transforming-growth-factor-beta and Precancerous-Conditions

Epithelial-mesenchymal transition (EMT) is a biological process that drives polarized, immotile epithelial cells to undergo multiple biochemical changes to acquire a mesenchymal cell phenotype. The characteristic features of EMT are cell apolarity, loss of cellular adhesion, reduced expression of E-cadherin and increased migratory capacity, as well as invasiveness. EMT is a physiological process that is essential for normal embryonic development. Additionally, abnormal activation of EMT contributes to some human pathologies such as tissue fibrosis, cancer cell invasion and metastasis. In both situations, the basic molecular mechanisms are similar, but lead to different effects depending on cell type and biological conditions of the environment. TGF-β is a multifunctional cytokine that controls proliferation, differentiation and other functions in many cell types. It has been found that neoplastic development converts TGF-β into an oncogenic cytokine. It activates various molecular processes, which are engaged in EMT initiation. All that makes TGF-β a key regulator of EMT.  

Topics: Animals; Cadherins; Cell Adhesion; Cell Differentiation; Disease Progression; Epithelial-Mesenchymal Transition; Humans; Mesenchymal Stem Cells; Neoplasm Invasiveness; Neoplasm Metastasis; Neoplasms; Precancerous Conditions; Signal Transduction; Transforming Growth Factor beta

It is sometimes difficult but finally possible to distinguish colitis-associated neoplasms from sporadic neoplasms. The frequency of detection of precursor lesions of carcinoma (e.g. dysplasia, intraepithelial neoplasia and adenoma) has increased in recent years, which is most probably due to better endoscopic detection and thus improved histological diagnosis. Carcinogenesis of colitis-associated neoplasms is different from carcinogenesis in sporadic neoplasms because mutations and epigenetic changes are different or may occur at a different point in time. In the present article, these differences will be described and placed in context with carcinogenesis in ulcerative colitis.

Topics: Adenoma; Carcinoma in Situ; Cell Transformation, Neoplastic; Chromosome Aberrations; Colitis, Ulcerative; Colonic Neoplasms; DNA Methylation; DNA Mutational Analysis; Epigenesis, Genetic; Humans; Intestinal Mucosa; Microsatellite Instability; Neoplasm Invasiveness; Neoplasm Staging; Oxidative Stress; Precancerous Conditions; Reactive Oxygen Species; Transforming Growth Factor beta

The transforming growth factor beta (TGFbeta) signaling pathway plays a vital role in the development and homeostasis of normal tissues. Abnormal function of this pathway contributes to the initiation and progression of cancer. Smad proteins are key signal transducers of the TGFbeta pathway and are essential for the growth suppression function of TGFbeta. Smads are bona fide tumor suppressors whose mutation, deletion, and silencing are associated with many types of human cancer. However, the involvement and functional mechanism of Smad proteins in cancer metastasis are poorly defined. Recent studies using genetically modified cancer cells and mouse tumor models have provided concrete evidence for a Smad-dependent mechanism for metastasis promotion by TGFbeta. Understanding the dual roles of Smad proteins in tumor initiation and progression has important implications for cancer therapeutics.

Topics: Animals; Bone Neoplasms; Breast Neoplasms; Humans; Mice; Models, Biological; Precancerous Conditions; Signal Transduction; Smad Proteins; Transforming Growth Factor beta; Tumor Suppressor Proteins

To reduce the incidence and mortality associated with invasive cancers, the Intraepithelial Neoplasia (IEN) Task Force recommends that carcinogenesis be viewed as a disease that requires treatment. This publication outlines the current knowledge of IEN of the ovary and reviews chemoprevention possibilities for ovarian cancer. Ovarian cancer has the highest mortality of all of the gynecological cancers and is the fourth leading cause of death from cancer in women. The IEN Task Force has defined precancer as a noninvasive lesion that has genetic abnormalities, loss of cellular control functions, and some phenotypic characteristics of invasive cancer with a substantial likelihood of developing invasive cancer. The IEN Task Force recommends targeting moderate to severe dysplasia for new IEN treatment agents in clinical trials. Ovarian cancer does not have a clear preinvasive lesion yet merits considerable study for new prevention strategies because of the high mortality associated with ovarian cancer. There is a great unmet clinical need for treatments that can prevent ovarian cancer by providing nonsurgical options that treat the entire epithelial layer. New prevention strategies hold significant promise to reduce the mortality from ovarian cancer.

Topics: Animals; Cyclooxygenase 2; Enzyme Inhibitors; Epithelium; Female; Genetic Markers; Humans; Isoenzymes; Membrane Proteins; Ovarian Neoplasms; Ovary; Phosphatidylinositol 3-Kinases; Precancerous Conditions; Prostaglandin-Endoperoxide Synthases; Retinoids; Transforming Growth Factor beta; Uterine Cervical Dysplasia

Topics: Adaptor Proteins, Signal Transducing; Animals; Carrier Proteins; Colitis, Ulcerative; Colorectal Neoplasms; Cyclooxygenase 2; Cytokines; DNA Repair; DNA-Binding Proteins; Genes, APC; Genes, DCC; Genes, p53; Genes, ras; Humans; Inflammation Mediators; Isoenzymes; Membrane Proteins; Mutation; MutL Protein Homolog 1; MutS Homolog 2 Protein; Neoplasm Proteins; Nitric Oxide; Nuclear Proteins; Precancerous Conditions; Prostaglandin-Endoperoxide Synthases; Proto-Oncogene Proteins; Signal Transduction; Transforming Growth Factor beta

Molecular biology studies have led to the identification of two different types of colorectal carcinomas. The first group, called LOH (for loss of heterozygosity), represents 80% of colorectal cancers and is characterised by aneuploidy, allelic losses and a location in the distal colon. The second group displays phenotypic microsatellite instability (MSI-positive tumours), has a near-diploid karyotype and a relatively low frequency of allelic losses. It accounts for 15% of all colorectal cancers and for about 30% of right-sided cancers. Four different pathways have been identified as responsible for tumour progression: the WNT/Wingless, the K-ras, the Transforming growth factor (TGF) and the P53 pathways. The involvement of these pathways depends on the tumour type. In LOH-positive tumours, the WNT/Wingless pathway is activated through an APC mutation, whereas MSI+ tumours do so through a catenin stabilising mutation. The TGFb growth inhibitory pathway is altered either by mutations in the signal transduction molecules SMAD2 and SMAD4 in LOH positive tumours or by mutations of TGFbRII in MSI+ tumours. In the p53 pathway, mutations in BAX may contribute to the adenoma-carcinoma transition just as p53 mutations may do in LOH positive tumours. Until now, cancer phenotype determination has had no clinical implications. However, the predictive value of the MSI status was recently stressed as a predictive factor for response to chemotherapy. Immunohistochemistry could represent a complementary strategy to molecular biology in assessing MSI status. This simple test would allow to screen all colorectal carcinomas for MSI status, which would provide valuable management information in addition to the histological assessment for tumour stage and grade.

Topics: Aneuploidy; Colonic Neoplasms; Colorectal Neoplasms; Disease Progression; Genes, ras; Humans; Loss of Heterozygosity; Molecular Biology; Precancerous Conditions; Proto-Oncogene Proteins; Transforming Growth Factor beta; Wnt Proteins; Zebrafish Proteins

The human placenta is a highly invasive tumor-like structure in which a subpopulation of placental trophoblast cells known as the "extravillous trophoblast" (EVT) invades the uterine decidua and its vasculature to establish adequate fetal-maternal exchange of molecules. By utilizing in vitro-propagated short-lived EVT cell lines we found that molecular mechanisms responsible for their invasiveness are identical to those of cancer cells; however, unlike cancer cells, their proliferation, migration, and invasiveness in situ are stringently controlled by decidua-derived transforming growth factor (TGF)-beta. By SV40T antigen transfection of normal EVT cells followed by a forced crisis regimen in culture we produced an immortalized premalignant derivative that is hyperproliferative, hyperinvasive, and deficient in gap-junctional intercellular communication. Both premalignant and malignant EVT (JAR and JEG-3 choriocarcinoma) cell lines were found to be TGF-beta-resistant. Using these cell lines, we investigated genetic changes responsible for transition of the normal EVT cells to premalignant and malignant phenotype. Hyperinvasiveness in both cases resulted from a downregulation of tissue inhibitor of metalloprotease (TIMP)-1 and plasminogen activator inhibitor (PAI)-1 genes. In contrast to normal EVT cells, both cell types failed to upregulate these genes in response to TGF-beta. Loss of TGF-beta response in malignant EVT cells was explained by the loss of expression of Smad3 gene. Differential mRNA display of normal and premalignant EVT cells identified up- and down-regulation of numerous known or novel genes in premalignant EVT cells, with potential oncogenic and (or) tumor-suppressor functions, e.g., loss of fibronectin and insulin-like growth factor binding protein (IGFBP-5). Premalignant EVT cells also lost IGF receptor type 2 (IGFR-II). IGFBP-5 was shown to be a negative regulator of IGF-1-induced proliferation of premalignant EVT cells, so that loss of IGFBP-5 as well as IGFR-II permitted their unrestricted proliferation in an IGF-I-rich microenvironment of the fetal-maternal interface. The present model may be a good prototype for identifying genetic changes underlying epithelial tumor progression.

Topics: Cell Line; Choriocarcinoma; Disease Progression; Female; Gene Expression; Humans; Neoplasm Invasiveness; Neoplasms; Placentation; Precancerous Conditions; Pregnancy; Signal Transduction; Transforming Growth Factor beta; Trophoblasts; Tumor Cells, Cultured

Topics: Acute-Phase Reaction; Genes, p53; Genes, ras; Humans; Lung Neoplasms; Mutation; Precancerous Conditions; Pulmonary Fibrosis; Receptors, Transforming Growth Factor beta; Risk Factors; Smoking; Transforming Growth Factor beta

Myelodysplastic syndromes (MDS) are clonal disorders, which frequently undergo leukemic transformation. It was recently shown that the promoter of the p15INK4b but not the p16INK4a gene is frequently and selectively hypermethylated in MDS. The p15INK4b gene is a cyclin dependent kinase inhibitor gene, which is actively transcribed after TGFbeta exposure. Methylation of the p15INK4b gene is significantly correlated with blastic bone marrow involvement, and sequential analyses have shown that methylation increases with disease evolution toward AML. These data strongly suggest that p15INK4b gene methylation is a mechanism allowing leukemic cells to escape to inhibitory signals from the bone marrow environment, however the exact role of p15INK4b gene methylation in disruption of the signal mediated by TGFbeta remains to be investigated.

Topics: Acute Disease; Animals; Antimetabolites, Antineoplastic; Azacitidine; Bone Marrow; Carrier Proteins; Cell Cycle; Cell Cycle Proteins; Cell Differentiation; Cell Transformation, Neoplastic; Chromosomes, Human, Pair 9; Clinical Trials, Phase II as Topic; Cyclin-Dependent Kinase Inhibitor p15; Cyclin-Dependent Kinase Inhibitor p16; Cyclin-Dependent Kinases; Decitabine; Disease Progression; DNA Methylation; Genes, p16; Genes, Tumor Suppressor; Hematopoiesis; Humans; Leukemia, Myeloid; Mice; Myelodysplastic Syndromes; Neoplasm Proteins; Precancerous Conditions; Precursor Cell Lymphoblastic Leukemia-Lymphoma; Transforming Growth Factor beta; Tumor Suppressor Proteins

The multistage evolution of squamous cell cancer on mouse skin has provided a model to dissect the biological and genetic changes that contribute to specific stages of carcinogenesis. Keratinocyte cell culture models have been developed that reproduce the genetic and epigenetic events in multistage skin carcinogenesis, and these provide insights into the biochemistry of the process. When the v-rasHa oncogene is transduced into normal mouse keratinocytes, the resultant papilloma phenotype is characterized by a high rate of cell proliferation, an aberrant program of differentiation marker expression, and resistance to terminal differentiation. These changes are attributed to differential effects on isoforms of protein kinase C coupled to activation of the epidermal growth factor receptor. Premalignant progression requires additional genetic changes in the v-rasHa-transduced cells. The acquisition of these changes is suppressed by transforming growth factor beta (TGF beta), and the absence of TGF beta in premalignant tumors indicates a high risk for malignant progression. Keratinocytes that are genetically null for the TGF beta 1 gene rapidly progress to squamous cell carcinomas when transduced with the v-rasHa oncogene. In culture, TGF beta 1 null keratinocytes exhibit a high rate of gene amplification that can be suppressed by concentrations of exogenous TGF beta well below those required to inhibit proliferation. This model is well-suited to identifying critical genetic changes that contribute to premalignant progression.

Topics: Animals; Calcium; Humans; Mice; Papilloma; Precancerous Conditions; RNA, Messenger; Skin Neoplasms; Transforming Growth Factor beta

Topics: Animals; Carcinogens; Cells, Cultured; Disease Progression; Fibroblast Growth Factor 10; Fibroblast Growth Factor 7; Fibroblast Growth Factors; Growth Substances; Mice; Precancerous Conditions; Skin Neoplasms; Transforming Growth Factor alpha; Transforming Growth Factor beta

The growth rate of tissues including tumors is determined by the difference between cell replication and cell death. Among different types of cell death, apoptosis, a form of programmed cell death, is of particular importance. Nongenotoxic carcinogens exert their carcinogenic effects not only via stimulation of cell replication but also by modulating the incidence of apoptosis. This can be seen at different stages of carcinogenesis: a) After initiation in the liver, many initiated cells may undergo apoptosis and never develop into preneoplastic foci, as suggested by both biological and mathematical studies. Thus, apoptosis appears to determine the efficiency of initiation. b) In the promotion stage, early preneoplastic hepatic foci originate either from treatment with a genotoxic carcinogen or spontaneously exhibit much higher rates of cell replication than normal cells, but nevertheless show little preferential growth. This is due to enhanced rates of apoptosis. Some tumor promoters were found to inhibit apoptosis and thereby accelerate foci growth and carcinogenesis. c) In neoplastic nodules and tumors, apoptosis has been shown to be an important growth determinant and to be regulated by growth regulatory hormones, which thereby may decrease or accelerate tumor growth. Studies on the regulation of apoptosis revealed that in the liver, transforming growth factor TGF-beta 1 is involved in the initiation of apoptosis. This was based on three lines of evidence: TGF-beta 1 induced apoptosis in isolated hepatocytes, b) in vivo hepatocytes undergoing apoptosis showed positive immunostaining with antibodies against a precursor of TGF-beta 1.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Apoptosis; Carcinogens; Cell Division; Cocarcinogenesis; Humans; Liver; Liver Neoplasms; Liver Neoplasms, Experimental; Precancerous Conditions; Transforming Growth Factor beta

Topics: DNA, Viral; Gene Rearrangement; Genes, Tumor Suppressor; Hepatitis B; Insulin-Like Growth Factor II; Liver Neoplasms; Precancerous Conditions; Proto-Oncogenes; Transforming Growth Factor alpha; Transforming Growth Factor beta

Topics: Animals; Cell Communication; Cell Differentiation; Cell Division; Cells, Cultured; Depression, Chemical; Epithelium; Extracellular Matrix; Gene Expression Regulation; Genes, Retinoblastoma; Hematopoietic Stem Cells; Humans; Intercellular Junctions; Interphase; Mice; Neoplasms; Precancerous Conditions; Retinoids; Steroids; Transforming Growth Factor beta

Biliary cancer has long been known to carry a poor prognosis, yet the molecular pathogenesis of carcinoma of the extrahepatic biliary system and its precursor lesions remains elusive. Here we investigated the role of Kras and canonical Wnt pathways in the tumorigenesis of the extrahepatic bile duct (EHBD) and gall bladder (GB). In mice, concurrent activation of Kras and Wnt pathways induced biliary neoplasms that resembled human intracholecystic papillary-tubular neoplasm (ICPN) and biliary intraepithelial neoplasia (BilIN), putative precursors to invasive biliary cancer. At a low frequency, these lesions progressed to adenocarcinoma in a xenograft model, establishing them as precancerous lesions. Global gene expression analysis revealed increased expression of genes associated with c-Myc and TGFβ pathways in mutant biliary spheroids. Silencing or pharmacologic inhibition of c-Myc suppressed proliferation of mutant biliary spheroids, whereas silencing of Smad4/Tgfbr2 or pharmacologic inhibition of TGFβ signaling increased proliferation of mutant biliary spheroids and cancer formation in vivo. Human ICPNs displayed activated Kras and Wnt signals and c-Myc and TGFβ pathways. Thus, these data provide direct evidence that concurrent activation of the Kras and canonical Wnt pathways results in formation of ICPN and BilIN, which could develop into biliary cancer.. This work shows how dysregulation of canonical cell growth pathways drives precursors to biliary cancers and identifies several molecular vulnerabilities as potential therapeutic targets in these precursors to prevent oncogenic progression.

Topics: Animals; Bile Duct Neoplasms; Bile Pigments; Biliary Tract Neoplasms; Carcinoma in Situ; Humans; Mice; Precancerous Conditions; Proto-Oncogene Proteins p21(ras); Transforming Growth Factor beta; Wnt Signaling Pathway

Early treatment of oral precancerous lesions is considered as a key strategy for in oral carcinogenesis prevention. Increasing evidence has suggested that the transforming growth factor beta (TGF-β) signaling pathway is tightly involved in the process of oral-carcinogenesis. In this study, we investigated the inhibition effect and potential mechanism of 5-aminolaevulinic acid photodynamic therapy (ALA-PDT) in human oral precancerous cells via TGF-β pathway.. Here, the dysplastic oral keratinocyte (DOK) cells were incubated with ALA concentration of 1 mM/mL for 4 h and then irradiated with a Helium-Neon (He-Ne) ion laser at 633 nm (200 mW/cm. The TGF-β signaling could exert in suppressive effects on DOK cells after ALA-PDT. The cell proliferation and migration rate of DOK cells was significantly reduced and apoptosis and ROS generation induced more effectively by ALA-PDT combined with LY2109761. Furthermore, cell cycle analysis revealed that the combined treatment resulted in G0/G1 phase arrest.. ALA-PDT suppresses the growth of oral precancerous cells by regulating the TGF-β signaling pathway, and its suppressive effect was enhanced using LY2109761. These results indicate that it could be a promising alternative treatment against oral precancerous lesions.

Topics: Aminolevulinic Acid; Carcinogenesis; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Humans; Photochemotherapy; Photosensitizing Agents; Precancerous Conditions; Transforming Growth Factor beta

Oral submucous fibrosis (OSF) is known as a potentially malignant disorder, which may result from chemical irritation due to areca nuts (such as arecoline). Emerging evidence suggests that fibrogenesis and carcinogenesis are regulated by the interaction of long noncoding RNAs (lncRNAs) and microRNAs. Among these regulators, profibrotic lncRNA

Topics: Arecoline; Biomarkers; Cell Transdifferentiation; Cells, Cultured; Collagen Type I; Collagen Type I, alpha 1 Chain; Down-Regulation; Fibroblasts; Gene Expression Regulation; Gene Silencing; Humans; MicroRNAs; Mouth Mucosa; Myofibroblasts; Oral Submucous Fibrosis; Precancerous Conditions; RNA, Long Noncoding; Transforming Growth Factor beta

One third of newly diagnosed breast cancers in the US are early-stage lesions. The etiological understanding and treatment of these lesions have become major clinical challenges. Because breast cancer risk factors are often linked to aberrant nitric oxide (NO) production, we hypothesized that abnormal NO levels might contribute to the formation of early-stage breast lesions. We recently reported that the basal level of NO in the normal breast epithelia plays crucial roles in tissue homeostasis, whereas its reduction contributes to the malignant phenotype of cancer cells. Here, we show that the basal level of NO in breast cells plummets during cancer progression due to reduction of the NO synthase cofactor, BH

Topics: Animals; Biomarkers; Breast; Breast Neoplasms; Disease Susceptibility; Epithelial Cells; Female; Gene Expression; Humans; Mice; Neoplastic Stem Cells; Nitric Oxide; Nitric Oxide Synthase Type I; Nitric Oxide Synthase Type II; Nitric Oxide Synthase Type III; Oxidative Stress; Precancerous Conditions; Receptor, ErbB-2; Transforming Growth Factor beta

Topics: Adult; B7-H1 Antigen; Carcinoma, Squamous Cell; Cell Proliferation; Cell Transformation, Neoplastic; Epithelial Cells; Female; Gene Expression Regulation, Neoplastic; Histocompatibility Antigens Class I; HLA-E Antigens; HLA-G Antigens; Humans; Immunologic Factors; Interleukin-10; Leukoplakia, Oral; Male; Middle Aged; Mouth Mucosa; Mouth Neoplasms; Precancerous Conditions; Transforming Growth Factor beta

Precancerous lesion, a well-established histopathologically premalignant tissue with the highest risk for tumourigenesis, develops preferentially from activation of DNA damage checkpoint and persistent inflammation. However, little is known about the mechanisms by which precancerous lesions are initiated and their physiological significance.. Laser capture microdissection was used to acquire matched normal liver, precancerous lesion and tumour tissues. miR-484(-/-), Ifnar1(-/-) and Tgfbr2(△hep) mice were employed to determine the critical role of the interferon (IFN)-microRNA pathway in precancerous lesion formation and tumourigenesis. RNA immunoprecipitation (RIP), pull-down and chromatin immunoprecipitation (ChIP) assays were applied to explore the underlying mechanisms.. miR-484 is highly expressed in over 88% liver samples clinically. DEN-induced precancerous lesions and hepatocellular carcinoma were dramatically impaired in miR-484(-/-) mice. Mechanistically, ectopic expression of miR-484 initiates tumourigenesis and cell malignant transformation through synergistic activation of the transforming growth factor-β/Gli and nuclear factor-κB/type I IFN pathways. Specific acetylation of H3K27 is indispensable for basal IFN-induced continuous transcription of miR-484 and cell transformation. Convincingly, formation of precancerous lesions were significantly attenuated in both Tgfbr2(△hep) and Ifnar1(-/-) mice.. These findings demonstrate a new protumourigenic axis involving type I IFN-microRNA signalling, providing a potential therapeutic strategy to manipulate or reverse liver precancerous lesions and tumourigenesis.

Topics: Acetylation; Animals; Carcinoma, Hepatocellular; Cell Transformation, Neoplastic; Hepatocytes; Humans; Interferon Type I; Liver; Liver Neoplasms; Mice; Mice, Knockout; MicroRNAs; NF-kappa B; NIH 3T3 Cells; Pentanones; Precancerous Conditions; Promoter Regions, Genetic; Protein Serine-Threonine Kinases; Receptor, Interferon alpha-beta; Receptor, Transforming Growth Factor-beta Type II; Receptors, Transforming Growth Factor beta; Signal Transduction; Transforming Growth Factor beta; Zinc Finger Protein GLI1

Topics: Activating Transcription Factor 2; Areca; Cell Line, Transformed; Female; Fibrosis; Humans; Male; MAP Kinase Kinase 4; Mouth Mucosa; Mouth Neoplasms; Nuts; Oncogene Protein p65(gag-jun); Plant Extracts; Precancerous Conditions; Transforming Growth Factor beta

Pancreatic ductal adenocarcinomas (PDACs) are highly metastatic with poor prognosis, mainly due to delayed detection. We hypothesized that intercellular communication is critical for metastatic progression. Here, we show that PDAC-derived exosomes induce liver pre-metastatic niche formation in naive mice and consequently increase liver metastatic burden. Uptake of PDAC-derived exosomes by Kupffer cells caused transforming growth factor β secretion and upregulation of fibronectin production by hepatic stellate cells. This fibrotic microenvironment enhanced recruitment of bone marrow-derived macrophages. We found that macrophage migration inhibitory factor (MIF) was highly expressed in PDAC-derived exosomes, and its blockade prevented liver pre-metastatic niche formation and metastasis. Compared with patients whose pancreatic tumours did not progress, MIF was markedly higher in exosomes from stage I PDAC patients who later developed liver metastasis. These findings suggest that exosomal MIF primes the liver for metastasis and may be a prognostic marker for the development of PDAC liver metastasis.

Topics: Animals; Base Sequence; Bone Marrow Cells; Carcinoma, Pancreatic Ductal; Cell Line, Tumor; Cell Movement; Exosomes; Female; Fibronectins; Gene Expression Regulation, Neoplastic; Hepatic Stellate Cells; Humans; Liver; Liver Neoplasms; Macrophage Migration-Inhibitory Factors; Macrophages; Mice; Mice, Inbred C57BL; Mice, Knockout; Pancreatic Neoplasms; Precancerous Conditions; RNA Interference; RNA, Small Interfering; Sequence Analysis, RNA; Signal Transduction; Transforming Growth Factor beta

Areca nut consumption has been implicated in the progression of Oral Submucous fibrosis (OSF); an inflammatory precancerous fibrotic condition. Our previous studies have demonstrated the activation of TGF-β signaling in epithelial cells by areca nut components and also propose a role for epithelial expressed TGF-β in the pathogenesis of OSF. Although the importance of epithelial cells in the manifestation of OSF has been proposed, the actual effectors are fibroblast cells. However, the role of areca nut and TGF-β in the context of fibroblast response has not been elucidated. Therefore, to understand their role in the context of fibroblast response in OSF pathogenesis, human gingival fibroblasts (hGF) were treated with areca nut and/or TGF-β followed by transcriptome profiling. The gene expression profile obtained was compared with the previously published transcriptome profiles of OSF tissues and areca nut treated epithelial cells. The analysis revealed regulation of 4666 and 1214 genes by areca nut and TGF-β treatment respectively. The expression of 413 genes in hGF cells was potentiated by areca nut and TGF-β together. Further, the differentially expressed genes of OSF tissues compared to normal tissues overlapped significantly with areca nut and TGF-β induced genes in epithelial and hGF cells. Several positively enriched pathways were found to be common between OSF tissues and areca nut +TGF-β treated hGF cells. In concordance, areca nut along with TGF-β enhanced fibroblast activation as demonstrated by potentiation of αSMA, γSMA and collagen gel contraction by hGF cells. Furthermore, TGF-β secreted by areca nut treated epithelial cells influenced fibroblast activation and other genes implicated in fibrosis. These data establish a role for areca nut influenced epithelial cells in OSF progression by activation of fibroblasts and emphasizes the importance of epithelial-mesenchymal interaction in OSF.

Topics: Areca; Cluster Analysis; Collagen; Disease Progression; Epithelial Cells; Epithelial-Mesenchymal Transition; Fibroblasts; Gene Expression Profiling; Genome, Human; Gingiva; Humans; Inflammation; Nuts; Oligonucleotide Array Sequence Analysis; Oral Submucous Fibrosis; Precancerous Conditions; Signal Transduction; Transcriptome; Transforming Growth Factor beta

Actinic cheilitis (AC) is an oral potentially malignant lesion which is the counterpart of actinic keratosis of the skin and has potential to develop into squamous cell carcinoma. Regulatory T cells (Tregs) have a critical role in modulating the antitumor immune responses. The presence of regulatory T cells in potentially malignant lesions has not been described. We chose investigate the involvement of regulatory T cells in potentially malignant lesions.. The frequency, phenotype, and activity of CD4+CD25+ T cells isolated from blood and lesion of AC patients were analyzed by flow cytometry. Cytokines were quantified by ELISA. Data were compared with samples from healthy subjects.. The frequency and suppressor activity of circulating CD4+CD25+ T cells was similar in AC patients and control subjects. However, the frequencies of IL-10-positive Tregs were higher in AC patients, and these cells inhibited interferon-gamma (IFN-γ) and increased interleukin (IL)-10 productions in co-cultures. Furthermore, CD4+CD25+ T cells accumulate in AC lesions. Lesions-derived regulatory T cells suppressed lymphocyte proliferation and pro-inflammatory cytokine production. Moreover, high levels of IL-10 and transforming growth factor-β (TGF-β), and low IFN-γ were detected in the potentially malignant lesions.. Therefore, our data show that Tregs accumulate in AC lesions, and these cells could be suppressing immune responses in a potentially malignant microenvironment.

Topics: Adult; Aged; Aged, 80 and over; Case-Control Studies; CD4 Antigens; CD4-Positive T-Lymphocytes; Cell Proliferation; Cheilitis; Humans; Inflammation Mediators; Interferon-gamma; Interleukin-10; Interleukin-2 Receptor alpha Subunit; Leukocytes, Mononuclear; Lip Neoplasms; Lymphocyte Activation; Lymphocyte Count; Middle Aged; Phenotype; Precancerous Conditions; T-Lymphocytes, Regulatory; Transforming Growth Factor beta; Tumor Microenvironment

NF-κB is considered a major contributor to tumor development, but how this factor functions in the initial stages of oncogenesis is not clear. In a model of Ras-induced transformation, we probed NF-κB function as preneoplastic cells formed tumors in mice. As previously shown, the p65 subunit of NF-κB acts as a tumor suppressor in normal cells by sustaining senescence following DNA damage. Our current data reveal that, following immortalization, p65 switches to an oncogene by counteracting the surveillance properties of immune cells. NF-κB exerts this effect by protecting transformed cells against macrophage-derived proapoptotic factors, tumor necrosis factor, and nitric oxide. Additionally, NF-κB acts through transforming growth factor beta (TGF-β) to mitigate T cell cytotoxicity and other factors to expand myeloid-derived suppressor cells. Together, these data suggest that NF-κB functions in the early stages of transformation by suppressing immune surveillance of both innate and adaptive immune cells, information that may be useful for targeted immunotherapies.

Topics: Adaptive Immunity; Animals; Cell Transformation, Neoplastic; Cytoskeletal Proteins; Immunity, Innate; Macrophages; Mice; Mice, Inbred C57BL; Mice, SCID; Mice, Transgenic; Microfilament Proteins; NF-kappa B; Phosphoproteins; Precancerous Conditions; ras Proteins; Risk Factors; Signal Transduction; Transforming Growth Factor beta

While there is evidence that specific T cell populations can promote the growth of established tumors, instances where T cell activity causes neoplasms to arise de novo are infrequent. Here, we employed two conditional mutagenesis systems to delete the TGF-β signaling pathway component Smad4 in T cells and observed the spontaneous development of massive polyps within the gastroduodenal regions of mice. The epithelial lesions contained increased levels of transcripts encoding IL-11, IL-6, TGF-β, IL-1β, and TNF-α, and lamina propria cells isolated from lesions contained abundant IL-17A+CD4+ T cells. Furthermore, we found that Smad4 deficiency attenuated TGF-β-mediated in vitro polarization of FoxP3+CD4+ T cells, but not IL-17A+CD4+ T cells, suggesting that the epithelial lesions may have arisen as a consequence of unchecked Th17 cell activity. Proinflammatory cytokine production likely accounted for the raised levels of IL-11, a cytokine known to promote gastric epithelial cell survival and hyperplasia. Consistent with IL-11 having a pathogenic role in this model, we found evidence of Stat3 activation in the gastric polyps. Thus, our data indicate that a chronic increase in gut Th17 cell activity can be associated with the development of premalignant lesions of the gastroduodenal region.

Topics: Animals; Disease Models, Animal; Gastrointestinal Neoplasms; Gene Expression; Interleukin-11; Interleukin-1beta; Interleukin-6; Intestinal Polyps; Mice; Mice, 129 Strain; Mice, Inbred C57BL; Mice, Mutant Strains; Mice, Transgenic; Precancerous Conditions; Smad4 Protein; T-Lymphocyte Subsets; Th17 Cells; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

High mammographic density is associated with a increased risk of breast cancer. We hypothesized that specific pathways exist that are associated with increased mammographic density, and may therefore be used to identify potential targets for chemoprevention. Histologically confirmed normal breast tissue was collected from women undergoing breast surgery who had available demographic data and mammograms for review. Women with low versus high mammographic breast density were compared. Differentially expressed genes using Affymetrix HG U133Plus2 chips were identified in dense versus non-dense tissue. Immunohistochemical analysis (IHC) of estrogen receptor, progesterone receptor, Ki67, and COX2 expression was performed. About 66 women were identified, 28 (42%) had high, and 38 (58%) had low mammographic density. About 73 genes had differential expression between normal breast tissue with high and low mammographic density (P < 0.001, fold change > or = 1.5 with a low false discovery rate (<10%). Network and canonical pathway analysis indicated decreased TGFbeta signaling (TGFBR2, SOS, SMAD3, CD44 and TNFRSF11B) in dense breast tissue relative to non-dense breast. By IHC, only COX2 expression in the stroma was statistically significant on multivariate analysis. TGFbeta ligands are currently the only growth factors known to prevent mammary epithelial cell proliferation. TGFbeta signaling has been reported to be inhibited by COX-2, and these molecules are highly differentially expressed in individuals at high risk of developing breast cancer. These results strongly suggest that COX2 inhibition should be investigated for breast cancer prevention despite possible increase in cardiovascular risk.

Topics: Adult; Aged; Aged, 80 and over; Anticarcinogenic Agents; Breast Neoplasms; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Down-Regulation; Female; Gene Expression Profiling; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Neoplastic; Gene Regulatory Networks; Humans; Immunohistochemistry; Ligands; Logistic Models; Mammography; Middle Aged; Oligonucleotide Array Sequence Analysis; Precancerous Conditions; Risk Assessment; Risk Factors; Signal Transduction; Transforming Growth Factor beta; Up-Regulation

Nodal, a potent embryonic morphogen in the transforming growth factor-beta family, is a proposed key regulator of melanoma tumorigenicity. However, there has been no systematic study of Nodal expression in melanocytic lesions. We investigated Nodal expression by immunohistochemistry in 269 melanocytic lesions, including compound nevi, dysplastic nevi, congenital nevi, Spitz nevi, melanoma in situ, malignant melanoma including the variant desmoplastic melanoma, and metastatic melanoma. We found that the Nodal expression was significantly increased in malignant lesions (including melanoma in situ, malignant melanoma, and metastatic melanoma) compared with compound nevi, Spitz nevi, and dysplastic nevi. Surprisingly, congenital nevi expressed a level of Nodal comparable with malignant lesions, whereas desmoplastic melanoma showed lower expression than nondesmoplastic malignant melanoma (P<0.05). Deep melanoma (Breslow depth >1 mm) displayed a higher percentage of Nodal-positive tumor cells than did superficial melanoma (Breslow depth < or =1 mm), although there was no statistical difference in the overall staining intensity (P=0.18). Melanomas in situ showed a lower level of Nodal expression than did deep melanomas and metastatic melanomas (P<0.05). The low expression of Nodal in normal and dysplastic nevi, and its increasing expression with the progression of malignant lesions, are suggestive of a role for Nodal in melanoma progression.

Topics: Biomarkers, Tumor; Dysplastic Nevus Syndrome; Humans; Immunohistochemistry; Melanoma; Nevus, Pigmented; Nodal Protein; Precancerous Conditions; Skin Neoplasms; Transforming Growth Factor beta

Oral lichen planus (OLP) is a chronic inflammatory disease of the oral mucosa which the World Health Organisation (WHO) considers a premalignant condition. One step in malignant development is so called epithelial mesenchymal transition (EMT), a process whereby epithelial cells acquire mesenchymal characteristics. EMT occurs during embryogenesis and wound healing but also in some human diseases such as cancer and fibrosis. A factor known to induce EMT is transforming growth factor-β (TGF-β), which uses the Smad proteins as mediators for its signalling. TGF-β is also often over-expressed in squamous cell carcinoma of the head and neck (SCCHN).. In the present study we mapped expression of Smad proteins in OLP lesions by immunohistochemistry, and compared to expression in normal and sensitive oral mucosa. The latter group of patients had developed SCCHN after shorter or longer periods of diffuse oral symptoms. The aim was to see if there were any signs of EMT related changes in the OLP lesions, as judged by changes in the TGF-β pathway.. Changes in the TGF-β pathway related to EMT are seen in the very earliest stages of oral malignancy and become more severe as lesions progress.

Topics: Adult; Aged; Carcinoma, Squamous Cell; Cell Transformation, Neoplastic; Disease Progression; Epithelial-Mesenchymal Transition; Female; Head and Neck Neoplasms; Humans; Immunohistochemistry; Lichen Planus, Oral; Male; Middle Aged; Mouth Mucosa; Precancerous Conditions; Smad Proteins; Smad2 Protein; Smad3 Protein; Smad4 Protein; Smad7 Protein; Transforming Growth Factor beta; Young Adult

Gallbladder cancer is a highly aggressive disease with poor prognosis that is two to six times more frequent in women than men. The development of gallbladder cancer occurs over a long time (more than 15 y) and evolves from chronic inflammation to dysplasia/metaplasia, carcinoma in situ, and invasive carcinoma. In the present study we found that, in female mice in which the oxysterol receptor liver X receptor-beta (LXRbeta) has been inactivated, preneoplastic lesions of the gallbladder developed and evolved to cancer in old animals. LXRbeta is a nuclear receptor involved in the control of lipid homeostasis, glucose metabolism, inflammation, proliferation, and CNS development. LXRbeta(-/-) female gallbladders were severely inflamed, with regions of dysplasia and high cell density, hyperchromasia, metaplasia, and adenomas. No abnormalities were evident in male mice, nor in LXRalpha(-/-) or LXRalpha(-/-)beta(-/-) animals of either sex. Interestingly, the elimination of estrogens with ovariectomy prevented development of preneoplastic lesions in LXRbeta(-/-) mice. The etiopathological mechanism seems to involve TGF-beta signaling, as the precancerous lesions were characterized by strong nuclear reactivity of phospho-SMAD-2 and SMAD-4 and loss of E-cadherin expression. Upon ovariectomy, E-cadherin was reexpressed on the cell membranes and immunoreactivity of pSMAD-2 in the nuclei was reduced. These findings suggest that LXRbeta in a complex interplay with estrogens and TGF-beta could play a crucial role in the malignant transformation of the gallbladder epithelium.

Topics: Age Factors; Animals; Apoptosis; Cadherins; Cell Proliferation; Estrogens; Female; Gallbladder; Gallbladder Neoplasms; Humans; Immunohistochemistry; Liver X Receptors; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Orphan Nuclear Receptors; Ovariectomy; Phosphorylation; Precancerous Conditions; Smad2 Protein; Smad4 Protein; Transforming Growth Factor beta

To dissect the role of constitutively altered Tgfbr1 signaling in pancreatic cancer development, we crossed Elastase-Kras(G12D) (EL-Kras) mice with Tgfbr1 haploinsufficient mice to generate EL-Kras/Tgfbr1(+/-) mice. Mice were euthanized at 6 to 9 months to compare the incidence, frequency, and size of precancerous lesions in the pancreas. Only 50% of all EL-Kras/Tgfbr1(+/-) mice developed preinvasive lesions compared with 100% of EL-Kras (wild-type Tgfbr1) mice. The frequency of precancerous lesions was 4-fold lower in haploinsufficient than in control mice. Paradoxically, the precancerous lesions of EL-Kras/Tgfbr1(+/-) mice were considerably larger than those in EL-Kras mice. Yet, the mitotic index of precancerous cells and the observable levels of fibrosis, lipoatrophy, and lymphocytic infiltration were reduced in EL-Kras/Tgfbr1(+/-) mice. We conclude that Tgfbr1 signaling promotes the development of precancerous lesions in mice. These findings suggest that individuals with constitutively decreased TGFBR1 expression may have a decreased risk of pancreatic cancer.

Topics: Animals; Apoptosis; Cell Growth Processes; Female; Haploidy; Mice; Mice, Inbred C57BL; Mice, Transgenic; Pancreatic Neoplasms; Precancerous Conditions; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins p21(ras); Receptor, Transforming Growth Factor-beta Type I; Receptor, Transforming Growth Factor-beta Type II; Receptors, Transforming Growth Factor beta; Signal Transduction; Transforming Growth Factor beta

Matrix metalloproteinases (MMPs) and transforming growth factor-beta1 (TGF-beta1) are important in many physiological and pathological processes.. Immunohistochemistry for MMP-2, MMP-9, membrane-type 1 MMP (MT1-MMP, MMP-14), tissue inhibitor of matrix metalloproteinase (TIMP)-2, and TGF-beta were performed on normal mucosa, nonatrophic oral lichen planus, atrophic oral lichen planus, and oral squamous cell carcinomas (OSCC) resulting from lichen planus.. Expression of MMPs progressively increased from normal mucosa to nonatrophic oral lichen planus, atrophic oral lichen planus, and OSCCs. Immunoscores of MMPs in atrophic oral lichen planus was significantly greater than nonatrophic oral lichen planus. Moreover, immunoscore of MMP-9 of OSCCs was significantly greater than both atrophic and nonatrophic lichen planus. Furthermore, expression of TIMP-2 and TGF-beta1 paralleled increases seen with MMPs.. Imbalance between MMPs and TIMPs may be involved in cancerization of oral lichen planus. MMP-2, MT1-MMP, and especially MMP-9 may be useful markers for judging potency of malignant transformation from oral lichen planus.

Topics: Adult; Age Factors; Biomarkers, Tumor; Biopsy, Needle; Case-Control Studies; Cell Transformation, Neoplastic; Cytokines; Disease Progression; Female; Humans; Immunohistochemistry; Lichen Planus, Oral; Male; Metalloproteases; Middle Aged; Mouth Neoplasms; Precancerous Conditions; Probability; Prognosis; Reference Values; Retrospective Studies; Risk Factors; Sensitivity and Specificity; Severity of Illness Index; Sex Factors; Tissue Inhibitor of Metalloproteinase-1; Transforming Growth Factor beta

The expression patterns of TGFB signaling proteins, such as TGFB1/2, TGFBR1(ALK5), TGFBR2, SMAD1/2/3, SMAD2/3, SMAD4, SMAD7, and of downstream targets of TGFB signaling, CDKN1A (p21CIP1), CDKN1B (p27KIP1), MYC, CDC25A, TP53, and RELA (p65NF-kB) were investigated in gastric carcinomas and other gastric lesions.. A total of 112 gastric carcinomas, 37 dysplasias, 54 intestinal metaplasias, 29 chronic atrophic gastritis and 54 normal gastric epithelium were analyzed by tissue microarray-based immunohistochemical analysis. Extensive changes in expression profiles of these proteins were observed. Three types of expression patterns were observed along the normal epithelium-atrophic gastritis-dysplasia-carcinoma sequence. (1) Expression of TGFB1/2, TGFBR1, MYC, and TP53 continually increased along this sequence. (2) Expression of SMAD4, CDKN1A, SMAD1/2/3, SMAD2/3, and CDKN1B was enhanced in dysplasia but decreased in carcinoma. (3) Expression of TGFBR2, SMAD7, RELA, and CDC25A was enhanced in dysplasia and the enhanced level was maintained in carcinoma. In addition, we also evaluated the clinical significance of the expression of TGFB signaling proteins in gastric carcinoma. TGFB and MYC were positively correlated with advanced stages, whereas SMAD1/2/3 and SMAD4 were strongly associated with earlier stages.. The extensive change in expression of TGFB signaling components is implicated during tumorigenesis of gastric neoplasias.

Topics: Adenocarcinoma; Aged; Aged, 80 and over; Cell Transformation, Neoplastic; Female; Gene Expression; Gene Expression Profiling; Humans; Immunohistochemistry; Male; Middle Aged; Precancerous Conditions; Signal Transduction; Stomach Neoplasms; Tissue Array Analysis; Transforming Growth Factor beta; Tumor Suppressor Protein p53

Barrett's esophagus (BE) is a precancerous condition. However, the mechanisms underlying the transformation from metaplastic to dysplastic to adenocarcinomatous epithelium are still poorly understood. As loss of transforming growth factor-beta growth inhibition is considered a hallmark of several human neoplasms, we evaluated the expression of Ski and SnoN (proteins that antagonize transforming growth factor-beta signaling through physical interaction with Smad complex and by recruiting histone deacetylases), as markers of the transforming growth factor-beta signaling pathway, in BE with and without dysplasia. Biopsy samples from 37 patients (26 men, aged 60 +/- 8 years) with histologically proven BE were evaluated; 10 patients had concomitant low-grade dysplasia, 7 high-grade dysplasia (HGD), and 6 HGD associated with adenocarcinoma. Ski and SnoN expression was assessed immunohistochemically. Neither Ski nor SnoN was expressed in normal esophageal epithelium, but both were strongly expressed in BE tissue, with intense cytoplasmic positivity. Expression of these proteins decreased markedly in dysplastic areas in patients with low-grade dysplasia and was absent in those with HGD or HGD/adenocarcinoma. Ski and SnoN proteins are overexpressed in BE and may be involved in abnormal signaling elicited by transforming growth factor-beta in this epithelium, enhancing the tumorigenesis process. These observations might help to elucidate the molecular mechanisms involved in the BE tumorigenesis process.

Topics: Adenocarcinoma; Aged; Barrett Esophagus; Cell Transformation, Neoplastic; DNA-Binding Proteins; Esophageal Neoplasms; Humans; Immunohistochemistry; Intracellular Signaling Peptides and Proteins; Male; Metaplasia; Middle Aged; Precancerous Conditions; Proto-Oncogene Proteins; Transforming Growth Factor beta

Transforming growth factor (TGF)-beta signaling has been associated with early tumor suppression and late tumor progression; however, many of the mechanisms that mediate these processes are not known. Using Cre/LoxP technology, with the whey acidic protein promoter driving transgenic expression of Cre recombinase (WAP-Cre), we have now ablated the type II TGF-beta receptor (T beta RII) expression specifically within mouse mammary alveolar progenitors. Transgenic expression of the polyoma virus middle T antigen, under control of the mouse mammary tumor virus enhancer/promoter, was used to produce mammary tumors in the absence or presence of Cre (T beta RII((fl/fl);PY) and T beta RII((fl/fl);PY;WC), respectively). The loss of TGF-beta signaling significantly decreased tumor latency and increased the rate of pulmonary metastasis. The loss of TGF-beta signaling was significantly correlated with increased tumor size and enhanced carcinoma cell survival. In addition, we observed significant differences in stromal fibrovascular abundance and composition accompanied by increased recruitment of F4/80(+) cell populations in T beta RII((fl/fl);PY;WC) mice when compared with T beta RII((fl/fl);PY) controls. The recruitment of F4/80(+) cells correlated with increased expression of known inflammatory genes including Cxcl1, Cxcl5, and Ptgs2 (cyclooxygenase-2). Notably, we also identified an enriched K5(+) dNp63(+) cell population in primary T beta RII((fl/fl);PY;WC) tumors and corresponding pulmonary metastases, suggesting that loss of TGF-beta signaling in this subset of carcinoma cells can contribute to metastasis. Together, our current results indicate that loss of TGF-beta signaling in mammary alveolar progenitors may affect tumor initiation, progression, and metastasis through regulation of both intrinsic cell signaling and adjacent stromal-epithelial interactions in vivo.

Topics: Animals; Bone Marrow Cells; Breast Cyst; Cell Differentiation; Cell Survival; Disease Progression; Hyperplasia; Lung Neoplasms; Mammary Neoplasms, Experimental; Mice; Neoplastic Stem Cells; Precancerous Conditions; Protein Serine-Threonine Kinases; Receptor, Transforming Growth Factor-beta Type II; Receptors, Transforming Growth Factor beta; Signal Transduction; Stromal Cells; Transforming Growth Factor beta

An important stage in tumorigenesis is the ability of a precancerous cell to escape natural anticancer signals imposed on it by neighboring cells and its microenvironment. We have previously characterized a system of intercellular induction of apoptosis whereby nontransformed cells selectively remove transformed cells from coculture via cytokine and reactive oxygen/nitrogen species (ROS/RNS) signaling. We report that irradiation of nontransformed cells with low doses of either high linear energy transfer (LET) alpha-particles or low-LET gamma-rays leads to stimulation of intercellular induction of apoptosis. The use of scavengers and inhibitors confirms the involvement of ROS/RNS signaling and of the importance of transformed cell NADPH oxidase in the selectivity of the system. Doses as low as 2-mGy gamma-rays and 0.29-mGy alpha-particles were sufficient to produce an observable increase in transformed cell apoptosis. This radiation-stimulated effect saturates at very low doses (50 mGy for gamma-rays and 25 mGy for alpha-particles). The use of transforming growth factor-beta (TGF-beta) neutralizing antibody confirms a role for the cytokine in the radiation-induced signaling. The system may represent a natural anticancer mechanism stimulated by extremely low doses of ionizing radiation.

Topics: Alpha Particles; Animals; Antibodies; Apoptosis; Cell Line, Transformed; Cell Transformation, Neoplastic; Dose-Response Relationship, Radiation; Fibroblasts; Gamma Rays; NADPH Oxidases; Precancerous Conditions; Rats; Reactive Nitrogen Species; Reactive Oxygen Species; Signal Transduction; Transforming Growth Factor beta

Transforming growth factor beta (TGF-beta) is frequently involved in gastrointestinal carcinogenesis although its contribution to oesophageal adenocarcinoma (AC) and its precursor Barrett's oesophageal epithelium (BE) metaplasia are unclear.. Expression of TGF-beta signalling components was assessed by reverse transcription-polymerase chain reaction (PCR), western blot, and immunohistochemistry in oesophageal endoscopic biopsies and cell lines. Genomic alterations in SMAD4 were characterised by fluorescence in situ hybridisation, methylation specific PCR, and sequencing. Functional integrity of TGF-beta signalling was assessed by characterisation of p21 and proliferation status. Smad4 negative BIC-1 cells were transiently transfected with smad4 and TGF-beta responsiveness evaluated.. smad4 mRNA expression was progressively reduced in the metaplasia-dysplasia-adenocarcinoma sequence (p<0.01). A quarter of AC samples displayed an abnormal Smad4 protein isoform, with no corresponding changes in gene sequence or organisation. Methylation of smad4 has not been described previously but we found promoter methylation in 70% of primary AC samples. In 6/8 oesophageal cell lines, chromosomal rearrangements affected the smad4 locus. Lack of smad4 expression in BIC-1 cells occurred secondary to loss of one copy and extensive deletion of the second allele's promoter region. TGF-beta dependent induction of p21 and downregulation of minichromosome maintenance protein 2 was lost in >80% of BE and AC. TGF-beta failed to inhibit proliferation in 5/8 oesophageal cell lines. In BIC-1, the antiproliferative response was restored following transient transfection of smad4 cDNA.. In BE carcinogenesis, downregulation of Smad4 occurs due to several different mechanisms, including methylation, deletion, and protein modification. Frequent alterations in TGF-beta signalling lead to a functionally significant impairment of TGF-beta mediated growth suppression.

Topics: Adenocarcinoma; Barrett Esophagus; Base Sequence; Cell Proliferation; Cell Transformation, Neoplastic; Disease Progression; DNA Methylation; Esophageal Neoplasms; Gene Expression Regulation, Neoplastic; Genome; Humans; Molecular Sequence Data; Neoplasm Proteins; Precancerous Conditions; Prospective Studies; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; RNA, Neoplasm; Signal Transduction; Smad4 Protein; Transfection; Transforming Growth Factor beta; Tumor Cells, Cultured

During breast cancer development, the luminal space of the mammary acinar unit fills with proliferating epithelial cells that exhibit growth factor-independence, cell attachment defects, and a more invasive fibroblastic phenotype. Here, we used primary cultures of mammary epithelial cells derived from genetically engineered mice to identify caveolin-1 (Cav-1) as a critical factor for maintaining the normal architecture of the mammary acinar unit. Isolated cultures of normal mammary epithelial cells retained the capacity to generate mammary acini within extracellular matrix. However, those from Cav-1 (-/-) mice exhibited defects in three-dimensional acinar architecture, including disrupted lumen formation and epidermal growth factor-independent growth due to hyperactivation of the p42/44 mitogen-activated protein kinase cascade. In addition, Cav-1-null mammary epithelial cells deprived of exogenous extracellular matrix underwent a spontaneous epithelial-mesenchymal transition, with reorganization of the actin cytoskeleton, and E-cadherin redistribution. Mechanistically, these phenotypic changes appear to be caused by increases in matrix metalloproteinase-2/9 secretion and transforming growth factor-beta/Smad-2 hyperactivation. Finally, loss of Cav-1 potentiated the ability of growth factors (hepatocyte growth factor and basic fibroblast growth factor) to induce mammary acini branching, indicative of a more invasive fibroblastic phenotype. Thus, a Cav-1 deficiency profoundly affects mammary epithelia by modulating the activation state of important signaling cascades. Primary cultures of Cav-1-deficient mammary epithelia will provide a valuable new model to study the spatial/temporal progression of mammary cell transformation.

Topics: Animals; Blotting, Western; Caveolin 1; Cell Transformation, Neoplastic; Cells, Cultured; Female; Fluorescent Antibody Technique; Growth Substances; Mammary Glands, Animal; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Mice; Microscopy, Electron, Transmission; Neoplasm Invasiveness; Precancerous Conditions; Signal Transduction; Smad2 Protein; Transforming Growth Factor beta

TGF-beta has been postulated to play an important role in the development of pancreatic cancers. More than 50% of human pancreatic cancers bear mutations of Sma- and Mad-related protein (Smad) 4, a critical protein required for TGF-beta signaling. To evaluate the in vivo function of TGF-beta in the development of pancreatic cancers, we generated a transgenic mouse model with pancreas-specific expression of Smad7, a specific inhibitor of TGF-beta signaling. Through the use of elastase I promoter, we directed the tissue specific expression of exogenous Smad7. Consistently, the exogenous Smad7 was detected only in the pancreas in the transgenic mice, and, furthermore, phosphorylation of Smad2 was blocked in the pancreatic tissues. At 6 months of age, most transgenic animals developed premalignant ductal lesions in the pancreas, with characteristics of pancreatic intraepithelial neoplasia (PanIN), a precursor to invasive pancreatic cancers. The premalignant lesions of the pancreas were accompanied by accelerated proliferation of the ductal epithelium and acinar cells, as well as increased fibrosis around the ductal lesions. This study not only demonstrated that in vivo inactivation of TGF-beta signaling is implicated in the development of early stage of pancreatic cancers, but also provided a promising animal model useful for the investigation and intervention of pancreatic cancers in humans.

Topics: Animals; Cell Proliferation; Cell Transformation, Neoplastic; Gene Expression Regulation; Mice; Mice, Transgenic; Organ Size; Organ Specificity; Pancreas; Precancerous Conditions; Signal Transduction; Smad7 Protein; Transforming Growth Factor beta; Transgenes

Platelets are rich sources of growth factors and enzymes that are implicated in a number of diseases including obesity, atherosclerosis, heart disease, syndrome X, liver and kidney diseases and certain types of cancers. In this research we investigated, if platelets in Zucker obese rats differ from their lean counterparts with respect to the levels of TGF-beta and COX isoforms, implicated in the pathogenesis of chronic diseases. In addition, we investigated if energy intake of the animals affects the platelet physiology. Platelets were isolated from obese and lean rats bearing preneoplastic lesions in their colon. Prior to platelet isolation these rats were fed either ad libitum (Ob or Ln) or energy restricted (Ob-ER or Ln-ER) diets for 8 weeks (n = 8/group). The levels of TGF-beta1/-beta2 and COX-1/-2 proteins in platelets were analyzed by Western blot. The platelets of the Ob rats had significantly higher levels of TGF-beta1, COX-1/-2 (p < 0.001) than did the platelets of the Ln rats and were not affected by moderate energy restriction. There were no significant differences in the protein expression of platelet TGF-beta2 among any of the groups. These results demonstrate that cytokines and candidates playing a role in the pathogenesis of chronic diseases, such as TGF-beta1 and COX-1/-2, are over-expressed in platelets of Zucker obese rats by comparison to their lean counterparts. These findings also demonstrate that the genotype of the animals exerts a significant effect on the biochemical composition of the platelets and could contribute to the pathogenesis of colon cancer and other metabolic abnormalities associated with obesity.

Topics: Animals; Blood Platelets; Colonic Neoplasms; Cyclooxygenase 1; Cyclooxygenase 2; Diet, Carbohydrate-Restricted; Energy Intake; Female; Isoenzymes; Membrane Proteins; Obesity; Precancerous Conditions; Rats; Rats, Zucker; Transforming Growth Factor beta; Transforming Growth Factor beta1; Transforming Growth Factor beta2

Cytokine gene polymorphisms and Helicobacter pylori (HP) genotypes have been linked to gastric cancer development in Western countries. We determined the role of host cytokine polymorphisms and bacterial virulent factors in the development of gastric intestinal metaplasia (IM) in a Chinese population with a high background gastric cancer incidence.. Three hundred two HP-infected noncancer individuals living in Shandong province of China with available DNA were studied. Polymorphisms in different loci of inflammatory cytokines Interleukin IL-1B, IL-1RN, Interleukin IL-8, IL-10, IL-18, tumor necrosis factor-A (TNF-A), and Transforming growth factor (TGF-B), were determined by allelic discriminating TaqMan polymerase chain reaction (PCR) or a variable number of tandem repeats. Presence of HP virulence factors in cagA, vacA, and babA2 were determined by PCR. Baseline gastric biopsies were assessed for the presence of IM.. Among HP-infected subjects, carriers of the IL-1B-511 T allele were associated with a modestly greater prevalence of IM (adjusted OR 2.0, 95% CI 1.0-3.7). There was no association between the presence of IM and polymorphisms in other inflammatory cytokines. Although most subjects from this region harbored the virulent HP strains, carriage of the vacA m1 strain was associated with a significantly higher prevalence of IM (adjusted OR 1.8, 1.1-3.0). The presence of both host (IL-1B-511 T) and HP (vacA m1) genotypes further increased the risk of IM (OR 5.7, 2.0-16) when compared with individuals with the low-risk genotype.. The carriage of proinflammatory IL-1B-511 and HP vacA m1 genotypes was associated with the development of gastric IM in the Chinese.

Topics: China; Cytokines; Female; Gastric Mucosa; Genes, Viral; Genotype; Helicobacter Infections; Helicobacter pylori; Humans; Interleukins; Male; Metaplasia; Middle Aged; Polymerase Chain Reaction; Polymorphism, Genetic; Precancerous Conditions; Stomach Neoplasms; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha; Virulence Factors

Pancreatic ductal adenocarcinoma (PDAC) is associated with an intense fibrotic reaction around the tumor known as desmoplastic reaction. This tissue is composed of interstitial matrix, predominantly type I collagen, together with proliferating fibroblastic cells. Despite the recognized importance of tumor-stromal interactions, very little is known about the interactions among pancreatic cells, myofibroblasts, and the interstitial matrix. The current study was undertaken to test the hypothesis that the desmoplastic reaction alters PDAC gene expression and cellular behavior. Evaluation of human pancreatic specimens showed increased fibrosis and enhanced membrane type 1-matrix metalloproteinase (MT1-MMP) expression in tumor specimens compared with normal pancreas. Using an in vitro model of tumor cell-stromal interactions, type I collagen and the extracellular matrix deposited by pancreatic fibroblasts and PDAC cells regulated motility of human papillomavirus-immortalized human pancreatic ductal epithelial (HPDE) cells. These "stromal" matrices also regulated MT1-MMP expression by HPDE cells, without affecting the expression of tissue inhibitor of metalloproteinase 2. Treatment with transforming growth factor-beta1 (TGF-beta1) type I receptor kinase inhibitors and function-blocking anti-TGF-beta1 antibody abrogated matrix-mediated MT1-MMP induction. TGF-beta1 also promoted MT1-MMP-dependent migration by HPDE cells. Moreover, compared with normal tissue, there was increased TGF-beta1 signaling in grade 3 tumor specimens as shown by increased phospho-Smad2 staining. These data show that the crosstalk between cancer cells and stromal elements mediated by TGF-beta1 influences cell surface- and pericellular matrix-degrading potential in vitro and may contribute to pancreatic cancer progression in vivo.

Topics: Carcinoma, Pancreatic Ductal; Cell Movement; Collagen Type I; Fibrosis; Humans; Immunohistochemistry; Matrix Metalloproteinases; Matrix Metalloproteinases, Membrane-Associated; Pancreatic Neoplasms; Precancerous Conditions; RNA, Messenger; Signal Transduction; Stromal Cells; Transforming Growth Factor beta; Transforming Growth Factor beta1

There is increasing evidence that stromal reaction in cancer has an important diagnostic and prognostic significance. Recent studies have shown that CD34-positive stromal cells and myofibroblasts may play an important role in host response to invasive cancer. The aim of our study was to analyze the expression of CD34, alpha-smooth muscle actin (SMA), and transforming growth factor beta1 (TGFbeta1) in squamous intraepithelial lesions (SILs) and squamous cell carcinoma (SCC) of the larynx and hypopharynx, to establish their significance, and to elucidate the mechanism of myofibroblast formation.. Immunohistochemistry was performed on samples of 42 resected larynges and 12 laryngeal biopsies of SILs and SCC using antibodies against SMA, CD34, CD31, TGFbeta1, and TGFbeta1 receptors. The expression of TGFbeta1 mRNA was detected with RNA in situ hybridization using specific oligonucleotides for TGFbeta1.. The stroma in normal laryngeal mucosa and SILs contained scattered CD34-positive cells, but there were no SMA-positive myofibroblasts. In contrast, the stroma of SCC contained SMA-positive myofibroblasts, but there were no CD34-positive stromal cells. This pattern of stromal reaction was also observed in the peritumoral zone. In adjacent normal tissue, there were CD34-positive stromal cells and no myofibroblasts. We found more intense TGFbeta1 expression in carcinoma cells than in the normal laryngeal epithelium and positive staining for both TGFbeta1 receptors on stromal cells of the normal mucosa. In SCC, many myofibroblasts expressed TGFbeta1 and both receptors for TGFbeta1. Expression of TGFbeta1 mRNA was similar to expression of TGFbeta1 protein.. Our study shows that disappearance of CD34-positive stromal cells and appearance of SMA-positive stromal myofibroblasts are associated with transformation of laryngeal SILs to SCC. This pattern of stromal reaction was found not only in the tumor but also in the peritumoral zone, defined as a band of host tissue between the invasive tumor front and adjacent normal tissue. Our findings also support the suggestion that overproduced TGFbeta1 in carcinoma cells mediates one of the mechanisms of transformation of stromal cells to myofibroblasts in laryngeal carcinogenesis.

Topics: Actins; Adult; Aged; Aged, 80 and over; Antigens, CD34; Biomarkers, Tumor; Carcinoma, Squamous Cell; Female; Humans; Hypopharynx; Immunohistochemistry; In Situ Hybridization; Laryngeal Neoplasms; Male; Middle Aged; Muscle, Smooth; Precancerous Conditions; RNA, Messenger; Transforming Growth Factor beta; Transforming Growth Factor beta1

NRP-154 is a tumorigenic epithelial cell line derived from the preneoplastic dorsal-lateral prostate of rats. These cells are exquisitely sensitive to TGF-beta induced apoptosis. In contrast, we find that NRP-154 cells can sustain overexpression of exogenous Bax protein, which is different from non-tumor cells where Bax functions as a ubiquitous stimulator of apoptosis. NRP-154 cells stably overexpressing Bax show increased sensitivity to TGF-beta induced apoptosis. The degree of TGF-beta induced apoptosis displays high correlation with cleavage of Bax at the amino-terminus. Our data indicate that prostate cancer cells can host high levels of latent Bax which can be activated through post-translational modification.

Topics: Animals; Apoptosis; bcl-2-Associated X Protein; Cell Line, Tumor; Epithelial Cells; Green Fluorescent Proteins; Humans; Male; Mice; Precancerous Conditions; Prostatic Neoplasms; Rats; Recombinant Fusion Proteins; Transforming Growth Factor beta; Transforming Growth Factor beta1

Upregulation of HER2/ErbB2/Neu occurs in 15-30% of human breast cancers and correlates with poor prognosis. Identification of ErbB2/Neu transcriptional targets should facilitate development of novel therapeutic approaches. Development of breast cancer is a multistep process; thus, to identify the transcriptomes associated with different stages of progression of tumorigenesis, we compared expression profiles of mammary tumors and preneoplastic mammary tissue from MMTV-Neu transgenic mice to expression profiles of wild-type mammary glands using Affymetrix microarrays. We identified 324 candidate genes that were unique to ErbB2/Neu-induced tumors relative to normal mammary gland tissue from wild-type controls. Expression of a subset of these genes (82) was also changed in the preneoplastic mammary glands compared to wild-type controls, indicating that they may play a pivotal role during early events of ErbB2/Neu-initiated mammary tumorigenesis. Further analysis of the microarray data revealed that expression of several known transforming growth factor (TGF)-beta target genes was altered, suggesting that the TGF-beta signaling cascade is downregulated in ErbB2/Neu-induced tumors. Western blot analysis for TGF-beta-Receptor-I/ALK5 and immunohistochemistry for TGF-beta-Receptor-I/ALK5 and phosphorylated/activated Smad2 confirmed that the Smad-dependent TGF-beta signaling cascade was inactive in these tumors. Although absent in most of the tumor, phosphorylated Smad2 was present in the periphery of tumors. Interestingly, presence of phosphorylated/activated Smad2 correlated with expression of Activin-Receptor-IB/ALK4, suggesting that although Smad-dependent TGF-beta signaling is absent in ErbB2/Neu-induced tumors, Activin signaling may be active at the leading edge of these tumors. Cumulatively, these data indicate that the TGF-beta pathway is intrinsically suppressed in ErbB2/Neu tumors via a mechanism involving loss of TGF-beta-Receptor-I/ALK5.

Topics: Activin Receptors; Animals; Cell Transformation, Neoplastic; Disease Progression; DNA-Binding Proteins; Female; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Mammary Neoplasms, Animal; Mice; Mice, Transgenic; Oligonucleotide Array Sequence Analysis; Precancerous Conditions; Receptor, ErbB-2; Signal Transduction; Smad2 Protein; Trans-Activators; Transcription, Genetic; Transforming Growth Factor beta; Up-Regulation

Transcriptional silencing of tumour suppressor genes by DNA hypermethylation plays a crucial role in the progression of gastric cancer. Many genes involved in the regulation of cell cycle, tissue invasion, DNA repair and apoptosis have been shown to be inactivated by this type of epigenetic mechanism.. Recent studies have demonstrated that DNA hypermethylation begins early in cancer progression, and in some cases, may precede the neoplastic process. Ageing is associated with DNA hypermethylation, and may provide a mechanistic link between ageing and cancer. Several reports have indicated that Epstein-Barr virus-related gastric cancer is associated with a high frequency of DNA hypermethylation, suggesting that viral oncogenesis might involve DNA hypermethylation with inactivation of tumour suppressor genes. Hypermethylation of hMLH1 with the resulting loss of its expression is known to cause microsatellite instability, which reflects genomic instability associated with defective DNA mismatch repair genes in the tumour.. In conclusion, recent studies demonstrate that DNA hypermethylation is a crucial mechanism of inactivation of tumour suppressor genes in gastric cancer. A better understanding of DNA hypermethylation will provide us with new opportunities in the diagnosis and therapy of gastric cancer.

Topics: Cadherins; Cell Line, Tumor; Core Binding Factor Alpha 3 Subunit; Cyclin-Dependent Kinase Inhibitor p16; DNA Methylation; DNA-Binding Proteins; DNA, Bacterial; Epstein-Barr Virus Infections; GTPase-Activating Proteins; Helicobacter Infections; Helicobacter pylori; Humans; Precancerous Conditions; Stomach Neoplasms; Transcription Factors; Transforming Growth Factor beta; Tumor Suppressor Protein p14ARF; Tumor Suppressor Proteins

In previous work we showed that interferon alfa-2b (IFN-alpha2b) increases apoptosis on rat hepatic preneoplastic foci. The aim of this study was to determine if transforming growth factor beta1 (TGF-beta1) was involved in the programmed cell death on the foci. Animals were divided into 6 groups: subjected to a 2-phase model (diethylnitrosamine plus 2-acetylaminofluorene) of preneoplasia development (group 1); treated with IFN-alpha2b during the 2 phases (group 2); treated with IFN-alpha2b during initiation with diethylnitrosamine (group 3); treated with IFN-alpha2b during 2-acetylaminofluorene administration (group 4); subjected only to an initiation stage (group 5); and treated with IFN-alpha2b during the initiation period (group 6). Serum TGF-beta1 levels were increased in IFN-alpha2b-treated rats. Immunohistochemical studies showed that IFN-alpha2b significantly increased the quantity of TGF-beta1-positive hepatocytes in groups 2 to 4. Phosphorylated-Smads-2/3 (p-Smads-2/3) proteins in liver nuclear extracts were significantly elevated. To determine the source of TGF-beta1, isolated hepatocytes, Kupffer cells, and peritoneal macrophages from animals in groups 1 and 5 were cultured with or without IFN-alpha2b. IFN-alpha2b stimulus induced several-fold increases of TGF-beta1 secretion from hepatocytes. Neither Kupffer cells nor peritoneal macrophages secreted detectable TGF-beta1 levels when they were treated with IFN-alpha2b. IFN-alpha2b-stimulated cultured hepatocytes from preneoplastic livers showed enhanced apoptosis, measured by fluorescence microscopy and caspase-3 activity. They presented higher nuclear accumulation of p-Smads-2/3, indicating increased TGF-beta1 signaling. When anti-TGF-beta1 was added to the culture media, TGF-beta1 activation and apoptosis induced by IFN-alpha2b were blocked. In conclusion, IFN-alpha2b-induced production of TGF-beta1 by hepatocytes from preneoplastic liver is involved in the apoptotic elimination of altered hepatic foci.

Topics: Animals; Apoptosis; Caspase 3; Caspases; Cell Nucleus; Cells, Cultured; Culture Media; DNA-Binding Proteins; Enzyme Activation; Hepatocytes; Interferon alpha-2; Interferon-alpha; Liver; Liver Neoplasms, Experimental; Male; Phosphorylation; Precancerous Conditions; Rats; Rats, Wistar; Recombinant Proteins; Smad2 Protein; Smad3 Protein; Trans-Activators; Transforming Growth Factor beta; Transforming Growth Factor beta1

The pro-peptide of transforming growth factor alpha (proTGFalpha) was recently found in hepatocyte nuclei preparing for DNA replication, which suggests a role of nuclear proTGFalpha for mitogenic signalling. This study investigates whether the nuclear occurrence of the pro-peptide is involved in the altered growth regulation of (pre)malignant hepatocytes. In human hepatocarcinogenesis, the incidence of proTGFalpha-positive and replicating nuclei gradually increased from normal liver, to dysplastic nodules, to hepatocellular carcinoma. ProTGFalpha-positive nuclei almost always were in DNA synthesis. Also, in rat hepatocarcinogenesis, proTGFalpha-positive nuclei occurred in (pre)malignant hepatocytes at significantly higher incidences than in unaltered hepatocytes. For functional studies unaltered (GSTp(-)) and premalignant (GSTp(+)) rat hepatocytes were isolated by collagenase perfusion and cultivated. Again, DNA synthesis occurred almost exclusively in proTGFalpha-positive nuclei. GSTp(+) hepatocytes showed an approximately 3-fold higher frequency of proTGFalpha-positive nuclei and DNA replication than GSTp(-) cells. Treatment of cultures with the mitogen cyproterone acetate (CPA) elevated the incidence of proTGFalpha-positive nuclei and DNA synthesis in parallel. Conversely, transforming growth factor beta1 (TGFbeta1) lowered both. These effects of CPA and TGFbeta1 were significantly more pronounced in GSTp(+) than in GSTp(-) hepatocytes. In conclusion, nuclear translocation of proTGFalpha increases in the course of hepatocarcinogenesis and appears to be involved in the inherent growth advantage of (pre)malignant hepatocytes.

Topics: Animals; Antineoplastic Agents; Cell Nucleus; Cyproterone Acetate; DNA; DNA Replication; Glutathione Transferase; Hepatocytes; Liver Neoplasms; Male; Precancerous Conditions; Protein Transport; Rats; Rats, Wistar; Transforming Growth Factor alpha; Transforming Growth Factor beta; Transforming Growth Factor beta1

Modulation of fibrogenesis, epithelial, and mesenchymal cell fates are prominent effects of transforming growth factor-beta (TGF-beta) signaling by Smad proteins. We have previously shown that Smad2 and Smad3 insufficiency leads to a loss of bile ducts. In addition, Smad3/4 activity is mediated by embryonic liver fodrin (ELF), a beta-Spectrin. In mouse elf(-/-) mutants and in liver explant cultures, loss of ELF function results in T lymphocytic proliferation and absent intrahepatic bile ducts. A similar phenotype is seen in a number of cholestatic diseases with progressive loss of intrahepatic bile ducts and fibrosis. However, the expression patterns of Smads or role of ELF in cholestatic and fibrotic liver diseases are not yet known.. We investigated the role of ELF in primary biliary cirrhosis (PBC), autoimmune hepatitis C, chronic viral hepatitis and in livers from mice deficient in Smad2/Smad3. We generated elf(+/-) mutant mice and analyzed for chronic liver disease and hepatocellular cancer (HCC) from 6 to 12 months. Perturbations in ELF expression were consistently seen only in PBC tissues. ELF expression was similarly aberrant in tissues from Smad2(+/-)/Smad3(+/-) mutant mice. Further studies indicated that ELF mislocalization is correlated with aberrant localization of Smad3 in some PBC tissues. Thirteen of 17 elf(+/-) mutant mice developed steatosis, fibrosis, hepatic dysplasia, with HCC in two mice.. These results suggest that a compromised cytoarchitecture and polarized trafficking of TGF-beta signaling molecules, ELF and Smad3 are involved in the pathogenesis of PBC as well as HCC.

Topics: Animals; Base Sequence; Biomarkers, Tumor; Biopsy, Needle; Blotting, Western; Carcinoma, Hepatocellular; Carrier Proteins; Cohort Studies; DNA-Binding Proteins; Ephrin-A2; Female; Humans; Immunohistochemistry; Liver Cirrhosis; Liver Neoplasms; Male; Mice; Mice, Mutant Strains; Microfilament Proteins; Molecular Sequence Data; Polymerase Chain Reaction; Precancerous Conditions; Signal Transduction; Smad2 Protein; Smad3 Protein; Spectrin; Trans-Activators; Transforming Growth Factor beta; Tumor Suppressor Proteins

In this study we analyzed by immunohistochemistry the expression of TGF-beta1 protein and TGF-beta receptors I and II in 4 low-grade dysplastic nodules, 2 high-grade dysplastic nodules, 6 early, 22 small, and 62 advanced hepatocellular carcinomas. The expression of TGF-beta1 protein by hepatocytes was decreased in advanced hepatocellular carcinoma compared with small or early hepatocellular carcinoma(P < .05). Frequent and intense staining of TGF-beta1 protein was noted in the sinusoidal endothelium of advanced hepatocellular carcinomas despite of its decreased staining in hepatocellular carcinoma cells. Reduced expression of TGF-beta receptors I and II compared with surrounding nontumorous tissue were noted from the early hepatocellular carcinoma stage suggesting that down-regulation of TGF-beta receptors is correlated with progression from premalignant to malignant phenotype. Reduced expression of both TGF-beta1 and TGF-beta receptor II in neoplastic hepatocytes were also significantly correlated with increased tumor size and increased proliferative activity(P < .05). These findings suggest that during hepatocarcinogenesis, the inhibitory effects of TGF-beta1 protein on hepatocellular carcinoma cells is outweighed by its effects on stromal elements, which, overall, contributes indirectly to a tumor growth stimulatory environment. Also, the growth-inhibitory effects of TGF-beta1 may have been further negated by reduced TGF-beta receptors on hepatocellular carcinoma cells.

Topics: Carcinoma, Hepatocellular; Focal Nodular Hyperplasia; Humans; Immunoenzyme Techniques; Ki-67 Antigen; Liver Neoplasms; Precancerous Conditions; Receptors, Transforming Growth Factor beta; Transforming Growth Factor beta; Transforming Growth Factor beta1

Several epidemiological studies have supported the concept that high energy intake, obesity, and/or hyperinsulinemia are risk factors for colon cancer. Previously, it was shown that Zucker obese rats are more sensitive to chemically induced colon cancer than their lean counterparts. The present study investigated whether moderate (20-25%) dietary energy restriction (ER) would attenuate colon carcinogenesis in the Zucker obese rat model. Six-week-old Zucker obese (fa/fa) rats and lean (Fa/Fa) rats received s.c. injections of azoxymethane at a dose of 10 mg/kg body weight once weekly for 2 weeks. A week later, obese rats (n = 16) were assigned to an ER diet (Ob-ER group), based on a low-fat AIN-93G semisynthetic diet. The remaining obese and lean rats (n = 16 rats/group) were fed the low-fat diet ad libitum (Ob group and Ln group, respectively). All rats were euthanized after 8 weeks, and their colons were assessed for aberrant crypt foci (ACF; n = 8/group) or for the expression of transforming growth factor (TGF)-beta and cyclooxygenase (COX) isoforms at the protein and mRNA transcript levels (n = 8/group). Ob rats had a higher number of advanced ACF (crypt multiplicity >or=7) than Ln rats. Dietary ER significantly reduced the appearance of advanced ACF in Ob-ER rats without significantly affecting the blood insulin level or body weights. TGF-beta and COX isoforms were differentially expressed in the colonic mucosae of Ob and Ln rats. Dietary ER significantly reduced TGF-beta1/beta2 and COX-1/2 protein expression in obese rats. This study is the first to demonstrate that moderate ER attenuated TGF-beta and COX protein expression and the carcinogenic process in Zucker obese rats. These findings provide insights leading to the proposal that the mechanism(s) underlying the early events of colon carcinogenesis in Zucker obese rats may extend beyond the role of excessive body weight and hyperinsulinemia per se.

Topics: Animals; Azoxymethane; Blood Glucose; Body Weight; Caloric Restriction; Carcinogens; Colonic Neoplasms; Cyclooxygenase 1; Cyclooxygenase 2; Eating; Female; Insulin; Isoenzymes; Lactic Acid; Membrane Proteins; Obesity; Precancerous Conditions; Prostaglandin-Endoperoxide Synthases; Rats; Rats, Zucker; RNA, Messenger; Transforming Growth Factor beta; Triglycerides

Topics: Apoptosis; Caspase 3; Caspases; Humans; Hyperplasia; Immunohistochemistry; Precancerous Conditions; Stomach; Stomach Neoplasms; Transforming Growth Factor beta; Tumor Cells, Cultured

We previously demonstrated that fasting/refeeding enhances the initiation phase of liver and colorectal carcinogenesis in rats. The present study was undertaken to establish whether cycles of fasting/refeeding carried out during the promotion phase of carcinogenesis may also affect the formation of aberrant crypt foci (ACF), preneoplastic lesions induced in the colon by azoxymethane (AOM). We were also interested in studying whether this effect might be mediated by changes in the proliferation, apoptosis or expression of TGFbeta1 and p21CIP genes in the colon. 44 male Fisher 344 rats were given a single dose of AOM (20 mg/kg s.c.) and one week later, they were exposed to 5 cycles of 4 days fasting followed by 7-10 days of refeeding (refed rats); controls were regularly fed; the rats were killed 2, 8 or 30 days after the last cycle of fasting. Fasting/refeeding caused a dramatic increase in crypt multiplicity when compared with regularly fed rats (AC/ACF was 4.30 +/- 1.3 in refed and 2.38 +/- 0.4 in regularly fed rats, P < 0.005 means +/- SD), while no significant changes were observed in the number of ACF/colon. In the two experimental groups, cell proliferation was higher in ACF than in the surrounding mucosa, but proliferative indexes were higher and the apoptotic index lower in ACF of refed rats compared with regularly fed rats. TGFbeta1 expression was higher in the ACF of refed rats than in those of fully fed controls while p21CIP was less expressed in refed rats than in controls. These results suggest that fasting/refeeding is a risk factor for colon cancer and must be taken into account for cancer prevention in humans.

Topics: Animals; Azoxymethane; Carcinogens; Cell Division; Colon; Cyclin-Dependent Kinase Inhibitor p21; Cyclins; Food Deprivation; Humans; Immunohistochemistry; In Situ Nick-End Labeling; Kinetics; Male; Mucous Membrane; Precancerous Conditions; Rats; Rats, Inbred F344; Time Factors; Transforming Growth Factor beta; Transforming Growth Factor beta1

The level of transforming growth factor beta1 (TGFbeta1) and transforming growth factor betaII receptor (TGFbetaRII) was determined immunohistochemically in normal tissues and tissues with different severities of lesions (basal cell hyperplasia, BCH; dysplasia, DYS; carcinoma in situ, CIS; and squamous cell carcinoma, SCC) from surgically resected human esophagi and esophageal biopsies of symptom-free subjects. The samples were from an area with high esophageal cancer incidence in northern China (Linzhou, formerly Linxian, and nearby county Huixian in Henan Province). Peroxidase immunostain (ABC) and conventional hematoxylin and eosin stain were used. The tissue sections were incubated with antibodies of TGFbeta1 and TGFbetaRII overnight. The immunoreactivity was observed in cytoplasm of the esophageal specimen. From normal to BCH to DYS to CIS and to SCC, the positive immunostaining rates for TGFbeta1 increased significantly (P < 0.05). A linear correlation between the positive immunostaining rates of TGFbeta1 and the different lesions was observed (P < 0.05). From well- to moderately- and poorly differentiated SCC, the positive immunostaining rates for TGFbeta1 decreased gradually, but the difference was not significant (P > 0.05). In contrast, with the lesions progressing from normal to BCH to DYS to CIS and to SCC, the positive immunostaining rates for TGFbetaRII decreased significantly (P < 0.05). From well- to moderately- and poorly differentiated SCC, the positive immunostaining rates for TGFbetaRII decreased significantly (P < 0.05). There was a linear correlation between the positive rates of TGFbetaRII and different lesions and SCC differentiation (P < 0.05). The present results indicated that the alterations of TGFbeta1 and TGFbetaRII is a frequent event in esophageal multistage carcinogenesis, the absent or lower expression of TGFbetaRII may lead to the loss of cell proliferation control by TGFbeta1 and the overexpression of TGFbeta1 may be a negative feedback response caused by the lower expression of TGFbetaRII protein.

Topics: Adult; Aged; Biomarkers, Tumor; Carcinoma; Cell Transformation, Neoplastic; Culture Techniques; Esophageal Neoplasms; Esophagectomy; Female; Humans; Immunohistochemistry; Male; Middle Aged; Precancerous Conditions; Probability; Prospective Studies; Receptors, Transforming Growth Factor beta; Sampling Studies; Sensitivity and Specificity; Statistics, Nonparametric; Transforming Growth Factor beta; Transforming Growth Factor beta1

In the present study, we performed an immunohistochemical examination of the expression of transforming growth factor-beta (TGF-beta), TGF-beta type II receptor (TGF-beta RII) and a trefoil peptide, pS2, in the several types of gastric cancer. The TGF-beta:TGF-beta RII ratios of IIc-like type and Ménétrier type closely resembled that of linitis type. pS2 was intensely expressed in cytoplasm of the superficial and foveolar epithelium, as well as in scirrhous type gastric cancers which retained the gastric or intestinal phenotype. However, pS2 expression was significantly (p < 0.05) reduced in linitis type gastric cancers (1 of 6; 17%) when compared with other scirrhous types of gastric cancers (13 of 22; 59%). A decrease in the TGF-beta:TGF-beta RII ratios in linitis type, IIc-like type and Ménétrier type gastric cancers may be associated with the fibrosis seen in these types of cancer. Furthermore, reduction of pS2 expression in linitis type gastric cancer may represent a dedifferentiation of the cancer from gastric or intestinal phenotype. Judging by the expression patterns of TGF-beta, TGF-beta RII and pS2, it is possible that IIc-like type and Ménétrier type gastric cancers are precursor lesions of linitis type gastric cancer.

Topics: Humans; Immunoenzyme Techniques; Linitis Plastica; Precancerous Conditions; Protein Serine-Threonine Kinases; Proteins; Receptor, Transforming Growth Factor-beta Type II; Receptors, Transforming Growth Factor beta; Stomach Neoplasms; Transforming Growth Factor beta; Trefoil Factor-1; Tumor Suppressor Proteins

The aim of the present study was to determine the relationships between bone morphogenetic proteins (BMPs), BMP receptor type IA and carcinogenesis of oral epithelium. A retrospective study was performed on material obtained from oral mucosa, including nine cases of normal mucosa (NB), eight cases of nonspecific chronic inflammation (NCI), seven cases of hyperkeratosis (HK), five cases of squamous cell papilloma (SCP), 29 cases of squamous cell carcinoma (SCC) with various grades of differentiation and 10 cases of epithelium adjacent to carcinoma (EAC). Six cases of NB from hard palate (NHP) were chosen as a control group. The benign groups consisted of NCI, HK and SCP. The antibodies against BMP-2/4, -5, receptor BMPR-IA and purified bovine BMP (bBMP-McAb) were utilised using an immunocytochemical method. The results demonstrated that the immunostaining of BMP-2/4, BMP-5, BMPR-IA and bBMP-McAb was weak and not consistent in normal and benign groups. The immunoreactivity level was independent of the clinical and pathological grading of SCC. All cases of SCC showed positive staining for BMP-2/4, BMP-5, BMPR-IA and bBMP-McAb except for three cases and one case of SCC which negatively stained for BMP-2/4 and BMP-5, respectively. The staining intensity and proportion of the positively stained cells were markedly increased in SCC when compared with that of the normal and benign groups except for EAC. The metastatic carcinoma cells in lymph nodes were strongly and positively stained for BMP-2/4 and BMP-5 when compared with the primary lesions. Our results indicate that there was an overexpression of BMP-2/4, BMP-5, bBMP-McAb and BMPR-IA in the high-risk premalignant and malignant lesions of oral epithelium. Our findings suggest that BMP-2/4 and BMP-5 but not BMPR-IA might be involved in the metastasis of oral carcinoma cells.

Topics: Analysis of Variance; Bone Morphogenetic Protein 2; Bone Morphogenetic Protein 5; Bone Morphogenetic Protein Receptors, Type I; Bone Morphogenetic Proteins; Carcinoma, Squamous Cell; Case-Control Studies; Cell Membrane; Cytoplasm; Epithelium; Humans; Immunohistochemistry; Leukoplakia, Oral; Lymphatic Metastasis; Mouth Mucosa; Mouth Neoplasms; Neoplasm Proteins; Palate; Papilloma; Precancerous Conditions; Protein Serine-Threonine Kinases; Receptors, Growth Factor; Retrospective Studies; Statistics, Nonparametric; Transforming Growth Factor beta

To investigate the effect of transforming growth factor beta 1 (TGF beta 1) and p27kip1 in gastric mucosa carcinogenesis.. RT-PCR was used to detect TGF beta 1 and p27kip1 mRNAs in normal gastric mucosa, simple hyperplasia, dysplasia and gastric carcinoma tissues respectively.. There were expressions of TGF beta 1 and p27kip1 mRNAs in normal gastric mucosa, simple hyperplasia, dysplasia and gastric carcinoma tissues, the expressive levels of TGF beta 1 and p27kip1 mRNAs decreased gradually among the four groups. The expressive level of TGF beta 1 and p27kip1 mRNAs in gastric carcinoma group were significantly lower than those in other three groups(P < 0.05).. The data indicate that TGF beta 1 and p27kip1 may play an important role in the development and carcinogenesis of gastric carcinoma. Semi-quantification PCR technique is effective for detecting mRNA expressive level in tissues.

Topics: Cell Cycle Proteins; Cyclin-Dependent Kinase Inhibitor p27; Cyclin-Dependent Kinases; Gastric Mucosa; Genes, Tumor Suppressor; Humans; Hyperplasia; Precancerous Conditions; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Stomach Neoplasms; Transforming Growth Factor beta; Transforming Growth Factor beta1; Tumor Suppressor Proteins

To study growth regulation in the beginning of carcinogenesis, we established a novel ex vivo model for co-cultivation of normal and putatively initiated hepatocytes. Rats received the genotoxic hepatocarcinogen N-nitrosomorpholine (NNM). This led to the appearance of hepatocytes expressing placental glutathione S-transferase (G(+) cells). These cells exhibited elevated rates of cell replication and apoptosis, as known from further advanced preneoplasia; G(+) cells were considered initiated. At days 20-22 post-NNM treatment their frequency was maximal (1-2%); approximately 40% were still single and 60% were arranged in mini foci. At this time-point liver cells were isolated by collagenase perfusion and cultivated. G(+) cells, identified by immunostaining of the culture-plates, were present at the same percentage as in vivo, excluding selective loss, enrichment or spontaneous expression of the G(+) phenotype. In untreated cultures G(+) hepatocytes showed significantly higher rates of replicative DNA synthesis than normal G(-) cells. Application of the hepatomitogen cyproterone acetate (CPA) elevated DNA replication preferentially in G(+) cells. Transforming growth factor beta1 (TGF-beta1) suppressed replicative DNA synthesis which was more pronounced in G(+) than in G(-) hepatocytes. Combined treatment with CPA and TGF-beta1 had no effect on G- cells, but considerably inhibited DNA replication in G(+) cells. This suggests that the effects of TGF-beta1 predominated in G(+) hepatocytes. We conclude that putatively initiated G(+) hepatocytes, both in vivo and in culture, exhibit higher basal rates of DNA replication than normal G(-) hepatocytes and an over-response to mitogens and growth inhibitors. Therefore, G(+) cells show (i) nearly identical behaviour in intact liver and in primary culture and (ii) inherent defects in growth control that are principally similar although somewhat less pronounced than in later stages of carcinogenesis. The present ex vivo system thus provides a novel and useful tool to elucidate biological and molecular changes during initiation of carcinogenesis.

Topics: Animals; Cell Division; Cells, Cultured; Cyproterone Acetate; DNA; Glutathione Transferase; Liver; Liver Neoplasms; Male; Nitrosamines; Phenobarbital; Phenotype; Precancerous Conditions; Rats; Rats, Wistar; Transforming Growth Factor beta

Injection of pig serum into rats twice a week for eight weeks induced transforming growth factor-beta1 (TGF-beta1) mRNA expression and protein production resulting in liver fibrosis without parenchymal cell injury. Eight-week treatment with pig serum reduced bromodeoxyuridine (BrdU) -positive hepatocytes 24 hr after 70% partial hepatectomy compared to that in the livers of rats treated with saline for eight weeks. Administration of a choline-deficient L-amino acid-defined (CDAA) diet for six weeks with pig serum coadministration, after pretreatment with pig serum for eight weeks, led to the development of preneoplastic lesions that were positive for the placental form of glutathione S-transferase (GSTP). Eight-week pretreatment with pig serum induced more GSTP-positive lesions and TGF-beta1 mRNA expression and protein concentration in the livers of rats subsequently fed a CDAA diet for six weeks than in rats fed the CDAA diet with saline treatment. These results indicate that TGF-beta1 induced by pig serum treatment inhibited hepatocyte proliferation but failed to prevent the development of preneoplastic lesions in a CDAA diet model.

Topics: Animals; Disease Models, Animal; Immunohistochemistry; Liver; Liver Neoplasms; Male; Precancerous Conditions; Rats; Rats, Wistar; Transforming Growth Factor beta

Cervical carcinogenesis is a multistep process initiated by 'high-risk' human papillomaviruses (HR-HPVs), most commonly HPV 16. Transforming growth factor-beta (TGF-beta) inhibits epithelial proliferation and down-regulates transcription of E6/E7 genes of HPV. Altered TGF-beta expression may be important in carcinogenesis. Quantitative RT-PCR was used to investigate TGF-beta1, beta2, and beta3 mRNA levels in nine specimens of normal cervix and 15 cervical precancers (eight HPV-positive, including five HPV 16-positive). Immunocytochemical expression of TGF-beta1, beta2, and beta3 was examined in cervical intraepithelial neoplasia (CIN) positive for HPV 16 (26), and in HPV-negative, normal ectocervical epithelium (9); reserve cell hyperplasia (12); and immature (7) and mature (15) squamous metaplasia. The intensity of staining for TGF-beta1 was measured using grey-scale image analysis. Microdissection was used to investigate epithelial and stromal (excluding crypts) levels of TGF-beta1 mRNA in HPV 16-positive cervical precancer. Normal cervix, including reserve cells and immature and mature metaplasia, showed strong immunocytochemical expression of all TGF-beta isoforms. Expression was decreased in the basal third of the epithelium in CIN 1, in the basal and middle thirds in CIN 2, and in all layers in CIN 3. Quantitative analysis of TGF-beta1 expression showed that the changes in CIN compared with normal ectocervix and mature metaplasia were statistically highly significant (p<0.001, ANOVA). TGF-beta1, beta2, and beta3 mRNA levels showed a significant decrease only in the five HPV 16-positive CIN samples when compared with normal (p=0. 0034, 0.0033, and 0.029, respectively). TGF-beta mRNA levels in HPV 16-positive epithelium also decreased from normal through low-grade to high-grade precancer. Stromal TGF-beta1 was absent or very low compared with epithelial production and was not altered in HPV 16 precancer. Progressive loss of epithelial TGF-beta expression and synthesis may be important in HPV 16-associated human cervical carcinogenesis.

Topics: Epithelium; Female; Gene Expression; Humans; Papillomaviridae; Precancerous Conditions; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; RNA, Neoplasm; Transforming Growth Factor beta; Uterine Cervical Dysplasia; Uterine Cervical Neoplasms

To investigate how glutathione-S-transferase placental form (GST-P)+ hyperplastic nodules (HNs) are selected and to determine the driving force for progression or regression of HNs, changes in transforming growth factor-beta1 (TGF-beta) and its receptors were examined during hepatocarcinogenesis initiated by N-nitrosodiethylamine (DEN) and promoted by nodularin. The induction of TGF-beta1 expression in the GST-P+ HNs was dependent on nodularin injections for 10 wk, which started the third week after DEN initiation. The kinetics of TGF-beta1 induction during carcinogenesis were quite different from that of simple regeneration after partial hepatectomy (PH): hepatocytes initiated with DEN alone induced TGF-beta1 expression for 24 d, and subsequent stimulation by PH on the fourteenth day after DEN initiation super-induced TGF-beta1 mRNA (50 times that of the control level), as opposed to a transient expression for less than 5 d by PH alone. GST-P+ HNs did not express TGF-beta receptors I (RI) and II (RII) during the early stage of carcinogenesis, whereas the surrounding hepatocytes strongly expressed both of these receptors. On cessation of nodularin injection, however, the expression of RI and RII in the HNs changed significantly: RII+ nodules appeared, and the number and area of RII+/- nodules were significantly increased at 10 wk after the cessation. These findings indicate that induction of TGF-beta expression in GST-P+ HNs might be a strong selection pressure that allows outgrowth of RII- nodules during liver carcinogenesis.

Topics: Alkylating Agents; Animals; Blotting, Northern; Diethylnitrosamine; Gene Expression Regulation, Neoplastic; Glutathione Transferase; Hyperplasia; Immunohistochemistry; Kinetics; Liver; Liver Neoplasms, Experimental; Male; Peptides, Cyclic; Precancerous Conditions; Rats; Rats, Inbred F344; Receptors, Transforming Growth Factor beta; Time Factors; Transforming Growth Factor beta

Retinoic acid (RA) was topically applied to the skin of Sencar mice during the promotion phase of specific tumor induction protocols that produce papillomas at low (12-O-tetradecanoylphorbol-13-acetate promoted, TPA) or high (mezerein-promoted) risk for premalignant progression and malignant conversion. RA consistently reduced the yield of papillomas and carcinomas in both protocols, but the frequency of malignant conversion in papillomas that emerged during RA treatment was not reduced. When TPA was reapplied after cessation of RA treatment, the number of papillomas increased 2-fold, suggesting that RA had not eliminated initiated cells. In vitro, RA prevented the emergence of transformed keratinocytes in an assay that mimics malignant conversion, suggesting that RA can suppress conversion if applied during the stage of premalignant progression. Examination of tumor markers at weeks 14 and 22 of the tumor-induction experiments in vivo indicated that papillomas evolving during RA treatment exhibited a phenotype of high progression risk, even in the TPA-promoted groups. In the majority of these tumors, the alpha6beta4 integrin and retinoid X receptor alpha transcripts were detected suprabasally, indicating an advanced state of premalignant progression. RA-treated tumors also expressed higher levels of transcripts for transforming growth factor (TGF)-beta1 and localized TGF-beta1 peptide in the basal portions of the tumor fronds. Because up-regulated expression of TGF-beta1 suppresses papilloma formation, these studies suggest a mechanism whereby RA can prevent papilloma eruption via a TGF-beta intermediate, but papillomas resistant to RA may have altered TGF-beta signaling and progress to carcinomas at an increased frequency.

Topics: Administration, Topical; Animals; Anticarcinogenic Agents; Antineoplastic Agents; Biomarkers, Tumor; Carcinogens; Carcinoma, Basal Cell; Cell Transformation, Neoplastic; Disease Progression; Diterpenes; Female; Immunohistochemistry; Mice; Mice, Inbred BALB C; Mice, Inbred SENCAR; Papilloma; Phenotype; Precancerous Conditions; Receptors, Retinoic Acid; Retinoid X Receptors; Risk Factors; Skin Neoplasms; Terpenes; Tetradecanoylphorbol Acetate; Transcription Factors; Transforming Growth Factor beta; Tretinoin

Invasion of the uterus by first trimester human placental extravillous trophoblast (EVT) cells depends on mechanisms shared by malignant cells. However, unlike tumor invasion, trophoblast invasion of the uterus is stringently controlled in situ by local molecules such as transforming growth factor (TGF)beta. Since EVT cells possess active invasion-associated genes but are nontumorigenic, our objective was to induce premalignant and then malignant phenotype into a normal EVT cell line in order to identify the molecular basis of tumor progression. Simian virus 40 large T antigen (SV40 Tag) was introduced into a normal human first trimester invasive EVT cell line, HTR8, established in our laboratory. Since the HTR8 line has a limited in vitro lifespan of 12-15 passages, SV40 Tag-transformed cells were selected on the basis of extended lifespan. A long-lived line, RSVT-2, was produced and an immortalized subclone, RSVT2/C, was further derived under a forced crisis regimen. We examined transformation-induced alterations in proliferative and invasive abilities, responses to the invasion and proliferation-regulating growth factor TGFbeta and changes in gene expression for invasion-associated enzymes or enzyme inhibitors. RSVT-2 and RSVT2/C cell lines were hyperproliferative and hyperinvasive when compared with the parental HTR8 cell line. They were also variably resistant to the anti-proliferative and anti-invasive signals from TGFbeta. Since both cell lines remained non-tumorigenic in nude mice, these properties indicate that they attained a premalignant phenotype. Both cell lines showed reduced expression of tissue inhibitor of metalloproteases (TIMP)-1, while TIMP-2 and plasminogen activator inhibitor (PAI)-I expression was was also reduced in RSVT2/C cells, thus contributing to their hyperinvasiveness. Their resistance to the anti-invasive action of TGFbeta was explained by the failure of TGFbeta to upregulate TIMPs and PAI-I, in contrast to the TGFbeta-induced upregulation noted in parental HTR8 cells.

Topics: Animals; Antigens, Viral, Tumor; Cell Division; Cell Line; Cell Transformation, Neoplastic; Choriocarcinoma; Clone Cells; Drug Resistance, Neoplasm; Female; Gene Expression Regulation, Neoplastic; Humans; Mice; Mice, Nude; Neoplasm Invasiveness; Phenotype; Plasminogen Activator Inhibitor 1; Precancerous Conditions; Pregnancy; Pregnancy Trimester, First; Simian virus 40; Tissue Inhibitor of Metalloproteinase-1; Tissue Inhibitor of Metalloproteinase-2; Transforming Growth Factor beta; Transplantation, Heterologous; Trophoblasts; Tumor Cells, Cultured

In the present retrospective study, liver cell dysplasia (LCD) occurring in cirrhotic livers associated or not associated with hepatocellular carcinoma (HCC) was immunohistochemically analyzed for the expression of hepatocyte growth factor receptor (c-met protein), Rb (retinoblastoma gene) protein, E-cadherin, and transforming growth factor-beta-1 (TGF-beta-1). Cytoplasmic c-met protein staining was observed in about half of the HCC's, and its prevalence was about twice as high in high grade vs. low grade tumors, but it was not correlated with proliferative activity as based on PCNA labelling. In LCD, reactivity for c-met protein was restricted to the small cell type. Nuclear staining for Rb protein was found in HCC's, and was not related to type, grade or proliferative activity, whereas no immunoreactivity was observed in normal, hyperplastic or dysplastic hepatocytes. Expression of E-cadherin prevailed in HCC's of lower grade, and particularly in those with a trabecular or acinar growth pattern. E-cadherin staining was detectable in normal and large dysplastic hepatocytes, but not in small dysplastic liver cells. TGF-beta-1 reactivity was observed in more than half the HCC's, but not in normal or dysplastic hepatocytes. These findings underline the phenotypic difference between large cell and small cell liver dysplasia, and support the hypothesis that small cell dysplasia is a precursor lesion in a hepatocarcinogenic pathway.

Topics: Cadherins; Carcinoma, Hepatocellular; Humans; Liver; Liver Cirrhosis; Liver Neoplasms; Precancerous Conditions; Proto-Oncogene Proteins c-met; Retinoblastoma Protein; Retrospective Studies; Transforming Growth Factor beta

Topics: Anticarcinogenic Agents; Antineoplastic Agents, Hormonal; Breast Neoplasms; Chemotherapy, Adjuvant; Disease Progression; Estrogen Antagonists; Female; Humans; Neoplasm Recurrence, Local; Precancerous Conditions; Receptors, Estrogen; Survival Rate; Tamoxifen; Transforming Growth Factor beta

We have addressed the notion that the progression of cancer of the uterine cervix is associated with a preferential constraint on the development of a type 1 cellular mediated response, which is necessary to efficiently eliminate (pre)neoplastic cells. Based on the importance of cytokines in the regulation of an appropriate immune response, we have evaluated the expression of IL-12p40, IL-10 and transforming growth factor-beta 1 (TGF-beta1). Using reverse transcriptase-polymerase chain reaction (RT-PCR), the expression of these three cytokines was evaluated in both low-grade (LG) and high-grade (HG) cervical squamous intraepithelial lesions (SIL) and in normal exocervix and transformation zone biopsies. Our results show that the average level of IL-12 increases within both the LG and HG SIL, compared with both control groups. Interestingly, the percentage of HG SIL expressing IL-12p40 was lower compared with LG SIL. In contrast, the expression of IL-10 increased in parallel with the severity of the lesion to a maximal level in HG SIL. Using immunohistochemistry, we ascertained the presence of IL-12 protein in SIL and IL-10 protein in the transformation zone and SIL biopsies. Both IL-12- and IL-10-producing cells were localized in the stroma, not within the SIL. Furthermore, in this study we also observed that the region of the cervix the most sensitive to lesion development, the transformation zone, was associated with higher average levels of the immunosuppressive cytokines IL-10 and TGF-beta1.

Topics: Biopsy; Cytokines; Epithelial Cells; Female; Humans; Immune Tolerance; Interleukin-10; Interleukin-12; Polymerase Chain Reaction; Precancerous Conditions; Transforming Growth Factor beta; Uterine Cervical Neoplasms

Transforming growth factor beta1 (TGF-beta1) is a cytokine known to play a key role in the control of cell growth. TGF-beta1 potently inhibits the proliferation of human and rodent-derived epithelial cells. Colonic precancerous and moderately differentiated cancer cells are responsive to TGF-beta1, whereas malignant colon cancer cells are resistant to the inhibitory action of the cytokine. These observations have been derived exclusively from in vitro studies. Therefore, the main aim of our study was to determine whether TGF-beta1 exerts a growth-restraining action on colon carcinogenesis in vivo. TGF-beta1 was sequestered into ethylene acetate copolymer matrices and "loaded" preparations were implanted intraperitoneally (i.p.) in rats. One week later, the animals were treated with dimethylhydrazine (DMH), a colon procarcinogen. Empty matrices devoid of TGF-beta1 but containing bovine serum albumin (BSA) carrier served as the appropriate control preparations. The number of aberrant crypt foci (ACF), considered to be preneoplastic lesions of the colon, was scored. Tumor formation and size were assessed at the appropriate times. TGF-beta1 released in a sustained manner from copolymer matrices: (i) markedly inhibited colonic ACF formation and the number of aberrant crypts and (ii) significantly reduced colonic tumor formation and size.

Topics: 1,2-Dimethylhydrazine; Animals; Colonic Neoplasms; Drug Implants; Male; Polymers; Precancerous Conditions; Rats; Receptors, Transforming Growth Factor beta; Transforming Growth Factor beta

Despite extensive research, the mechanisms of prostate carcinogenesis are not well understood. The slow progress in this area is due, at least in part, to lack of a suitable animal model for prostate carcinogenesis. We have developed an animal model, based on the existing sex hormone-induced prostate carcinogenesis in the Noble rat, by substantially increasing the dosage of testosterone while keeping the level of estrogen unchanged. Using the modified method of combination of testosterone and estradiol-17beta (T+E2), it has been shown in Noble rats that prostate carcinogenesis followed a multi-step process involving hyperplasia, dysplasia, and carcinoma. We have demonstrated the importance of TGF-alpha, TGF-beta1 and bFGF in the development of prostate carcinogenesis. This study also established the roles of VEGF and IGF-1, initially as paracrine factors in epithelial-stromal interactions during the process of carcinogenesis and subsequently switching over to an autocrine mode during the establishment of carcinoma.

Topics: Adenocarcinoma; Animals; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Therapy, Combination; Endothelial Growth Factors; Estradiol; Fibroblast Growth Factor 2; Hyperplasia; Immunohistochemistry; Lymphokines; Male; Precancerous Conditions; Prostate; Prostatic Neoplasms; Rats; Rats, Inbred Strains; Receptor Protein-Tyrosine Kinases; Receptors, Growth Factor; Receptors, Vascular Endothelial Growth Factor; Testosterone; Transforming Growth Factor alpha; Transforming Growth Factor beta; Transforming Growth Factor beta1; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors

Many studies have been conducted to assess the potential preneoplastic nature of colonic aberrant crypt foci (ACF), but still the biological significance of these foci and their relationship to colon neoplasia remains to be elucidated. In the present paper a battery of variables suggested to be indicative for colon cancer development has been studied in relation to ACF in rats. These include: (i) the degree of dysplasia; (ii) the type of mucus production; (iii) the cellular immunohistochemical expression and distribution of transforming growth factors alpha and beta and their respective receptors, epidermal growth factor receptor and transforming growth factor beta receptors I and II and phosphorylated cellular tyrosine. The parameters have been investigated in ACF selected from a previous study where the foci were induced under different circumstances, leading to disparities in the number as well as the crypt multiplicity obtained. The present study showed that for all parameters investigated, apart from sialomucin production, the different experimental conditions had no effect on the individual ACF, irrespective of the number and distribution of the different categories of ACF among the various diets. However, it was shown that the degree of dysplasia correlated strongly with crypt multiplicity and that all the investigated ACF lacked expression of transforming growth factor alpha and expressed a reduced amount of transforming growth factor beta compared with normal crypts. These observations may indicate that ACF are preneoplastic lesions and supports the suggestion that they may, at least in the rat, have the potential to gradually progress to tumors, but no single ACF showed particular characteristics indicating specific proneness to tumor development. The study could not confirm the presence of sialomucin-producing ACF as a valid marker for tumor development.

Topics: Animals; Cell Transformation, Neoplastic; Colon; Colonic Neoplasms; Dietary Fats; Dietary Fiber; Dietary Sucrose; ErbB Receptors; Gene Expression Regulation; Growth Substances; Intestinal Mucosa; Male; Mucins; Precancerous Conditions; Rats; Receptors, Growth Factor; Receptors, Transforming Growth Factor beta; Sialomucins; Transforming Growth Factor alpha; Transforming Growth Factor beta

The aim of this study was to evaluate a possible relationship between oxidative stress and transforming growth factor beta 1 (TGF beta 1) expression in human colon adenocarcinoma. Crohn's disease, an inflammatory pathology of the intestine often regarded to as precancerous, was also examined. Indices of impaired redox balance were monitored in blood and in bioptic samples from 10 adult patients with adenocarcinoma of the colon and from five patients with Crohn's disease. On tissue samples TGF beta 1 mRNA expression was also determined. Ten healthy adults provided normal reference values for plasma indices of oxidative stress, and normal tissue distant from the lesions was used for comparative analysis. Fluorescent adducts with plasma proteins of malonaldehyde (MDA) and 4-hydroxynonenal (HNE) were significantly lower than controls in the plasma from cancer patients and significantly higher in the plasma from Crohn's patients. In adenocarcinoma biopsies, susceptibility to lipid peroxidation processes and TGF beta 1 expression were below the relative control; in Crohn's disease, lipid peroxidation and cytokine expression were both above the relative control. The findings obtained suggest the existence of an association between oxidative damage and fibrogenic cytokine expression in the human intestine. Further studies are needed to conclusively prove the correlation between the two events.

Topics: Adenocarcinoma; Adult; Aged; Aged, 80 and over; Case-Control Studies; Colonic Neoplasms; Crohn Disease; Female; Gene Expression; Humans; Male; Malondialdehyde; Middle Aged; Oxidative Stress; Precancerous Conditions; RNA, Messenger; RNA, Neoplasm; Transforming Growth Factor beta

Previous studies have shown 5- to 10-fold higher rates of apoptosis in prestages of liver cancer (putative preneoplastic cell foci [PPF]) than in unaltered liver; fasting or withdrawal of tumor promoters enhanced apoptosis even further. We studied whether transforming growth factor beta 1 (TGF-beta 1), an inducer of apoptosis in normal liver, might be involved in induction of apoptosis in PPF. PPF were produced in 7-week-old female Sprague-Dawley rats with a single oral dose of the genotoxic carcinogen 7,12-dimethylbenz(a)anthracene (DMBA). At 24 weeks of age, TGF-beta 1 was injected into animals (40 micro g/kg intravenously) either once and they were killed 4 hours later (single-dose experiment) or eight times at 24-hour intervals and they were killed 24 hours after the last administration (multiple-dose experiment). Further subgroups received daily subcutaneous injections of tamoxifen (TAM) (8 mg/kg) for 4 consecutive weeks before TGF-beta 1 treatment. In normal liver, the apoptosis incidence was low in solvent- and TAM-only-treated animals, in the single- as well as the multiple-dose experiment. TGF-beta 1, increased the apoptosis incidence severalfold, and the combined administration of TGF-beta 1 with TAM caused a further strong increase. The already-elevated basal apoptotic incidence in PPF was further increased by TGF-beta 1, and particularly by TGF-beta 1 plus TAM treatments, which resulted in a reduction of foci number and size. In summary, these results show that TGF-beta 1 can induce apoptosis in PPF. This apoptosis-inducing activity is strongly enhanced by the additional treatment with the antiestrogen TAM, which by itself does not have any cell death-inducing effect in the liver or PPF. The elevated apoptotic activity of PPF in response to TGF-beta 1 can lead to a selective reduction of the liver load with preneoplastic cells.

Topics: Animals; Apoptosis; Cell Division; Estrogen Antagonists; Female; Liver Neoplasms, Experimental; Precancerous Conditions; Rats; Rats, Sprague-Dawley; Tamoxifen; Transforming Growth Factor beta

Foci of altered hepatocytes are preneoplastic lesions capable of progressing to hepatocellular carcinomas. To characterize the growth of preneoplastic hepatic lesions, size of hepatic foci was analyzed with regard to growth factor regulation and hepatocyte proliferation in focal and non-focal hepatocytes. Twelve-day-old female B6C3F1 mice were initiated with a single dose of the potent mutagen N-nitrosodiethylamine (DEN) (5 mg/kg body weight). Beginning at 6 weeks of age, mice were exposed for 16 weeks to 2038 p.p.m. unleaded gasoline (UG) vapor or 1 p.p.m. ethinyl estradiol (EE) in the diet. Analysis of hepatic foci demonstrated that UG significantly increased, but EE significantly decreased the size of DEN-initiated foci. Hepatic labeling index (LI), as measured by the incorporation of 5-bromo-2'-deoxyuridine, was similar in non-focal hepatocytes at 16 weeks in all groups (0.4-0.8%) and greatly increased in hepatic foci. Hepatocyte LI was significantly increased in DEN/UG foci (29%, n = 41) and significantly decreased in DEN/EE foci (6%, n = 23) relative to DEN/control focal hepatocytes (18%, n = 25). The mean LI of foci correlated with the focal size differences observed in the treatment groups. Immunohistochemical analysis with antibodies directed to the negative growth regulator transforming growth factor-beta 1 (TGF-beta1) demonstrated a consistent decrease of TGF-beta 1 in DEN/Ct and DEN/UG hepatic foci relative to non-lesion hepatocytes. Similar results were seen with mannose 6-phosphate/insulin-like growth factor-II receptor (M6P/IGF-II R), which facilitates activation of latent TGF-beta 1. In contrast, only 50% of DEN/EE foci had decreased levels of TGF-beta 1 and M6P/IGF-II R relative to non-focal hepatocytes. These data suggest that proliferative responses observed in hepatic foci may be correlated with foci size. In contrast, chemically induced proliferative responses in non-focal hepatocytes after subchronic exposure cannot necessarily be used to predict proliferative effects in preneoplastic cell populations. Furthermore, these studies suggest that hepatic foci may occur by M6P/IGF-II R enhancing activation of latent TGF-beta 1 in non-focal hepatocytes but not in the focal hepatocytes, thereby affording focal hepatocytes a selective growth advantage.

Topics: Air Pollutants; Animals; Biomarkers, Tumor; Carcinogens; Cell Division; Diet; Diethylnitrosamine; Ethinyl Estradiol; Female; Gasoline; Liver; Liver Neoplasms, Experimental; Male; Mice; Mice, Inbred C3H; Mice, Inbred C57BL; Mice, Inbred Strains; Mitotic Index; Models, Biological; Mutagens; Precancerous Conditions; Receptor, IGF Type 2; Transforming Growth Factor beta

Transforming growth factor beta 1 (TGF beta 1) is a multifunctional cytokine. The role of TGF beta 1 in hepatocarcinogenesis is still a matter of discussion. To assess the expression of TGF beta 1 in human liver tumors, the following study was conducted.. Formalin fixed, paraffin embedded sections of 50 hepatocellular carcinomas (HCC), 30 cholangiocellular carcinomas (CCC), 15 hepatocellular adenomas (HCA), 15 focal nodular hyperplasias (FNH), and 20 normal livers (NL) were immunostained with a monoclonal anti-TGF beta 1 antibody (clone TB-21). TGF beta 1 mRNA was measured in snap frozen tissue of 2 HCC, 3 HCA, 2 FNH, and 3 NL of the immunohistochemistry group using slot blot hybridizations. Total RNA was extracted, and slot blots were hybridized with 32P endlabeled TGF beta 1 oligonucleotides. TGF beta 1 mRNA was measured in cpm with a scintillation counter.. TGF beta 1 protein was strongly expressed in 14/15 FNH and 13/15 HCA, whereas it was scarcely detectable in 46/50 HCC and 25/30 CCC. All NL were moderately positive. The 2 HCC cases contained far less TGF beta 1 mRNA than the HCA, FNH, and NL examined here.. TGF beta 1 expression is markedly lower in malignant liver tumors than in benign tumors or NL. Therefore, TGF beta 1 down-regulation may be an important step in hepatocarcinogenesis. Additionally, TGF beta 1 immunostaining may be useful in distinguishing well-differentiated HCC from adenomas.

Topics: Adenoma; Carcinoma, Hepatocellular; Cholangiocarcinoma; Humans; Hyperplasia; Immunohistochemistry; In Situ Hybridization; Liver; Liver Neoplasms; Precancerous Conditions; RNA, Messenger; Transforming Growth Factor beta

We examined the effects of inflammatory cytokines, such as interleukin-1 alpha (IL-1 alpha), interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF alpha), transforming growth factor-beta (TGF beta) and lipopolysaccharide (LPS), on the urokinase-type plasminogen activator (uPA) gene expression in RC-K8 human pre-B lymphoma cells. Recombinant IL-1 alpha, recombinant IL-1 beta and LPS but not recombinant IL-6, recombinant TNF alpha and TGF beta dose-dependently increased uPA accumulation in the conditioned medium. Northern blot analysis revealed that uPA mRNA levels rapidly increased with a peak induction at 2 h after stimulation with IL-1 alpha and IL- 1 beta, but uPA mRNA increase by LPS began at 9 h after stimulation and the increase was maintained until the experiment ended at 24 h. These responses were independent of de novo synthesis, rather amplified in the presence of a protein synthesis inhibitor. The effects by IL-1 alpha and Il-1 beta were prevented by addition of anti-IL-1 alpha and anti-IL-1 beta neutralizing antibodies, respectively. In contrast, both antibodies did not prevent LPS-induced uPA gene expression. Therefore, it is unlikely that the effect by LPS is through induction of IL-1. Both IL-1 alpha and IL- 1 beta rapidly activated uPA gene transcription, but not increased stability of uPA mRNA. These results suggest that both IL-1 alpha and IL-1 beta cause a rapid activation of uPA gene transcription in which de novo protein synthesis is not required and that LPS induces uPA gene expression independently of the IL-1 pathway. These modulations of uPA production by inflammatory mediators may be implicated in tumor growth and metastasis.

Topics: Antigen-Antibody Reactions; Cells, Cultured; Cytokines; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Neoplastic; Humans; Interleukin-1; Interleukin-6; Lipopolysaccharides; Lymphoma, B-Cell; Precancerous Conditions; Transforming Growth Factor beta; Tumor Cells, Cultured; Tumor Necrosis Factor-alpha; Urokinase-Type Plasminogen Activator

The association of human papillomavirus (HPV) with a high proportion of cervical cancers should allow the efficiency of cytological screening methods to be improved. We report here that quantitative detection of HPV types 16, 18, 31 and 33 DNA and the corresponding E7 transcripts by polymerase chain reaction (PCR) may be of value in identifying precancers and cancers. In clinical specimens with major cervical lesions, the level of E7 transcription does not appear to be related to concomitant transcription of either transformation growth factor-beta (TGF beta) or granulocyte-macrophage colony stimulating factor (GM-CSF) genes.

Topics: Base Sequence; Biopsy; DNA Primers; DNA-Binding Proteins; DNA, Viral; Female; Gene Expression; Granulocyte-Macrophage Colony-Stimulating Factor; Humans; Molecular Sequence Data; Oncogene Proteins, Viral; Papillomaviridae; Papillomavirus E7 Proteins; Polymerase Chain Reaction; Precancerous Conditions; Species Specificity; Transcription, Genetic; Transforming Growth Factor beta; Uterine Cervical Neoplasms

Chronic exposure of rats to the liver tumor promoter phenobarbital (PB) significantly reduces the ability of normal hepatocytes, but not of initiated hepatocytes, to respond to mitogenic stimuli. This reduced proliferative ability of normal hepatocytes was correlated with a marked elevation in hepatic concentration of the potent mito-inhibitory factor, transforming growth factor-beta 1 (TGF-beta 1). PB also increased the mannose 6-phosphate/insulin-like growth factor-II (M6P/IGF-II) receptor concentration in hepatocytes, with a concomitant up-regulation in gene expression. Since the M6P/IGF-II receptor facilitates the proteolytic activation of TGF-beta 1, this suggests that PB increases the capacity of normal hepatocytes to activate TGF-beta 1. In contrast, a subset of preneoplastic lesions induced with N-nitrosodiethylamine did not demonstrate elevated levels of the M6P/IGF-II receptor or TGF-beta 1 in response to PB. These findings emphasize the potential importance of TGF-beta 1 during liver tumor promotion with PB and suggest that reduction of M6P/IGF-II receptor levels in liver tumors may provide the tumor cells with an important selective growth advantage.

Topics: Animals; Liver; Liver Neoplasms, Experimental; Male; Phenobarbital; Precancerous Conditions; Rats; Rats, Inbred F344; Receptor, IGF Type 2; RNA, Messenger; Transforming Growth Factor beta

The purpose of our studies was to re-evaluate the rat tracheal epithelial (RTE) transformation system and to identify critical variables that affect the development of enhanced growth variants (EGV). The enhanced growth variant colony, which is a preneoplastic cell variant, is the quantifiable transformation endpoint in RTE cultures. Using a standard protocol the frequency of EGV colony formation was shown to be inversely related to the number of clonogenic cells (CFU) seeded per dish in control cultures as well as in cultures treated with the transforming agent 6-nitrochrysene (6-NC). Experiments showed that the major mechanisms that underlie the CFU density-dependent inhibition of EGV colony formation are depletion of growth factors from and accumulation of autocrine TGF-beta in the media. Thus the cells themselves are creating the selection environment, which allows only the EGVs to survive. The effects of agents such as 6-NC, which increase the frequency of EGV colony formation, are to induce a cellular phenotype that is less susceptible to the selection environment. We showed that TGF-beta-neutralizing antibodies added to the selection media significantly increased EGV colony formation in control cultures but not in 6-NC-exposed cultures. In addition we demonstrated that the development of EGV colonies is much less susceptible to inhibition by (exogenous) TGF-beta in 6-NC-exposed than in control cultures. Thus spontaneous and 6-NC EGV colony formation are distinguishable based on TGF-beta sensitivity. To conduct quantitative cell transformation experiments with RTE cells it is essential that the number of surviving CFU per dish is the same in control and treated cultures. Under the conditions used in the studies described here, 350-500 CFU per culture was found to be the optimum CFU density. Besides 6-NC, agents that have been shown to increase EGV colony frequency under conditions similar to those described here are nitrosamines, NNK, nickel compounds and X-rays.

Topics: Animals; Cell Count; Cell Transformation, Neoplastic; Chrysenes; Culture Media, Serum-Free; Growth Substances; Male; Precancerous Conditions; Rats; Rats, Inbred F344; Tracheal Neoplasms; Transforming Growth Factor beta; Tumor Stem Cell Assay

A recent study from our laboratory demonstrated that cyclosporine (CsA), a prototype immunosuppressant, enhanced the growth of carcinogen-induced enzyme altered foci in rat liver, suggesting that CsA may stimulate development of hepatocellular carcinomas. In the present study, we examined (i) whether CsA accelerates development of hepatocellular carcinomas in experimental animals, (ii) whether CsA stimulates the proliferation of resting hepatocyte in vivo and (iii) whether CsA modulates the production of growth factors implicated in liver cell growth, hepatocyte growth factor (HGF), transforming growth factor alpha (TGF alpha) and transforming growth factor beta 1 (TGF beta 1). Foci of hepatocytes, positive for glutathione S-transferase placental form were induced in male F344 rats by a single dose of diethylnitrosamine followed by 7 weeks promotion by a choline-deficient diet. The animals were then divided in two groups, and subsequent development of hepatocellular carcinomas was compared in rats fed a basal diet or a basal diet containing 0.015% CsA. Development of hepatocellular carcinoma was accelerated in the rats maintained on a CsA diet. Feeding a CsA diet as the sole treatment, for 2, 4 and 10 weeks induced significant increases in liver weight, and resulted also in an enhanced incorporation by hepatocytes of 5-bromo-2-deoxy-uridine. Serum levels of glutamate-oxaloacetate transferase, glutamate-pyruvate transferase and lactic dehydrogenase were not altered by feeding a CsA diet. Northern Blot analyses of the expression of HGF, TGF alpha and TGF beta 1 mRNAs in the liver showed similar patterns of expression between rats fed a basal diet and a CsA diet. The levels of HGF mRNA were not altered in the lungs and kidneys of rats fed a CsA diet. These results indicate that CsA stimulates rat liver cell proliferation in vivo without inducing liver cell necrosis, and that this effect may contribute to accelerated development of hepatocellular carcinomas in rats fed a CsA diet. As previously observed with BR 931, a hypolipidemic peroxisome proliferator, stimulation of liver cell growth by CsA did not entail changes in the production of HGF, TGF alpha or TGF beta 1.

Topics: Alanine Transaminase; Animals; Aspartate Aminotransferases; Base Sequence; Cell Division; Cyclosporine; Hepatocyte Growth Factor; Kidney; L-Lactate Dehydrogenase; Liver; Liver Neoplasms, Experimental; Liver Regeneration; Lung; Male; Molecular Sequence Data; Organ Size; Precancerous Conditions; Rats; Rats, Inbred F344; RNA, Messenger; Stimulation, Chemical; Transforming Growth Factor alpha; Transforming Growth Factor beta

Eosinophilia in tissues and/or circulating blood is known to be associated with a wide variety of malignancies but the role of the eosinophil in neoplastic conditions is not known. Using the cheek pouch of the Syrian hamster as an experimental model for oral carcinogenesis, it has recently been shown that eosinophils at sites of developing oral cancer express the multifunctional cytokine, transforming growth factor alpha (TGF-alpha). This study investigated the time course of eosinophil infiltration, tissue eosinophilia associated with malignant epithelium, and eosinophil-derived TGF-alpha mRNA during the 16-week 7,12-dimethylbenz[a]anthracene (DMBA)-induced oral cancer development process. The results reveal that the occasional eosinophil is normally present in the lamina propria of hamster oral mucosa. With progressive DMBA treatments, there is an increase of eosinophils infiltrating into the lamina propria. By weeks 12-16, the number of eosinophils is significantly higher in DMBA-treated pouches than in control pouches treated with the vehicle mineral oil alone. Analysis of the infiltrating eosinophils into fully developed hamster oral carcinomas reveals that tissue eosinophilia is associated with 78% of the stromal areas associated with malignant epithelium, while only 7% of sites associated with non-tumor oral epithelium (normal, hyperplastic-dysplastic) exhibited eosinophilia. Furthermore, the majority of the eosinophils associated with malignant epithelium were found to contain TGF-alpha mRNA. The number of TGF-alpha mRNAs containing eosinophils associated with malignant oral epithelium is significantly higher than that associated with nonmalignant oral epithelium. Together, these results suggest that eosinophils are recruited to tumor-developing sites, that they predominantly associate with malignant epithelium, and that most tumor-associated eosinophils express the cytokine TGF-alpha.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Cell Transformation, Neoplastic; Cricetinae; Eosinophils; Gene Expression; Male; Mesocricetus; Mouth Neoplasms; Precancerous Conditions; RNA, Messenger; Transforming Growth Factor beta

Cellular distribution of both transcripts and protein of transforming growth factor (TGF)-beta 1 was studied in preneoplastic nodules (6 cases) and primary hepatic carcinomas (16 hepatocellular carcinomas and 2 mixed tumors of hepatocellular carcinoma and cholangiocellular carcinoma) produced by Solt-Farber's protocol in rats using in situ hybridization and immunohistochemistry. The TGF-beta 1 transcripts were primarily observed in nonparenchymal cells, some of which were desmin-positive perisinusoidal cells, surrounding or within the preneoplastic nodules or carcinomas. The distribution of latent TGF-beta 1 protein was similar to the transcripts. However, mature TGF-beta 1, which was identified with CC-antibody, was only detected in nonparenchymal cells and connective tissue associated with carcinomas, but was not observed in preneoplastic nodules or in normal liver with the exception of the periportal space. There was no difference in TGF-beta 1 expression associated with tumor types or the differentiation status of primary hepatic carcinomas. The present study demonstrates that nonparenchymal cells, particularly desmin-positive perisinusoidal cells, are the principal source of TGF-beta 1 production during hepatocarcinogenesis. Furthermore, the data suggest that the close interaction between nonparenchymal cells and carcinoma cells may be necessary for the activation of latent TGF-beta 1. It is hypothesized that regulatory effects of TGF-beta 1 on growth of preneoplastic or carcinoma cells in the liver are exerted via paracrine mechanism.

Topics: Animals; Carcinoma; Immunohistochemistry; Liver; Liver Neoplasms; Nucleic Acid Hybridization; Precancerous Conditions; Rats; Rats, Inbred F344; Reference Values; Transforming Growth Factor beta

The growth of three non-tumorigenic human colonic adenoma cell lines, designated AA/C1, RG/C2 and RR/C1, was inhibited by low concentrations of transforming growth factor beta (TGF-beta) (0.05-0.5 ng ml-1). However, the growth of five human colon cancer cell lines under identical conditions was resistant to high concentrations of TGF-beta (2-10 ng ml-1). This is the first report of well-characterized premalignant human colonic cells showing sensitivity to TGF-beta. The TGF-beta-sensitive adenoma cell line AA/C1 was derived from a relatively large adenoma with a K-ras gene mutation and represents a relatively late-stage adenoma, indicating that loss of response to TGF-beta occurs at a relatively late stage in colorectal carcinogenesis and that the presence of a ras gene mutation does not necessarily confer resistance to TGF-beta. Of further interest, the RG/CZ cell line has a p53 mutation showing that p53 mutations do not necessarily lead to TGF-B insensitivity. Furthermore, in this paper we show that the conversion of the AA/C1 adenoma cell line to a tumorigenic phenotype [Williams et al., (1990) Cancer Res., 50, 4724] is accompanied by a reduced response to the growth-inhibitory effects of TGF-beta up to 10 ng ml-1. Reduced responsiveness to the inhibitory effects of TGF-beta may be an important event in the loss of growth control in colorectal carcinogenesis.

Topics: Adenoma; Carcinoma; Cell Line, Transformed; Cell Transformation, Neoplastic; Colorectal Neoplasms; Dose-Response Relationship, Drug; Drug Resistance; Genes, ras; Humans; Mutation; Phenotype; Precancerous Conditions; Transforming Growth Factor beta; Tumor Cells, Cultured