transforming-growth-factor-alpha and Hyperplasia

Elevated serum levels of parathyroid hormone (PTH) contribute to the increased morbidity and mortality in renal failure patients. Parathyroid gland hyperplasia is a major cause of high serum PTH. The present studies used the rat model of renal failure to address the mechanisms underlying uremia-induced parathyroid hyperplasia and the antiproliferative properties of vitamin D therapy (1,25-dihydroxyvitamin D (1,25(OH)(2)D(3)) or its less calcemic analogs). Enhanced TGFalpha/EGFR co-expression is the major mitogenic signal in uremic parathyroid glands. At early stages of renal failure, vitamin D therapy efficiently counteracts uremia- and high phosphorus-induced hyperplasia by inhibiting the increases in parathyroid-TGFalpha/EGFR co-expression. In established hyperparathyroidism, characterized by highly enhanced-TGFalpha/EGFR co-expression, vitamin D therapy arrests growth by suppressing EGFR-growth signals from the plasma membrane and nuclear EGFR actions as a transactivator of the cyclin D1 gene, an important contributor to parathyroid hyperplasia in humans. In advanced renal failure, reduced-parathyroid vitamin D receptor levels limits the antiproliferative efficacy of vitamin D therapy. However, non-antiproliferative doses of 1,25-dihydroxyvitamin D enhance the anti-EGFR actions of EGFR-tyrosine kinase inhibitors (TKI). In fact, combined 1,25-dihydroxyvitamin D/TKI therapy inhibits parathyroid hyperplasia more efficiently than phosphorus restriction, the most powerful promoter of parathyroid growth arrest available at present.

Topics: Cell Division; ErbB Receptors; Humans; Hyperplasia; Parathyroid Glands; Renal Insufficiency; Signal Transduction; Transforming Growth Factor alpha; Vitamin D

In the current vascular interventional environment, high restenosis rates have increased awareness of the significance of intimal hyperplasia, a chronic structural lesion that develops after vessel wall injury, and which can lead to luminal stenosis and occlusion. Intimal hyperplasia may be defined as the abnormal migration and proliferation of vascular smooth muscle cells with associated deposition of extracellular connective tissue matrix. The pathology of intimal hyperplasia is reviewed with particular attention to its physiology, pharmacology, cell biology and molecular biology.

Topics: Blood Platelets; Humans; Hyperplasia; Leukocytes; Muscle Contraction; Muscle, Smooth, Vascular; Platelet-Derived Growth Factor; Signal Transduction; Transforming Growth Factor alpha; Tunica Intima

Prostatic inflammation is the driving force in benign prostatic hyperplasia (BPH). This work investigated the potential modulatory effect of COX-2 inhibition on ADAM-17/EGFR/ERK1/2 axis.. Adult male Wistar rats were used.. Celecoxib (10 and 20 mg/kg; i.p.) was injected i.p. daily for three weeks. Testosterone (TST) (3 mg/kg; s.c.) was used to induce BPH.. Prostatic inflammation and hyperplasia were assessed by organ weight and histopathology. Inflammatory mediators were measured using ELISA technique. Protein analysis was performed using western blotting and immunohistochemistry. Gene expression analysis was performed using qRT-PCR. Statistical analyses included one-way ANOVA and Tukey's multiple comparison test.. Testosterone-treated rats had a marked increase in COX-2, prostate weight, and index. Moreover, TST-induced COX-2 was inferred from cytoskeletal changes and was attributable to the overexpression of PGE2, NF-κB (p65), and IL-6. COX-2-derived PGE2 increased the activity of ADAM-17, TGF-α, and TNF-α. Consequently, EGFR-ERK1/2 pathway was over-activated, disrupting anti-apoptotic Bcl-2, cyclin D1, and pro-apoptotic Bax. Celecoxib reversed these effects.. COX-2 stimulates the ERK1/2 pathway via PGE2-ADAM-17-catalyzed shedding of TGF-α in testosterone-induced BPH. The results indicate a functional correlation between inflammation and hyperplasia in BPH.

Topics: ADAM17 Protein; Animals; Celecoxib; Cyclooxygenase 2; Dinoprostone; ErbB Receptors; Hyperplasia; Inflammation; Male; MAP Kinase Signaling System; Prostatic Hyperplasia; Rats; Rats, Sprague-Dawley; Rats, Wistar; Testosterone; Transforming Growth Factor alpha

The parathyroid gland plays an essential role in mineral and bone metabolism. Cultivation of physiological human parathyroid cells has yet to be established and the method by which parathyroid cells differentiate from pluripotent stem cells remains uncertain. Therefore, it has been hard to clarify the mechanisms underlying the onset of parathyroid disorders, such as hyperparathyroidism. In this study, we developed a new method of parathyroid cell differentiation from human induced pluripotent stem (iPS) cells. Parathyroid cell differentiation occurred in accordance with embryologic development. Differentiated cells, which expressed the parathyroid hormone, adopted unique cell aggregation similar to the parathyroid gland. In addition, these differentiated cells were identified as calcium-sensing receptor (CaSR)/epithelial cell adhesion molecule (EpCAM) double-positive cells. Interestingly, stimulation with transforming growth factor-α (TGF-α), which is considered a causative molecule of parathyroid hyperplasia, increased the CaSR/EpCAM double-positive cells, but this effect was suppressed by erlotinib, which is an epidermal growth factor receptor (EGFR) inhibitor. These results suggest that TGF-α/EGFR signaling promotes parathyroid cell differentiation from iPS cells in a similar manner to parathyroid hyperplasia.

Topics: Cell Differentiation; Epithelial Cell Adhesion Molecule; ErbB Receptors; Humans; Hyperplasia; Induced Pluripotent Stem Cells; Parathyroid Glands; Receptors, Calcium-Sensing; Transforming Growth Factor alpha

In secondary hyperparathyroidism (SHPT), enhanced parathyroid levels of transforming growth factor-α (TGFα) increase EGF receptor (EGFR) activation causing parathyroid hyperplasia, high parathyroid hormone (PTH) and also reductions in vitamin D receptor (VDR) that limit vitamin D suppression of SHPT. Since anti-EGFR therapy is not an option in human SHPT, we evaluated ADAM17 as a therapeutic target to suppress parathyroid hyperplasia because ADAM17 is required to release mature TGFα, the most potent EGFR-activating ligand.. Computer analysis of the ADAM17 promoter identified TGFα and C/EBPβ as potential regulators of the ADAM17 gene. Their regulation of ADAM17 expression, TGFα/EGFR-driven growth and parathyroid gland (PTG) enlargement were assessed in promoter-reporter assays in A431 cells and corroborated in rat and human SHPT, using erlotinib as anti-EGFR therapy to suppress TGFα signals, active vitamin D to induce C/EBPβ or the combination.. While TGFα induced ADAM17-promoter activity by 2.2-fold exacerbating TGFα/EGFR-driven growth, ectopic C/EBPβ expression completely prevented this vicious synergy. Accordingly, in advanced human SHPT, parathyroid ADAM17 levels correlated directly with TGFα and inversely with C/EBPβ. Furthermore, combined erlotinib + calcitriol treatment suppressed TGFα/EGFR-cell growth and PTG enlargement more potently than erlotinib in part through calcitriol induction of C/EBPβ to inhibit ADAM17-promoter activity, mRNA and protein. Importantly, in rat SHPT, the correction of vitamin D deficiency effectively reversed the resistance to paricalcitol induction of C/EBPβ to suppress ADAM17 expression and PTG enlargement, reducing PTH by 50%.. In SHPT, correction of vitamin D and calcitriol deficiency induces parathyroid C/EBPβ to efficaciously attenuate the severe ADAM17/TGFα synergy, which drives PTG enlargement and high PTH.

Topics: ADAM Proteins; ADAM17 Protein; Animals; Antineoplastic Agents; Apoptosis; Blotting, Western; Calcitriol; CCAAT-Enhancer-Binding Protein-beta; Cell Proliferation; Cells, Cultured; ErbB Receptors; Erlotinib Hydrochloride; Gene Expression Regulation; Humans; Hyperparathyroidism, Secondary; Hyperplasia; Immunoenzyme Techniques; Kidney Diseases; Parathyroid Glands; Parathyroid Hormone; Rats; Real-Time Polymerase Chain Reaction; Receptors, Calcitriol; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Transforming Growth Factor alpha; Vitamin D; Vitamins

NOP16, also known as HSPC111, has been identified as a MYC and estrogen regulated gene in in vitro studies, hence coexpression levels were strongly correlated. Importantly, high expression of NOP16 was associated with poor clinical outcome in breast cancer patients. However, coexpression of NOP16, MYC and estrogen receptor (ESR1) varied widely in tumors and cell lines suggesting that transcriptional regulation differed according to pathological environments. The goal of this study was to determine the expression patterns of Nop16, Myc and Esr1 in murine mammary tumors with disparate histopathological and molecular features. We hypothesized that tumor environments with relatively high Myc levels would have different coexpression patterns than tumor environments with relatively low Myc levels. We measured levels of Myc and Nop16 mRNA and protein in tumors from WAP-c-myc mice that were of high grade and metastasized frequently. In contrast, Myc and Nop16 mRNA and proteins levels were significantly lower in the less aggressive tumors that developed in NRL-TGFα mice. Tumors from both mouse lines express ESR1 protein and we found that Esr1 mRNA levels correlated positively with Myc levels in both models. However, Myc and Nop16 transcript levels correlated positively only in tumors from NRL-TGFα mice. We identified prominent NOP16 protein in nuclei and less prominent staining in the cytoplasm of luminal cells of ducts and lobules from normal mammary glands as well as in hyperplasias and tumors obtained from NRL-TGFα mice. This staining pattern was reversed in tumors from WAP-c-Myc mice as nuclear staining was faint or absent and cytoplasmic staining more pronounced. In summary, the regulation of expression and localization of NOP16 varies in tumor environments with high versus low MYC levels and demonstrate the importance of stratifying clinical breast cancers based on MYC levels.

Topics: Adenocarcinoma; Animals; Cell Line, Tumor; Cell Nucleus; Cytoplasm; Estrogen Receptor alpha; Female; Gene Expression Regulation, Neoplastic; Hyperplasia; Mammary Glands, Animal; Mammary Neoplasms, Experimental; Mice; Mice, Transgenic; Neoplasm Metastasis; Nuclear Proteins; Proto-Oncogene Proteins c-myc; RNA, Messenger; Staining and Labeling; Transcription, Genetic; Transforming Growth Factor alpha

Familial occurrence of Ménétrier disease is rare and has been reported only in few instances.. Affected patients from a large pedigree were evaluated at the clinical, endoscopic, and pathological levels.. Affected members presented with gastropathy of variable severity but without protein loss. Endoscopy and pathology findings were consistent with Ménétrier disease; however, gastric transforming growth factor α (TGF-α) immunohistochemistry and real-time polymerase chain reaction showed no increase in TGF-α expression.. We describe a unique, 4-generation pedigree with autosomal dominant gastropathy exhibiting the typical clinical, endoscopic, and pathological findings of Ménétrier-like disease, though in the absence of protein loss and with no increase in the levels of gastric TGF-α. Members of this family may be affected by a novel and previously unrecognised hereditary form of gastric hyperplasia.

Topics: Case-Control Studies; Child, Preschool; Family; Female; Gastric Mucosa; Gastritis, Hypertrophic; Genes, Dominant; Humans; Hyperplasia; Male; Pedigree; Proteins; Stomach; Transforming Growth Factor alpha

We have previously indicated that glycyrrhizin (GL), a major component of licorice, has glucocorticoid-like anti-inflammatory effects in cultured airway epithelial cells and suggested its usefulness in the treatment of inflammatory respiratory diseases. On the other hand, mucus hypersecretion in the respiratory tract and goblet cell hyperplasia in the airway epithelium contribute to the morbidity and mortality associated with airway inflammatory diseases. This study, therefore, aimed to examine the effects of GL on airway mucus hyperproduction and define the mechanisms behind these effects. In an in vivo model, GL significantly attenuated goblet cell hyperplasia and MUC5AC mRNA expression in mice treated with lipopolysaccharide or interleukin-4. In addition, GL significantly attenuated MUC5AC protein and mRNA expression by tumor growth factor (TGF)-alpha in cultured NCI-H292 cells. GL also attenuated TGF-alpha-stimulated MUC5AC promoter activity in a luciferase reporter gene assay, but did not affect the stability of MUC5AC mRNA. Taken together, we concluded that GL has an inhibitory effect on mucus hyperproduction both in vivo and in vitro and that GL-mediated inhibition may be mediated through the inhibition of MUC5AC gene transcription.

Topics: Animals; Cell Line; Disease Models, Animal; Dose-Response Relationship, Drug; Gene Expression Regulation; Glycyrrhizic Acid; Goblet Cells; Hyperplasia; Interleukin-4; Lipopolysaccharides; Lung Diseases, Obstructive; Male; Mice; Mice, Inbred ICR; Mucin 5AC; Mucus; Promoter Regions, Genetic; Transforming Growth Factor alpha

Transforming growth factor (TGF)-alpha and its receptor, the epidermal growth factor receptor, are induced after lung injury and are associated with remodeling in chronic pulmonary diseases, such as pulmonary fibrosis and asthma. Expression of TGF-alpha in the lungs of adult mice causes fibrosis, pleural thickening, and pulmonary hypertension, in addition to increased expression of a transcription factor, early growth response-1 (Egr-1). Egr-1 was increased in airway smooth muscle (ASM) and the vascular adventitia in the lungs of mice conditionally expressing TGF-alpha in airway epithelium (Clara cell secretory protein-rtTA(+/-)/[tetO](7)-TGF-alpha(+/-)). The goal of this study was to determine the role of Egr-1 in TGF-alpha-induced lung disease. To accomplish this, TGF-alpha-transgenic mice were crossed to Egr-1 knockout (Egr-1(ko/ko)) mice. The lack of Egr-1 markedly increased the severity of TGF-alpha-induced pulmonary disease, dramatically enhancing airway muscularization, increasing pulmonary fibrosis, and causing greater airway hyperresponsiveness to methacholine. Smooth muscle hyperplasia, not hypertrophy, caused the ASM thickening in the absence of Egr-1. No detectable increases in pulmonary inflammation were found. In addition to the airway remodeling disease, vascular remodeling and pulmonary hypertension were also more severe in Egr-1(ko/ko) mice. Thus, Egr-1 acts to suppress epidermal growth factor receptor-mediated airway and vascular muscularization, fibrosis, and airway hyperresponsiveness in the absence of inflammation. This provides a unique model to study the processes causing pulmonary fibrosis and ASM thickening without the complicating effects of inflammation.

Topics: Airway Resistance; Albuterol; Animals; Bronchial Hyperreactivity; Cells, Cultured; Disease Models, Animal; Early Growth Response Protein 1; ErbB Receptors; Fibroblasts; Humans; Hyperplasia; Lung; Lung Compliance; Methacholine Chloride; Mice; Mice, Knockout; Mice, Transgenic; Muscle, Smooth; Muscle, Smooth, Vascular; Pulmonary Artery; Pulmonary Fibrosis; Recombinant Fusion Proteins; Transforming Growth Factor alpha; Weight Loss

In secondary hyperparathyroidism, enhanced expression of TGF-alpha in the parathyroid leads to its own upregulation, generating a feed-forward loop for TGF-alpha activation of its receptor, EGFR receptor (EGFR), which promotes parathyroid hyperplasia. These studies examined the role of activator protein 2alpha (AP2), an inducer of TGF-alpha gene transcription, in the upregulation of parathyroid TGF-alpha in secondary hyperparathyroidism. In rat and human secondary hyperparathyroidism, parathyroid AP2 expression strongly correlated with TGF-alpha levels and with the rate of parathyroid growth, as expected. Furthermore, the increases in rat parathyroid content of AP2 and its binding to a consensus AP2 DNA sequence preceded the increase in TGF-alpha induced by high dietary phosphate. More significant, in A431 cells, which provide a model of enhanced TGF-alpha and TGF-alpha self-induction, mutating the core AP2 site of the human TGF-alpha promoter markedly impaired promoter activity induced by endogenous or exogenous TGF-alpha. Important for therapy, in five-sixths nephrectomized rats fed high-phosphate diets, inhibition of parathyroid TGF-alpha self-induction using erlotinib, a highly specific inhibitor of TGF-alpha/EGFR-driven signals, reduced AP2 expression dosage dependently. This suggests that the increases in parathyroid AP2 occur downstream of EGFR activation by TGF-alpha and are required for TGF-alpha self-induction. Indeed, in A431 cells, erlotinib inhibition of TGF-alpha self-induction caused parallel reductions in AP2 expression and nuclear localization, as well as TGF-alpha mRNA and protein levels. In summary, increased AP2 expression and transcriptional activity at the TGF-alpha promoter determine the severity of the hyperplasia driven by parathyroid TGF-alpha self-upregulation in secondary hyperparathyroidism.

Topics: Animals; Case-Control Studies; Female; Humans; Hyperparathyroidism, Secondary; Hyperplasia; Parathyroid Glands; Rats; Rats, Sprague-Dawley; Severity of Illness Index; Transcription Factor AP-2; Transforming Growth Factor alpha; Uremia

Calcitriol, acting through vitamin D receptors (VDR) in the parathyroid, suppresses parathyroid hormone synthesis and cell proliferation. In secondary hyperparathyroidism (SH), VDR content is reduced as hyperplasia becomes more severe, limiting the efficacy of calcitriol. In a rat model of SH, activation of the EGF receptor (EGFR) by TGF-alpha is required for the development of parathyroid hyperplasia, but the relationship between EGFR activation and reduced VDR content is unknown. With the use of the same rat model, it was found that pharmacologic inhibition of EGFR activation with erlotinib prevented the upregulation of parathyroid TGF-alpha, the progression of growth, and the reduction of VDR. Increased TGF-alpha/EGFR activation induced the synthesis of liver-enriched inhibitory protein, a potent mitogen and the dominant negative isoform of the transcription factor CCAAT enhancer binding protein-beta, in human hyperplastic parathyroid glands and in the human epidermoid carcinoma cell line A431, which mimics hyperplastic parathyroid cells. Increases in liver-enriched inhibitory protein directly correlated with proliferating activity and, in A431 cells, reduced VDR expression by antagonizing CCAAT enhancer binding protein-beta transactivation of the VDR gene. Similarly, in nodular hyperplasia, which is the most severe form of SH and the most resistant to calcitriol therapy, higher TGF-alpha activation of the EGFR was associated with an 80% reduction in VDR mRNA levels. Thus, in SH, EGFR activation is the cause of both hyperplastic growth and VDR reduction and therefore influences the efficacy of therapy with calcitriol.

Topics: Animals; Calcitriol; Carcinoma, Squamous Cell; CCAAT-Enhancer-Binding Protein-beta; Cell Line, Tumor; Disease Models, Animal; Drug Resistance; ErbB Receptors; Erlotinib Hydrochloride; Female; Genes, Reporter; Humans; Hyperparathyroidism, Secondary; Hyperplasia; Protein Kinase Inhibitors; Quinazolines; Rats; Rats, Sprague-Dawley; Receptors, Calcitriol; Renal Insufficiency, Chronic; Transforming Growth Factor alpha

Using a mouse predisposed to neoplasia by a germ line mutation in Apc (Apc(Min)), we tested whether induced hyperplasia is sufficient to increase intestinal tumor multiplicity or size in the intestine. We found that hyperplasia in the jejunum correlated with a significant increase in tumor multiplicity. However, tumor multiplicity was unchanged in the hyperplastic colon. This result indicates that even an intestine predisposed to neoplasia can, in certain regions including the colon, accommodate net increased cell growth without developing more neoplasms. Where hyperplasia correlated with increased tumor multiplicity, it did not increase the size or net growth of established tumors. This result suggests that the event linking hyperplasia and neoplasia in the jejunum is tumor establishment. Two novel observations arose in our study: the multiple intestinal neoplasia (Min) mutation partially suppressed both mitosis and transforming growth factor alpha-induced hyperplasia throughout the intestine; and zinc treatment alone increased tumor multiplicity in the duodenum of Min mice.

Topics: Animals; Apoptosis; Colonic Neoplasms; Duodenal Neoplasms; Ethylnitrosourea; Female; Genes, APC; Hyperplasia; Ileal Neoplasms; Jejunal Neoplasms; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; Mitosis; Mutation; Transforming Growth Factor alpha; Transgenes; Zinc

The presence of neuroendocrine (NE) cells in gastric adenocarcinoma (GCa) is well documented, however, their significance is controversial. There is no evidence in the literature concerning the possible effect of these cells on the expression of TGF-alpha and EGFR, which are believed to confer growth advantage to tumor cells. 101 partial or total gastrectomy specimens from patients operated for conventional gastric adenocarcinoma were included in the study. In each case immunohistochemistry was performed on sequential tissue sections for chromogranin A (ChrA), TGF-alpha and EGFR. Samples were graded based on the number of ChrA-positive cells (0-3). TGF-alpha and EGFR expressions were evaluated according to both the intensity (0-2) and quantification of the positively stained areas (0-3). Follow-up data was available in 54 patients. Twenty-seven patients died of disease, while 27 patients were alive with a follow-up of at least 15 months. ChrA expression was detected in 54.4% of the tumor specimens. TGF-alpha was stained positively in 42.6% and EGFR in 49.5% of the cases. NE cells in GCa was related to TGF-alpha (p<0.0001) and EGFR expression (p<0.05), and TGF-alpha/EGFR coexpression (p<0.001). Among histopathologic variables, the presence of NE cells was significantly related to grade, stage and lymph node status. Although the presence of NE cells had no effect on survival, the expression of EGFR (p<0.0001) and TGF-alpha (p=0.002) were related to survival. The results of our study suggest that the presence of NE cells may have an effect on the expression of TGF-alpha and EGFR in GCa, and the autocrine mechanism between TGF-alpha and EGFR plays an important role in the prognosis of gastric carcinoma.

Topics: Adenocarcinoma; Adult; Aged; Aged, 80 and over; Chromogranin A; ErbB Receptors; Female; Follow-Up Studies; Gastrins; Gene Expression Regulation, Neoplastic; Humans; Hyperplasia; Kaplan-Meier Estimate; Male; Middle Aged; Neurosecretory Systems; Prognosis; Retrospective Studies; Stomach Neoplasms; Transforming Growth Factor alpha

Identification of biomarkers that indicate an increased risk of breast cancer or that can be used as surrogates for evaluating treatment efficacy is paramount to successful disease prevention and intervention. An ideal biomarker would be identifiable before lesion development. To test the hypothesis that changes in cell turnover precede mammary carcinogenesis, we evaluated epithelial cell proliferation and apoptosis in mammary glands from transgenic mice engineered to develop mammary cancer due to expression in mammary epithelia of transforming growth factor alpha (TGF-alpha) or c-myc. In transgenic glands, before lesion development, epithelial cell turnover was enhanced overall compared with nontransgenic glands, indicating that aberrant cell turnover in normal epithelia may contribute to tumorigenesis. In addition, in tumor-containing glands, proliferation in normal epithelia was higher than in tumor-free transgenic glands, suggesting these cell populations influence one another. Finally, although c-myc glands displayed a uniformly high epithelial cell turnover regardless of age, cell turnover was reduced with aging in nontransgenic and TGF-alpha mice, indicating that some growth and death regulatory mechanisms remain intact in TGF-alpha epithelia. These observations support the evaluation of cell turnover as a biomarker of cancer risk and indicator of prevention/treatment efficacy in preclinical models and warrant validation in human breast cancer.

Topics: Aging; Animals; Apoptosis; Bromodeoxyuridine; Cell Proliferation; Epithelial Cells; Epithelium; Female; Hyperplasia; Mammary Neoplasms, Experimental; Mice; Mice, Inbred C57BL; Mice, Transgenic; Proto-Oncogene Proteins c-myc; Transforming Growth Factor alpha

MTI/G-Gly mice and hGAS mice, overexpressing glycine-extended gastrin (G-Gly) and progastrin, respectively, display colonic mucosa hyperplasia, hyperproliferation, and an increased susceptibility to intestinal neoplasia. Here, we have used these transgenic mice to analyze in vivo the modulation of intracellular signaling pathways that may be responsible for the proliferative effects of gastrin precursors. The expression, activation, and localization of signaling and cell-to-cell adhesion molecules were studied using immunofluorescence and Western blot techniques on colonic tissues derived from MTI/G-Gly, hGAS, or wild-type FVB/N mice. These analyses revealed an up-regulation of Src tyrosine kinase and related signaling pathways [phosphatidyl inositol 3'-kinase (PI3K)/Akt, Janus-activated kinase (JAK) 2, signal transducer and activator of transcription (STAT) 3, and extracellular-signal regulated kinases (ERK)] in both MTI/G-Gly and hGAS mice compared with the wild-type control animals as well as an overexpression of transforming growth factor-alpha (TGF-alpha). In contrast, overexpression of the gastrin precursors did not affect the activation status of STAT1 nor the expression and the distribution of adhesion proteins (focal adhesion kinase, cadherins, and catenins). We report for the first time that the transition from a normal colonic epithelium to a hyperproliferative epithelium in MTI/G-Gly and hGAS mice may be a consequence of the up-regulation of Src, PI3K/Akt, JAK2, STAT3, ERKs, and TGF-alpha. Deregulation of cell adhesion, a late event in tumor progression, does not occur in these transgenic models.

Topics: Animals; Cell Adhesion; Cell Proliferation; Colon; DNA-Binding Proteins; Female; Gastrins; Hyperplasia; Intestinal Mucosa; Janus Kinase 2; Male; Mice; Phosphatidylinositol 3-Kinases; Protein Precursors; Protein-Tyrosine Kinases; Proto-Oncogene Proteins; Signal Transduction; src-Family Kinases; STAT3 Transcription Factor; Trans-Activators; Transforming Growth Factor alpha; Up-Regulation

Wild-type transforming growth factor alpha (TGFalpha) expression in lactotrope cells in the pituitary gland led to lactotrope-specific pituitary hyperplasia and adenomata. To indicate whether the EGF receptor is involved in this TGFalpha-mediated phenotype, we bred TGFalpha mice with mice expressing the cytoplasmic truncated-EGF receptor (EGFR-tr), which is dominant-negative in other models. These bitransgenic mice developed pituitary pathology despite expression of the dominant-negative receptor. To further characterize this observation, we generated two lineages of transgenic mice that overexpress mutant forms of TGFalpha: a processed soluble form (s TGFalpha) and a cytoplasmic-deleted form (TGFalphaDeltaC). While sTGFalpha expression in lactotrope cells failed to induce autocrine lactotrope hyperplasia, the pituitary became very enlarged due to proliferation of neighboring interstitial cells. In contrast, the TGFalphaDeltaC mice did not develop a phenotype, although the mRNA and protein were present in the pituitary and this form of TGFalpha was confirmed to be biologically active and targeted properly to the plasma membrane of cultured CHO cells. The results suggest that the cytoplasmic domain of TGFalpha is required for autocrine parenchymal tumor formation in the pituitary gland. This signal cannot be inhibited by the EGFR-tr. Conversely, the released form of TGFalpha appears to have primarily paracrine activity.

Topics: Animals; Cell Division; Cell Membrane; CHO Cells; Coloring Agents; Cricetinae; Cytoplasm; ErbB Receptors; Hyperplasia; Mice; Mice, Transgenic; Mitotic Index; Phenotype; Pituitary Gland; Protein Structure, Tertiary; Signal Transduction; Solubility; Transforming Growth Factor alpha

Increase of intramucosal transforming growth factor alpha (TGFalpha) levels in the gastric fundus leads to oxyntic atrophy and massive foveolar hyperplasia in both metallothionein (MT)-TGFalpha mice and patients with Ménétrier's disease. We have evaluated the hypothesis that increased levels of TGFalpha in the fundus induces an antral pattern of cell differentiation in fundic glands by studying Pdx1, a transcription factor whose expression normally is confined to the gastric antrum.. Induction of Pdx1 expression was evaluated in Pdx1(lacZ/+)/MT-TGFalpha bigenic mice treated with zinc. The distribution of Pdx1 in MT-TGFalpha mice and Ménétrier's disease patients was evaluated with anti-Pdx1 antibodies. Transcript levels were evaluated by quantitative polymerase chain reaction in mouse and human tissues and AGS cells.. In Pdx1(lacZ/+) mice, Pdx1 was expressed in antral mucosal cells including gastrin cells and TFF2-expressing deep glandular mucous cells. Zinc treatment for 2 to 8 weeks in Pdx1(lacZ/+)/MT-TGFalpha transgenic mice resulted in expression of Pdx1 throughout the fundus. No ectopic fundic Pdx1 expression was observed in either H. felis-infected or DMP777-treated mice. In MT-TGFalpha mice, 8 weeks of zinc treatment elicited nuclear Pdx1 staining throughout the fundic mucosa. TGFalpha treatment in AGS cells led to increases in Pdx1 and gastrin messenger RNA expression. Fundic sections from Ménétrier's disease patients showed nuclear Pdx1 staining throughout the fundic glands. Treatment of a Ménétrier's disease patient with an anti-epidermal growth factor receptor monoclonal antibody reduced fundic expression of both Pdx1 and gastrin.. Overexpression of TGFalpha in MT-TGFalpha mice and Ménétrier's disease patients elicits ectopic expression in the fundus of Pdx1, consistent with the phenotype of antralization.

Topics: Animals; Atrophy; Epithelium; Gastric Fundus; Gastrins; Gastritis, Hypertrophic; Gene Expression; Homeodomain Proteins; Hyperplasia; Mice; Mice, Transgenic; Mucins; Muscle Proteins; Parietal Cells, Gastric; Peptides; Trans-Activators; Transforming Growth Factor alpha; Trefoil Factor-2

The parathyroid hyperplasia secondary to kidney disease is associated with enhanced expression of the growth promoter transforming growth factor-alpha (TGF-alpha). TGF-alpha stimulates growth through activation of its receptor, the epidermal growth factor receptor (EGFR), normally expressed in the parathyroid glands. Because enhanced coexpression of TGF-alpha and EGFR causes aggressive cellular growth, these studies utilized highly specific inhibitors of EGFR tyrosine kinase, a step mandatory for TGF-alpha-induced EGFR activation, to assess the contribution of growth signals from enhanced expression of TGF-alpha exclusively or both TGF-alpha and EGFR to the rapid parathyroid growth induced by kidney disease and exacerbated by high-phosphorus (P) and low-calcium (Ca) diets in rats. The enhancement in parathyroid gland weight and proliferating activity (proliferating cell nuclear antigen/Ki67) induced by kidney disease and aggravated by either high P or low Ca intake, within the first week after 5/6 nephrectomy, in rats, coincided with simultaneous increases (2- to 3-fold) in TGF-alpha and EGFR content. Conversely, prevention of the increases in both TGF-alpha and EGFR paralleled the efficacy of either P restriction or high-Ca intake in ameliorating uremia-induced parathyroid hyperplasia. More importantly, suppression of TGF-alpha/EGFR signaling, through prophylactic administration of potent and highly selective inhibitors of ligand-induced EGFR activation, completely prevented both high-P- and low-Ca-induced parathyroid hyperplasia as well as TGF-alpha self-upregulation. Thus enhanced parathyroid TGF-alpha/EGFR expression, self-upregulation, and growth signals occur early in kidney disease, are aggravated by low-Ca and high-P intake, and constitute the main pathogenic mechanism of the severity of parathyroid hyperplasia.

Topics: Animals; Calcium, Dietary; ErbB Receptors; Female; Hyperplasia; Kidney Diseases; Parathyroid Glands; Phosphorus, Dietary; Rats; Rats, Sprague-Dawley; Severity of Illness Index; Transforming Growth Factor alpha; Up-Regulation

EBV latent membrane protein 1 (LMP1) is an oncoprotein frequently expressed in nasopharyngeal carcinoma. We have generated transgenic mice expressing the nasopharyngeal carcinoma-derived CAO strain of LMP1 and LMP1 of the B95-8 strain, using the viral ED-L2 promoter for epithelial expression. LMP1(CAO) and LMP1(B95-8) induce transforming growth factor alpha expression and epidermal hyperplasia. However, levels of total epidermal growth factor receptor (EGFR) decline with the appearance of phosphorylated EGFR products, suggesting that the negative feedback loop upon EGFR expression is intact or that there is faster turnover at these early stages of carcinogenesis. In the L2LMP1(CAO) mice, increased levels of vascular endothelial growth factor are also seen at an early stage in the skin. As the phenotype worsens, with increasing hyperplasia and vascularization leading to keratoacanthoma, p16(INK4a) and matrix metalloproteinase 9 expression is induced. The lesions can progress spontaneously to carcinoma. Carcinoma cell lines developed from these mice show high levels of total and phosphorylated EGFR. These data show that the induction of signaling through EGFR by LMP1 is an early event in carcinogenesis and that any inhibition upon EGFR expression is lifted during progression. Furthermore, expression of LMP1 is not sufficient to inhibit induction of p16(INK4a) in response to abnormal proliferation. These data are consistent with the cooperative effects seen between LMP1 and loss of the INK4a locus in transgenic mice and with the frequency of loss of this locus in EBV-associated nasopharyngeal carcinoma.

Topics: Animals; Cell Growth Processes; Cell Transformation, Neoplastic; Cyclin-Dependent Kinase Inhibitor p16; ErbB Receptors; Hyperplasia; Matrix Metalloproteinase 9; Mice; Mice, Inbred C57BL; Mice, Transgenic; Skin; Skin Neoplasms; Transforming Growth Factor alpha; Up-Regulation; Vascular Endothelial Growth Factor A; Viral Matrix Proteins

It was reported that the parathyroid gland hyperplasia correlated with enhanced co-expression of TGF-alpha and its receptor EGFR at early stages of renal failure. This time, we investigated the time course for EGFR and its ligands, TGF-alpha, and EFG expression, and the influence of high-phosphorus (P) diet to EGFR and EGF expression, and the effect of EGFR-tyrosine kinase inhibitor (Gefitinib, [IRESSA; AstraZeneca]; TKI) in rat PTGs with established stage of renal failure. The levels of EGFR, EGF, TGF-alpha mRNA in rat PTGs were increased for the time periods. The serum intact PTH levels, and EGFR, EGFmRNA in rat PTGs were suppressed in normal-P diet group. Nuclei positive cells for PCNA in TKI group were suppressed. The levels of p21mRNA were increased in TKI group. These results suggested that the enhanced expression of EGFR, TGF-alpha and EGF participate in the cell proliferation of hyperplastic PTGs in established stage of renal failure.

Topics: Animals; Cell Proliferation; Disease Models, Animal; Epidermal Growth Factor; ErbB Receptors; Gefitinib; Hyperplasia; Intracellular Signaling Peptides and Proteins; Male; Parathyroid Glands; Parathyroid Hormone; Phosphorus, Dietary; Quinazolines; Rats; Rats, Sprague-Dawley; Renal Insufficiency; Time Factors; Transforming Growth Factor alpha

While epidermal growth factor receptor (EGFR) plays a pivotal role in the repair process of epithelial cells, it is also involved in the overproduction of mucus and goblet cell hyperplasia (GCH), which occurs in chronic airway diseases such as asthma. Among the EGFR ligands, transforming growth factor (TGF)-alpha is thought to be the most important in the synthesis of mucus. Pro-TGF-alpha is cleaved to give an active form by members of the matrix metalloproteinases (MMP)/a disintegrin and metalloproteinases (ADAM) family. Thus MMP/ADAM inhibitors might prevent GCH by inhibiting transactivation of EGFR. Upon stimulation of differentiating normal human bronchial epithelial (NHBE) cells by IL-13, GCH was induced. The mucin genes MUC5AC, MUC5B, and MUC2 were upregulated whereas the expression of ciliated cell markers was greatly repressed. GM6001, a broad-spectrum inhibitor for MMP/ADAM, inhibited IL-13-induced mucin gene expression and mucus production as measured by periodic acid-Schiff staining. This was accompanied by an inhibition of TGF-alpha release. These results suggest that MMP/ADAMs play a pivotal role in the development of GCH in lung epithelial cells.

Topics: Bronchi; Cell Differentiation; Cells, Cultured; Dipeptides; Enzyme Inhibitors; Epithelial Cells; ErbB Receptors; Gene Expression Regulation; Goblet Cells; Humans; Hyperplasia; Interleukin-13; Metalloendopeptidases; Mucin 5AC; Mucin-5B; Mucins; Mucus; Rosaniline Dyes; Transforming Growth Factor alpha

The epidermal growth factor receptor (EGF-R) system plays a crucial role in mucus production in vitro and in rats. However, the role of the EGF-R system in humans is not known. We compared the localization of EGF-R and its ligands (epidermal growth factor and transforming growth factor alpha) in the epithelia of sinuses with chronic sinusitis and in those of healthy controls. Immunohistochemical techniques were employed to identify the presence of EGF-R and its ligands in the sinus mucosa. We found EGF-R in goblet cells, basal cells, and submucosal gland cells, but not in ciliated cells. Immunoreactivity for both epidermal growth factor and transforming growth factor alpha was found in the epithelial cells and inflammatory cells and in some submucosal gland cells. There was stronger staining of EGF-R and its ligand proteins in chronic sinusitis specimens than in controls. The interrelated localization of EGF-R and its ligands suggests a role in mucus production in the epithelium of the sinus mucosa.

Topics: Adult; Case-Control Studies; Chronic Disease; Epidermal Growth Factor; ErbB Receptors; Female; Goblet Cells; Humans; Hyperplasia; Immunohistochemistry; Ligands; Male; Maxillary Sinusitis; Metaplasia; Middle Aged; Mucus; Neutrophil Activation; Tomography, X-Ray Computed; Transforming Growth Factor alpha; Tumor Necrosis Factor-alpha

Granular cell tumors (GCT) are uncommon benign neoplasms that have a predilection for the head and neck region. These tumors can frequently be associated with pseudoepitheliomatous hyperplasia (PEH), which in turn may be mistaken for squamous cell carcinoma. Although epidermal growth factors are overexpressed in squamous cell carcinomas of the head and neck, their presence in PEH, especially its relation to GCT, is unknown. We hypothesize that the expression of epidermal growth factor receptor (EGFR), epidermal growth factor (EGF), and transforming growth factor alpha (TGFalpha) in GCT have a role in the development of PEH overlying some GCT. Sections from 13 cases of GCT (five with overlying PEH) were examined histologically and evaluated immunohistochemically using monoclonal antibodies for EGFR, EGF, and TGFalpha. These were compared with nine cases of PEH independent of GCT. Two of five GCT with overlying PEH and two of six GCT without overlying PEH stained positively for TGFalpha. None of the GCT stained with EGFR or EGF. All cases of PEH, whether or not associated with GCT, were reactive for EGFR and EGF. Four of the five cases of PEH overlying GCT stained with TGFalpha. The staining pattern and intensity of all three antibodies were comparable to that of the adjacent normal squamous mucosa. Among the three antibodies, only TGFalpha in GCT appears to be related to the development of PEH. Epidermal growth factor receptor and EGF do not seem to be directly involved. The reason of PEH formation associated with GCT in the absence of growth factors is unknown.

Topics: Adolescent; Adult; Aged; Antibodies, Monoclonal; Carcinoma, Squamous Cell; Child; Diagnosis, Differential; Epidermal Growth Factor; ErbB Receptors; Female; Granular Cell Tumor; Head and Neck Neoplasms; Humans; Hyperplasia; Immunohistochemistry; Male; Middle Aged; Retrospective Studies; Transforming Growth Factor alpha

The purpose of this study was to identify a mediator produced by human colon cancer cells that is responsible for the induction of hyperplasia in the adjacent mucosa.. Seventy human colon cancer surgical specimens were immunostained to determine the presence of cytokines that can induce hyperplasia in the adjacent mucosal. Human colon cancer cells with low and high metastatic potential were implanted into the cecal wall of nude mice. The resulting lesions were studied by immunohistochemistry to detect possible mediators of mucosal hyperplasia.. Immunostaining of 70 colon cancer specimens from 70 patients suggested that mucosal hyperplasia and distant metastasis were associated with the expression of interleukin (IL)-15 and, to a lesser extent, transforming growth factor alpha. The production of IL-15 by colon cancer cells was not associated with the infiltration of natural killer cells into the tumors. Cecal tumors produced in nude mice by human colon cancer cells with low and high metastatic potential (KM12C and KM12SM cells, respectively) expressed similar levels of transforming growth factor alpha, and expression of IL-15 was detected only in the metastatic KM12SM cells and was associated with hyperplasia of the surrounding mucosa. The expression of the IL-15 receptor in rat intestinal epithelial cells (IEC6 cells) was confirmed by immunoblotting with antibodies against IL-15 receptor alpha and IL-2 receptor beta and gamma subunits and by a binding assay using (125)I-labeled IL-15 (K(d) = 0.011 nM). IL-15 stimulated proliferation of the IEC6 cells, even under serum starvation. Treatment of IEC6 cells with IL-15 decreased doxorubicin-mediated cytotoxicity. In IEC6 cells treated with either IL-15- or KM12SM-conditioned medium, immunoblotting revealed a decrease in the production of p21Waf1, Bax, and Bak and an increase in the production of cyclin E, proliferating cell nuclear antigen, the phosphorylated active form of AKT, basic fibroblast growth factor, and vascular endothelial growth factor, changes associated with cell growth, survival, and induction of angiogenesis.. These data indicate that IL-15 produced by metastatic colon carcinoma cells can induce hyperplasia in the mucosa adjacent to colon cancer, thus contributing to angiogenesis and progression of the disease.

Topics: Animals; Cell Division; Cell Line; Cell Line, Tumor; Cells, Cultured; Colonic Neoplasms; Culture Media, Conditioned; Disease Progression; DNA Fragmentation; Dose-Response Relationship, Drug; Enzyme-Linked Immunosorbent Assay; Epithelial Cells; Humans; Hyperplasia; Immunoblotting; Immunohistochemistry; Interleukin-15; Kinetics; Mice; Mice, Inbred BALB C; Mice, Nude; Mucous Membrane; Neoplasm Metastasis; Neoplasm Transplantation; Neovascularization, Pathologic; Proliferating Cell Nuclear Antigen; Rats; Receptors, Interleukin-2; Reverse Transcriptase Polymerase Chain Reaction; Time Factors; Transforming Growth Factor alpha

Whey acidic protein (WAP)-transforming growth factor (TGF)-alpha transgenic mice acquire both cancerous and noncancerous mammary lesions. For this study, we evaluated the effect of mouse strain background on the incidence, latency, and histotype of two noncancerous lesions, hyperplastic alveolar nodules (analogous to typical hyperplasias in women), and macrocysts. These lesions display characteristics of fibrocystic changes observed in breasts of women, and in both mice and humans are associated with an uncertain risk of progression to neoplasia. Virgin transgenic mice of the (C57BL/6J;SJL)F2 background developed very few hyperplastic alveolar nodules and no macrocysts. In contrast, when the WAP-TGF-alpha transgene was carried on the FVB/N strain, congenic virgin transgenic mice acquired both lesion types with approximately 100% penetrance. In the (FVB;C57BL/6J)F1 background, hyperplastic alveolar nodule incidence was reduced to approximately the nontransgenic mouse level, and macrocyst latency was increased dramatically. Crossing into C57BL/6 resulted in elimination of the macrocyst phenotype. Finally, FVB strain transgenic mammary epithelium transplanted into nontransgenic recipients of the FVB/N or (FVB;C57BL/6J)F1 backgrounds displayed macrocyst latency characteristic of the recipient, and not donor, mouse strain. Quantitative real-time polymerase chain reaction analysis demonstrated that, despite the difference in macrocyst incidence between (FVB;C57BL/6J)F1 and C57BL/6 virgin transgenic mice (81% versus 0%), the level of TGF-alpha expression was not different. FVB strain transgenic mice expressed only twofold more TGF-alpha than the other backgrounds. These findings indicate that C57BL/6J modifier alleles inhibit mammary lesion incidence and macrocyst latency in a semidominant manner, and that suppression of lesion development can involve host factors that are independent of mammary epithelial genotype.

Topics: Animals; Female; Fibrocystic Breast Disease; Hyperplasia; Mammary Glands, Animal; Mice; Mice, Inbred C57BL; Mice, Inbred Strains; Mice, Transgenic; Phenotype; Species Specificity; Transforming Growth Factor alpha

To study the expression of transforming growth factor alpha, beta 1 in hyperplastic tissue after endoscopic polypectomy and the effect of corticosteroid.. Forty patients with nasal polyps were divided into two groups randomly: corticosteroid group (n = 20) with topical application of Budesonide (BUD, 400 micrograms/d) after endoscopic polypectomy and control group (n = 20) without corticosteroid after surgery. The hyperplastic tissues in operative cavity obtained in the 1st and 8th weeks after operation were studied with HE staining and immunohistochemistry technique respectively.. Morphological changes of hyperplastic tissue after endoscopic polypectomy included pseudostratified epithelium, highly edematous lamina proper and inflammatory cells infiltration, in which the main infiltrative cells were eosinophils (67.5%). Transforming growth factor alpha(TGF alpha) protein was highly expressed in epithelial cells, grand cells and inflammatory cells in the hyperplastic tissue. Transforming growth factor beta 1 (TGF beta 1) protein was highly expressed in inflammatory cells in the hyperplastic tissue. The expression of TGF alpha and beta 1 was significantly decreased after topical BUD spray (P < 0.01, 0.05).. Transforming growth factor alpha and beta 1 may play an important role in the formation and recurrence of nasal polyps.

Topics: Adult; Anti-Inflammatory Agents; Budesonide; Female; Humans; Hyperplasia; Male; Nasal Mucosa; Nasal Polyps; Transforming Growth Factor alpha; Transforming Growth Factor beta

Verrucous carcinoma (VC) is a locally invasive, nonmetastasizing variant of squamous cell carcinoma (SCC) with distinct clinical and histologic features. Molecular alterations detectable by immunohistochemical analyses in VC have not been extensively studied. This study investigates the expression of p53, epidermal growth factor receptor (EGFR), transforming growth factor-alpha (TGF-alpha), and cyclin D1 in VC, verrucous hyperplasia (VH), and classic SCC of the head and neck. Twenty-six cases of VC, 12 cases of SCC of various differentiations, and 4 cases of VH were studied. Formalin-fixed, paraffin-embedded archival material was used for immunohistochemistry (avidin-biotin immunoperoxidase technique) to study the expression of oncogenes and their tumor markers. Identification of p53 protein was found in 100% of VH, 88% of VC, and 100% of SCC. EGFR expression was noted in 25% of VH, 54% of VC, 40% of well-differentiated SCC (WDSCC), and 100% of moderately and poorly differentiated SCC (MDSCC/PDSCC). TGF-alpha was detected in 25% of VH, 88% of VC, 80% WDSCC, and 100% of MDSCC/PDSCC. Cyclin-D1 expression was seen in 75% of VH, 35% of VC, 100% of WDSCC, 67% of MDSCC, and 50% of PDSCC. Correlation between the level of expression of all markers and the grade of this group of squamous lesions revealed statistically significant correlation coefficients for p53 and EGFR but not for TGF-alpha and cyclin D1.

Topics: Biomarkers, Tumor; Carcinoma, Squamous Cell; Carcinoma, Verrucous; Cell Differentiation; Cyclin D1; Epithelium; ErbB Receptors; Head and Neck Neoplasms; Humans; Hyperplasia; Immunohistochemistry; Transforming Growth Factor alpha; Tumor Suppressor Protein p53

This study was conducted to evaluate the clinical significance of the localization of epidermal growth factor receptor (EGF-r), transforming growth factor (TGF)-alpha, and erbB-2 in the development, progression and prognosis of squamous cell cancers (SCCs) of the lung.. The localization of EGF-r, TGF-alpha, and erbB-2 was evaluated immunohistochemically in 60 archival specimens of SCC of the lung and in 60 lung specimens without cancer. To clarify the patterns of expression of EGF-r in these tumors, the patterns of expression of EGF-r in cells in culture were monitored after challenging normal human bronchial epithelial and SCC cell lines with either EGF or TGF-alpha at physiological concentrations.. The expression of EGF-r, erbB-2, and TGF-alpha were significantly higher in SCC and associated precancerous lesions than in the normal bronchial epithelium and hyperplastic lesions of noncancer specimens. A statistically significant stepwise increase in expression from uninvolved bronchial epithelium to precancerous lesions to SCC was observed with EGF-r and TGF-alpha. The localization of EGF-r in the cytoplasm (P = 0.04), but not in the membrane (P = 0.20), of SCCs was significantly associated with poor overall survival of subjects. To demonstrate the biological relevance of cytoplasmic expression of EGF-r, we noted that there was a prompt reduction in the membrane expression and a concomitant increase in cytoplasmic expression of EGF-r after adding either EGF or TGF-alpha to the cell culture medium. Overall, the study identified an involvement of EGF-r and TGF-alpha in the development of SCCs. The prognostic importance of EGF-r expression in the cytoplasm of lung cancer probably is an indication of the prognostic importance of trafficking of the EGF-r receptor between the Golgi apparatus and cell membranes and of internalization of EGF-r after an interaction with one of the EGF-r ligands at the cellular membrane surface.

Topics: Carcinoma, Squamous Cell; Cell Membrane; Cytoplasm; Epithelial Cells; ErbB Receptors; Humans; Hyperplasia; Immunoenzyme Techniques; Ligands; Lung Neoplasms; Precancerous Conditions; Prognosis; Receptor, ErbB-2; Survival Rate; Transforming Growth Factor alpha; Tumor Cells, Cultured

The parathyroid (PT) hyperplasia induced by renal failure can be further enhanced by high dietary phosphate (P) or completely abolished by P restriction. To identify potential mechanisms mediating these opposing effects of dietary P on PT growth, this study first focused on p21(WAF1) (p21) because high P reduces while low P enhances serum 1,25-dihydroxyvitamin D, whose potent antiproliferative properties result from the induction of p21. In addition to reducing p21, high P-induced PT growth could result from increased PT expression of the growth promoter transforming growth factor-alpha (TGF-alpha), known to be elevated in hyperplastic and adenomatous human PT glands.. The time course for dietary P regulation of PT expression of TGF-alpha and p21 was assessed for seven days after 5/6 nephrectomy in rats and correlated with the degree of PT hyperplasia and secondary hyperparathyroidism.. In P-restricted 5/6 nephrectomized rats, PT-p21 mRNA and protein increased by day 2, independent of changes in serum 1,25-dihydroxyvitamin D, and remained higher than in the high P counterparts for up to seven days. The PT hyperplasia of the high P group could not be attributed to a reduction of PT-p21 expression from normal control values. Instead, PT-TGF-alpha protein was higher in uremic rats compared with normal controls and increased further with high dietary P intake. PT levels of proliferating cell nuclear antigen (PCNA), an index of cell mitoses, correlated inversely with p21 and directly with TGF-alpha. Consistent with these findings, PT gland size and serum PT hormone levels, similar in both dietary groups at day 2, were higher in the high P group by day 5. Induction of p21 by low P and of TGF-alpha by high P was specific for the PT glands. Dietary P had no effect either on intestinal growth or p21 or TGF-alpha protein content.. These findings suggest that low P induction of p21 could prevent PT hyperplasia in early uremia, whereas high P enhancement of TGF-alpha may function as an autocrine signal to stimulate growth further.

Topics: Animals; Cell Division; Cyclin-Dependent Kinase Inhibitor p21; Cyclins; Diet; Hyperparathyroidism, Secondary; Hyperplasia; Intestines; Male; Parathyroid Glands; Phosphates; Proliferating Cell Nuclear Antigen; Rats; Rats, Sprague-Dawley; RNA, Messenger; Time Factors; Transforming Growth Factor alpha; Uremia

Maspin is a novel serine protease inhibitor (serpin) with tumor suppressive activity. To date, despite the mounting evidence implicating the potential diagnostic/prognostic and therapeutic value of maspin in breast and prostate carcinoma, the lack of a suitable animal model hampers the in vivo investigation on the role of maspin at different stages of tumor progression. In this study, we used MMTV/TGF-alpha transgenic mouse model to study the expression profile of maspin in mammary tumor progression. Histopathological examinations of MMTV/TGF-alpha transgenic mice revealed TGF-alpha expression leading to hyperproliferation, hyperplasia, and occasional carcinoma in mammary gland. Interestingly, when MMTV/TGF-alpha transgenic mice were breed to homozygocity, they also developed characteristic skin papillomas. Immunohistochemistry analysis of maspin expression in the breast tissues of TGF-alpha transgenic mice showed a direct correlation between down-regulation of maspin expression and tumor progression. The loss of maspin expression was concomitant with the critical transition from carcinoma in situ to invasive carcinoma. Subsequent in-situ hybridization analyses suggest that the down-regulation of maspin expression is primarily a transcriptional event. This data is consistent with the tumor suppressive role of maspin. Furthermore, our data suggests that MMTV/TGF-alpha transgenic mouse model is advantageous for in vivo evaluation of both the expression and the biological function of maspin during the slow multi-stage carcinogenesis of mammary gland.

Topics: Animals; Carcinoma in Situ; Disease Progression; Down-Regulation; Female; Genes, Tumor Suppressor; Hyperplasia; Immunohistochemistry; In Situ Hybridization; Mammary Glands, Animal; Mammary Neoplasms, Experimental; Mammary Tumor Virus, Mouse; Mice; Mice, Transgenic; Neoplasm Invasiveness; Protein Biosynthesis; Proteins; RNA, Neoplasm; Serpins; Transcription, Genetic; Transforming Growth Factor alpha

High dietary phosphorus (P) worsens uremia-induced parathyroid (PT) hyperplasia through increases in the growth promoter transforming growth factor-alpha (TGF-alpha). In contrast, P restriction prevents PT hyperplasia by inducing the cell cycle inhibitor p21. Since 1,25(OH)2D3-antiproliferative action in various cell types involve increases in p21, we studied whether induction of p21 by 1,25(OH)2D3 or the vitamin D analog, 19-Nor-1,25(OH)2D2, could counteract the PT hyperplasia induced by high dietary P in early uremia.. Normal (N) and uremic (U; 5/6 nephrectomized) female Sprague-Dawley rats were fed high P (HP), low P (LP) or high Ca (HCa) diets and administered intraperitoneally (IP) either vehicle or vitamin D metabolites for seven days, as follows: N-HP; U-HP + vehicle; U-HP + 1,25(OH)2D3 (4 ng/day); U-HP + 19-Nor-1,25(OH)2D2 (30 ng/day); U-LP; U-HCa. Serum PTH and PT gland weight assessed secondary hyperparathyroidism. Immunohistochemical quantitation of two markers of mitotic activity, Ki67 and PCNA measured PT hyperplasia. Immunohistochemical expression of PT p21 and TGF-alpha addressed potential mechanisms regulating PT cell growth.. 1,25(OH)2D3 and 19-Nor-1,25(OH)2D2 were effective in suppressing both PTH secretion and PT hyperplasia induced by uremia and high dietary P independent of increases in ionized Ca. Both vitamin D compounds enhanced PT p21 expression and prevented high P-induced increases in PT TGF-alpha content. Induction of PT p21 and reduction of TGF-alpha content also occurred when uremia-induced PT hyperplasia was suppressed by high dietary Ca.. In early uremia, vitamin D suppression of high P-induced PT hyperplasia and high dietary Ca arrest of PT growth involve induction of PT p21 and prevention of increases in TGF-alpha.

Topics: Animals; Blood; Calcium, Dietary; Cyclin-Dependent Kinase Inhibitor p21; Cyclins; Dose-Response Relationship, Drug; Ergocalciferols; Female; Hyperplasia; Parathyroid Glands; Parathyroid Hormone; Phosphorus, Dietary; Rats; Rats, Sprague-Dawley; Transforming Growth Factor alpha; Uremia; Vitamin D

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

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

We investigated tamoxifen's effects on the expression of growth regulatory genes in the endometrium to identify the mechanism by which tamoxifen induces proliferation.. Using immunohistochemical techniques, we analyzed 39 endometrial specimens for expression of Ki-67, lactoferrin, transforming growth factor-alpha, tumor necrosis factor receptor-II, adrenomedullin, estrogen receptors, and progesterone receptors. Twenty specimens were obtained from postmenopausal breast cancer patients treated with tamoxifen (20 mg/day) for at least 6 months to include two endometrial adenocarcinoma specimens. Five secretory phase, three proliferative phase, and seven atrophic endometrial specimens were used as controls. In addition, four endometrial adenocarcinoma specimens were reviewed from patients not treated with tamoxifen. Intensity of immunostaining was quantified using digitized imaging techniques.. Overexpression of both estrogen receptors and progesterone receptors, and an elevated proliferative index were the most consistent effects observed in benign endometrial specimens from tamoxifen-treated patients compared with atrophic controls (P <. 003). This staining pattern was also evident in adenocarcinomas from patients who received tamoxifen. Benign endometrium from tamoxifen-treated patients also expressed transforming growth factor-alpha, tumor necrosis factor receptor-II, lactoferrin, and adrenomedullin at levels comparable with those found in proliferative endometrial specimens.. These data provide further documentation that the uterotropic effects of tamoxifen may be due, at least in part, to the induction of estrogen receptors and progesterone receptors, as well as other genes associated with the proliferative phase. Furthermore, analysis of estrogen receptors, progesterone receptors, and Ki-67 may be useful in identifying postmenopausal individuals on tamoxifen, who are at increased risk for developing endometrial cancer.

Topics: Adrenomedullin; Antineoplastic Agents, Hormonal; Breast Neoplasms; Endometrial Neoplasms; Endometrium; Female; Gene Expression Regulation, Neoplastic; Genes, Regulator; Humans; Hyperplasia; Immunohistochemistry; Ki-67 Antigen; Lactoferrin; Peptides; Receptors, Estrogen; Receptors, Progesterone; Receptors, Tumor Necrosis Factor; Tamoxifen; Transforming Growth Factor alpha

By means of the technique of messenger RNA (mRNA) differential display, we previously isolated a partial DNA clone found to be down-regulated at the polytetrafluoroethylene (PTFE) hyperplastic arterial anastomosis compared with the normal artery. The partial DNA gene sequence was found to be homologous with interferon gamma up-regulated protein (IGUP) first found in human psoriatic keratinocytes. We cloned the entire IGUP gene from human vascular smooth muscle cells (VSMCs) to determine its regulation by gamma interferon (gamma-IFN) and other cytokines in cultured human VSMCs.. By means of polymerase chain reaction, the IGUP gene was amplified from a QUICK-Clone complementary DNA human aorta kit using 5' and 3' oligonucleotide primers to the known IGUP sequence. Immunohistocytochemistry studies compared normal artery and distal anastomotic IH. Human VSMCs were stimulated with 1000 U/mL of gamma-IFN, 5 ng/mL of platelet-derived growth factor BB (PDGF-BB), 3. 2 ng/mL basic fibroblast growth factor, 3.3 ng/mL transforming growth factor beta(TGF-beta), 10 ng/mL of vascular endothelial growth factor, and 10% fetal bovine serum (FBS) for zero, 24, 48 and 72 hours. Western blot analysis of lysates of the stimulated VSMCs was performed to determine up-regulation of IGUP.. DNA sequencing confirmed the cloning of the entire coding region of the IGUP gene with 100% homology to the known IGUP DNA sequence. There was strong expression of IGUP in quiescent VSMCs and marked reduction of expression of IGUP in proliferating smooth muscle cells. gamma-IFN was the only cytokine, of the cytokines evaluated, to up-regulate production of IGUP in VSMCs.. IGUP is a novel protein in VSMCs found to be down-regulated in areas of anastomotic IH, as compared with a normal artery. We have now shown IGUP to be up-regulated only by gamma-IFN in human VSMCs. IGUP may, therefore, be the intermediary for the known gamma-IFN inhibition of human VSMC proliferation.

Topics: Base Sequence; Becaplermin; Blotting, Western; Cells, Cultured; Cloning, Molecular; Endothelial Growth Factors; Fibroblast Growth Factor 2; Humans; Hyperplasia; Immunohistochemistry; Interferon-gamma; Lymphokines; Molecular Sequence Data; Muscle Proteins; Muscle, Smooth, Vascular; Platelet-Derived Growth Factor; Proteasome Endopeptidase Complex; Proto-Oncogene Proteins c-sis; Transforming Growth Factor alpha; Tunica Intima; Up-Regulation; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors

Pseudoepitheliomatous hyperplasia has occasionally been reported in cutaneous T-cell lymphoma (CTCL). This association raises the question of the relationship between epidermal hyperplasia and the lymphomatous infiltrate. Because epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha) have been demonstrated to be involved in epidermal proliferation through binding to EGF receptor (EGFr), we tested the hypothesis that these cytokines could be secreted by lymphomatous cells, and induce the overlying pseudoepitheliomatous hyperplasia. The purposes of this study were: (i) to describe the clinical and immunohistological features of pseudoepitheliomatous hyperplasia; (ii) to determine its frequency in a large series of CTCLs; and (iii) to evaluate the expression of EGF, TGF-alpha and EGFr in CTCL with or without pseudoepitheliomatous hyperplasia. Eleven cases of CTCL with pseudoepitheliomatous hyperplasia were collected from a series of 353 cases of cutaneous lymphoma registered from 1990 to 1996. They consisted of eight of 28 (28.5%) CD30+ large T-cell lymphomas and three of 148 (2%) cases of mycosis fungoides. Epidermal expression of EGF, EGFr and TGF-alpha was stronger in CTCL than in control normal human skin. Lymphomatous T cells expressed EGF and TGF-alpha whereas no expression of these cytokines could be detected in cutaneous and nodal B-cell lymphomas, nor in a normal lymph node. In addition, epidermal expression of EGFr was stronger in CTCL with pseudoepitheliomatous hyperplasia than in control cases of CTCL without pseudoepitheliomatous hyperplasia, suggesting that these cytokines, in association with other factors, are probably involved in the epidermal hyperplasia observed in some cases of CTCL.

Topics: Epidermal Growth Factor; Humans; Hyperplasia; Immunohistochemistry; Immunophenotyping; Lymphoma, T-Cell, Cutaneous; Neoplasm Proteins; Skin Neoplasms; Transforming Growth Factor alpha

The ErbB2 receptor tyrosine kinase (RTK) is expressed in basal cells of squamous epithelia and the outer root sheath of hair follicles. We previously showed that constitutive expression of activated ErbB2 directed to these sites in the skin by the keratin 14 (K14) promoter produces prominent hair follicle abnormalities and striking skin hyperplasia in transgenic mice. However, perinatal lethality precluded the establishment of a transgenic line for analysis of ErbB2 function in adult animals. To investigate the significance of ErbB2 signaling in epithelial tissues during and post development, we developed a K14-rtTA/TetRE-ErbB2 'Tet-On' bitransgenic mouse system. These mice were normal until the ErbB2 transgene was induced by exposure to doxycycline (Dox). Prenatal induction resulted in perinatal death. Postnatally, ErbB2 transgene expression was observed at 4 h after the initiation of Dox, and reached a plateau at 24 h. Skin hyperplasia followed after 2 days and these changes reverted to normal upon Dox withdrawal. In adults, as in the neonates, prolonged ErbB2 induction caused prominent skin and hair follicle hyperplasias. Severe hyperplasias in the cornea, eye lids, tongue and esophagus were also observed. ErbB2 transgene induction was accompanied by increased expression of TGFalpha, a ligand of epidermal growth factor receptor (EGFR), and to a lesser extent, EGFR, further enhancing RTK signal transduction. We conclude that ErbB2 plays important roles in both development and maintenance of hair follicles and diverse squamous epithelia and that this ligand-inducible and tissue-specific 'Tet-On' transgenic mouse system provides a means to study transgenes with perinatal toxicity.

Topics: Animals; Animals, Newborn; Cell Division; Cornea; Doxycycline; Epidermis; ErbB Receptors; Esophagus; Genes, erbB-2; Hair Follicle; Hyperplasia; Keratins; Mice; Mice, Transgenic; Oncogene Proteins v-erbB; Organ Specificity; RNA, Messenger; Tongue; Transforming Growth Factor alpha; Transgenes; Up-Regulation

Transgenic Sprague-Dawley rats expressing either human transforming growth factor-alpha (TGFalpha) or simian virus 40 large and small T antigen (TAg), each under the control of the phosphoenolpyruvate carboxykinase (PEPCK) promoter, were developed as an approach to the study of the promotion of hepatocarcinogenesis in the presence of a transgene regulatable by diet and/or hormones. Five lines of PEPCK-TGFalpha transgenic rats were established, each genetic line containing from one to several copies of the transgene per haploid genome. Two PEPCK-TAg transgenic founder rats were obtained, each with multiple copies of the transgene. Expression of the transgene was undetectable in the TGFalpha transgenic rats and could not be induced when the animals were placed on a high-protein, low-carbohydrate diet. The transgene was found to be highly methylated in all of these lines. No pathological alterations in the liver and intestine were observed at any time (up to 2 years) during the lives of these rats. One line of transgenic rats expressing the PEPCK-TAg transgene developed pancreatic islet cell hyperplasias and carcinomas, with few normal islets evident in the pancreas. This transgene is integrated as a hypomethylated tandem array of 10 to 12 copies on chromosome 8q11. Expression of large T antigen is highest in pancreatic neoplasms, but is also detectable in the normal brain, kidney, and liver. Mortality is most rapid in males, starting at 5 months of age and reaching 100% by 8 months. Morphologically, islet cell differentiation in the tumors ranges from poor to well differentiated, with regions of necrosis and fibrosis. Spontaneous metastasis of TAg-positive tumor cells to regional lymph nodes was observed. These studies indicate the importance of DNA methylation in the repression of specific transgenes in the rat. However, the expression of the PEPCK-TAg induces neoplastic transformation in islet cells, probably late in neuroendocrine cell differentiation. T antigen expression during neoplastic development may result in a pervasive change in the islet cell growth properties with selection of a transformed phenotype as a possible requirement for cell viability.

Topics: Animals; Animals, Genetically Modified; Antigens, Polyomavirus Transforming; Cell Transformation, Neoplastic; Female; Gene Expression; Hyperplasia; Islets of Langerhans; Male; Pancreatic Neoplasms; Phosphoenolpyruvate Carboxykinase (GTP); Rats; Rats, Sprague-Dawley; Recombinant Fusion Proteins; Survival Analysis; Transforming Growth Factor alpha; Transgenes

Human cDNAs corresponding to two epidermal growth factor-related products that are overexpressed in human breast cancers, that for c-erbB-2 (HER-2) and for transforming growth factor alpha (TGFalpha), have been cloned downstream of the mouse mammary tumor virus (MMTV) long terminal repeat promoter and injected into the pronucleus of fertilized oocytes of Sprague-Dawley rats to produce transgenic offspring. Expression of the transgenic mRNAs is not detectable in mammary tissue from virgin transgenic rats but is detected in mammary tissue from certain lines of mid-pregnant transgenic rats. When two such lines of either type of transgenic rat are subjected to repeated cycles of pregnancy and lactation, they produce, primarily in the mammary glands, extensive pathologies, whereas virgin transgenic rats produce no such abnormalities. Multiparous transgenic female offspring from c-erbB-2-expressing lines develop a variety of focal hyperplastic and benign lesions that resemble lesions commonly found in human breasts. These lesions include lobular and ductal hyperplasia, fibroadenoma, cystic expansions, and papillary adenomas. More malignant lesions, including ductal carcinoma in situ and carcinoma, also develop stochastically at low frequency. The mammary glands of transgenic females invariably fail to involute fully after lactation. Similar phenotypes are observed in female MMTV-TGFalpha transgenic rats. In addition, multiparous TGFalpha-expressing female transgenics frequently develop severe pregnancy-dependent lactating hyperplasias as well as residual lobules of hyperplastic secretory epithelium and genuine lactating adenomas after weaning. These transgenic rat models confirm the conclusions reached in transgenic mice that overexpression of the c-erbB-2 and TGFalpha genes predisposes the mammary gland to stochastic tumor development.

Topics: Animals; Animals, Genetically Modified; Female; Gene Expression; Hyperplasia; Mammary Glands, Animal; Mammary Neoplasms, Experimental; Mammary Tumor Virus, Mouse; Precancerous Conditions; Pregnancy; Rats; Rats, Sprague-Dawley; Receptor, ErbB-2; Transforming Growth Factor alpha

Topics: Epidermal Growth Factor; Fibroblast Growth Factors; Humans; Hyperplasia; Immunohistochemistry; Male; Platelet-Derived Growth Factor; Prostate; Severity of Illness Index; Transforming Growth Factor alpha

Immune reactions in the gut are associated with increased epithelial cell proliferation. Here we have studied the role of keratinocyte growth factor (KGF; FGF7) and transforming growth factor-alpha (TGF-alpha) in the epithelial cell hyperplasia seen in explants of fetal human small intestine after activation of lamina propria T cells with the superantigen Staphylococcus aureus enterotoxin B (SEB). After the addition of SEB to the explants there is a 10-fold increase in KGF mRNA by 72 h of culture. KGF transcripts were abundant in the lamina propria using in situ hybridization and the culture supernatants contained elevated amounts of KGF protein. SEB had no direct effect on KGF mRNA and protein production by cultured lamina propria mesenchymal cells, but both were upregulated by TNF-alpha. Accompanying the increase in KGF there was also an increase in TGF-alpha precursor proteins in the culture supernatants and the phosphorylated form of the EGFR receptor was also detected in the tissue. Increased TGF-alpha precursor proteins were also detected in the supernatants of control explants stimulated with KGF alone. The direct addition of KGF and TGF-alpha enhanced epithelial cell proliferation and antibodies against KGF and TGF-alpha partially inhibited SEB-induced crypt hyperplasia. These results suggest molecular cross-talk between the KGF/KGFR and the TGF-alpha/EGFR in immune-mediated crypt cell hyperplasia.

Topics: Drug Interactions; Enterotoxins; Epithelial Cells; Fetus; Fibroblast Growth Factor 10; Fibroblast Growth Factor 7; Fibroblast Growth Factors; Growth Substances; Humans; Hyperplasia; Immunosuppressive Agents; Intestine, Small; Lymphocyte Activation; Organ Culture Techniques; RNA, Messenger; Stromal Cells; Superantigens; Tacrolimus; Th1 Cells; Transforming Growth Factor alpha; Up-Regulation

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

Hypertrophic gastric mucosa in transgenic mice overexpressing transforming growth factor (TGF)-alpha showed mucosal cellular hyperplasia with dysplasia, suppression of gastric acid secretion, and chief and parietal cell depletion. In order to clarify the effects of TGF-alpha on the gastric mucosa, we analyzed the stomach of TGF-alpha transgenic mice by mucin histochemical staining and immunohistochemical analysis of TGF-alpha. In transgenic mice, especially those older than 3 months, the fundic gland was notably atrophic but the total mucosa was thickened. The mucous neck cells were hypersecretory and associated with abnormal sulfation. Mucosal hyperplasia was caused by proliferation of surface epithelial cells, associated with formation of intracytoplasmic lumina. The hyperplastic foveolar cells revealed production of a high amount of sialomucin. In addition, the involved stomach regionally revealed collagenous fibrosis in the submucosal layer. The wide distribution of TGF-alpha in the hyperplastic foveolar cells was in sharp contrast to negative expression in the foveolar cells in the control mice. These findings demonstrated the various regulatory functions of TGF-alpha in mucin production, fibrogenesis, and neck cell proliferation in the stomach.

Topics: Aging; Animals; Gastric Mucosa; Histocytochemistry; Hyperplasia; Immunohistochemistry; Mice; Mice, Transgenic; Mucins; Parietal Cells, Gastric; Sialomucins; Transforming Growth Factor alpha

A case of well-differentiated adenocarcinoma (Borrmann type 3) of the stomach in a 76-year-old man associated with the typical skin manifestations of acanthosis nigricans and with multiple protruding lesions showing epithelial hyperplasia of the esophagus is reported. The advanced tumor was located in the cardiac region of the stomach, and measured approximately 8 cm in diameter, with partial invasion to the esophagus. The associated cutaneous lesions were characterized by hyperpigmentation and by protruding verrucous papules on the torso, head, face, neck, upper extremities, perineum, and inguinal region. Histologically, the protruding skin lesions showed keratinocytes proliferation throughout the epidermis, resulting in diffuse hyperkeratosis, papillomatosis, and acanthosis of the skin. Immunohistological analysis showed coexpression of transforming growth factor alpha (TGF-alpha) and epidermal growth factor (EGF) receptors in the tumor from the stomach. It is reasonable to conclude from this evidence that gastric carcinoma cells secrete TGF alpha in an autocrine for auto-stimulation. EGF receptor expression was also noted on the papillomatous hyperplasia of the cutaneous lesion. Serum level of TGF alpha, determined by an enzyme-linked immunosorbent assay, was high (144 pg/ml; normal, 22.0 +/- 16 pg/ml (Mean +/- SD)). Serum TGF alpha abruptly decreased to 49 pg/ml on day 7 after the total gastrectomy, and then gradually increased to 77 pg/ml within 28 days. Amelioration of the cutaneous lesions and the protruding lesions in the esophagus was observed after surgical resection of the gastric carcinoma. This suggests that the TGF alpha stimulates the proliferation of keratinocytes involved with EGF receptor. Large amounts of circulating TGF alpha in the blood over a long period released by the primary tumor seem to act as an endocrine-like mechanism causing epidermal and esophageal epithelial cells to proliferate. There is a possible link in the pathogenesis of the acanthosis nigricans as a cutaneous paraneoplastic syndrome, and epithelial hyperplasia of the esophagus.

Topics: Acanthosis Nigricans; Adenocarcinoma; Aged; Epithelium; ErbB Receptors; Esophagus; Humans; Hyperplasia; Male; Paraneoplastic Syndromes; Skin Diseases; Stomach Neoplasms; Transforming Growth Factor alpha

Wa-1 mutant mice possess a defect in the production of transforming growth factor-alpha (TGF-alpha) that leads to a phenotype characterized by wavy hair and curly whiskers. In light of recent evidence indicating the importance of TGF-alpha in epithelial tumorigenesis, this study characterizes the responsiveness of wa-1 mice to skin tumor promotion by the phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA). The responsiveness of wa-1 mice to TPA was compared with that of SENCAR and C57BL/6 mice, representing mouse lines highly sensitive and resistant to skin tumor promotion, respectively. Wa-1 mice were found to be very resistant to skin tumor promotion by TPA after initiation with 10 nmol DMBA, similar to C57BL/6 mice. TPA failed to induce a dramatic increase in TGF-alpha mRNA and protein in the skin of wa-1 mice, whereas TGF-alpha mRNA and protein were dramatically induced in the skin (both epidermis and dermis) of SENCAR and C57BL/6 mice. TPA treatment dramatically increased mRNA levels of two other EGF receptor ligands, amphiregulin and heparin binding-EGF, however, in the skin of all three mouse lines. Comparison of histologic changes in skin revealed that wa-1 mice exhibited only modest sustained epidermal hyperplasia after multiple treatments with TPA, similar in magnitude to that of C57BL/6 mice and significantly lower than that of SENCAR mice. The current data indicate that wa-1 mice are relatively resistant to TPA promotion. Possible mechanisms for this resistance are discussed.

Topics: Amphiregulin; Animals; Antineoplastic Agents; Carcinogens; EGF Family of Proteins; Epidermal Growth Factor; Female; Glycoproteins; Growth Substances; Heparin; Heparin-binding EGF-like Growth Factor; Hyperplasia; Intercellular Signaling Peptides and Proteins; Male; Mice; Mice, Inbred C57BL; Mice, Inbred SENCAR; Mice, Mutant Strains; Neutrophils; RNA, Messenger; Skin; Skin Neoplasms; Tetradecanoylphorbol Acetate; Transforming Growth Factor alpha

Mice lacking p27(Kip1) have been created by gene targeting in embryonic stem cells. These mice are larger than the control animals, with thymus, pituitary, and adrenal glands and gonadal organs exhibiting striking enlargement. CDK2 activity is elevated about 10-fold in p27(-/-) thymocytes. Development of ovarian follicles seems to be impaired, resulting in female sterility. Similar to mice with the Rb mutation, the p27(-/-) mice often develop pituitary tumors spontaneously. The retinas of the mutant mice show a disturbed organization of the normal cellular layer pattern. These findings indicate that p27(Kip1) acts to regulate the growth of a variety of cells. Unexpectedly, the cell cycle arrest mediated by TGFbeta, rapamycin, or contact inhibition remained intact in p27(-/-) cells, suggesting that p27(Kip1) is not required in these pathways.

Topics: Animals; Base Sequence; Body Constitution; Cell Cycle; Cell Cycle Proteins; Cell Division; Cyclin-Dependent Kinase Inhibitor p27; Cyclin-Dependent Kinases; DNA Primers; DNA, Complementary; Enzyme Inhibitors; Female; Gene Expression; Gene Targeting; Genes, Tumor Suppressor; Heterozygote; Hyperplasia; Infertility, Female; Male; Mice; Mice, Knockout; Microtubule-Associated Proteins; Molecular Sequence Data; Phenotype; Pituitary Neoplasms; Polyenes; Retinal Dysplasia; Sirolimus; Tissue Distribution; Transforming Growth Factor alpha; Tumor Suppressor Proteins

The mechanism of gastric mucosal adaptation to continued aspirin (ASA) administration is unknown. We have investigated growth and proliferation markers in healthy subjects under prolonged ASA treatment. In eight healthy volunteers, ASA treatment (2 g/day) was continued for 14 days. Endoscopy was performed before medication; at days 3, 7, and 14 of ASA treatment; and at days 16 and 18 (2 and 4 days, respectively, after medication was ceased). Gastric biopsies from oxyntic and antral mucosa were studied by histology and by histochemistry for proliferating cell nuclear antigen (PCNA), epidermal growth factor (EGF), transforming growth factor-alpha (TGF-alpha), and epidermal growth factor receptor (EGFr). ASA treatment did not change the expression of EGF and EGFr significantly. The PCNA index showed local inconsistent variations. However, increased TGF-alpha expression after ASA was noted, particularly in hyperplastic surface epithelium. Edema and teleangiectases were common in gastric mucosa after ASA. An increasing incidence of foveolar hyperplasia was also noted in the antral mucosa. Healthy subjects on prolonged ASA treatment gradually develop parameters of chronic reactive gastritis accompanied by increased TGF-alpha expression in gastric surface epithelial cells, especially in hyperplastic areas.

Topics: Adaptation, Physiological; Adult; Anti-Inflammatory Agents, Non-Steroidal; Aspirin; Biomarkers; Drug Tolerance; Gastric Mucosa; Humans; Hyperplasia; Male; Transforming Growth Factor alpha

To investigate the effect of p53 tumor suppressor gene loss in the mouse skin model of multistage carcinogenesis, p53 knockout mice, generated by gene targeting (p53 -/-), were mated to transgenic mice expressing v-rasHa (HK1.ras), v-fos (HK1.fos), or human transforming growth factor alpha+HK1.TGFalpha) exclusively in the epidermis, by means of a keratin K1-based targeting vector (HK1). HK1-p53 transgenic progeny expressing wild-type p53 alleles (p53 +/+) or hemizygous for the p53 knockout allele (p53+/-) were identical to parental HK1 lines and exhibited neonatal epidermal hyperplasia or wound-associated hyperplasia in adults, together with spontaneous or 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced benign papillomas. Mating to p53-/- did not lead to the expected tumorigenesis in adults. Instead, whereas HK1.ras or HK1.TGFalpha transgenic mice null for p53 (HK1.ras-p53-/- and HK1.TGFalpha-p53-/-, respectively) retained the neonatal epidermal hyperplasia phenotype, in adults, spontaneous and TPA-promoted papilloma formation was blocked. Similarly, wound-associated epidermal hyperplasia/hyperkeratosis, a hallmark of adult HK1.fos phenotypes, was completely absent in HK1.fos-p53 -/- mice. Histological, immunofluorescence, and bromodeoxyuridine labeling analysis of neonatal or adult epidermis in HK1-p53 transgenic genotypes +/+, +/-, and -/- for p53 revealed no obvious differences in morphology, expression of keratinocyte differentiation markers, or mitotic index attributed to p53 loss. To determine whether the paradoxical absence of papillomas centered on up-regulation of p53 target genes, WAF1/CIP1/p21 RNA expression levels were examined in TPA promotion experiments. WAF1/CIP1/p21 expression increased in response to TPA promotion in all HK1-p53 transgenic genotypes regardless of p53 status. However, in HK1-p53 null genotypes, although TPA-induced, p53-independent WAF1/CIP1/p21 expression was observed, no large increase in expression was associated with the observed paradoxical tumorigenesis block. These data suggest that epidermis is somewhat resistant to the neoplastic effects of p53 loss, possibly possessing several compensatory systems. Alternatively, there may be a requirement forp53 expression in response to TPA or a wound-promotion stimulus in mouse epidermis.

Topics: Animals; Animals, Newborn; Cell Differentiation; Cell Division; Cell Transformation, Neoplastic; Cocarcinogenesis; Crosses, Genetic; Cyclin-Dependent Kinase Inhibitor p21; Cyclins; Epidermis; Genes, fos; Genes, p53; Genes, ras; Hyperplasia; Keratinocytes; Mice; Mice, Knockout; Mice, Transgenic; Oncogene Protein p21(ras); Oncogene Proteins v-fos; Recombinant Fusion Proteins; Tetradecanoylphorbol Acetate; Transforming Growth Factor alpha; Transgenes

Overexpression of transforming growth factor-alpha (TGF-alpha) in the gastric mucosa of metallothionein-TGF alpha (MT-TGF alpha) transgenic mice leads to a marked alteration in the ontogeny of the fundic cellular lineages. Induction of the transgene leads to the over-production of mucous cells with a concomitant diminution in the development of parietal cell and chief cell lineages. We have sought to define more precisely the mucous cell lineages involved in the mucous cell hyperplasia in MT-TGF alpha mice by investigating the expression of trefoil peptides in MT-TGF alpha mice. MT-TGF alpha mice and their non-transgenic littermates were treated with cadmium sulfate beginning at 13 days of age. Animals were then sacrificed at intervals over the following 2 weeks and gastric mucosa was examined for expression of trefoil peptides and TGF alpha by immunohistochemistry and in situ hybridization. No TGF alpha mRNA expression could be demonstrated by in situ hybridization in non-transgenic mice. In MT-TGF alpha mice, in situ grains for TGF alpha mRNA were detected at the base of fundic glands in 13 day old animals, whereas the expression was observed more widely in the mucosa of older animals (28 days). TGF alpha immunoreactivity was observed in foveolar mucous cells and residual parietal cells in MT-TGF alpha mice at all ages. By in situ hybridization, pS2 mRNA was detected in the surface mucous cells in normal gastric mucosa. In MT-TGF alpha mice, pS2 mRNA was found throughout the expanded foveolar region. By in situ hybridization, spasmolytic peptide (SP) expression was observed in the region of the progenitor zone in both groups of mice. By immunohistochemistry, SP expression was noted in a broad band of mucous neck cells deep to the progenitor zone. No gastric expression of intestinal trefoil factor (ITF) was noted in either group of mice. The results demonstrate that the expansion of the foveolar mucous cell compartment in MT-TGF alpha mice is due to the hyperplasia of normal surface cells expressing their particular mucin-associated trefoil peptide, pS2.

Topics: Animals; Biomarkers; DNA Primers; Gastric Mucosa; Gene Expression Regulation; Growth Substances; Hyperplasia; Immunohistochemistry; In Situ Hybridization; Metallothionein; Mice; Mice, Transgenic; Mucins; Muscle Proteins; Neuropeptides; Peptides; Polymerase Chain Reaction; Proliferating Cell Nuclear Antigen; RNA, Messenger; Transforming Growth Factor alpha; Trefoil Factor-2; Trefoil Factor-3

Transforming growth factor (TGF)-alpha stimulates the growth and development of mammary epithelial cells and is implicated in the pathogenesis of human breast cancer. In this report we evaluate the consequences of overexpressing TGF-alpha in the mammary gland of transgenic mice and examine associated cellular mechanisms. When operating on a FVB/N genetic background (line MT100), TGF-alpha induced the stochastic development of mammary adenomas and adenocarcinomas f secretory epithelial origin in 64% of multiparous females. In contrast, tumors were exceedingly rare in virgin MT100 females, MT100 males, and multiparous FVB/N females. In MT100 females multiple foci of hyperplastic secretory lesions preceded the development of frank tumors; these initial lesions appeared during the involution period after the first lactation. Serial transplantation of these hyperplasias indicated an absence of proliferative immortality. Nevertheless, they gave rise to tumors at a low frequency and after a prolonged latency in virgin hosts; in multiparous hosts, tumors developed earlier and at a high incidence. The TGF-alpha transgene was highly expressed in hyperplasias and tumors but not in virgin and nonlesion-bearing tissue, suggesting that TGF-alpha overexpression provides a selective growth advantage. TGF-alpha also induced at lactation a 6.4-fold increase in DNA synthesis in MT100 epithelial cells, many of which were binucleated. MT100 mammary tissue experienced an obvious delay in involution, resulting in the postlactational survival of a significant population of unregressed secretory epithelial cells. In contrast, another line of transgenic mice on a CD-1 genetic background (MT42), in which TGF-alpha overexpression induced liver but not mammary tumors, failed to demonstrate postlactational epithelial cell survival. These data show that TGF-alpha promotes mammary tumorigenesis in multiparous MT100 mice by stimulating secretory epithelial cell proliferation during lactation and prolonging survival during involution. These points support the notion that TGF-alpha can act as a mitogen and also as a differentiation factor in mammary epithelium.

Topics: Adenocarcinoma; Adenoma; Animals; Cell Division; Cell Line; Cell Survival; Epithelium; Female; Gene Expression; Humans; Hyperplasia; Mammary Glands, Animal; Mammary Neoplasms, Animal; Mice; Mice, Transgenic; Precancerous Conditions; Tissue Transplantation; Transforming Growth Factor alpha

The c-myc oncogene is commonly amplified in breast cancer and is known to interact synergistically with transforming growth factor alpha (TGF alpha) in vitro to promote phenotypic transformation of mammary epithelial cells. In addition, both genes are under sex steroid hormone regulation in breast cancer. We have used a bitransgenic mouse approach to test the relevance of Myc-TGF alpha interaction in mammary gland tumorigenesis of virgin animals in vivo. We mated single transgenic TGF alpha and c-myc mouse strains to yield double transgenic offspring for TGF alpha and c-myc. All (20 of 20) double transgenic TGF alpha/c-myc animals developed synchronous mammary tumors at a mean age of 66 days. An unexpected finding was that tumor latency and frequency in males and virgin females were identical. Thus, two gene products that are known to be coinduced in breast cancer by the sex hormones estrogen and progesterone strongly synergize to induce synchronous mammary tumors, independent of sex. The tumors, despite being estrogen receptor positive, were readily transplanted as highly malignant s.c. cancers in ovariectomized nude mice. Although approximately one-half of single transgenic c-myc virgin females also eventually developed mammary gland tumors, these were stochastic and arose after a long latency period of 9-12 months. Single transgenic virgin TGF alpha females and males, c-myc males, and transgene-negative littermates did not develop tumors (ages up to 15 months). The salivary glands of double transgenic animals also coexpress the two transgenes and show pathological abnormalities ranging from hyperplasias to frank adenocarcinomas. In contrast, the salivary glands of single transgenic and wild-type animals showed only mild hyperplasias or metaplasias, but tumors were not observed. In situ hybridization analysis of mammary and salivary glands revealed that hyperplastic and tumorous areas colocalize with regions that overexpress both the TGF alpha and c-myc transgenes. This indicates that there is a requirement for the presence of both proteins for transformation of these glands. In summary, TGF alpha and c-Myc synergize in an extremely powerful way to cause breast and salivary gland tumorigenesis in males and virgin females without a requirement for pregnancies.

Topics: Adenocarcinoma; Animals; Base Sequence; Cell Transformation, Neoplastic; Cocarcinogenesis; Crosses, Genetic; Estrogens; Female; Gene Expression Regulation, Neoplastic; Genes, myc; Hyperplasia; Male; Mammary Neoplasms, Experimental; Mammary Tumor Virus, Mouse; Metaplasia; Mice; Mice, Nude; Mice, Transgenic; Molecular Sequence Data; Neoplasm Proteins; Neoplasm Transplantation; Neoplasms, Hormone-Dependent; Ovariectomy; Progesterone; Proto-Oncogene Proteins c-myc; Receptors, Estrogen; Repetitive Sequences, Nucleic Acid; Salivary Gland Neoplasms; Salivary Glands; Sex Factors; Transforming Growth Factor alpha

Glandular stomach carcinogenesis after N-nitrosomethylurea (NMU) treatment was examined in transgenic mice bearing a human transforming growth factor alpha (TGF-alpha) cDNA driven by the mouse metallothionein-I promoter (mouse line MT100) in the inbred mouse line FVB/N. Untreated MT100 mice exhibit a severe age-related gastric fundic hyperplasia. Both sexes of MT100 mice were given 10 weekly intragastric intubations of 0.5 mg NMU per mouse from 6 weeks of age and/or zinc chloride in drinking water to stimulate transgene expression from 5.5 weeks of age to the experiment termination. Animals were killed sequentially at 10, 19 and 29 experimental weeks. Several histochemical markers (AB-PAS, TGF-alpha, pepsinogen isozyme 1, proliferating cell nuclear antigen) were used. Abnormal histochemical patterns were found in untreated MT100 and NMU-treated MT100 mice for all 4 markers of differentiation and carcinogenesis. Precancerous lesions including atypical and/or adenomatous hyperplasia were found in the fundic region of 16/22 male and 8/22 female MT100 mice but not in 27 male and 24 female FVB/N mice treated with NMU. One of 22 MT100 males had fundic carcinoma. FVB/N mice treated with NMU had neither precancerous lesions nor carcinomas in the fundus. Well differentiated adenocarcinomas in the pyloric region were induced at incidences of 2/22 male and 1/22 female MT100 mice treated with NMU and 4/27 male and 4/24 female FVB/N mice treated with NMU. Both strains also had a high incidence (55 to 92%) of squamous cell carcinomas of the forestomach. In conclusion, TGF-alpha induced a hyperplastic lesion in the gastric fundus that appeared to predispose the MT100 mice to carcinogenesis by NMU.

Topics: Adenocarcinoma; Animals; Female; Hyperplasia; Immunohistochemistry; Male; Methylnitrosourea; Mice; Mice, Transgenic; Pepsinogens; Precancerous Conditions; Stomach; Stomach Neoplasms; Transforming Growth Factor alpha

Roles for transforming growth factor-alpha (TGF alpha) in the stomach include cell migration and proliferation, inhibition of acid secretion, and cytoprotection. The authors have previously shown increased TGF alpha expression in rat gastric mucosa in response to acute gastric injury. They also have shown that TGF alpha immunoreactivity is increased in the gastric mucosa of four patients with Ménétrier's disease. To further characterize TGF alpha immunoreactivity in human gastric mucosa, the authors have performed immunohistochemical analysis with an anti-TGF alpha monoclonal antibody on human gastric biopsies (n = 25) showing either normal (n = 8), mild reactive/reparative change in common conditions with or without associated gastritis (n = 13), and exaggerated mucosal change in proliferative conditions (Ménétrier's disease, hypertrophic lymphocytic gastritis, and hyperplastic polyps) (n = 17). All normal biopsies showed a predictable pattern of TGF alpha immunostaining, with significant positivity found only in foveolar cells at the luminal surface and parietal cells, sparing foveolar cells in the gastric pits, mucous neck cells and chief cells of the gastric glands. Three patients with mild foveolar hyperplasia without associated inflammation did not deviate from the normal pattern except in foci of reactive epithelial change. Ten of 11 patients with chronic active gastritis, in addition to this normal staining pattern, demonstrated significant immunoreactivity in deeper foveolar cells and mucous neck cells showing reactive epithelial changes, defined as the presence of nuclear enlargement and nucleolar prominence with or without mucin depletion. Three cases of ulceration with associated reactive epithelial changes also showed increased immunoreactivity. Furthermore, five cases of Ménétrier's disease with massive foveolar hyperplasia and minimal inflammation (MFH) and six cases with hypertrophic lymphocytic gastritis (HLG) have been studied, and both show full-thickness TGF alpha immunoreactivity restricted to the gastric epithelium. This pattern of staining is indistinguishable from that observed in two cases of hyperplastic polyps but differs significantly from that observed in cases of mild foveolar hyperplasia. These results further define patterns of TGF alpha immunostaining in normal, reactive/reparative and exaggerated proliferative human gastric biopsies, confirm participation of TGF alpha in the response to gastric mucosal injury, and provide

Topics: Gastric Mucosa; Gastritis, Hypertrophic; Humans; Hyperplasia; Immunohistochemistry; Transforming Growth Factor alpha

We investigated the localization of TGF-alpha and EGF receptor in psoriatic plaques, especially the clinically-determined transitional zone from uninvolved to involved psoriatic skin by immunohistochemistry. TGF-alpha was not increased in the transitional area compared with normal epidermis. It started to increase within the edge of psoriatic plaques. In contrast, EGF receptor increased up to the suprabasal layers even in the uninvolved skin adjacent to psoriatic plaques, compared with normal epidermis. Slight epidermal hyperplasia was also observed in the clinically-determined transitional area. This result suggests that the increase of EGF receptor precedes that of TGF-alpha in psoriatic plaque formation.

Topics: Epidermis; ErbB Receptors; Humans; Hyperplasia; Immunohistochemistry; Psoriasis; Reference Values; Staining and Labeling; Transforming Growth Factor alpha

Hyperplasia of transitional cell epithelium adjacent to human transitional cell carcinomas (TCC) is a common finding in pathology. This hyperplasia may be a precancerous aberration. Alternatively, it has been suggested that the hyperplasia is due to paracrine action of tumour-derived growth factors. In this study we tested the latter hypothesis using the mouse tumorigenic TCC cell line NUC-1. Transplantation of NUC-1 tumour cells into the urinary bladder submucosa of syngeneic mice in vivo induced hyperplasia of normal adjacent urothelium in all tested mice. Implantation of normal mouse bladder mucosa did not induce urothelial hyperplasia. In vitro, conditioned medium of NUC-1 cells induced the proliferation of the mouse urothelial cell line g/G, which closely resembles normal urothelial cells. This induction was inhibited by transforming growth factor beta 1 (TGF beta 1). Similarly, TGF beta 1 inhibited the fibroblast growth factor-1 (FGF-1) and FGF-2 induced proliferation of g/G cells. Chemico-physical examination, bioassays with conditioned media, and RNA analysis of NUC-1 cells revealed that these cells secreted a growth factor with FGF-like properties. These results indicate that epithelial hyperplasia surrounding carcinomas is not necessarily a precancerous aberration, but may result from direct paracrine action of tumour-derived growth factors.

Topics: Animals; Carcinoma, Transitional Cell; Cell Division; Cell Line; Culture Media, Conditioned; Dithiothreitol; DNA Replication; Epidermal Growth Factor; Epithelium; Fibroblast Growth Factor 1; Fibroblast Growth Factor 2; Granulocyte-Macrophage Colony-Stimulating Factor; Growth Substances; Humans; Hyperplasia; Mice; Mucous Membrane; Neoplasm Transplantation; Thymidine; Transforming Growth Factor alpha; Transforming Growth Factor beta; Transplantation, Isogeneic; Tumor Cells, Cultured; Urinary Bladder; Urinary Bladder Neoplasms

Male, Sprague-Dawley rats were injected subcutaneously with the colon carcinogen 1,2-dimethylhydrazine (DMH) at a dosage of 9.5 mg DMH base/per kg rat body weight once weekly for 8 weeks; control rats received an equivalent volume of the vehicle. Analyses of variance showed that in carcinogen-treated as well as in non-carcinogen-treated rats, the proliferative zone height and the crypt height in colonic crypts located over the aggregates of lymphoid nodules (ALN) were significantly higher than in colonic crypts located away from the ALN. Immunohistochemical localization of transforming growth factor alpha (TGF alpha) showed that this mitogenic factor was found in cells in the proliferative zone of colonic crypts located over the ALN, but TGF alpha was not detectable in cells in the proliferative zone of colonic crypts located away from the ALN. Examination of histological sections of the colon taken through the ALN of DMH-treated rats revealed that eight out of 25 DMH-treated rats had microscopic adenocarcinomas (AC) within the ALN, but in the same rats no microscopic AC were seen in histological sections taken away from the ALN. Furthermore, there was no evidence of an adenomatous precursor to these microscopic, endophytic AC, suggesting that the endophytic AC arose de novo. Therefore, because of (i) the significantly higher proliferative activity in colonic crypts located over the ALN, (ii) the localization of TGF alpha in the proliferative zone of the colonic crypts associated with ALN and (iii) the high incidence of endophytic AC associated with ALN, it seems likely that factors emanating from the ALN are promotional to carcinogenesis in the colonic epithelium that is located in close proximity to the ALN.

Topics: 1,2-Dimethylhydrazine; Adenocarcinoma; Animals; Carcinogens; Cell Cycle; Cell Division; Cocarcinogenesis; Colon; Colonic Neoplasms; Dimethylhydrazines; Epithelium; Hyperplasia; Immunohistochemistry; Lymphoid Tissue; Male; Rats; Rats, Sprague-Dawley; Transforming Growth Factor alpha

The E6 and E7 early genes of human papillomavirus type 16 have been shown in vitro to play a central role in the transforming capability of this virus. To explore their effects on differentiating epithelial cells in vivo, we used a bovine cytokeratin 10 (K10) promoter to target the expression of E6 and E7 to the suprabasal layers of the epidermis of transgenic mice. In two different lines of mice efficiently expressing the transgene, animals displayed generalized epidermal hyperplasia, hyperkeratosis and parakeratosis in the skin and the forestomach, both known to be sites of K10 expression. Northern (RNA) blot analysis revealed high levels of E6 and E7 transcripts, and in situ hybridizations localized these transcripts to the suprabasal strata of epidermis. In vivo labeling of proliferating cells showed two distinct effects of E6 and E7 expression in the epidermis: (i) an increase in the number of growing cells in the undifferentiated basal layer and (ii) abnormal proliferation of differentiated cells in the suprabasal strata. The expression of c-myc in the skin of transgenics was higher than that in control animals. The induction of c-myc transcription by topical application of tetradecanoyl phorbol acetate was prevented by simultaneous treatment with transforming growth factor beta 1 in nontransgenic skin but not in transgenic skin. In addition, transforming growth factor alpha was found to be overexpressed in the suprabasal layers of the transgenic epidermis. These findings suggest that autocrine mechanisms are involved in the development and maintenance of epidermal hyperplasia. Animals of both lines developed papillomas in skin sites exposed to mechanical irritation and wounding, suggesting that secondary events are necessary for progression to neoplasia. Collectively, these results provide new insights into the tumor promoter activities of human papillomavirus type 16 in epithelial cells in vivo.

Topics: Animals; Epidermal Cells; Epidermis; Gene Expression; Genes, myc; Hyperplasia; Keratinocytes; Mice; Mice, Transgenic; Mitosis; Oncogene Proteins, Viral; Oncogenes; Papillomaviridae; Papillomavirus E7 Proteins; Repressor Proteins; RNA, Messenger; Transforming Growth Factor alpha

The mechanisms by which the peroxisome proliferator (PP) class of non-genotoxic carcinogens perturb growth regulation and cause rodent liver cancer are unknown. Using a soft agar cloning assay, we have demonstrated that PPs synergize with the physiological liver mitogen epidermal growth factor (EGF) to cause the clonal expansion of rat hepatocytes associated with the early stages of tumourigenesis. In the presence of EGF (25 ng/ml), the PP nafenopin (100 microM) was able to stimulate a 5-fold increase in the number of colonies (35 colonies/50,000 hepatocytes compared to seven in the control). EGF alone or nafenopin alone gave 11 and 14 colonies respectively. TGF alpha, which acts through the EGF receptor, also synergized with nafenopin, whereas HGF was inactive, despite its potency as an hepatocyte growth factor. The ability to promote colony formation was shared by the potent PP Wyeth-14,643 but not by the less potent compounds methylclofenapate or trichloroacetic acid. TGF beta, a physiological negative regulator of liver growth, was able to inhibit the nafenopin/EGF-stimulated colony formation at 0.25 ng/ml, a concentration below that required for TGF beta-induced hepatocyte apoptosis. The colonies formed are derived from and consist of hepatocytes, since they express the hepatocyte-specific marker albumin, although the majority are negative for the PP-induced cytochrome, P4504A1. Pre-treatment in vivo with the genotoxic carcinogen dimethylhydrazine hydrochloride (150 mg/kg) caused a doubling in the number of colonies from 35 to 75/50,000 hepatocytes. Taken together, these data suggest that some PPs act as hepatocarcinogens by synergizing with EGF and/or TGF alpha to promote the clonal expansion of spontaneously initiated hepatocytes. This clonal expansion may be inhibited by TGF beta. Such a synergy may provide a mechanistic basis for the hepatocarcinogenicity of this class of non-genotoxic carcinogens.

Topics: Albumins; Animals; Biomarkers; Carcinogens; Cell Division; Cell Transformation, Neoplastic; Cells, Cultured; Clone Cells; Cocarcinogenesis; Colony-Forming Units Assay; Cytochrome P-450 CYP4A; Cytochrome P-450 Enzyme System; DNA Replication; Drug Synergism; Epidermal Growth Factor; Hyperplasia; Liver; Liver Neoplasms, Experimental; Male; Microbodies; Mixed Function Oxygenases; Nafenopin; Rats; Rats, Wistar; Transforming Growth Factor alpha

The expression of transforming growth factor-alpha (TGF-alpha) was studied in 33 surgically excised human hepatocellular carcinomas (HCCs), focal nodular hyperplasias (FNHs), and the surrounding liver tissue from patients who were life-long residents of Hungary. Monoclonal antibodies were used to localize TGF-alpha and hepatitis B surface antigen (HBsAg) using an avidin-biotin-peroxidase immunohistochemical method on paraffin-embedded sections. Transforming growth factor-alpha was detected in the tumor tissue in 13 of 16 patients with HCC (81%) and in 12 of 17 patients with FNH (71%). Three patients with HCC were actively infected with hepatitis B virus, indicated by the detection of HBsAg in the serum and in adjacent nontumorous liver. Transforming growth factor-alpha was detected in the same nontumorous hepatocytes as HBsAg, often in areas of the hepatocyte cytoplasm, with a "ground glass" appearance. Bile duct cells were stained for TGF-alpha in the surrounding nontumorous liver tissue and a more intensive immunostaining was observed in the proliferating bile ducts in the FNH cases, which suggests that TGF-alpha may participate in the growth regulation of bile ducts.

Topics: Adolescent; Adult; Aged; Carcinoma, Hepatocellular; Female; Hepatitis B; Hepatitis B Surface Antigens; Humans; Hungary; Hyperplasia; Liver; Liver Cirrhosis; Liver Neoplasms; Male; Middle Aged; Transforming Growth Factor alpha

To assess the effects of transforming growth factor alpha (TGF-alpha) on mammalian skin in vivo, we have targeted its expression to the epidermis of transgenic mice using a vector based on the human K1 (HK1) gene. Neonatal mice expressing the HK1.TGF-alpha transgene were often smaller than normal littermates and had precocious eyelid opening and wrinkled, scaly skin with diffuse alopecia. Juvenile transgenic mouse epidermis was uniformly hyperkeratotic, but this pattern was generally less pronounced in adult transgenic mice unless they expressed high levels of the HK1.TGF-alpha transgene. Spontaneous, squamous papillomas occurred at sites of wounding in adult mice expressing high levels of HK1.TGF-alpha; however, most were prone to regression. Immunoreactive TGF-alpha was 2-6 times higher in the epidermis of these HK1.TGF-alpha lines. Immunoreactive epidermal growth factor receptor had a normal pattern of expression in nonphenotypic adult epidermis, but a marked reduction in the receptor population was detected in hyperplastic newborn epidermis and phenotypic adult epidermis. Autoradiographic localization of 125I-epidermal growth factor showed a similar pattern of distribution, suggesting that the sites of increased TGF-alpha expression induced epidermal growth factor receptor down-regulation. These data demonstrate the in vivo effect of deregulated TGF-alpha expression on epidermal proliferation and differentiation and suggest a potential role for TGF-alpha in carcinogenesis and other hyperproliferative epidermal disorders.

Topics: Animals; Base Sequence; Cell Division; Epidermal Growth Factor; Epidermis; ErbB Receptors; Hyperplasia; Keratosis; Mice; Mice, Transgenic; Molecular Sequence Data; Papilloma; Skin Neoplasms; Transforming Growth Factor alpha

The epidermal growth factor (EGF) homologues encoded by vaccinia virus, myxoma virus, and malignant rabbit fibroma virus have been shown to contribute to the pathogenicity of virus infection upon inoculation of susceptible hosts. However, since the primary structures of these growth factors and the disease profiles induced by different poxvirus genera vary substantially, the degree to which the various EGF homologues perform similar roles in viral pathogenesis remains unclear. In order to determine whether different EGF-like growth factors can perform qualitatively similar functions in the induction of myxomatosis in rabbits, we created recombinant myxoma virus variants in which the native growth factor, myxoma growth factor (MGF), was disrupted and replaced with either vaccinia virus growth factor, Shope fibroma growth factor, or rat transforming growth factor alpha. Unlike the control virus containing an inactivated MGF gene, which caused marked attenuation of the disease syndrome and substantially less proliferation of the epithelial cell layers in the conjunctiva and respiratory tract, the recombinant myxoma virus strains expressing heterologous growth factors produced infections which were both clinically and histopathologically indistinguishable from wild-type myxomatosis. We conclude that these poxviral and cellular EGF-like growth factors, which are diverse with respect to primary structure and origin, have similar biological functions in the context of myxoma virus pathogenesis and are mitogenic for the same target cells.

Topics: Animals; Conjunctiva; Epidermal Growth Factor; Fibroma Virus, Rabbit; Genome, Viral; Growth Substances; Hyperplasia; Intercellular Signaling Peptides and Proteins; Mutagenesis, Insertional; Myxoma virus; Myxomatosis, Infectious; Peptides; Rabbits; Skin Neoplasms; Transforming Growth Factor alpha; Tumor Virus Infections; Vaccinia virus

Eight lines of transgenic mice expressing a mouse mammary tumor virus (MMTV) human transforming growth factor-alpha (TGF alpha) fusion gene were established. Three lines with distinctive phenotypes are presented. All have proliferative changes of the mammary gland. One line has sebaceous gland hyperplasia of the skin. Five histologic patterns of mammary gland hyperplasia based on two of these lines were identified: cystic hyperplasia, solid hyperplasia, dysplasia, adenoma, and adenocarcinoma. Human TGF alpha mRNA and protein were produced in all patterns but appeared reduced in solid hyperplasia, dysplasia, and adenocarcinoma. TGF alpha immunoreactivity in the mammary tissue, cystic fluid, and serum did not show significant differences; hyperplasia developed in 65% of multiparous mice and 45% of virgin mice by 12 months of age. Adenocarcinoma developed in 40% of multiparous mice and 30% of virgin mice by 16 months of age. These transgenic lines may provide useful models of mammary and sebaceous gland hyperplasia analogous to human disease.

Topics: Animals; Cysts; Hyperplasia; Immunohistochemistry; Mammary Glands, Animal; Mammary Tumor Virus, Mouse; Mice; Mice, Transgenic; Microscopy, Electron; Nucleic Acid Hybridization; Radioimmunoassay; RNA, Messenger; Skin; Transforming Growth Factor alpha

To determine at what stage there is increased expression of transforming growth factor alpha (TGF alpha) in preneoplastic diseases of the breast and to determine if this would assist in the histological diagnosis of different intraduct epithelial proliferations.. Specimens were retrieved from the archives of 17 cases of ductal hyperplasia, six cases of atypical ductal hyperplasia and 13 cases of ductal carcinoma in situ together with 12 'normal' breast biopsy specimens. Sections were stained immunohistochemically for TGF alpha. The staining was assessed semi-quantitatively taking into account both the staining intensity and the proportion of cells stained.. Minimal expression of TGF alpha was observed in normal breast tissue. Increased levels of expression were seen in ductal hyperplasia, atypical ductal hyperplasia, and ductal carcinoma in situ. Increased levels of expression of TGF alpha were also found in morphologically normal ducts immediately adjacent to areas of intraduct epithelial proliferation.. Increased expression of TGF alpha occurs in the early stages of intraduct epithelial proliferation and will not help the histopathologist distinguish atypical ductal hyperplasia from either ductal hyperplasia or ductal carcinoma in situ. The molecular changes within a cell may precede the morphological changes observed by light microscopy thereby reflecting the biological potential of the epithelium.

Topics: Adult; Aged; Breast; Breast Neoplasms; Carcinoma in Situ; Carcinoma, Intraductal, Noninfiltrating; Female; Humans; Hyperplasia; Middle Aged; Precancerous Conditions; Transforming Growth Factor alpha

The hyperplastic capacity of adipose tissue resides in a group of fibroblast-like adipocyte precursor cells. There is evidence to suggest that their proliferation and differentiation is regulated by insulin-like growth factor-I (IGF-I) and transforming growth factor-beta (TGF-beta) but there is less information about other growth factors which may also participate in adipocyte precursor cell hyperplasia. Transforming growth factor-alpha (TGF-alpha) is a 50 amino acid polypeptide which has been shown to stimulate proliferation in both neoplastic and normal cell types acting through the epidermal growth factor (EGF) receptor. We have studied the regulation of DNA synthesis and the activity of lipoprotein lipase by TGF-alpha in chicken adipocyte precursor cells in vitro. Both TGF-alpha and EGF stimulated incorporation of [3H]thymidine into DNA in a dose-dependent manner. TGF-alpha was approximately 180-fold more potent than EGF. Addition of TGF-alpha in combination with IGF-I, TGF-beta 1 or platelet-derived growth factor produced a synergistic increase in DNA synthesis. Short-term incubation with TGF-alpha reduced lipoprotein lipase activity by 23%. These results show that TGF-alpha is a potent mitogen in these adipocyte precursor cells and can inhibit their differentiation in vitro and may participate in the regulation of adipose tissue development in vivo.

Topics: Adipose Tissue; Animals; Cell Differentiation; Cell Division; Cells, Cultured; Chickens; DNA; Dose-Response Relationship, Drug; Epidermal Growth Factor; Hyperplasia; Lipoprotein Lipase; Mitogens; Transforming Growth Factor alpha