colon cancer tumorigenesis.. Human colon cancer cell lines were analyzed using next generation sequencing-based targeted mRNA capture. The effects of overexpression and silencing of HOXA5 transcripts were evaluated in vitro and using a xenograft nude mouse model.. We identified three novel transcripts (HOXA5 short, long 1, and long 2) transcribed from the HOXA6-HOXA5 locus in HCT116 colon cancer cells using next generation sequencing-based targeted mRNA capture. Knockdown of HOXA5 long 1 and long 2 transcripts did not affect cell growth, while selective silencing of HOXA5 short RNA inhibited cell growth independent of HOXA5 expression. Stable overexpression of HOXA5 short RNA promoted proliferation and migration of colon cancer cell lines HCT116, DLD1, and HT-29 and accelerated tumor growth in the xenograft mouse model. In vitro translation assays suggested HOXA5 short RNA was a functional long non-coding RNA (lncRNA). Consistent with these observations, expression of HOXA5 short RNA was upregulated in advanced colon cancer tissues. Ingenuity Pathway Analysis of differentially expressed genes between HOXA5 short RNA overexpressed and silenced HCT116 cells revealed that HOXA5 short RNA preferentially modified expression of epidermal growth factor (EGF) signal-related genes. Western blot analysis demonstrated that stable overexpression of HOXA5 short RNA increased EGF receptor levels and facilitated its phosphorylation in both HCT116 cells and xenograft tumors.. Our results suggested that HOXA5 short RNA, a novel lncRNA, may play a crucial role in colon tumor growth through activation of EGF signaling.

Topics: Animals; Carcinogenesis; Cell Movement; Cell Proliferation; Colonic Neoplasms; Epidermal Growth Factor; ErbB Receptors; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Gene Silencing; Genes, Homeobox; HCT116 Cells; Homeodomain Proteins; HT29 Cells; Humans; Mice; Mice, Nude; Phosphoproteins; RNA, Long Noncoding; Xenograft Model Antitumor Assays

BACKGROUND The mammalian cyclic guanosine monophosphate (cGMP)-dependent protein kinases type II (PKG II) plays critical physiological or pathological functions in different tissues. However, the biological effects of PKG II are dependent on cGMP. Published data indicated that L-arginine (L-Arg) promoted NO production, NO can activate soluble guanylate cyclase (sGC), and catalyzes guanosine triphosphate (GTP) into cGMP, which suggested L-Arg could activate PKG II. Therefore, the present work was performed to address: (i) whether L-Arg could be a potential alternative in PKG II activation, and (ii) whether L-Arg also contributes to PKG II against cancer. MATERIAL AND METHODS Nude BALB/c mice were inoculated with human MCF-7, HepG2, and SW480 cell lines via subcutaneous (s.c.) injecting. After 7 days of inoculation, Ad-PKG II was injected into the cancer tissues every 4 days, and the next day 10 μmol/mouse L-Arg was administered. Western blotting and immunohistochemistry were used to assess protein expression. RESULTS Our results demonstrated that L-Arg significantly activated PKG II and effectively ameliorated xenograft tumor development through inhibiting cancer growth, angiogenesis, and metastasis, which was partially dependent on blocking of epidermal growth factor receptor (EGFR) activity, as well as downstream signaling pathways such as Erk1/2. CONCLUSIONS Our results provide an exciting new insight: L-Arg is a potential alternative to PKG II activation.

Topics: Animals; Arginine; Carcinogenesis; Cell Line, Tumor; Cell Proliferation; Cyclic GMP-Dependent Protein Kinases; Enzyme Activation; Epidermal Growth Factor; ErbB Receptors; Extracellular Signal-Regulated MAP Kinases; Female; Humans; Mice, Inbred BALB C; Mice, Nude; Neoplasm Metastasis; Neovascularization, Pathologic; Proto-Oncogene Proteins c-akt; Signal Transduction; Tumor Burden; Xenograft Model Antitumor Assays

Recent studies suggest that the β-blocker drug carvedilol prevents skin carcinogenesis but the mechanism is unknown. Carvedilol is one of a few β-blockers identified as biased agonist based on an ability to promote β-arrestin-mediated processes such as ERK phosphorylation. To understand the role of phosphoproteomic signaling in carvedilol's anticancer activity, the mouse epidermal JB6 P+ cells treated with EGF, carvedilol, or their combination were analyzed using the Phospho Explorer Antibody Array containing 1318 site-specific and phospho-specific antibodies of over 30 signaling pathways. The array data indicated that both EGF and carvedilol increased phosphorylation of ERK's cytosolic target P70S6 K while its nuclear target ELK-1 were activated only by EGF; Furthermore, EGF-induced phosphorylation of ELK-1 and c-Jun was attenuated by carvedilol. Subcellular fractionation analysis indicated that ERK nuclear translocation induced by EGF was blocked by co-treatment with carvedilol. Western blot and luciferase reporter assays confirmed that the biased β-blockers carvedilol and alprenolol blocked EGF-induced phosphorylation and activation of c-Jun/AP-1 and ELK-1. Consistently, both carvedilol and alprenolol strongly prevented EGF-induced neoplastic transformation of JB6 P+ cells. Remarkably, oral carvedilol treatment significantly inhibited the growth of A375 melanoma xenograft in SCID mice. As nuclear translocation of ERK is a key step in carcinogenesis, inhibition of this event is proposed as a novel anticancer mechanism for biased β-blockers such as carvedilol.

Topics: Adrenergic beta-Antagonists; Animals; Anticarcinogenic Agents; Carcinogenesis; Carvedilol; Epidermal Growth Factor; HEK293 Cells; Humans; Male; Melanoma; Mice, Inbred NOD; Mice, SCID; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Phosphorylation; Proteome; Proto-Oncogene Proteins c-jun

Cripto-1 is an oncogenic protein that belongs to the epidermal growth factor (EGF)-cripto-1/FRL1/cryptic (CFC) family. It has been shown to stimulate tumorigenesis and metastasis by promoting cancer cell proliferation, epithelial-to-mesenchymal transition (EMT), and tumor angiogenesis. However, the role of Cripto-1 in cell survival and apoptosis remains largely undefined. In the present study, we found that Cripto-1 is significantly upregulated in a number of human cancer cell lines. The membrane-associated but not the soluble form of Cripto-1 promotes resistance to drug-induced caspase-3 cleavage, an indicator of apoptosis. Consequently, Cripto-1 silencing sensitizes human cancer cells to chemotherapy drugs including cytarabine, cisplatin and taxol. Our mechanistic studies revealed that Cripto-1 promotes apoptosis resistance by inducing NF-κB-mediated Survivin expression through activation of TAK-1. We also found that Cripto-1 silencing does not affect growth of un-treated cancer cells, and Cripto-1 forms self-assembled punctiforms and changes its subcellular distribution upon cytarabine treatment. Thus, the anti-apoptotic activity of Cripto-1 could be an inducible function that can be activated by external stimuli such as drug stimulation. Our findings suggested that targeting the Cripto-1/TAK-1/NF-κB/Survivin pathway may be an effective approach to combat apoptosis resistance in cancer.

Topics: Apoptosis; Carcinogenesis; Cell Line; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cisplatin; Cytarabine; Drug Resistance, Neoplasm; Epidermal Growth Factor; Epithelial-Mesenchymal Transition; GPI-Linked Proteins; HEK293 Cells; Humans; Inhibitor of Apoptosis Proteins; Intercellular Signaling Peptides and Proteins; MAP Kinase Kinase Kinases; Neoplasm Proteins; Neovascularization, Pathologic; NF-kappa B; Paclitaxel; Signal Transduction; Survivin

Epidermal growth factor (EGF) and estrogen are potent regulators of breast tumorigenesis. Their short‑term actions on human breast epithelial cells have been investigated extensively. However, the consequence of a long‑term exposure to EGF and estrogen remains to be fully elucidated. The present study examined the effects of long‑term exposure to EGF and 17β‑estradiol on the proliferation, transformation, expression of markers of stemness, and tumorigenesis of MCF7 human breast adenocarcinoma cells. Exposure to EGF and/or 17β‑estradiol irreversibly enhanced the proliferation rate of MCF7 cells, even following withdrawal. However, in a mouse xenograft experiment, no significant difference in tumor volume was observed between tumors derived from cells exposed to EGF, 17β‑estradiol or EGF + 17β‑estradiol. Immunohistochemistry performed on tumors derived from 17β‑estradiol‑exposed cells revealed reduced cell proliferation and vessel scores, according to the results obtained using Ki67 and von Willebrand factor staining, respectively. The EGF‑ and/or 17β‑estradiol‑treated cells exhibited an increased ratio of cluster of differentiation (CD)44+/CD24‑ cells and enhanced ability to form mammospheres. Furthermore, the long‑term exposure of MCF7 cells to EGF and 17β‑estradiol altered their responsiveness to short‑term stimulatory or inhibitory treatments with EGF, 17β‑estradiol, transforming growth factor‑β1 (TGFβ1), Iressa and SB431542. Therefore, the findings indicated that sustained exposure of MCF7 cells to EGF and/or 17β‑estradiol resulted in enhanced cell proliferation and mammosphere formation, an increased ratio of CD44+/CD24‑ cells, and altered responses to short‑term treatments with EGF, 17β‑estradiol, TGFβ1, and drugs inhibiting these signaling pathways. However, this sustained exposure was not sufficient to affect tumor take or volume in a xenograft mouse model.

Topics: Animals; Benzamides; Carcinogenesis; Cell Proliferation; Cell Transformation, Neoplastic; Dioxoles; Epidermal Growth Factor; Estradiol; Female; Gefitinib; Humans; MCF-7 Cells; Mice, SCID; Models, Biological; Neoplastic Stem Cells; Phenotype; Quinazolines; Spheroids, Cellular; Tamoxifen; Xenograft Model Antitumor Assays

Activated platelets release functional, high m.w. epidermal growth factor (HMW-EGF). In this study, we show platelets also express epidermal growth factor (EGF) receptor (EGFR) protein, but not ErbB2 or ErbB4 coreceptors, and so might respond to HMW-EGF. We found HMW-EGF stimulated platelet EGFR autophosphorylation, PI3 kinase-dependent AKT phosphorylation, and a Ca

Topics: Autocrine Communication; B-Cell Lymphoma 3 Protein; Blood Platelets; Carcinogenesis; Carcinoma, Squamous Cell; Cell Movement; Cells, Cultured; Epidermal Growth Factor; Epithelial-Mesenchymal Transition; ErbB Receptors; Humans; Interleukin-1beta; Mouth Neoplasms; Neoplasm Invasiveness; Platelet Activation; Proto-Oncogene Proteins; Transcription Factors

PI3K/Akt signaling is activated in cancers and governs tumor initiation and progression, but how Akt is activated under diverse stresses is poorly understood. Here we identify AMPK as an essential regulator for Akt activation by various stresses. Surprisingly, AMPK is also activated by growth factor EGF through Ca2+/Calmodulin-dependent kinase and is essential for EGF-mediated Akt activation and biological functions. AMPK phosphorylates Skp2 at S256 and promotes the integrity and E3 ligase activity of Skp2 SCF complex leading to K63-linked ubiquitination and activation of Akt and subsequent oncogenic processes. Importantly, AMPK-mediated Skp2 S256 phosphorylation promotes breast cancer progression in mouse tumor models, correlates with Akt and AMPK activation in breast cancer patients, and predicts poor survival outcomes. Finally, targeting AMPK-mediated Skp2 S256 phosphorylation sensitizes cells to anti-EGF receptor targeted therapy. Our study sheds light on how stress and EGF induce Akt activation and new mechanisms for AMPK-mediated oncogenesis and drug resistance.

Topics: Adenylate Kinase; Animals; Calcium; Calcium-Calmodulin-Dependent Protein Kinase Kinase; Carcinogenesis; Cell Line, Tumor; Cell Movement; Cell Survival; Disease Progression; Drug Resistance, Neoplasm; Enzyme Activation; Epidermal Growth Factor; ErbB Receptors; Fibroblasts; Glycolysis; Human Umbilical Vein Endothelial Cells; Humans; Mice; Neovascularization, Pathologic; Phosphorylation; Phosphoserine; Proto-Oncogene Proteins c-akt; S-Phase Kinase-Associated Proteins; Signal Transduction; Stress, Physiological; Ubiquitination

Pancreatic ductal adenocarcinoma (PDAC) is a highly malignant cancer that lacks effective targets for therapy. Alteration of epidermal growth factor (EGF) expression has been recognized as an essential molecular event in pancreatic carcinogenesis. Accumulating studies have demonstrated that miRNAs play critical roles in EGF signaling regulation, tumor initiation, cell proliferation and apoptosis. Here, we demonstrated that miR-21 expression was induced by EGF in pancreatic cancer cells. miR-21 promoted EGF-induced proliferation, inhibited cell apoptosis and accelerated cell cycle progression. In vivo experiments confirmed the influence of miR-21 on tumor growth. Mechanistic studies revealed that miR-21 targeted MAPK/ERK and PI3K/AKT signaling pathways to modulate cell proliferation. In addition, Spry2 was proven to be a target of miR-21. Furthermore, miR-21 and Spry2 were significantly related to clinical features and may be valuable predictors of PDAC patient prognosis.

Topics: Adenocarcinoma; Aged; Animals; Apoptosis; Carcinogenesis; Carcinoma, Pancreatic Ductal; Cell Cycle; Cell Movement; Cell Proliferation; Disease-Free Survival; Epidermal Growth Factor; Female; Gene Expression Regulation, Neoplastic; Heterografts; Humans; Intracellular Signaling Peptides and Proteins; Kaplan-Meier Estimate; Male; Membrane Proteins; Mice; MicroRNAs; Middle Aged; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Signal Transduction

Disassembly of nucleosomes in which genomic DNA is packaged with histone regulates gene expression. However, the mechanisms underlying nucleosome disassembly for gene expression remain elusive. We show here that epidermal growth factor receptor activation results in the binding of the RNF8 forkhead-associated domain to pyruvate kinase M2-phosphorylated histone H3-T11, leading to K48-linked polyubiquitylation of histone H3 at K4 and subsequent proteasome-dependent protein degradation. In addition, H3 polyubiquitylation induces histone dissociation from chromatin, nucleosome disassembly, and binding of RNA polymerase II to

Topics: Carcinogenesis; Cell Line, Tumor; Cyclin D1; DNA-Binding Proteins; Epidermal Growth Factor; Gene Expression Regulation; Glycolysis; Histones; Humans; Lysine; Models, Biological; Nucleosomes; Phosphothreonine; Promoter Regions, Genetic; Protein Domains; Proteolysis; Proto-Oncogene Proteins c-myc; Ubiquitin-Protein Ligases; Ubiquitination

Topics: A549 Cells; Animals; bcl-2-Associated X Protein; Carcinogenesis; Cell Cycle; Cell Line, Tumor; E1A-Associated p300 Protein; E2F4 Transcription Factor; Epidermal Growth Factor; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Neoplastic; HeLa Cells; Humans; Mice; Mice, Transgenic; Securin; Ubiquitin Thiolesterase

Ras GTPase-activating proteins (GAPs) are important regulators for Ras activation, which is instrumental in tumor development. However, the mechanism underlying this regulation remains elusive. We demonstrate here that activated EGFR phosphorylates the Y593 residue of the protein known as family with sequence similarity 129, member B (FAM129B), which is overexpressed in many types of human cancer. FAM129B phosphorylation increased the interaction between FAM129B and Ras, resulting in reduced binding of p120-RasGAP to Ras. FAM129B phosphorylation promoted Ras activation, increasing ERK1/2- and PKM2-dependent β-catenin transactivation and leading to the enhanced glycolytic gene expression and the Warburg effect; promoting tumor cell proliferation and invasion; and supporting brain tumorigenesis. Our studies unearthed a novel and important mechanism underlying EGFR-mediated Ras activation in tumor development.

Topics: Amino Acid Sequence; Antibody Specificity; beta Catenin; Brain Neoplasms; Carcinogenesis; Cell Line, Tumor; Cell Proliferation; Enzyme Activation; Epidermal Growth Factor; ErbB Receptors; Humans; Models, Biological; Molecular Sequence Data; Neoplasm Invasiveness; Phosphoproteins; Phosphorylation; Phosphoserine; Protein Binding; Proto-Oncogene Proteins p21(ras); ras GTPase-Activating Proteins; Transcriptional Activation

Colorectal tumor is a heterogeneous disease, with varying clinical presentation and prognosis in patients. To establish a platform encompassing this diversity, we generated 55 colorectal tumor organoid lines from a range of histological subtypes and clinical stages, including rare subtypes. Each line was defined by gene expression signatures and optimized for organoid culture according to niche factor requirements. In vitro and in xenografts, the organoids reproduced the histopathological grade and differentiation capacity of their parental tumors. Notably, we found that niche-independent growth is predominantly associated with the adenoma-carcinoma transition reflecting accumulation of multiple mutations. For matched pairs of primary and metastatic organoids, which had similar genetic profiles and niche factor requirements, the metastasis-derived organoids exhibited higher metastatic capacity. These observations underscore the importance of genotype-phenotype analyses at a single-patient level and the value of our resource to provide insights into colorectal tumorigenesis and patient-centered therapeutic development.

Topics: Animals; Carcinogenesis; Colorectal Neoplasms; Epidermal Growth Factor; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Genetic Heterogeneity; Genome, Human; Humans; Male; Mice, Inbred NOD; Mice, SCID; Mutation; Organoids; Stem Cell Niche; Transforming Growth Factor beta; Transplantation, Heterologous; Tumor Cells, Cultured; Wnt Proteins

The X-linked inhibitor of apoptosis protein (XIAP) contains three N-terminal BIR domains that mediate anti-apoptosis and one C-terminal RING finger domain whose function(s) are not fully defined. Here we show that the RING domain of XIAP strongly inhibits the expression of p63α, a known tumor suppressor. XIAP knockdown in urothelial cells or RING deletion in knockin mice markedly upregulates p63α expression. This RING-mediated p63α downregulation is critical for the malignant transformation of normal urothelial cells following EGF treatment. We further show that the RING domain promotes Sp1-mediated transcription of miR-4295 which targets the 3'UTR of p63α mRNA and consequently inhibits p63α translation. Our results reveal a previously unknown function of the RING of XIAP in promoting miR-4295 transcription, thereby reducing p63α translation and enhancing urothelial transformation. Our data offer novel insights into the multifunctional effects of the XIAP RING domain on urothelial tumorigenesis and the potential for targeting this frequently overexpressed protein as a therapeutic alternative.

Topics: Animals; Apoptosis; Carcinogenesis; Cell Adhesion; Cell Proliferation; Cell Transformation, Neoplastic; Epidermal Growth Factor; Epithelial Cells; Gene Expression Regulation, Neoplastic; Humans; Methionine; Mice; Mice, Transgenic; MicroRNAs; Protein Biosynthesis; Protein Domains; Sp1 Transcription Factor; Transcription Factors; Tumor Suppressor Proteins; Up-Regulation; Urinary Bladder; Urinary Bladder Neoplasms; X-Linked Inhibitor of Apoptosis Protein

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

Many types of human tumour cells overexpress the dual-specificity phosphatase Cdc25A. Cdc25A dephosphorylates cyclin-dependent kinase and regulates the cell cycle, but other substrates of Cdc25A and their relevant cellular functions have yet to be identified. We demonstrate here that EGFR activation results in c-Src-mediated Cdc25A phosphorylation at Y59, which interacts with nuclear pyruvate kinase M2 (PKM2). Cdc25A dephosphorylates PKM2 at S37, and promotes PKM2-dependent β-catenin transactivation and c-Myc-upregulated expression of the glycolytic genes GLUT1, PKM2 and LDHA, and of CDC25A; thus, Cdc25A upregulates itself in a positive feedback loop. Cdc25A-mediated PKM2 dephosphorylation promotes the Warburg effect, cell proliferation and brain tumorigenesis. In addition, we identify positive correlations among Cdc25A Y59 phosphorylation, Cdc25A and PKM2 in human glioblastoma specimens. Furthermore, levels of Cdc25A Y59 phosphorylation correlate with grades of glioma malignancy and prognosis. These findings reveal an instrumental function of Cdc25A in controlling cell metabolism, which is essential for EGFR-promoted tumorigenesis.

Topics: Animals; beta Catenin; Brain Neoplasms; Carcinogenesis; cdc25 Phosphatases; Cell Line, Tumor; Cell Nucleus; Epidermal Growth Factor; Glioblastoma; Glycolysis; Humans; Mice; Phosphorylation; Phosphoserine; Phosphotyrosine; Prognosis; Protein Binding; Proto-Oncogene Proteins c-myc; Pyruvate Kinase; src-Family Kinases; Transcriptional Activation

Glucagon-like peptide-1 (GLP-1) secreted from enteroendocrine L cells promotes nutrient disposal via the incretin effect. However, the majority of L cells are localized to the distal gut, suggesting additional biological roles for GLP-1. Here, we demonstrate that GLP-1 receptor (GLP-1R) signaling controls mucosal expansion of the small bowel (SB) and colon. These actions did not require the epidermal growth factor (EGF) or intestinal epithelial insulin-like growth factor (IGF1) receptors but were absent in Glp1r(-/-) mice. Polyp number and size were increased in SB of exendin-4-treated Apc(Min/+) mice, whereas polyp number was reduced in SB and colon of Glp1r(-/-):Apc(Min/+) mice. Exendin-4 increased fibroblast growth factor 7 (Fgf7) expression in colonic polyps of Apc(Min/+) mice and failed to increase intestinal growth in mice lacking Fgf7. Exogenous exendin-4 and Fgf7 regulated an overlapping set of genes important for intestinal growth. Thus, gain and loss of GLP-1R signaling regulates gut growth and intestinal tumorigenesis.

Topics: Animals; Carcinogenesis; Cell Proliferation; Colon; Epidermal Growth Factor; Exenatide; Female; Fibroblast Growth Factor 7; Glucagon-Like Peptide-1 Receptor; Incretins; Intestinal Mucosa; Intestine, Small; Male; Mice; Mice, Inbred C57BL; Peptides; Receptor, IGF Type 1; Signal Transduction; Venoms

We previously demonstrated that sialidase NEU3, a key glycosidase for ganglioside degradation, is up-regulated in various human cancers, leading to increased cell invasion, motility and survival of cancer cells possibly through activation of EGF signaling. Its up-regulation is also important for promotion of the stage of colorectal carcinogenesis in vivo in human NEU3 transgenic mice treated with azoxymethane for the induction of aberrant crypt foci in the colon mucosa, accompanied by enhanced phosphorylation of EGF receptor (EGFR). To address whether the activation of EGF signaling by the sialidase is associated with oncogenic transformation, we here analyzed the effects of overexpression of NEU3 and EGFR in NIH-3T3 cells. When NEU3 was stably transfected with or without EGFR, it was associated with significant increases in clonogenic growth, clonogenicity on soft agar and in vivo tumor growth in nude mice either with or without the receptor overexpression in the presence of EGF, compared with the levels in their vector controls. Despite the fact that the endogenous level of EGFR is known to be extremely low in these cells, NEU3 significantly enhanced the phosphorylation of Akt and ERK, as well as that of the receptor. The NEU3-mediated activation was largely abrogated by the EGFR inhibitor AG1478 or PD153035, but significant clonogenic growth still remained. NEU3 was then found to activate Src kinase, and the clonogenicity was completely suppressed by an Src inhibitor, PP2. The activity-null mutants failed to activate Src and EGFR, indicating that ganglioside modulation by NEU3 may be necessary for the activation. NEU3 and Src were co-immunoprecipitated with EGFR in NEU3- and EGFR- transfected cells. These findings identify NEU3 as an essential participant in tumorigenesis through the EGFR/Src signaling pathway and a potential target for inhibiting EGFR-mediated tumor progression.

Topics: Animals; Carcinogenesis; Cell Proliferation; Enzyme Activation; Epidermal Growth Factor; ErbB Receptors; Gangliosides; Gene Expression Regulation, Neoplastic; Humans; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Neuraminidase; NIH 3T3 Cells; Signal Transduction; src-Family Kinases; Transfection; Up-Regulation

Hepatocellular carcinoma (HCC) is on the rise and the sixth most common cancer worldwide. To combat HCC effectively research is directed towards its early detection and the development of targeted therapies. Given the fact that epidermal growth factor (EGF) is an important mitogen for hepatocytes we searched for disease regulated proteins to improve an understanding of the molecular pathogenesis of EGF induced HCC. Disease regulated proteins were studied by 2DE MALDI-TOF/TOF and a transcriptomic approach, by immunohistochemistry and advanced bioinformatics.. Mapping of EGF induced liver cancer in a transgenic mouse model identified n = 96 (p < 0.05) significantly regulated proteins of which n = 54 were tumour-specific. To unravel molecular circuits linked to aberrant EGFR signalling diverse computational approaches were employed and this defined n = 7 key nodes using n = 82 disease regulated proteins for network construction. STRING analysis revealed protein-protein interactions of > 70% disease regulated proteins with individual proteins being validated by immunohistochemistry. The disease regulated network proteins were mapped to distinct pathways and bioinformatics provided novel insight into molecular circuits associated with significant changes in either glycolysis and gluconeogenesis, argine and proline metabolism, protein processing in endoplasmic reticulum, Hif- and MAPK signalling, lipoprotein metabolism, platelet activation and hemostatic control as a result of aberrant EGF signalling. The biological significance of the findings was corroborated with gene expression data derived from tumour tissues to evntually define a rationale by which tumours embark on intriguing changes in metabolism that is of utility for an understanding of tumour growth. Moreover, among the EGF tumour specific proteins n = 11 were likewise uniquely expressed in human HCC and for n = 49 proteins regulation in human HCC was confirmed using the publically available Human Protein Atlas depository, therefore demonstrating clinical significance.. Novel insight into the molecular pathogenesis of EGF induced liver cancer was obtained and among the 37 newly identified proteins several are likely candidates for the development of molecularly targeted therapies and include the nucleoside diphosphate kinase A, bifunctional ATP-dependent dihydroyacetone kinase and phosphatidylethanolamine-binding protein1, the latter being an inhibitor of the Raf-1 kinase.

Topics: Animals; Carcinogenesis; Carcinoma, Hepatocellular; Epidermal Growth Factor; ErbB Receptors; Gene Expression Regulation, Neoplastic; Humans; Liver Neoplasms; Mice; Neoplasm Proteins; p38 Mitogen-Activated Protein Kinases; Protein Interaction Maps; Proteomics; Signal Transduction

Up-regulation of core fucosylation catalyzed by α1,6-fucosyltransferase (Fut8) has been observed in hepatocellular carcinoma (HCC). Here, to explore the role of Fut8 expression in hepatocarcinogensis, we established the chemical-induced HCC models in the male wild-type (WT; Fut8(+/+)), hetero (Fut8(+/-)), and knockout (KO; Fut8(-/-)) mice by use of diethylnitrosamine (DEN) and pentobarbital (PB). In the Fut8(+/+) and Fut8(+/-) mice, multiple large and vascularized nodules were induced with an increased expression of Fut8 after DEN and PB treatment. However, the formation of HCC in Fut8(-/-) mice was suppressed almost completely. This potent inhibitory effect of Fut8 deficiency on tumorigenesis was also confirmed by the abolished tumor formation of Fut8 KO human hepatoma cell line cells by use of a xenograft tumor model. Furthermore, loss of the Fut8 gene resulted in attenuated responses to epidermal growth factor (EGF) and hepatocyte growth factor (HGF) in the HepG2 cell line, which provides the possible mechanisms for the contribution of Fut8 to hepatocarcinogensis. Taken together, our study clearly demonstrated that core fucosylation acts as a critical functional modulator in the liver and implicated Fut8 as a prognostic marker, as well as a novel, therapeutic target for HCC.

Topics: Animals; Carcinogenesis; Carcinoma, Hepatocellular; Cell Line, Tumor; Down-Regulation; Epidermal Growth Factor; Fucosyltransferases; Hep G2 Cells; Hepatocyte Growth Factor; Humans; Liver Neoplasms; Male; Mice; Signal Transduction

The aim of the present study was to investigate the extensive invasion of tumor cells into normal brain tissue, a life‑threatening feature of malignant gliomas. How invasive tumor cells migrate into normal brain tissue and form a secondary tumor structure remains to be elucidated. In the present study, the morphological and phenotypic changes of glioma cells during invasion in a C6 glioma model were investigated. C6 glioma cells were stereotactically injected into the right putamen region of adult Sprague‑Dawley rats. The brain tissue sections were then subjected to hematoxylin and eosin, immunohistochemical or immunofluorescent staining. High magnification views of the tissue sections revealed that C6 cells formed tumor spheroids following implantation and marked invasion was observed shortly after spheroid formation. In the later stages of invasion, certain tumor cells invaded the perivascular space and formed small tumor clusters. These small tumor clusters exhibited certain common features, including tumor cell multilayers surrounding an arteriole, which occurred up to several millimeters away from the primary tumor mass; a high proliferation rate; and similar gene expression profiles to the primary tumor. In conclusion, the present study revealed that invading tumor cells are capable of forming highly proliferative cell clusters along arterioles near the tumor margin, which may be a possible cause of the recurrence of malignant glioma.

Topics: Animals; Arterioles; Biomarkers, Tumor; Brain Neoplasms; Carcinogenesis; Cell Line, Tumor; Cell Proliferation; Eosine Yellowish-(YS); Epidermal Growth Factor; Gene Expression; Glioma; Hematoxylin; Hypoxia-Inducible Factor 1, alpha Subunit; Male; Neoplasm Transplantation; Nerve Growth Factor; Putamen; Rats; Rats, Sprague-Dawley; Spheroids, Cellular; Staining and Labeling; Stereotaxic Techniques; Twist-Related Protein 1; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factor Receptor-2

Histone deacetylase 2 (HDAC2) is aberrantly regulated and plays a pivotal role in the development of hepatocellular carcinoma (HCC) through regulation of cell-cycle components at the transcriptional level, but the underlying mechanism leading to oncogenic HDAC2 remains unknown. In this study, we show that expression of CK2α (casein kinase II α subunit) was up-regulated in a large cohort of human HCC patients, and that high expression of CK2α was significantly associated with poor prognosis of HCC patients in terms of five-year overall survival. It was also found that CK2α over-expression positively correlated with HDAC2 over-expression in a subset of HCCs. We observed that treatment with epidermal growth factor (EGF) elicited an increase in CK2α expression and Akt phosphorylation, causing induction of HDAC2 expression in liver cancer cells. It was also observed that ectopic expression of dominant-negative CK2α blocked EGF-induced HDAC2 expression, and that ectopic CK2α expression attenuated the suppressive effect of Akt knockdown on HDAC2 expression in liver cancer cells. Targeted disruption of CK2α influenced the cell cycle, causing a significant increase in the number of liver cancer cells remaining in G₂/M phase, and suppressed growth via repression of Cdc25c and cyclin B in liver cancer cells. Taken together, our findings suggest the oncogenic potential of CK2α in liver tumorigenesis. Furthermore, a regulatory mechanism for HDAC2 expression is proposed whereby EGF induces transcriptional activation of HDAC2 by CK2α/Akt activation in liver cancer cells. Therefore, this makes CK2α a promising target in cancer therapy.

Topics: Carcinogenesis; Carcinoma, Hepatocellular; Casein Kinase II; Cell Line, Tumor; Cell Proliferation; Cohort Studies; Epidermal Growth Factor; ErbB Receptors; Gene Expression Regulation, Neoplastic; Histone Deacetylase 2; Humans; Liver; Liver Neoplasms; Mutant Proteins; Neoplasm Proteins; Phosphorylation; Protein Processing, Post-Translational; Proto-Oncogene Proteins c-akt; Recombinant Proteins; RNA Interference; Signal Transduction; Survival Analysis

RAS genes are among the most frequently mutated proto-oncogenes in cancer. However, how Ras stability is regulated remains largely unknown. Here, we report a regulatory loop involving the E3 ligase Nedd4-1, Ras, and PTEN. We found that Ras signaling stimulates the expression of Nedd4-1, which in turn acts as an E3 ubiquitin ligase that regulates Ras levels. Importantly, Ras activation, either by oncogenic mutations or by epidermal growth factor (EGF) signaling, prevents Nedd4-1-mediated Ras ubiquitination. This leads to Ras-induced Nedd4-1 overexpression, and subsequent degradation of the tumor suppressor PTEN in both human cancer samples and cancer cells. Our study thus unravels the molecular mechanisms underlying the interplay of Ras, Nedd4-1, and PTEN and suggests a basis for the high prevalence of Ras-activating mutations and EGF hypersignaling in cancer.

Topics: Animals; Carcinogenesis; Cell Line, Tumor; Endosomal Sorting Complexes Required for Transport; Epidermal Growth Factor; HEK293 Cells; HeLa Cells; Hep G2 Cells; Humans; Mice; Mice, Nude; Nedd4 Ubiquitin Protein Ligases; Neoplasms; NIH 3T3 Cells; Protein Binding; PTEN Phosphohydrolase; ras Proteins; Signal Transduction; Transplantation, Heterologous; Ubiquitin-Protein Ligases; Ubiquitination; Up-Regulation

Epidermal growth factor (EGF) receptor (EGFR) has been implicated in tumor development and invasion. Dimerization and autophosphorylation of EGFR are the critical events for EGFR activation. However, the regulation of EGF-dependent and EGF-independent dimerization and phosphorylation of EGFR has not been fully understood. Here, we report that cytoplasmic protein plakophilin-2 (PKP2) is a novel positive regulator of EGFR signaling. PKP2 specifically interacts with EGFR via its N-terminal head domain. Increased PKP2 expression enhances EGF-dependent and EGF-independent EGFR dimerization and phosphorylation. Moreover, PKP2 knockdown reduces EGFR phosphorylation and attenuates EGFR-mediated signal activation, resulting in a significant decrease in proliferation and migration of cancer cells and tumor development. Our results indicate that PKP2 is a novel activator of the EGFR signaling pathway and a potential new drug target for inhibiting tumor growth.

Topics: Animals; Carcinogenesis; Cell Line, Tumor; Cell Movement; Cell Proliferation; Epidermal Growth Factor; ErbB Receptors; Female; HEK293 Cells; Humans; Ligands; Mammary Neoplasms, Experimental; Mice; Mice, Inbred NOD; Mice, SCID; Neoplasm Transplantation; Plakophilins; Protein Multimerization; Receptor, ErbB-2; Signal Transduction; Tumor Burden

Grade IV glioblastoma is characterized by increased kinase activity of epidermal growth factor receptor (EGFR); however, EGFR kinase inhibitors have failed to improve survival in individuals with this cancer because resistance to these drugs often develops. We showed that tumor necrosis factor-α (TNFα) produced in the glioblastoma microenvironment activated atypical protein kinase C (aPKC), thereby producing resistance to EGFR kinase inhibitors. Additionally, we identified that aPKC was required both for paracrine TNFα-dependent activation of the transcription factor nuclear factor κB (NF-κB) and for tumor cell-intrinsic receptor tyrosine kinase signaling. Targeting aPKC decreased tumor growth in mouse models of glioblastoma, including models of EGFR kinase inhibitor-resistant glioblastoma. Furthermore, aPKC abundance and activity were increased in human glioblastoma tumor cells, and high aPKC abundance correlated with poor prognosis. Thus, targeting aPKC might provide an improved molecular approach for glioblastoma therapy.

Topics: Animals; Carcinogenesis; Drug Delivery Systems; Enzyme-Linked Immunosorbent Assay; Epidermal Growth Factor; ErbB Receptors; Erlotinib Hydrochloride; Flow Cytometry; Fluorescent Antibody Technique; Glioblastoma; Humans; Immunoblotting; Immunohistochemistry; Immunoprecipitation; Kaplan-Meier Estimate; Mice; NF-kappa B; Paracrine Communication; Protein Kinase C; Quinazolines; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction; Tumor Necrosis Factor-alpha

Chemokines are relevant molecules in shaping the tumor microenvironment, although their contributions to tumorigenesis are not fully understood. We studied the influence of the chemokine CX3CL1/fractalkine in de novo breast cancer formation using HER2/neu transgenic mice. CX3CL1 expression was downmodulated in HER2/neu tumors, yet, paradoxically, adenovirus-mediated CX3CL1 expression in the tumor milieu enhanced mammary tumor numbers in a dose-dependent manner. Increased tumor multiplicity was not a consequence of CX3CL1-induced metastatic dissemination of the primary tumor, although CX3CL1 induced epithelial-to-mesenchymal transition in breast cancer cells in vitro. Instead, CX3CL1 triggered cell proliferation by induction of ErbB receptors through the proteolytic shedding of an ErbB ligand. This effect was important insofar as mammary tumorigenesis was delayed and tumor multiplicity was reduced by genetic deletion of CX3CL1 in HER2/neu mice, but not in polyoma middle T-antigen oncomice. Our findings support the conclusion that CX3CL1 acts as a positive modifier of breast cancer in concert with ErbB receptors.

Topics: Animals; Breast Neoplasms; Carcinogenesis; Cell Line, Tumor; Cell Proliferation; Chemokine CX3CL1; Epidermal Growth Factor; Epithelial-Mesenchymal Transition; Female; Humans; Lymph Nodes; Lymphatic Metastasis; Mammary Glands, Animal; Mammary Neoplasms, Animal; Mammary Neoplasms, Experimental; MCF-7 Cells; Mice; Mice, Inbred C57BL; Mice, Transgenic; Receptor, ErbB-2; Receptors, Chemokine; Signal Transduction; Transcriptional Activation

Selenium (Se) is an essential micronutrient that exerts its functions via selenoproteins. Little is known about the role of Se in inflammatory bowel disease (IBD). Epidemiological studies have inversely correlated nutritional Se status with IBD severity and colon cancer risk. Moreover, molecular studies have revealed that Se deficiency activates WNT signaling, a pathway essential to intestinal stem cell programs and pivotal to injury recovery processes in IBD that is also activated in inflammatory neoplastic transformation. In order to better understand the role of Se in epithelial injury and tumorigenesis resulting from inflammatory stimuli, we examined colonic phenotypes in Se-deficient or -sufficient mice in response to dextran sodium sulfate (DSS)-induced colitis, and azoxymethane (AOM) followed by cyclical administration of DSS, respectively. In response to DSS alone, Se-deficient mice demonstrated increased morbidity, weight loss, stool scores, and colonic injury with a concomitant increase in DNA damage and increases in inflammation-related cytokines. As there was an increase in DNA damage as well as expression of several EGF and TGF-β pathway genes in response to inflammatory injury, we sought to determine if tumorigenesis was altered in the setting of inflammatory carcinogenesis. Se-deficient mice subjected to AOM/DSS treatment to model colitis-associated cancer (CAC) had increased tumor number, though not size, as well as increased incidence of high grade dysplasia. This increase in tumor initiation was likely due to a general increase in colonic DNA damage, as increased 8-OHdG staining was seen in Se-deficient tumors and adjacent, non-tumor mucosa. Taken together, our results indicate that Se deficiency worsens experimental colitis and promotes tumor development and progression in inflammatory carcinogenesis.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Azoxymethane; Carcinogenesis; Colitis; Colonic Neoplasms; Deoxyguanosine; Dextran Sulfate; Diet; DNA Damage; Epidermal Growth Factor; Gene Expression Regulation; Inflammation; Mice; Mice, Inbred C57BL; Selenium; Signal Transduction; Transforming Growth Factor beta; Weight Loss

KLF5 is an essential basic transcriptional factor that regulates a number of physiopathological processes. In this study, we tested whether and how KLF5 modulates the epithelial-mesenchymal transition (EMT). Using transforming growth factor β (TGF-β)- and epidermal growth factor (EGF)-treated epithelial cells as an established model of EMT, we found that KLF5 was downregulated during EMT and that knockdown of KLF5 induced EMT even in the absence of TGF-β and EGF treatment, as indicated by phenotypic and molecular EMT properties. Array-based screening suggested and biochemical analyses confirmed that the microRNA 200 (miR-200) microRNAs, a group of well-established EMT repressors, were transcriptionally activated by KLF5 via its direct binding to the GC boxes in miR-200 gene promoters. Functionally, overexpression of miR-200 prevented the EMT induced by KLF5 knockdown or by TGF-β and EGF treatment, and ectopic expression of KLF5 attenuated TGF-β- and EGF-induced EMT by rescuing the expression of miR-200. In mouse prostates, knockout of Klf5 downregulated the miR-200 family and induced molecular changes indicative of EMT. These findings indicate that KLF5 maintains epithelial characteristics and prevents EMT by transcriptionally activating the miR-200 family in epithelial cells.

Topics: Animals; Base Sequence; Binding Sites; Carcinogenesis; Down-Regulation; Epidermal Growth Factor; Epithelial Cells; Epithelial-Mesenchymal Transition; Gene Knockdown Techniques; Hep G2 Cells; Humans; Kruppel-Like Transcription Factors; Male; Mice; Mice, Knockout; MicroRNAs; Promoter Regions, Genetic; Prostate; Protein Binding; RNA, Small Interfering; Transcription, Genetic; Transcriptional Activation; Transforming Growth Factor beta

Androgen receptor (AR) plays a critical role in bladder cancer (BCa) development. Our early studies found AR knock-out mice (with few androgens and deleted AR) failed to develop BCa, yet 50% of castrated mice (with few androgens and existing AR) still developed BCa in an N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) carcinogen-induced BCa mouse model, suggesting the existing AR in BCa of castrated mice may still play important roles in promoting BCa development at the castration level of androgens. The mechanism underlying this and/or which factors potentiate AR function at the castration level of androgen remains unclear. Epidermal growth factor (EGF), a key player in BCa progression, has been demonstrated to be able to potentiate AR transactivation in prostate cancer. In the present study, we found that EGF could increase BCa cell growth, migration and invasion in the presence of AR under the low amount of androgen and EGF was able to potentiate AR transactivation through EGFR by activating PI3K/AKT and MAPK pathway at castration androgen level. The increased suppression effects by EGFR inhibitor of PD168393 on AR function after addition of anti-androgen, Casodex, further suggested AR might play a key role in the effects of EGF on BCa progression and metastasis. Collectively, our results indicate that EGF may be able to potentiate AR transactivation that leads to enhancing BCa progression, which may help us to develop a better therapeutic approach to treat BCa via targeting both EGF and AR signaling.

Topics: Androgens; Animals; Butylhydroxybutylnitrosamine; Carcinogenesis; Castration; Disease Models, Animal; Disease Progression; Epidermal Growth Factor; ErbB Receptors; Humans; Male; Mice; Mitogen-Activated Protein Kinase Kinases; Phosphatidylinositol 3-Kinases; Quinazolines; Receptors, Androgen; Signal Transduction; Transcriptional Activation; Urinary Bladder Neoplasms

Somatic mutations in the EGFR proto-oncogene occur in ~15% of human lung adenocarcinomas and the importance of EGFR mutations for the initiation and maintenance of lung cancer is well established from mouse models and cancer therapy trials in human lung cancer patients. Recently, we identified DOK2 as a lung adenocarcinoma tumor suppressor gene. Here we show that genomic loss of DOK2 is associated with EGFR mutations in human lung adenocarcinoma, and we hypothesized that loss of DOK2 might therefore cooperate with EGFR mutations to promote lung tumorigenesis. We tested this hypothesis using genetically engineered mouse models and find that loss of Dok2 in the mouse accelerates lung tumorigenesis initiated by oncogenic EGFR, but not that initiated by mutated Kras. Moreover, we find that DOK2 participates in a negative feedback loop that opposes mutated EGFR; EGFR mutation leads to recruitment of DOK2 to EGFR and DOK2-mediated inhibition of downstream activation of RAS. These data identify DOK2 as a tumor suppressor in EGFR-mutant lung adenocarcinoma.

Topics: Adaptor Proteins, Signal Transducing; Adenocarcinoma; Adenocarcinoma of Lung; Animals; Carcinogenesis; Cell Line; Epidermal Growth Factor; ErbB Receptors; Extracellular Signal-Regulated MAP Kinases; Gene Knockout Techniques; Genomics; Humans; Lung Neoplasms; Male; Mice; Mice, Transgenic; Mutation; Phosphoproteins; Proto-Oncogene Mas; ras Proteins; Tumor Suppressor Proteins