epidermal-growth-factor and Hyperplasia

Asthma remains a severe health problem since current therapies are directed to suppressing, rather than preventing or reversing, the primary disease process. Clearly, a greater understanding of the pathogenesis of asthma is critical to the development of better therapeutic modalities. In this review, we discuss the recent advancements in research targeting the role of airway remodeling in asthma.. Epithelial fragility and abnormalities are being recognized as important facets of asthma, as are other features of remodeling such as angiogenesis, goblet cell hyperplasia and thickened lamina reticularis. Significantly, these anomalies occur early in disease pathogenesis. However, their impact on disease severity remains unclear.. Although an altered immune response is undoubtedly important to the pathogenesis of asthma, there is increasing evidence that the tissue-specific manifestations occur independently of inflammation and significantly impact on disease development and severity.

Topics: ADAM Proteins; alpha Catenin; Animals; Asthma; Epidermal Growth Factor; GABA Modulators; Genetic Therapy; Glucocorticoids; Goblet Cells; Humans; Hyperplasia; Mice; Mucous Membrane; Myocytes, Smooth Muscle; Neovascularization, Pathologic; Respiratory System

HB-EGF is a heparin-binding member of the EGF family that was initially identified in the conditioned medium of human macrophages. Soluble mature HB-EGF is proteolytically processed from a larger membrane-anchored precursor and is a potent mitogen and chemotactic factor for fibroblasts, smooth muscle cells but not endothelial cells. HB-EGF activates two EGF receptor subtypes, HER1 and HER4 and binds to cell surface HSPG. The transmembrane form of HB-EGF is a juxtacrine growth and adhesion factor and is uniquely the receptor for diphtheria toxin. HB-EGF gene expression is highly regulated, for example by cytokines, growth factors, and transcription factors such as MyoD. HB-EGF has been implicated as a participant in a variety of normal physiological processes such as blastocyst implantation and wound healing, and in pathological processes such as tumor growth, SMC hyperplasia and atherosclerosis.

Topics: Amino Acid Sequence; Animals; Arteriosclerosis; Binding Sites; Cell Adhesion; Cell Division; Cell Membrane; Chromosome Mapping; Epidermal Growth Factor; Gene Expression Regulation; Genes; Heparan Sulfate Proteoglycans; Heparin; Heparin-binding EGF-like Growth Factor; Humans; Hyperplasia; Intercellular Signaling Peptides and Proteins; Molecular Sequence Data; Muscular Diseases; Neoplasms; Promoter Regions, Genetic; Protein Binding; Receptors, Cell Surface; Reproduction; Signal Transduction; Wound Healing

Human exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and chlorinated analogs commonly results in pathological changes in the skin and its appendages characterized by thickening of the epidermis (acanthosis), hyperkeratosis and squamous metaplasia of the epithelial lining of the sebaceous glands. Acneform lesions (chloracne) develop as hair follicles dilate and fill with keratin and sebaceous glands become cystic. In animal models it has been found that the chloracneogenic potential of the halogenated aromatic compounds examined corresponds with the relative affinity of these same compounds for the cytosolic TCDD receptor. This receptor controls the coordinate expression of a number of inducible enzyme activities and in certain cell targets can alter normal programs of proliferation and differentiation. In this report we describe some of our ongoing studies on the mechanisms of action of TCDD in normal human epidermal cells and squamous cell carcinoma (SCC) lines. These systems permit detailed investigation of the molecular and biochemical events underlying pathologic changes in the skin and offer the potential of establishing a risk assessment model for halogenated aromatic compounds by using human target cells.

Topics: Animals; Carcinoma, Squamous Cell; Cell Division; Cells, Cultured; Chromosome Mapping; Dioxins; Epidermal Growth Factor; Humans; Hyperplasia; Polychlorinated Dibenzodioxins; Receptors, Aryl Hydrocarbon; Receptors, Drug; Risk; Skin

Systemic-to-pulmonary shunt malfunction contributes to morbidity in children with complex congenital heart disease after palliative procedure. Neointimal hyperplasia might play a role in the pathogenesis increasing risk for shunt obstruction. The aim was to evaluate the role of epidermal growth factor receptor (EGFR) and matrix-metalloproteinase 9 (MMP-9) in the formation of neointimal within shunts. Immunohistochemistry was performed with anti-EGFR and anti-MMP-9 on shunts removed at follow-up palliative or corrective procedure. Whole-genome single-nucleotide polymorphisms genotyping was performed on DNA extracted from patients´ blood samples and allele frequencies were compared between the group of patients with shunts displaying severe stenosis (≥ 40% of lumen) and the remaining group. Immunohistochemistry detected EGFR and MMP-9 in 24 of 31 shunts, located mainly in the luminal area. Cross-sectional area of EGFR and MMP-9 measured in median 0.19 mm

Topics: Child; Constriction, Pathologic; Epidermal Growth Factor; ErbB Receptors; Heart Diseases; Humans; Hyperplasia; Neointima; Tissue Inhibitor of Metalloproteinase-1

Topics: Animals; Cicatrix; Epidermal Growth Factor; Hyperplasia; Male; Rabbits; Stem Cells; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A; Wound Healing

Benign prostatic hyperplasia (BPH) poses a significant health concern amongst elderly males. Canagliflozin (Cana), a selective sodium-glucose co-transporter 2 (SGLT2) inhibitor, has a powerful anti-inflammatory influence. Nevertheless, its role in treating BPH has not been clarified. Therefore, the study aimed to investigate the potential ameliorative effect of Cana on experimentally induced BPH in rats and explore the underlying mechanisms compared to the standard finasteride (Fin). The study employed histological analysis, biochemical assays using ELISA, and western blotting. Animals were categorized into four groups: Control (2.5 ml/kg CMC, orally + 3 ml/kg olive oil, subcutaneous), BPH (3 mg/kg testosterone, subcutaneous + CMC orally), Fin-treated BPH (5 mg/kg, orally), and Cana-treated BPH (5 mg/kg, orally), for 28 days. The BPH group showed obvious BPH manifestations including an increase in prostate weight (PW), prostate index (PI), dihydrotestosterone (DHT) level, and histological aberrations compared to control. Fin and Cana therapy had a comparable impact. Cana treatment significantly reduced PW and PI, besides it improved prostatic biochemical, and histopathological features compared to BPH, consistent with in silico study findings. Cana was associated with downregulation of the androgen axis, increased miR-128b expression, with a lowered expression of epidermal growth factor (EGF) and its receptor. Phosphorylation of STAT3 and its downstream proliferative markers were significantly reduced suggesting apoptotic activity. Cana markedly rescued the BPH-induced upregulation of IL-1β, and iNOS levels. Altogether, the current study demonstrates that Cana could impede BPH progression, possibly by modulating miR-128b/EGFR/EGF and JAK2/STAT3 pathways and downregulating AR, cyclin D1, and PCNA immunoreactivity.

Topics: Aged; Animals; Canagliflozin; Epidermal Growth Factor; ErbB Receptors; Finasteride; Humans; Hyperplasia; Janus Kinase 2; Male; MicroRNAs; Prostate; Prostatic Hyperplasia; Rats; Sodium-Glucose Transporter 2 Inhibitors; STAT3 Transcription Factor

Otitis media (OM), the most common childhood illness, can be caused by bacterial and/or viral infection. Hyperplasia of the middle ear (ME) mucosa is an important component of OM that contributes to its deleterious sequelae. Our previous research revealed that ME mucosal hyperplasia in bacterially induced OM was associated with expression of the heparin-binding epidermal growth factor (HB-EGF) gene, and that HB-EGF induced the proliferation of ME mucosal explants in culture. We used single-cell RNA-Seq to identify ME cells that express

Topics: Animals; Endothelial Cells; Epidermal Growth Factor; Female; Heparin-binding EGF-like Growth Factor; Humans; Hyperplasia; Male; Mice, Inbred C57BL; Otitis Media; Rats, Sprague-Dawley; Virus Diseases

Atypical adenomatous hyperplasia (AAH) of the lung is a pre-invasive lesion (PL) with high risk of progression to lung cancer (LC). However, the pathways involved are uncertain. We searched for novel mechanistic biomarkers of AAH in an EGF transgenic disease model of lung cancer. Disease regulated proteins were validated by Western immunoblotting and immunohistochemistry (IHC) of control and morphologically altered respiratory epithelium. Translational work involved clinical resection material. Collectively, 68 unique serum proteins were identified by 2DE-MALDI-TOF mass spectrometry and 13 reached statistical significance (p < 0.05). EGF, amphiregulin and the EGFR endosomal sorting protein VPS28 were induced up to 5-fold while IHC confirmed strong induction of these proteins. Furthermore, ApoA1, α-2-macroglobulin, and vitamin-D binding protein were nearly 6- and 2-fold upregulated in AAH; however, ApoA1 was oppositely regulated in LC to evidence disease stage dependent regulation of this tumour suppressor. Conversely, plasminogen and transthyretin were highly significantly repressed by 3- and 20-fold. IHC confirmed induced ApoA1, Fetuin-B and transthyretin expression to influence calcification, inflammation and tumour-infiltrating macrophages. Moreover, serum ApoA4, ApoH and ApoM were 2-, 2- and 6-fold repressed; however tissue ApoM and sphingosine-1-phosphate receptor expression was markedly induced to suggest a critical role of sphingosine-1-phosphate signalling in PL and malignant transformation. Finally, a comparison of three different LC models revealed common and unique serum biomarkers mechanistically linked to EGFR, cMyc and cRaf signalling. Their validation by IHC on clinical resection material established relevance for distinct human lung pathologies. In conclusion, we identified mechanistic biomarker candidates recommended for in-depth clinical evaluation.

Topics: Amphiregulin; Animals; Biomarkers, Tumor; Disease Models, Animal; Endosomal Sorting Complexes Required for Transport; Epidermal Growth Factor; Humans; Hyperplasia; Lung; Mice; Mice, Transgenic; Precancerous Conditions; Proteomics; Signal Transduction; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Up-Regulation

The airway epithelium of cigarette smokers undergoes dramatic remodeling with hyperplasia of basal cells (BC) and mucus-producing cells, squamous metaplasia, altered ciliated cell differentiation and decreased junctional barrier integrity, relevant to chronic obstructive pulmonary disease and lung cancer. In this study, we show that epidermal growth factor receptor (EGFR) ligand amphiregulin (AREG) is induced by smoking in human airway epithelium as a result of epidermal growth factor (EGF)-driven squamous differentiation of airway BC stem/progenitor cells. In turn, AREG induced a unique EGFR activation pattern in human airway BC, distinct from that evoked by EGF, leading to BC- and mucous hyperplasia, altered ciliated cell differentiation and impaired barrier integrity. Further, AREG promoted its own expression and suppressed expression of EGF, establishing an autonomous self-amplifying signaling loop in airway BC relevant for promotion of EGF-independent hyperplastic phenotypes. Thus, EGF-AREG interplay in airway BC stem/progenitor cells is one of the mechanisms that mediates the interconnected pathogenesis of all major smoking-induced lesions in the human airway epithelium. Stem Cells 2017;35:824-837.

Topics: Adult; Airway Remodeling; Amphiregulin; Cell Differentiation; Cell Proliferation; Cilia; Down-Regulation; Epidermal Growth Factor; ErbB Receptors; Female; Humans; Hyperplasia; Male; Respiratory Mucosa; Smoking; Stem Cells; Up-Regulation

Chronic Obstructive Pulmonary Disease (COPD) is characterized by lung and systemic inflammation as well as airway goblet cell hyperplasia (GCH). Mucin production is activated in part by stimulation of the epidermal growth factor (EGF) receptor pathway through neutrophils and macrophages. How circulating cytokine levels relate to GCH is not clear.. We performed phlebotomy and bronchoscopy on 25 subjects (six nonsmokers, 11 healthy smokers, and eight COPD subjects FEV1 30-60 %). Six endobronchial biopsies per subject were performed. GCH was measured by measuring mucin volume density (MVD) using stereological techniques on periodic acid fast-Schiff stained samples. We measured the levels of chemokines CXCL8/IL-8, CCL2/MCP-1, CCL7/MCP-3, CCL22/MCD, CCL3/MIP-1α, and CCL4/MIP-1β, and the cytokines IL-1, IL-4, IL-6, IL-9, IL-17, EGF, and vascular endothelial growth factor (VEGF). Differences between groups were assessed using one-way ANOVA, t test, or Chi squared test. Post hoc tests after ANOVA were performed using Bonferroni correction.. MVD was highest in healthy smokers (27.78 ± 10.24 μL/mm(2)) compared to COPD subjects (16.82 ± 16.29 μL/mm(2), p = 0.216) and nonsmokers (3.42 ± 3.07 μL/mm(2), p < 0.0001). Plasma CXCL8 was highest in healthy smokers (11.05 ± 8.92 pg/mL) compared to nonsmokers (1.20 ± 21.92 pg/mL, p = 0.047) and COPD subjects (6.01 ± 5.90 pg/mL, p = 0.366). CCL22 and CCL4 followed the same trends. There were no significant differences in the other cytokines measured. When the subjects were divided into current smokers (healthy smokers and COPD current smokers) and non/ex-smokers (nonsmokers and COPD ex-smokers), plasma CXCL8, CCL22, CCL4, and MVD were greater in current smokers. No differences in other cytokines were seen. Plasma CXCL8 moderately correlated with MVD (r = 0.552, p = 0.003).. In this small cohort, circulating levels of the chemokines CXCL8, CCL4, and CCL22, as well as MVD, attain the highest levels in healthy smokers compared to nonsmokers and COPD subjects. These findings seem to be driven by current smoking and are independent of airflow obstruction.. These data suggest that smoking upregulates a systemic pattern of neutrophil and macrophage chemoattractant expression, and this correlates significantly with the development of goblet cell hyperplasia.

Topics: Adult; Aged; Case-Control Studies; Chemokine CCL2; Chemokine CCL22; Chemokine CCL3; Chemokine CCL4; Chemokine CCL7; Chemokines; Cytokines; Epidermal Growth Factor; Female; Goblet Cells; Humans; Hyperplasia; Interleukin-1; Interleukin-17; Interleukin-4; Interleukin-6; Interleukin-8; Interleukin-9; Lung; Male; Middle Aged; Mucins; Pulmonary Disease, Chronic Obstructive; Smoking; Vascular Endothelial Growth Factor A

To explore the molecular mechanism of moxibustion at stomach meridian acupoints for precancerous lesions of chronic atrophic gastritis (CAG).. Fifty male SD rats were randomly divided into a normal group, a model group, a stomach meridian group, a control point group and a vitacoenzyme group, 10 rats in each group. The CAG precancerous lesion model was made in all the groups except the normal group. The rats in the normal group and model group were bundled for 30 min per day; the rats in the stomach meridian group and control point group were bundled and treated with moxibustion at stomach meridian acupoints or control points for 30 min per day; the rats in the vitacoenzyme group were treated with intragastric administration of vitacoenzyme, once per day. All the treatment was given for 20 weeks. The pathological morphological change of gastric mucosa was observed under optical microscope; the expression of epidermal growth factor (EGF), transforming growth factor alpha (TGF-alpha), vascular endothelial growth factor (VEGF), gastric mucosal proliferatig cell nuclear antigen (PCNA), argyrophilic protein of nucleolar organizer regions (Ag-NORs) in gastric mucosal cells were detected by enzyme linked immuno sorbent assay (ELISA).. Compared with the normal group, in the model group the gastric mucosal cells showed dysplasia and the expression of EGF, TGF-alpha, PCNA, VEGF, Ag-NORs in gastric mucosa cells in the model group was increased significantly (all P < 0.05). Compared with the model group, the gastric mucosa lesion gradually recovered and the expression of EGF, TGF-alpha, PCNA, VEGF, Ag-NORs in gastric mucosal cells was gradually decreased in the stomach meridian group, control point group and vitacoenzyme group, in which the stomach meridian group had the most significant effects (all P < 0.05).. Moxibustion at stomach meridian acupoints can obviously decrease the expression of cell proliferative factors in gastric mucosa in rats with CAG precancerous lesions, inhibit the gastric mucosal cell dysplasia, and promote the recovery of gastric mucosa.

Topics: Acupuncture Points; Animals; Cell Proliferation; Epidermal Growth Factor; Gastric Mucosa; Gastritis, Atrophic; Humans; Hyperplasia; Male; Moxibustion; Proliferating Cell Nuclear Antigen; Rats; Rats, Sprague-Dawley; Vascular Endothelial Growth Factor A

The epidermal growth factor receptor (EGFR) system is a key regulator of epithelial development and homeostasis. Its functions in the sebaceous gland (SG), however, remain poorly characterized. In this study, using a transgenic mouse line with tissue-specific and inducible expression of the EGFR ligand epigen, we showed that increased activation of the EGFR in skin keratinocytes results in enlarged SGs and increased sebum production. The phenotype can be reverted by interrupting transgene expression and is EGFR dependent, as gland size and sebum levels return to normal values after crossing to the EGFR-impaired mouse line Wa5. Intriguingly, however, the SG enlargement appears only if EGFR activation occurs before birth. Importantly, the enlarged sebaceous glands are associated with an increased expression of the transcription factor MYC and of the transmembrane proteins LRIG1, an established negative-feedback regulator of the EGFR/ERBB tyrosine kinase receptors and a stem cell marker. Our findings identify EGFR signaling as a major pathway determining SG activity and suggest a functional relationship between the EGFR/ERBB system and MYC/LRIG1 in the commitment of stem cells toward specific progenitor cell types, with implications for our understanding of their role in tissue development, homeostasis, and disease.

Topics: Animals; Epidermal Growth Factor; Epidermis; Epigen; ErbB Receptors; Hair Follicle; Hyperplasia; Keratinocytes; Membrane Glycoproteins; Mice; Mice, Transgenic; Nerve Tissue Proteins; Proto-Oncogene Proteins c-myc; Sebaceous Glands; Sebum; Signal Transduction

Otitis media is one of the most common pediatric infections. While it is usually treated without difficulty, up to 20% of children may progress to long-term complications that include hearing loss, impaired speech and language development, academic underachievement, and irreversible disease. Hyperplasia of middle ear mucosa contributes to the sequelae of acute otitis media and is of important clinical significance. Understanding the role of growth factors in the mediation of mucosal hyperplasia could lead to the development of new therapeutic interventions for this disease and its sequelae.. From a whole genome gene array analysis of mRNA expression during acute otitis media, we identified growth factors with expression kinetics temporally related to hyperplasia. We then tested these factors for their ability to stimulate mucosal epithelial growth in vitro, and determined protein levels and histological distribution in vivo for active factors.. From the gene array, we identified seven candidate growth factors with upregulation of mRNA expression kinetics related to mucosal hyperplasia. Of the seven, only HB-EGF (heparin-binding-epidermal growth factor) induced significant mucosal epithelial hyperplasia in vitro. Subsequent quantification of HB-EGF protein expression in vivo via Western blot analysis confirmed that the protein is highly expressed from 6 hours to 24 hours after bacterial inoculation, while immunohistochemistry revealed production by middle ear epithelial cells and infiltrating lymphocytes.. Our data suggest an active role for HB-EGF in the hyperplasia of the middle ear mucosal epithelium during otitis media. These results imply that therapies targeting HB-EGF could ameliorate mucosal growth during otitis media, and thereby reduce detrimental sequelae of this childhood disease.

Topics: Animals; Disease Models, Animal; Ear, Middle; Epidermal Growth Factor; Epithelium; Heparin-binding EGF-like Growth Factor; Hyperplasia; Inflammation; Mice; Mice, Inbred C57BL; Mucous Membrane; Otitis Media; Rats, Sprague-Dawley; RNA, Messenger

Glucose transporter member 1 (GLUT-1) is one of the major facilitated glucose transporters and contributes to the promotion of keratinocyte proliferation in psoriasis and carcinogenic lesions. In this study, we postulate that GLUT-1 is involved in ultraviolet B (UVB)-induced epidermal hyperplasia. The purpose of this study is to investigate the possible role of GLUT-1 in UVB-induced hyperplasia.. The effects of UVB on GLUT-1 expression levels were investigated in in vitro and in vivo studies. In addition, the involvement of epidermal growth factor (EGF) and hypoxia inducible factor-1 alpha (HIF-1α), transcriptional factors for GLUT-1, in GLUT-1-related events were investigated.. GLUT-1 mRNA and its protein levels were markedly increased by UVB irradiation in HaCaT cells. In in vivo studies, a strong immunofluorescence signal of GLUT-1 was clearly observed around the basal layer of the epidermis, which proliferated excessively by UVB irradiation. In HaCaT cells, EGF mRNA and its protein levels were markedly increased by UVB irradiation, and then the GLUT-1 mRNA level was significantly increased by treatment with EGF. Additionally, the upregulation of GLUT-1 by both UVB irradiation and treatment with EGF was significantly suppressed by transfection with HIF-1α siRNA.. We conclude that GLUT-1 is involved in UVB-induced epidermal hyperplasia by enhancing proliferation of epidermal basal cells, and the GLUT-1-related event might be regulated by an increase in HIF-1α stimulated by EGF.

Topics: Animals; Blotting, Western; Cell Proliferation; Enzyme-Linked Immunosorbent Assay; Epidermal Growth Factor; Epidermis; Fluorescent Antibody Technique, Indirect; Glucose Transporter Type 1; Humans; Hyperplasia; Hypoxia-Inducible Factor 1, alpha Subunit; Keratinocytes; Male; Mice; Models, Animal; Real-Time Polymerase Chain Reaction; RNA, Messenger; RNA, Small Interfering; Transfection; Ultraviolet Rays

Epidermal growth factor (EGF) is a mitogen widely used when culturing adult neural stem cells in vitro. Although proliferative effects can also be observed in vivo, intracerebroventricular infusion of EGF has been found to counteract neuronal determination and promote glial differentiation instead. However, EGF receptor activation has different effects on the subventricular zone (SVZ) in mice and rats, possibly because of species differences in SVZ cell composition. Specifically in the rat, EGF stimulation of the SVZ induces the formation of hyperplastic polyps. The present study aims at molecular and morphological characterization of these subventricular polyps. Using immunohistochemistry, electron microscopy, and gene expression analysis, we demonstrate in hyperplastic EGF-induced polyps an upregulation in protein expression of Sox2, Olig2, GFAP, nestin, and vimentin. We found polyp-specific dysplastic changes in the form of coexpression of Sox2 and Olig2. This highly proliferative, Sox2/Olig2 coexpressing dysplastic cell type is >10-fold enriched in the hyperplastic polyps compared with control SVZ and most likely causes the polyp formation. Unique ultrastructural features of the polyps include a lack of ependymal cell lining as well as a large number of cells with large, light, ovoid nuclei and a cytoplasm with abundant ribosomes, whereas other polyp cells contain invaginated nuclei but fewer ribosomes. EGF also induced changes in the expression of Id genes Id1, Id2, and Id4 in the SVZ. Taken together, we here demonstrate dysplastic, structural, and phenotypical changes in the rat SVZ following EGF stimulation, which are specific to hyperplastic polyps.

Topics: Aging; Animals; Biomarkers; Cell Proliferation; Epidermal Growth Factor; Gene Expression Regulation; Humans; Hyperplasia; Inhibitor of Differentiation Proteins; Lateral Ventricles; Male; Mice; Microscopy, Confocal; Models, Biological; Polyps; Rats; Rats, Inbred F344; RNA, Messenger; Stem Cells

Amphiregulin (AREG) and epiregulin (EREG) have been found to play pivotal roles in several malignancies. However, the correlation between their expression and clinicopathological factors in colorectal carcinoma (CRC) is yet to be further investigated. To clarify the clinical significance of AREG and EREG expression in CRC, we detected serum and tissue levels of AREG and EREG.. We detected serum AREG and EREG levels by ELISA, and tissue levels by immunohistochemical test in 73 patients with CRC. The correlation between each independent clinicopathological characteristic and AREG and EREG levels was examined.. There was significant correlation between serum AREG level and vascular invasion. There was no correlation between EREG serum level and any clinicopathological characteristics. Among the 73 primary lesions, 51 were AREG-positive, and 48 were EREG-positive. AREG-positive status was significantly correlated with depth of tumor invasion, distant metastases, and nerve invasion. EREG-positive status was significantly correlated with depth of tumor invasion and distant metastases. Coexpression analysis showed that 46 patients were both AREG-positive and EREG-positive.. High serum and tissue levels of AREG and high tissue level of EREG are predictors of a poor prognosis in patients with CRC.

Topics: Adenocarcinoma; Adult; Aged; Aged, 80 and over; Amphiregulin; Biomarkers, Tumor; China; Colorectal Neoplasms; Disease Progression; EGF Family of Proteins; Enzyme-Linked Immunosorbent Assay; Epidermal Growth Factor; Epiregulin; Female; Glycoproteins; Humans; Hyperplasia; Immunoenzyme Techniques; Intercellular Signaling Peptides and Proteins; Male; Middle Aged; Neoplasm Invasiveness; Neoplastic Cells, Circulating; Precancerous Conditions; Prognosis

We showed previously that vascular smooth muscle cells (VMSC) from spontaneously hypertensive rats (SHR) exhibit increased proliferation. The present study was undertaken to examine whether the enhanced levels of endogenous angiotensin (ANG) II and endothelin (ET)-1 contribute to the enhanced proliferation of VSMC from SHR and to further investigate the underlying mechanisms responsible for this response. The enhanced proliferation of VSMC from SHR compared with Wistar-Kyoto (WKY) rats was attenuated by losartan, BQ-123, BQ-788, and AG-1478, inhibitors of AT(1), ET(A), ET(B) and epidermal growth factor (EGF-R) receptors, respectively. In addition, BQ-123 and BQ-788 also attenuated the enhanced production of superoxide anion (O(2)(-)) and NADPH oxidase activity. Furthermore, diphenyleneiodonium (DPI, inhibitor of NADPH oxidase), N-acetyl-L-cysteine (NAC, O(2)(-) scavenger), and PP2 (inhibitor of c-Src) also inhibited the augmented proliferation of VSMC from SHR to WKY levels. In addition, the enhanced phosphorylation of EGF-R in VSMC from SHR compared with WKY was also attenuated by inhibitors of AT(1), ET(A), ET(B), and EGF-R but not by inhibitors of platelet-derived growth factor receptor or insulin-like growth factor receptor. Furthermore, the enhanced phosphorylation of ERK1/2 in VSMC from SHR was also attenuated by AT(1), ET(A), ET(B), c-Src, and EGF-R inhibitors. The phosphorylation of c-Src was significantly augmented in VSMC from SHR compared with VSMC from WKY and was attenuated by DPI and NAC. These data suggest that endogenous vasoactive peptides, through increased oxidative stress and resultant activation of c-Src, transactivate EGF-R, which through mitogen-activated protein (MAP) kinase signaling may contribute to the hyperproliferation of VSMC from SHR.

Topics: Angiotensin II; Angiotensin II Type 1 Receptor Blockers; Animals; Cell Proliferation; Cells, Cultured; CSK Tyrosine-Protein Kinase; Disease Models, Animal; Endothelin A Receptor Antagonists; Endothelin B Receptor Antagonists; Endothelin-1; Enzyme Inhibitors; Epidermal Growth Factor; ErbB Receptors; Free Radical Scavengers; Hyperplasia; Hypertension; Mitogen-Activated Protein Kinases; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; NADPH Oxidases; Oxidative Stress; Phosphorylation; Protein-Tyrosine Kinases; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Receptor, Angiotensin, Type 1; Receptor, Endothelin A; Receptor, Endothelin B; Signal Transduction; src-Family Kinases; Superoxides

About a quarter of peripheral vein grafts fail due in part to intimal hyperplasia. The proliferative capacity and response to growth inhibitors of medial smooth muscle cells and adventitial fibroblasts in vitro were studied to test the hypothesis that intrinsic differences in cells of vein grafts are associated with graft failure.. Cells were grown from explants of the medial and adventitial layers of samples of vein grafts obtained at the time of implantation. Vein graft patency and function were monitored over the first 12 months using ankle pressures and Duplex ultrasound to determine vein graft status. Cells were obtained from veins from 11 patients whose grafts remained patent (non-stenotic) and from seven patients whose grafts developed stenosis. Smooth muscle cells (SMCs) derived from media and fibroblasts derived from adventitia were growth arrested in serum-free medium and then stimulated with 1 muM sphingosine-1-phosphate (S1P), 10 nM thrombin, 10 ng/ml epidermal growth factor (EGF), 10 ng/ml platelet-derived growth factor-BB (PDGF-BB), PDGF-BB plus S1P, or PDGF-BB plus thrombin for determination of incorporation of [(3)H]-thymidine into DNA. Cells receiving PDGF-BB or thrombin were also treated with or without 100 microg/ml heparin, which is a growth inhibitor. Cells receiving thrombin were also treated with or without 150 nM AG1478, an EGF receptor kinase inhibitor.. SMCs and fibroblasts from veins of patients that developed stenosis responded more to the growth factors, such as PDGF-BB alone or in combination with thrombin or S1P, than cells from veins of patients that remained patent (P = .012). In addition, while PDGF-BB-mediated proliferation of fibroblasts from grafts that remained patent was inhibited by heparin (P < .03), PDGF-BB-mediated proliferation of fibroblasts from veins that developed stenosis was not (P > .5).. Inherent differences in the proliferative response of vein graft cells to PDGF-BB and heparin may explain, in part, the variability among patients regarding long term patency of vein grafts.

Topics: Aged; Ankle; Becaplermin; Blood Pressure; Cell Proliferation; Cells, Cultured; Constriction, Pathologic; DNA Replication; Epidermal Growth Factor; Female; Fibroblasts; Graft Occlusion, Vascular; Heparin; Humans; Hyperplasia; Lower Extremity; Lysophospholipids; Male; Middle Aged; Myocytes, Smooth Muscle; Peripheral Vascular Diseases; Platelet-Derived Growth Factor; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-sis; Quinazolines; Saphenous Vein; Sphingosine; Thrombin; Time Factors; Tyrphostins; Ultrasonography, Doppler, Duplex; Vascular Patency

Arterial injury induces smooth muscle cell (SMC) proliferation, migration, and intimal accumulation of cells and extracellular matrix. These processes are regulated by the administration of the glycosaminoglycans heparin and heparan sulfate, but little is known about the role of endogenous heparan sulfate proteoglycans in the vessel wall. We investigated the response to carotid injury of syndecan-1-null mice to assess the function of one of a conserved family of transmembrane heparan and chondroitin sulfate proteoglycans.. Syndecan-1-null mice developed a large neointimal lesion after injury, whereas wild-type mice made little or none. This was accompanied by a significant increase in both medial and intimal SMC replication. Cultured syndecan-1-null SMCs showed a significant increase in proliferation in response to PDGF-BB, thrombin, FGF2, EGF, and serum. In response to thrombin, PDGF-BB, and serum syndecan-1-null SMCs expressed more PDGF-B chain message than did wild-type SMCs. Downregulation of PDGF-BB or PDGFRbeta inhibited thrombin-, PDGF-BB-, and serum-induced DNA synthesis in syndecan-1-null SMCs.. These results suggest the possibility that syndecan-1 may limit intimal thickening in injured arteries by suppressing SMC activation through inhibition of SMC PDGF-B chain expression and PDGFRbeta activation.

Topics: Animals; Becaplermin; Carotid Artery Injuries; Carotid Artery, Common; Cell Movement; Cell Proliferation; Cells, Cultured; Disease Models, Animal; DNA Replication; Epidermal Growth Factor; Fibroblast Growth Factor 2; Hyperplasia; Mice; Mice, Inbred C57BL; Mice, Knockout; Muscle, Smooth, Vascular; Platelet-Derived Growth Factor; Proto-Oncogene Proteins c-sis; Receptor, Platelet-Derived Growth Factor beta; Signal Transduction; Syndecan-1; Thrombin; Time Factors; Tunica Intima

Muraglitazar, a PPARalpha/gamma dual agonist, was dosed orally to rats once daily for 13 weeks to evaluate urinary and urothelial changes of potential relevance to urinary bladder tumorigenesis. Groups of 17 young or aged rats per sex were fed a normal or 1% NH4Cl-supplemented diet and were dosed with 0, 1, or 50 mg/kg muraglitazar. Lithogenic ions and sediment were profiled from freshly voided urine samples collected 24 h after dosing, and drug exposures were measured. Urinary citrate, oxalate, and epidermal growth factor (EGF) were assayed from 18-h urine collections. Urothelium was assessed by light microscopy, scanning electron microscopy, and BrdU and TUNEL immunohistochemistry. When fed a normal diet, urine pH was higher in males (above 6.5). Urine volume/body weight was greater in females. Urine soluble/total calcium and magnesium and phosphorus/creatinine ratios were lower in male rats fed a normal diet. Urine citrate levels were decreased and oxalate was increased in young male rats treated with 50 mg/kg muraglitazar compared to age/sex/diet-matched controls. No changes in urine sediment were detected 24 h after dosing. In young male rats treated with 50 mg/kg on normal diet, multifocal urothelial necrosis and proliferation were observed, whereas urothelial apoptosis and urine EGF levels were unchanged compared to age/sex/diet-matched controls. Urothelial necrosis and proliferation were not correlated to systemic or urinary drug exposures and were prevented by dietary acidification. These data suggest that muraglitazar-associated changes in urine composition predispose to urothelial cytotoxicity and proliferation in the urinary bladder of young male rats and that urine sediment must be profiled at multiple daily timepoints to fully qualify drug-induced changes in urine composition.

Topics: Age Factors; Animals; Apoptosis; Calcium; Cell Proliferation; Citrates; Creatinine; Dose-Response Relationship, Drug; Epidermal Growth Factor; Female; Glycine; Hyperplasia; Magnesium; Male; Oxalates; Oxazoles; Peroxisome Proliferators; Phosphorus; PPAR alpha; PPAR gamma; Rats; Rats, Sprague-Dawley; Sex Factors; Time Factors; Urinary Bladder; Urine; Urothelium

Retinoids are widely used in the treatment of photoaging to stimulate dermal repair. However, retinoids also induce epidermal hyperplasia, which can lead to excessive scaling. Scaling is the major deterrent to topical retinoid therapy. Keratinocyte growth is strongly stimulated via ligand activation of EGFR. We examined regulation of EGFR ligands by retinoids and the role of EGFR in retinoid-induced hyperplasia in human skin in vivo. Topical treatment of human skin with all-trans retinoic acid (tRA) induces EGFR ligands heparin-binding (HB)-EGF and amphiregulin (AR), and reduces betacellulin mRNA levels. Laser capture microdissection-coupled real-time reverse transcription-PCR reveals that tRA increases HB-EGF mRNA throughout the epidermis, whereas AR induction is limited to basal keratinocytes. Topical tRA activates extracellular signal-regulated kinase 1/2 (Erk1/2) downstream EGFR effectors in human skin in vivo. tRA increases the soluble forms of AR and HB-EGF proteins, and induces epidermal hyperplasia, in human skin organ culture. Neutralization of HB-EGF or AR with specific antibodies strongly reduces tRA-induced epidermal hyperplasia. Finally, inhibition of EGFR activation by genistein reduces epidermal hyperplasia caused by topical retinoid treatment. These data demonstrate the central role of EGFR activation in retinoid-induced epidermal hyperplasia, and suggest that EGFR inhibitors can mitigate retinoid-induced scaling.

Topics: Amphiregulin; Antibodies; Cells, Cultured; EGF Family of Proteins; Epidermal Growth Factor; Epidermis; ErbB Receptors; Glycoproteins; Heparin-binding EGF-like Growth Factor; Humans; Hyperplasia; Intercellular Signaling Peptides and Proteins; Ligands; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Retinoids; RNA, Messenger; Skin Diseases; Tretinoin

Human Cripto-1 (CR-1) is overexpressed in approximately 80% of human breast, colon and lung carcinomas. Mouse Cr-1 upregulation is also observed in a number of transgenic (Tg) mouse mammary tumors. To determine whether CR-1 can alter mammary gland development and/or may contribute to tumorigenesis in vivo, we have generated Tg mouse lines that express human CR-1 under the transcriptional control of the mouse mammary tumor virus (MMTV). Stable Tg MMTV/CR-1 FVB/N lines expressing different levels of CR-1 were analysed. Virgin female MMTV/CR-1 Tg mice exhibited enhanced ductal branching, dilated ducts, intraductal hyperplasia, hyperplastic alveolar nodules and condensation of the mammary stroma. Virgin aged MMTV/CR-1 Tg mice also possessed persistent end buds. In aged multiparous MMTV/CR-1 mice, the hyperplastic phenotype was most pronounced with multifocal hyperplasias. In the highest CR-1-expressing subline, G4, 38% (12/31) of the multiparous animals aged 12-20 months developed hyperplasias and approximately 33% (11/31) developed papillary adenocarcinomas. The long latency period suggests that additional genetic alterations are required to facilitate mammary tumor formation in conjunction with CR-1. This is the first in vivo study that shows hyperplasia and tumor growth in CR-1-overexpressing animals.

Topics: Adenocarcinoma; Animals; Cell Division; DNA Primers; DNA, Complementary; Epidermal Growth Factor; Female; GPI-Linked Proteins; Growth Substances; Hyperplasia; Intercellular Signaling Peptides and Proteins; Mammary Glands, Animal; Mammary Neoplasms, Animal; Membrane Glycoproteins; Mice; Mice, Transgenic; Neoplasm Proteins

Heparin-binding EGF-like growth factor (HB-EGF), a member of the EGF-family, is thought to be important for keratinocyte functions. HB-EGF is first synthesized as a membrane-anchored form, and its soluble form is released by ectodomain shedding. Here we investigate the role of HB-EGF in epidermal hyperplasia induced by all-trans retinoic acid (tRA) treatment. HB-EGF is normally expressed in epidermis of normal adult mice at very low levels, but topical tRA treatment results in epidermal hyperplasia, concomitant with the strong induction of HB-EGF expression in the suprabasal layer. tRA-induced epidermal hyperplasia was reduced both in the keratinocyte-specific HB-EGF null mice (K5-HB(del/del)) and knock-in mice expressing the uncleavable mutant form of HB-EGF (HB(uc/uc)), as compared with wild-type HB-EGF knock-in mice (HB(lox/lox)). Among ErbB tyrosine kinase receptors, EGF receptor (EGFR) and ErbB2 were selectively activated by tRA treatment in skin from wild-type mice, while the activation of these ErbB receptors was significantly reduced in the skin of HB-EGF null mice. These results indicate that expression of HB-EGF and generation of its soluble form, followed by activation of EGFR and ErbB2, are pivotal processes in tRA-induced epidermal hyperplasia.

Topics: Animals; Cell Proliferation; Epidermal Growth Factor; Epidermis; ErbB Receptors; Female; Heparin-binding EGF-like Growth Factor; Hyperplasia; Immunohistochemistry; Intercellular Signaling Peptides and Proteins; Keratinocytes; Mice; Mice, Inbred Strains; Mice, Transgenic; Receptor, ErbB-2; RNA, Messenger; Time Factors; Tretinoin

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

As a part of synthetic studies on MMP (matrix metalloproteinase)/ADAM (a disintegrin and metalloproteinase) inhibitors, we have preliminarily communicated that azasugar-based compound 1a exhibited a potential inhibitory activity on some metalloprotease-catalyzed proteolytic reactions. To find promising candidates for the topical treatment of psoriasis, we investigated stability in aqueous solution of compound 1a and its derivative 1b and then optimized the P1' substuent (2-5). In the present study, we synthesized novel derivatives of compound 1a and evaluated their inhibitory activity toward MMP-1, -3, and -9, TACE, and HB-EGF shedding, from a viewpoint of versatility of azasugars as a functional scaffold. As a result, it was found that compound 1b demonstrated desirable inhibitory activity as an antipsoriatic agent, and some of the derivatives showed selective inhibitory activity. In addition, it was found that compound 1b exhibited a significant therapeutic effect on a mouse TPA-induced epidermal hyperplasia model. Therefore, compound 1b could become a promising candidate as a practical antipsoriatic agent.

Topics: ADAM Proteins; ADAM17 Protein; Animals; Aza Compounds; Carbohydrates; Disease Models, Animal; Disintegrins; Epidermal Growth Factor; Heparin-binding EGF-like Growth Factor; Hydroxamic Acids; Hyperplasia; Intercellular Signaling Peptides and Proteins; Matrix Metalloproteinase Inhibitors; Metalloendopeptidases; Mice; Models, Molecular; Protease Inhibitors; Psoriasis; Skin; Stereoisomerism; Structure-Activity Relationship; Sulfones

Epithelial-mesenchymal transition (EMT) facilitates migration and invasion of epithelial tumor cells. Cripto-1 (CR-1), a member of the epidermal growth factor-CFC protein family increases migration of cells in vitro. Here the expression of molecular markers and signaling molecules characteristic of EMT were assessed in mammary gland hyperplasias and tumors from mice expressing the human CR-1 transgene by the MMTV promoter (MMTV-CR-1) and in mouse mammary epithelial cell line HC-11 overexpressing CR-1 (HC-11/CR-1). Western blot analysis showed decreased expression of E-cadherin in MMTV-CR-1 tumors and in HC-11/CR-1 cells. The expression of N-cadherin, vimentin, cyclin-D1, and of the zinc-finger transcription factor, snail, was increased in MMTV-CR-1 tumors. Increased snail mRNA was also found in HC-11/CR-1 cells. Expression of phosphorylated (P)-c-Src, P-focal adhesion kinase (FAK), P-Akt, P-glycogen synthease kinase 3beta (GSK-3beta), dephosphorylated (DP)-beta-catenin, and various integrins such as, alpha 3, alpha v, beta 1, beta 3, and beta 4 was also increased in MMTV-CR-1 tumors. Immunohistochemistry showed positive staining for vimentin, N-cadherin, cyclin-D1, smooth muscle actin, fibronectin, snail, and beta-catenin in MMTV-CR-1 tumor sections. HC-11/CR-1 cells treated with the c-Src inhibitor PP2 reduced the expression of P-c-Src and of P-FAK, P-Akt, P-GSK-3beta, DP-beta-catenin all known to be activated by c-Src. Migration of HC-11/CR-1 cells was also reduced by PP2 treatment. These results suggest that CR-1 may play a significant role in promoting the increased expression of markers and signaling molecules associated with EMT.

Topics: Animals; Biomarkers, Tumor; Blotting, Western; Breast Neoplasms; Cell Line; Cell Movement; CSK Tyrosine-Protein Kinase; Enzyme Inhibitors; Epidermal Growth Factor; Epithelial Cells; Humans; Hyperplasia; Immunohistochemistry; Mammary Glands, Animal; Membrane Glycoproteins; Membrane Proteins; Mesoderm; Mice; Mice, Transgenic; Neoplasm Invasiveness; Neoplasm Proteins; Promoter Regions, Genetic; Protein-Tyrosine Kinases; Receptors, Virus; Reverse Transcriptase Polymerase Chain Reaction; src-Family Kinases; Transgenes

Epidermal growth factor (EGF) modulates Leydig cell proliferation, steroidogenesis, spermiogenesis, and Sertoli cell activity. It plays an important role in repairing ischemia-reperfusion injury in different tissues. The aim of this study was to evaluate the effects of sustained and local administration of EGF on improving bilateral testicular tissue after torsion. A total of 57 Wistar albino rats were used. For the EGF transport system, 1x2 cm gelatin films containing 2 microg EGF were used. Torsion was created by rotating the right testis 720 degrees in a clockwise direction for 4 h in all groups except the control group. Then, in the torsion group, bilateral orchiectomy was performed. After returning the torsioned ipsilateral testes to their normal state, the bilateral testes were wrapped by 1x2 cm unloaded gelatin films in the gelatin (G7 and G21) groups and, by 2 microg EGF loaded gelatin films in the EGF 7 and EGF 21 groups. The testes were removed on the seventh and 21st days, respectively, for biochemical and histological examination. Histologically, Johnsen's spermatogenesis criteria and mean seminiferous tubule diameter (MSTD) measurements were used. The EGF7 group did not show significant loss of Sertoli cells, while in the G7 group the number of these cells decreased. The ipsilateral ischemic testis of the EGF21 group showed Leydig cell hyperplasia, and the contralateral non-ischemic testes in this group were similar to the control group. In the G21 group, the bilateral testes showed Sertoli cell only syndrome in some sections, and most of the cells were undergoing apoptosis. The mean spermatogenesis scores and MSTD in the EGF7 and EGF21 groups were higher than in the G7 and G21 groups ( P<0.05). Malondialdehyde levels were significantly lower in the EGF groups than in the G groups ( P<0.05). Glutathione peroxidase (GSH-Px) levels in the G21 group were significantly higher than in the EGF21 group. Our study shows that local and sustained EGF release after testicular torsion improves bilateral testicular injury. EGF administration may be a new treatment choice for bilaterally injured testis after detorsion without removing the twisted testis.

Topics: Animals; Apoptosis; Epidermal Growth Factor; Glutathione Peroxidase; Hyperplasia; Leydig Cells; Male; Malondialdehyde; Orchiectomy; Rats; Rats, Wistar; Reperfusion Injury; Seminiferous Tubules; Sertoli Cells; Spermatic Cord Torsion; Spermatogenesis; Testis; Time Factors

Hyperplastic mucosa adjacent to colon cancer, being a reactive change, accelerates cancer progression and its metastasis through expression of angiogenic factors. We investigated promoter methylation in hyperplastic mucosa adjacent to orthotopic KM12SM colon cancer in mice. In the hyperplastic mucosa adjacent to KM12SM tumors in the cecum of athymic mice, reductions in the levels of the mutL homologue 1 (MLH1) and O6-methylguanine-DNA methyltransferase (MGMT) proteins were detected by immunohistochemistry and immunoblotting. To examine the effects of growth factors and cytokines on promoter methylation and repressed expression of the MLH1 and MGMT genes, a rat intestinal epithelial cell line, IEC6, was treated with epidermal growth factor (EGF) and interleukin (IL)-15 for 35 days. Protein levels of MLH1 and MGMT were reduced in EGF- and IL-15-treated IEC6 cells. A methylation-sensitive restriction enzyme assay revealed that CpG methylation was present in the promoter regions of the MLH1 and MGMT genes in DNAs extracted from hyperplastic mucosa adjacent to KM12SM tumors. These findings suggest that promoter CpG methylation affects expression of MLH1 MGMT genes in hyperplastic mucosa adjacent to colon cancer.

Topics: Adaptor Proteins, Signal Transducing; Animals; Carrier Proteins; Colon; Colonic Neoplasms; CpG Islands; DNA Methylation; Epidermal Growth Factor; Epithelial Cells; Gene Expression Regulation, Neoplastic; Hyperplasia; Immunoblotting; Immunoenzyme Techniques; Interleukin-15; Intestinal Mucosa; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Mucous Membrane; MutL Protein Homolog 1; Neoplasm Proteins; Neoplasm Transplantation; Nuclear Proteins; O(6)-Methylguanine-DNA Methyltransferase; Precancerous Conditions; Promoter Regions, Genetic; Rats

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

As previously described, SPC/myc transgenic mice developed bronchioloalveolar adenocarcinomas derived from alveolar type II (AT II) cells within 10-14 months, whereas SPC/IgEGF transgenic mice developed hyperplasias. Our purpose was to determine the potential interplay of environmental and genetic factors in lung tumorigenesis.. Six-week-old SPC/myc and SPC/IgEGF transgenic mice, overexpressing c-myc and a secretable form of the epidermal growth factor (IgEGF) under the control of the surfactant protein C (SPC) promoter, were treated with a single dose of the tobacco carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). As control groups, SPC/myc and SPC/IgEGF transgenic mice were treated with NaCl and non-transgenic littermates were treated with NNK or NaCl, respectively.. After 6 months, none of the NaCl-treated transgenic littermates showed bronchioloalveolar hyperplasia and adenocarcinoma formation, whereas 100% of the NNK-treated SPC/myc transgenic mice did. The effect of NNK on SPC/IgEGF transgenic mice was less pronounced, inducing hyperplasia in the lung in only 16.7% of them. In 90% of the NNK-treated non-transgenic littermates no neoplastic changes were detected in the lung.. These results demonstrate that the progression of pulmonary bronchioloalveolar adenocarcinomas, induced by expression of c-myc as a transgene, was accelerated by NNK, suggesting that c-myc cooperates with NNK-induced mutations.

Topics: Adenocarcinoma, Bronchiolo-Alveolar; Animals; Carcinogens; Epidermal Growth Factor; Gene Expression Regulation, Neoplastic; Hyperplasia; Intercellular Signaling Peptides and Proteins; Lung; Lung Neoplasms; Mice; Mice, Transgenic; Nitrosamines; Peptides; Proto-Oncogene Proteins c-myc; Pulmonary Surfactant-Associated Protein C; Pulmonary Surfactants

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

Angioplasty stimulates proliferation and migration of vascular smooth muscle cells (VSMC), leading to neointimal thickening and vascular restenosis. In a rat model of balloon catheter injury (BCI), we investigated whether alterations in expression of Ca2+-activated K+ channels (KCa) contribute to intimal hyperplasia and vascular restenosis.. Function and expression of KCa in mature medial and neointimal VSMC were characterized in situ by combined single-cell RT-PCR and patch-clamp analysis. Mature medial VSMC exclusively expressed large-conductance KCa (BKCa) channels. Two weeks after BCI, expression of BKCa was significantly reduced in neointimal VSMC, whereas expression of intermediate-conductance KCa (IKCa1) channels was upregulated. In the aortic VSMC cell line, A7r5 epidermal growth factor (EGF) induced IKCa1 upregulation and EGF-stimulated proliferation was suppressed by the selective IKCa1 blocker TRAM-34. Daily in vivo administration of TRAM-34 to rats significantly reduced intimal hyperplasia by approximately 40% at 1, 2, and 6 weeks after BCI. Two weeks of treatment with the related compound clotrimazole was equally effective. Reduction of intimal hyperplasia was accompanied by decreased neointimal cell content, with no change in the rate of apoptosis or collagen content.. The switch toward IKCa1 expression may promote excessive neointimal VSMC proliferation. Blockade of IKCa1 could therefore represent a new therapeutic strategy to prevent restenosis after angioplasty.

Topics: Angioplasty, Balloon; Animals; Cell Line; Cells, Cultured; Clotrimazole; Epidermal Growth Factor; Graft Occlusion, Vascular; Hyperplasia; Intermediate-Conductance Calcium-Activated Potassium Channels; Large-Conductance Calcium-Activated Potassium Channels; Muscle, Smooth, Vascular; Patch-Clamp Techniques; Potassium Channel Blockers; Potassium Channels; Potassium Channels, Calcium-Activated; Pyrazoles; Rats; Rats, Sprague-Dawley; RNA, Messenger; Tunica Intima

Cleavage of membrane-anchored heparin-binding EGF-like growth factor (proHB-EGF) via metalloprotease activation yields amino- and carboxy-terminal regions (HB-EGF and HB-EGF-C, respectively), with HB-EGF widely recognized as a key element of epidermal growth factor receptor transactivation in G protein-coupled receptor signaling. Here, we show a biological role of HB-EGF-C in cells. Subsequent to proteolytic cleavage of proHB-EGF, HB-EGF-C translocated from the plasma membrane into the nucleus. This translocation triggered nuclear export of the transcriptional repressor, promyelocytic leukemia zinc finger (PLZF), which we identify as an HB-EGF-C binding protein. Suppression of cyclin A and delayed entry of S-phase in cells expressing PLZF were reversed by the production of HB-EGF-C. These results indicate that released HB-EGF-C functions as an intracellular signal and coordinates cell cycle progression with HB-EGF.

Topics: Active Transport, Cell Nucleus; Animals; Cell Line; Cell Membrane; Cell Nucleus; Cyclin A; DNA-Binding Proteins; Epidermal Growth Factor; Female; Genes, Regulator; Heparin-binding EGF-like Growth Factor; Humans; Hyperplasia; Intercellular Signaling Peptides and Proteins; Keratinocytes; Kruppel-Like Transcription Factors; Mice; Mice, Inbred C57BL; Peptide Hydrolases; Promyelocytic Leukemia Zinc Finger Protein; Protein Precursors; Protein Structure, Tertiary; Repressor Proteins; S Phase; Signal Transduction; Skin; Transcription Factors

Heparin-binding EGF-like growth factor (HB-EGF) is first synthesized as a membrane-anchored form (proHB-EGF), and its soluble form (sHB-EGF) is released by ectodomain shedding from proHB-EGF. To examine the significance of proHB-EGF processing in vivo, we generated mutant mice by targeted gene replacement, expressing either an uncleavable form (HBuc) or a transmembrane domain-truncated form (HBdeltatm) of the molecule. HB(uc/uc) mice developed severe heart failure and enlarged heart valves, phenotypes similar to those in proHB-EGF null mice. On the other hand, mice carrying HBdeltatm exhibited severe hyperplasia in both skin and heart. These results indicate that ectodomain shedding of proHB-EGF is essential for HB-EGF function in vivo, and that this process requires strict control.

Topics: Animals; Cell Surface Extensions; Epidermal Growth Factor; Gene Targeting; Heart Defects, Congenital; Heart Valves; Heparin-binding EGF-like Growth Factor; Hyperplasia; Intercellular Signaling Peptides and Proteins; Mice; Mice, Mutant Strains; Mutation; Protein Processing, Post-Translational; Protein Structure, Tertiary; Skin Abnormalities; Solubility

Sebaceous adenoma (SA) is a rare solitary tumour with a predilection for the forehead and scalp. In the English literature, less than 10 cases of SA have been described in the oral cavity. The objective of this study was to examine the clinicopathologic features and evaluate the expression of epidermal growth factor and its receptor, estrogen receptor and androgen receptor in SA and in its differential diagnoses including sebaceous gland hyperplasia (SGH) and Fordyce's granules (FG). Additionally, we analysed the proliferative potential of sebaceous cells from SA, SGH and FG by measuring proliferating cell nuclear antigen (PCNA) expression and quantification of argyrophilic nuclear organizer regions (AgNORs). The SA showed many clinicopathologic similarities to cases previously reported including the biphasic population of cells, in the periphery of lobules undifferentiated basaloid cells whereas the central area was formed by mature sebocytes. SA was composed of 198 lobules of sebaceous cells, whereas SGH and FG showed a mean of 21 +/- 7.81 and 5.84 +/- 2.83, respectively. The AgNOR and PCNA indices were similar in SA, SGH and FG. These data suggest that lobule counts may be used as additional criteria in distinguishing SA of the oral cavity from other intraoral sebaceous gland lesions.

Topics: Adenoma; Adolescent; Adult; Aged; Aged, 80 and over; Choristoma; Diagnosis, Differential; Epidermal Growth Factor; ErbB Receptors; Female; Humans; Hyperplasia; Middle Aged; Mouth Diseases; Mouth Neoplasms; Nucleolus Organizer Region; Proliferating Cell Nuclear Antigen; Receptors, Androgen; Receptors, Estrogen; Sebaceous Glands; Sweat Glands

The activation of vascular smooth muscle cells (SMCs) in neointimal hyperplasia involves signaling through receptor tyrosine kinases as well as G protein-coupled receptors. Overexpression of G protein-coupled receptor kinase-2 (GRK2) in SMCs can attenuate mitogenic signaling and proliferation in response to not only several G protein-coupled receptor agonists, but also platelet-derived growth factor (PDGF). To test whether overexpression of GRK2 could inhibit other SMC responses implicated in neointimal hyperplasia, we assessed SMC chemotaxis and mitogenic signaling evoked by PDGF and G(q)-coupled receptor agonists. To test the effects of GRK2 overexpression on neointimal hyperplasia in vivo, we employed a rabbit autologous vein graft model system. GRK2 overexpression reduced PDGF-promoted SMC chemotaxis by 85% (P<0.01), but had no effect on chemotaxis promoted by epidermal growth factor (EGF). Congruently, GRK2 overexpression reduced by approximately 50% (P<0.05) the [(3)H]thymidine incorporation induced by combinations of PDGF and Gq-coupled receptor agonists, but had no effect on that induced by PDGF plus EGF. PDGF-, but not EGF-promoted phosphoinositide 3-kinase activity in SMCs was also inhibited by GRK2 overexpression. In rabbit vein grafts, we achieved GRK2 overexpression in medial SMCs, reduced cell proliferation during the first week after graft implantation, and reduced steady state neointimal thickness by 29% (P<0.01), without affecting medial thickness or potentiating SMC apoptosis. Because of its ability to dampen chemotactic and mitogenic signaling through PDGF and Gq-coupled receptors, GRK2 overexpression in SMCs may be a useful therapeutic approach for neointimal hyperplasia.

Topics: Animals; Aorta; beta-Adrenergic Receptor Kinases; Cell Division; Cells, Cultured; Chemotaxis; Cyclic AMP-Dependent Protein Kinases; Epidermal Growth Factor; Heterotrimeric GTP-Binding Proteins; Hyperplasia; Jugular Veins; Microscopy, Electron; Mitogens; Myocytes, Smooth Muscle; Platelet-Derived Growth Factor; Rabbits; Tunica Intima

We reported previously that mast cell tryptase is a growth factor for dog tracheal smooth muscle cells. The goals of our current experiments were to determine if tryptase also is mitogenic in cultured human airway smooth muscle cells, to compare its strength as a growth factor with that of other mitogenic serine proteases, and to determine whether its proteolytic actions are required for mitogenesis. Highly purified preparations of human lung beta-tryptase (1-30 nM) caused dose-dependent increases in DNA synthesis in human airway smooth muscle cells. Maximum tryptase-induced increases in DNA synthesis far exceeded those occurring in response to coagulation cascade proteases, such as thrombin, factor Xa, or factor XII, or to other mast cell proteases, such as chymase or mastin. Irreversibly abolishing tryptase's catalytic activity did not alter its effects on increases in DNA synthesis. We conclude that beta-tryptase is a potent mitogenic serine protease in cultured human airway smooth muscle cells. However, its growth stimulatory effects in these cells occur predominantly via nonproteolytic actions.

Topics: Animals; Anticoagulants; Becaplermin; Cell Division; Cells, Cultured; Chymases; DNA; Dogs; Dose-Response Relationship, Drug; Epidermal Growth Factor; Factor Xa; Factor XII; Fibroblast Growth Factor 2; Hemostatics; Humans; Hyperplasia; Insulin-Like Growth Factor I; Mast Cells; Mitogens; Muscle, Smooth; Platelet-Derived Growth Factor; Proto-Oncogene Proteins c-sis; Receptor, PAR-2; Receptors, Thrombin; RNA, Messenger; Serine Endopeptidases; Thrombin; Trachea; Tryptases

Phosphonamide-based inhibitors were synthesized and evaluated for the inhibitory activities against the shedding of epidermal growth factors, amphiregulin and heparin-binding EGF-like growth factor, that would participate in the development of psoriasis. All compounds exhibited excellent inhibitory activities for these EGF sheddings; however, they also inhibited matrix metalloproteinases (MMPs). To avoid adverse effects reported by the clinical development of MMP inhibitors, the antedrug concept was introduced. Among the phosphonamide inhibitors, the 2,2,2-trifluoroethyl ester 8d and 2,2-difluoroethyl ester 8c showed rapid decomposition in human plasma, which is an essential property for the antedrug. Topical applications of these compounds significantly suppressed TPA-induced epidermal hyperplasia in murin skin, a model of psoriasis. These results suggested that the phosphonamide-based inhibitors have a therapeutic potential for the treatment of psoriasis as an antedrug application.

Topics: Amphiregulin; Animals; Cell Line; Disease Models, Animal; Drug Stability; EGF Family of Proteins; Epidermal Growth Factor; Glycoproteins; Growth Substances; Heparin-binding EGF-like Growth Factor; Humans; Hydroxylamines; Hyperplasia; Intercellular Signaling Peptides and Proteins; Isoquinolines; Magnetic Resonance Spectroscopy; Matrix Metalloproteinase Inhibitors; Metalloendopeptidases; Mice; Protease Inhibitors; Psoriasis; Recombinant Proteins; Skin; Tetradecanoylphorbol Acetate; Tetrahydroisoquinolines

To investigate the roles of retinoic acid (RA) receptors (RARs) in the physiology of epidermis that does not express RAR beta, conditional spatio-temporally controlled somatic mutagenesis was used to selectively ablate RAR alpha in keratinocytes of RAR gamma-null mice. Keratinocyte proliferation was maintained in adult mouse epidermis lacking both RAR alpha and RAR gamma, as well as in RAR beta-null mice. All RAR-mediated signalling pathways are therefore dispensable in epidermis for homeostatic keratinocyte renewal. However, topical treatment of mouse skin with selective retinoids indicated that RXR/RAR gamma heterodimers, in which RXR transcriptional activity was subordinated to that of its RAR gamma partner, were required for retinoid-induced epidermal hyperplasia, whereas RXR homodimers and RXR/RAR alpha heterodimers were not involved. RA-induced keratinocyte proliferation was studied in mutant mice in which RXR alpha, RXR alpha and RAR alpha, RAR gamma, or RXR alpha and RAR gamma genes were specifically disrupted in either basal or suprabasal keratinocytes. We demonstrate that the topical retinoid signal is transduced by RXR alpha/RAR gamma heterodimers in suprabasal keratinocytes, which, in turn, stimulate proliferation of basal keratinocytes via a paracrine signal that may be heparin-binding EGF-like growth factor.

Topics: Alleles; Animals; Cell Division; Crosses, Genetic; Dimerization; Epidermal Cells; Epidermal Growth Factor; Epidermis; Gene Targeting; Heparin-binding EGF-like Growth Factor; Homeostasis; Hyperplasia; Intercellular Signaling Peptides and Proteins; Keratinocytes; Mice; Mice, Knockout; Mice, Transgenic; Mutagenesis; Paracrine Communication; Protein Multimerization; Receptors, Retinoic Acid; Retinoic Acid Receptor alpha; Retinoic Acid Receptor gamma; Retinoid X Receptors; Retinoids; Tamoxifen; Transcription Factors; Transcription, Genetic; Tretinoin

Previous studies demonstrated that heparin-binding epidermal growth factor-like growth factor (HB-EGF) contributes to carcinogenesis and carcinoma progression. In this study, we investigated its expression in human pancreatic adenocarcinoma.. We immunohistochemically investigated the expression of HB-EGF in 40 cases of pancreatic adenocarcinoma.. HB-EGF was only occasionally and faintly expressed in normal and hyperplastic pancreas duct epithelia. In pancreatic adenocarcinoma, 22 (55.0%) of the 40 cases were classified as positive for HB-EGF. Its expression was more frequently observed in cases with a low Ki-67 labeling index, well differentiated. early stage, small size, without lymph node metastasis and low EGF-R expression.. These results suggest that HB-EGF mainly plays a role in early phase of the progression of pancreatic adenocarcinoma.

Topics: Adenocarcinoma; Aged; Epidermal Growth Factor; ErbB Receptors; Female; Heparin-binding EGF-like Growth Factor; Humans; Hyperplasia; Immunohistochemistry; Intercellular Signaling Peptides and Proteins; Ki-67 Antigen; Male; Middle Aged; Pancreas; Pancreatic Neoplasms; Reference Values

Sun-protected human skin was maintained in organ culture and treated with all-trans retinoic acid in the presence or absence of reversible or irreversible pharmacologic antagonists of c-erbB receptor tyrosine kinase activity. In the absence of these inhibitors, all-trans retinoic acid induced epidermal hyperplasia comparable to that induced in intact skin by all-trans retinol or all-trans retinoic acid itself. There was a strong correlation between inhibition of epidermal hyperplasia in organ culture and inhibition of epidermal-growth-factor-dependent keratinocyte growth in monolayer culture. In additional studies it was shown that all-trans retinoic acid could overcome the known inhibitory effects of calcium on expression of HB-EGF-like growth factor mRNA in organ-cultured skin. Further, it was shown that an antibody to HB-EGF-like growth factor inhibited retinoid-stimulated epidermal hyperplasia in organ culture and reduced proliferation in cultured keratinocytes. In contrast, the c-erbB receptor tyrosine kinase antagonists and the neutralizing HB-EGF-like growth factor antibody were ineffective in inhibiting all-trans-retinoic-acid-dependent survival and proliferation of human dermal fibroblasts. Taken together, these data indicate (i) that retinoid-induced epidermal hyperplasia in human skin proceeds through c-erbB, and (ii) that HB-EGF-like growth factor is one of the c-erbB ligands mediating this effect.

Topics: Adult; Antibodies; Calcium; Cell Division; Cell Survival; Epidermal Growth Factor; Epidermis; ErbB Receptors; Fibroblasts; Gene Expression; Heparin-binding EGF-like Growth Factor; Humans; Hyperplasia; Intercellular Signaling Peptides and Proteins; Keratinocytes; Keratolytic Agents; Organ Culture Techniques; Receptors, Cell Surface; RNA, Messenger; Tretinoin

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

A murine model of vascular injury-induced neointimal hyperplasia was developed by using a photoactive dye, rose bengal. Photoactivation of rose bengal induced vascular injury to the femoral arteries of C57B1/6 mice and resulted in an occlusive neointimal hyperplasia after 4 weeks. The cellular elements of the hyperplastic neointima were found to be alpha-actin-positive vascular smooth muscle cells expressing epidermal growth factor (EGF) receptor at high levels. EGF-Gen, an EGF-R-specific inhibitor with potent anticancer activity, suppressed the formation of hyperplastic neointima. Morphometric analysis of serial tissue sections at 4 weeks after vascular injury showed that in 75% of the EGF-Gen-treated mice, the maximal stenosis index was only 0.44 +/- 0.13, whereas in 75% of phosphate-buffered saline (PBS)-treated mice, the maximal stenosis index was 1.20 +/- 0.25. The mean neointima/media ratios for areas of maximum neointimal hyperplasia were 0.59 +/- 0.16 (n = 24) for the EGF-Gen-treated group, 0.99 +/- 16 (n = 45) for the PBS group (EGF-Gen vs. PBS, p = 0.0017), and 1.03 +/- 18 (n = 8) for group treated with unconjugated genistein (EGF-Gen vs. Gen, p = 0.0088). EGF-Gen treatment of mice with vascular injury to the left femoral artery was not associated with any clinical signs of toxicity or histopathologic lesions in any of the organs, including the uninjured right femoral artery. EGF-Gen also inhibited VSMC migration in vitro, without affecting VSMC proliferation and viability, suggesting that EGF-Gen is blocking neointima formation by inhibiting cellular migration to vascular injury sites. In conclusion, EGF-Gen may be useful as a nontoxic prophylactic agent for prevention of restenosis in clinical settings.

Topics: Animals; Antineoplastic Agents; Cell Movement; Constriction, Pathologic; Disease Models, Animal; Epidermal Growth Factor; ErbB Receptors; Genistein; Hyperplasia; Male; Mice; Mice, Inbred C57BL; Muscle, Smooth, Vascular; Protein-Tyrosine Kinases; Recombinant Proteins; Tunica Intima; Up-Regulation; Vascular Diseases; Vasoconstriction

Epidermal growth factor (EGF) causes proliferation in renal tubular cells but, when it is combined with transforming growth factor-beta1, it causes hypertrophy by a mechanism that requires the activity of the retinoblastoma family of proteins. In contrast, ammonia causes hypertrophy by decreasing lysosomal proteolysis; in some cell types, it also decreases cellular proliferation. These studies were designed to determine whether ammonia, like transforming growth factor-beta1, could convert EGF-induced hyperplasia to hypertrophy. Cultured NRK-52E cells were incubated with EGF and/or ammonia and the protein/DNA ratio was measured, as a marker of hypertrophy. Addition of ammonia to EGF-treated NRK-52E cells converted EGF-induced hyperplasia to hypertrophy, because of a decrease in DNA synthesis. The mechanism involved no change in EGF-induced protein synthesis. Inhibition of lysosomal function with a proton pump inhibitor or lysosomal protease inhibitors also converted the response of EGF-treated cells to hypertrophy. Expression of the human papilloma virus 16 E7 protein (which inactivates all members of the retinoblastoma family) prevented ammonia from converting EGF-induced hyperplasia to hypertrophy. It is concluded that ammonia converts EGF-induced hyperplasia to hypertrophy by a mechanism that involves suppression of lysosomal function and this response can be blocked by inhibiting the activity of the retinoblastoma family of proteins.

Topics: Alkalies; Ammonium Chloride; Animals; Cell Division; Cell Line; DNA; Drug Synergism; Epidermal Growth Factor; Hyperplasia; Hypertrophy; Kidney; Lysosomes; Oncogene Proteins, Viral; Papillomavirus E7 Proteins; Rats; Retinoblastoma Protein

In vivo the effects of sustained hydrostatic pressure on the bladder wall and its components are evident under physiological and pathological conditions. We previously reported that exposure of bladder smooth muscle cells to 20 and 40 cm. H2O hydrostatic pressure for as little as 1 hour resulted in the up-regulation of heparin binding epidermal growth factor messenger RNA in a time dependent fashion as well as in activation of the heparin binding epidermal growth factor growth factor gene. In our current study we investigated the use of CRM197 as an agent for blocking undesirable cellular level events, such as smooth muscle cell hyperplasia, eliminating the irreversible alterations in bladder and kidney function that result from chronic and/or severe bladder outlet obstruction.. Control and experimental neonatal ovine smooth muscle cells were exposed to 0.3 pressure and 8.5 cm. H2O, respectively, for 7 days. We evaluated the mitogenic activity of the supernatant medium from bladder smooth muscle cells exposed to 8.5 cm. H2O for 5 days (conditioned medium) before and after the addition of 0.1 mg./ml. CRM197. Bladder smooth muscle cell apoptosis was also assessed after CRM197 exposure. Statistical analysis was performed using the Student t test with p <0.05 considered significant.. Exposing bladder smooth muscle cells to sustained 8.5 cm. H2O hydrostatic pressure for 7 days resulted in increased cell proliferation. Conditioned medium contained mitogenic activity, which was ablated after CRM197 was added. No direct toxic effect of CRM197 on bladder smooth muscle cell growth was appreciated (no apoptosis).. We demonstrated a proliferative response of neonatal bladder smooth muscle cells after exposure to sustained hydrostatic pressure. This response was partially due to the release of heparin binding epidermal growth factor and was blocked by adding CRM197. These data support the potential use of CRM197 in drug targeted therapy for diseases involving bladder outlet obstruction.

Topics: Apoptosis; Bacterial Proteins; Cell Division; Cells, Cultured; Culture Media, Conditioned; Diphtheria Toxin; Epidermal Growth Factor; Humans; Hydrostatic Pressure; Hyperplasia; Muscle, Smooth; Urinary Bladder

Goblet-cell hyperplasia is a critical pathological feature in hypersecretory diseases of airways. However, the underlying mechanisms are unknown, and no effective therapy exists. Here we show that stimulation of epidermal growth factor receptors (EGF-R) by its ligands, EGF and transforming growth factor alpha (TGFalpha), causes MUC5AC expression in airway epithelial cells both in in vitro and in vivo. We found that a MUC5AC-inducing epithelial cell line, NCI-H292, expresses EGF-R constitutively; EGF-R gene expression was stimulated further by tumor necrosis factor alpha (TNFalpha). EGF-R ligands increased the expression of MUC5AC at both gene and protein levels, and this effect was potentiated by TNFalpha. Selective EGF-R tyrosine kinase inhibitors blocked MUC5AC expression induced by EGF-R ligands. Pathogen-free rats expressed little EGF-R protein in airway epithelial cells; intratracheal instillation of TNFalpha induced EGF-R in airway epithelial cells, and subsequent instillation of EGF-R ligands increased the number of goblet cells, Alcian blue-periodic acid-Schiff staining (reflecting mucous glycoconjugates), and MUC5AC gene expression, whereas TNFalpha, EGF, or TGFalpha alone was without effect. In sensitized rats, three intratracheal instillations of ovalbumin resulted in EGF-R expression and goblet-cell production in airway epithelium. Pretreatment with EGF-R tyrosine kinase inhibitor, BIBX1522, prevented goblet-cell production both in rats stimulated by TNFalpha-EGF-R ligands and in an asthma model. These findings suggest potential roles for inhibitors of the EGF-R cascade in hypersecretory diseases of airways.

Topics: Animals; Epidermal Growth Factor; ErbB Receptors; Gene Expression Regulation; Goblet Cells; Humans; Hyperplasia; Immunohistochemistry; Mucin 5AC; Mucins; Rats; Respiratory System; Tumor Cells, Cultured; Tumor Necrosis Factor-alpha

Amphiregulin (Ar) and Cripto (Cr) are autocrine growth factors for mammary cells and both have been observed to exhibit high expression in human mammary tumors, in contrast with adjacent tissues. To investigate whether Ar and Cr play roles in the progression of mammary cell proliferation to unregulated growth and tumor formation, the levels of expression were examined in transgenic mice (TGM) that over-express several different oncogenes: MMTV-Polyoma virus middle T antigen (MMTV-PyMT), MMTV-c-ErbB2 (c-neu, HER2) and MT-hTGF alpha. These transgenic mice all produce mammary tumors but with different rates of progression. The levels of Ar were induced up to 10-fold in association with hyperplasia in 2 of the TGM. Cr overexpression was consistently observed in hyperplastic mammary glands in all the animal models, decreasing in overt tumors in 2 of the TGM models. In MMTV-PyMT mammary glands, the levels of Cr expression rose 7- to 10-fold in hyperplastic tissue and 25-fold the levels in tumors compared to age-matched transgene negative mice. Ar and especially Cr thus should have potential value as markers of preneoplastic change in mammary tissue.

Topics: Amphiregulin; Animals; Antigens, Viral, Tumor; Antineoplastic Agents; Biomarkers, Tumor; Cell Division; EGF Family of Proteins; Epidermal Growth Factor; Female; Genes, erbB-2; Glycoproteins; GPI-Linked Proteins; Growth Substances; Humans; Hyperplasia; Intercellular Signaling Peptides and Proteins; Mammary Glands, Animal; Mammary Neoplasms, Experimental; Mammary Tumor Virus, Mouse; Membrane Glycoproteins; Mice; Mice, Inbred Strains; Mice, Transgenic; Neoplasm Proteins; Oncogenes; Polyomavirus; Precancerous Conditions; Pregnancy; Receptor, ErbB-2

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

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

In previous papers we have demonstrated that sialoadenectomy inhibited MPA-induced mammary tumorigenesis in BALB/c mice. To further explore the role of EGF in this experimental model, we evaluated its effects on mammary glands of sialoadenectomized (sialox) MPA-treated female mice and on tumor growth. MPA-treated sialox mice were injected s.c. (n = 3) or not (n = 6) with 5 microg EGF every 36 h for 45 days; MPA-treated sham-operated mice were used as controls (n = 6). Mammary glands from sialox MPA-treated mice are considerably less developed as compared with sham-operated animals. The exogenous administration of EGF restores the usual MPA-induced growth pattern of the glands, thus confirming a role for EGF either in mediating or cooperating with MPA in inducing the mammary architectural changes observed in MPA-treated mice. On the other hand, primary cultures of progestin-dependent (PD) ductal mammary adenocarcinoma in vivo tumor lines and of lobular progestin-independent (PI) tumor lines were used to evaluate the effect of EGF on tumor growth. In vitro EGF was found to stimulate cell proliferation of lobular PI tumor cells and of fibroblastic cells from both types of tumors at concentrations higher than 0.1-0.5 ng/ml and in the presence of 1-5% of charcoal-stripped fetal calf serum. Conversely, no proliferative effects were observed in ductal PD cells under the same experimental conditions, regardless of the presence of 10 nM MPA. It can be concluded that although EGF plays an important role in MPA-induced mammary carcinogenesis, it is not necessary in PD tumor growth.

Topics: Adenocarcinoma; Animals; Carcinogens; Cell Division; Epidermal Growth Factor; Female; Hyperplasia; Mammary Glands, Animal; Mammary Neoplasms, Experimental; Medroxyprogesterone Acetate; Mice; Mice, Inbred BALB C; Salivary Glands; Tumor Cells, Cultured

Systemic treatment with epidermal growth factor (EGF) induces growth of all wall layers of the urinary tract in pigs and rats. We have previously described that the EGF stimulated urothelium in Goettingen minipigs accumulates glycoproteins. The aim of the present study was to examine and partly characterize glycoproteins in the urothelium and in the urine from rats treated with EGF. Seventy-two female Wistar rats were allocated into five groups receiving EGF treatment (150 microg/kg per day) for 0 (controls), 1, 2, 3 and 4 weeks before being killed. Glycoconjugates were characterized by means of lectins on tissue sections, and using Western blotting, in bladder extracts and in urine. The characterization mostly focused on the expression of the mucin-type core structures T and Tn using the lectins peanut agglutinin (PNA) and Vicia villosa (VVA) and specific monoclonal antibodies. The thickened EGF-stimulated urothelium retained the normal differentiation pattern as judged from the appearance on electron microscopy and from the expression of carbohydrate structures. Within the urothelium and in the urine there was increased expression of mucin-type glycoproteins suggesting increased urothelial production and excretion of mucin-type glycoproteins. In conclusion, the EGF stimulated hyperplastic urothelium most probably excretes increased amounts of mucin-type glycoproteins to the urine but it retains the normal pattern of differentiation as assessed by lectin characterization.

Topics: Animals; Cell Differentiation; Epidermal Growth Factor; Female; Glycoproteins; Hyperplasia; Lectins; Microscopy, Electron; Organ Size; Rats; Rats, Wistar; Swine; Swine, Miniature; Ureter; Urinary Bladder; Urinary Tract; Urothelium

Systemic treatment with epidermal growth factor (EGF) induces growth of all wall layers of the urinary tract in pigs and rats. In this study, we describe the time-dependent growth of the ureter and bladder. Forty-eight female Wistar rats were allocated into five groups receiving EGF treatment (150 microg/kg per day) for 0 (controls), 1, 2, 3 or 4 weeks before being killed. The 24-h urine excretion was increased only in the group treated for 4 weeks with EGF. Measured by a simple infusion device, EGF significantly increased the bladder capacity by more than 50% in all the EGF-treated groups. The volumes of the wall layers of the ureter and bladder were quantified using stereology. After 4 weeks of treatment with EGF, the total volumes of the ureter and bladder were 1.8- and 2.1-fold larger than in the control group (the urothelium was 2.8- and 3.5-fold larger and the muscular coat 1.6- and 1.6-fold larger in the ureter and bladder, respectively). In conclusion, the EGF-induced growth of the urinary tract is characterized by increased bladder capacity, and increased volume of all wall layers --most prominently the urothelium.

Topics: Animals; Diuresis; Epidermal Growth Factor; Female; Hyperplasia; Organ Size; Rats; Rats, Wistar; Swine; Swine, Miniature; Time Factors; Ureter; Urinary Bladder; Urinary Tract; Urothelium

Pituitary hyperplasia as well as proliferation of the endometrium are typical responses to estrogen administration in rodents. Both insulin-like growth factor-I (IGF-I) and epidermal growth factor (EGF) have been implicated as paracrine mediators and amplifiers of estrogen action in the rodent uterus. The auto/paracrine role of IGF-I, EGF, their receptors and IGF binding proteins in pituitary proliferation has not yet been solved. Here we have used a semi-quantitative reverse transcription polymerase chain reaction (RT PCR) assay to demonstrate the changes in IGF-I mRNA and EGF mRNA abundance in the proliferating male rat pituitary in response to estradiol benzoate (EB; 1 mg/kg b.w. twice weekly i.m. for 3 weeks) and modifying effect of drugs antagonizing the pituitary enlargement - antiestrogen tamoxifen (TAM, 5 mg/kg b.w. daily) and also the dopaminergic agonist terguride (TER, 0.66 mg/kg b.w. daily, routinely used for the treatment of prolactinomas). In three separate experiments, EB induced a 2.2-2.5 fold increase in pituitary weight. The abundance of IGF-I and EGF mRNAs in pituitaries of EB-treated animals did not differ from the controls in two experiments and in the third series with the most marked pituitary hyperplasia mRNAs of both growth factors were even significantly decreased. Antiestrogen TAM administered with EB partially blocked the EB-induced proliferation and significantly stimulated IGF-I mRNA (p=0.003) and EGF mRNA (p=0.023) expression, while EB or TAM alone did not stimulate mRNAs of the studied growth factors. Significant antiproliferative effect of dopaminergic agonist TER on EB-induced pituitary proliferation (p=0.006) was accompanied with decreased IGF-I mRNA (p=0.025), but not EGF mRNA abundance. Our results suggest that the estrogen-induced pituitary proliferation is independent of the local expression of IGF-I and EGF mRNAs.

Topics: Animals; Dopamine Agonists; Epidermal Growth Factor; Estradiol; Estrogen Antagonists; Gene Expression Regulation; Hyperplasia; Insulin-Like Growth Factor I; Lisuride; Male; Organ Size; Pituitary Gland; Rats; Rats, Wistar; RNA, Messenger; Tamoxifen

To determine the effect of systemic treatment with epidermal growth factor (EGF) on the induction of growth in the urinary tract.. Mature Goettingen minipigs were treated daily with vehicle (Tris-HCl; n = 5) or EGF (30 micrograms/kg) (n = 6) for 4 weeks. The total number of smooth muscle cells was counted using an optical disector in a 20 microns thick cross-section of the ureter and the mean smooth muscle cell volume estimated. Cell proliferation was detected by immunostaining for the marker Ki67.. The ureters of the animals treated with EGF were longer and thicker than those of the controls and the median cross-sectional area of the ureter was 3.3-fold larger; the growth involved all wall layers. The median (range) number of smooth muscle cells in a 20 microns thick cross-section of the ureter was 11 (9-12) x 10(3) in the pigs treated with placebo and 55 (19-80) x 10(3) in those treated with EGF, and the median (range) volume of the smooth muscle cells was 2.3 (2.2-2.4) x 10(3) and 4.0 (3.0-4.5) x 10(3) mm3, respectively.. There were two likely mechanisms contributing to smooth muscle cell hyperplasia, the division of fully differentiated smooth muscle cells and division of fibroblasts in the borderline between the submucosal layer and muscular coat, with ensuing differentiation into smooth muscle cells. Treatment with EGF induces the growth of all wall layers in the urinary tract with remarkable hyperplastic and hypertrophic changes of the smooth muscle cells in the muscular coat.

Topics: Actins; Animals; Epidermal Growth Factor; Hyperplasia; Hypertrophy; Immunohistochemistry; Muscle, Smooth; Swine; Swine, Miniature; Urinary Tract

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

The ability was investigated of epidermal growth factor (EGF) and hepatocyte growth factor (HGF) to stimulate DNA synthesis in hepatocytes isolated from C57B1/6J mice following 1, 3, 7, 30 and 90 days pre-treatment with the hepatomegalic drug, phenobarbitone (PB). A 3-fold increase in S-phase labelled hepatocytes was observed in the absence of growth factors after 3 days treatment with PB, which was not seen at other investigated time points. This suggests that the proliferative influence present in vivo at this time interval is maintained in the ex vivo model. Maximum labelling indices of > 5-fold the unstimulated control value were observed in hepatocytes isolated from control and 1 day PB pre-treated mice when cultured in the presence of 5 or 10 ng/ml EGF or HGF. Hepatocytes isolated from 3, 7, 30 or 90 day treated mice showed a considerably reduced responsiveness to growth factors; maximum labelling indices did not exceed by a factor of 2 the value obtained in the absence of growth factors. However, the apparent decrease in responsiveness to growth factors in hepatocytes isolated from 3 day pre-treated mice was due to an increased background level of proliferation and the attainment of a 'ceiling level' of DNA synthesis at approx. 35%. DNA synthesis was not further enhanced by addition of both EGF and HGF. This maximal level of stimulation may indicate that only a specific hepatocyte sub-population is capable of responding to growth factors under the conditions employed. The loss in sensitivity to mitogenic stimuli after 7 days PB pre-treatment correlates with a reported decrease in receptor protein and mRNA levels in rats and coincides with the in vivo shift from hyperplasia to hypertrophy.

Topics: Animals; Cell Division; Cell Separation; Cells, Cultured; DNA Replication; Drug Synergism; Epidermal Growth Factor; Growth Substances; Hepatocyte Growth Factor; Hyperplasia; Liver; Male; Mice; Mice, Inbred C57BL; Phenobarbital; Time Factors

The rat treated with bile duct ligation (BDL) and furan is a unique animal model of massive bile ductular hyperplasia in which normal liver parenchyma is largely replaced with well-differentiated proliferated bile ductules. We have now developed a simple cell isolation procedure to obtain and culture viable bile ductular epithelial cells in high numbers and with a high degree of purity from the livers of BDL/furan-treated rats. Primary monolayer cell cultures were readily established when the isolated bile ductular epithelial cells were cultured in plastic tissue culture wells coated with rat tail tendon type I collagen plus bovine plasma fibronectin. Under these conditions, epidermal growth factor (EGF) was mitogenic for the cultured cells, and they retained phenotypic features typical of hyperplastic bile ductular epithelium but did not show evidence of ductal morphogenesis in vitro. In contrast, when the isolated bile ductular cells were cultured for 7 to 16 days in the presence of 25 ng EGF/mL and 10% fetal bovine serum on type I collagen gels, they formed into branching ductal structures whose ultrastructural features very closely resembled those of polarized hyperplastic bile ductules/ducts in vivo. Histological preparations of these gel cultures further showed that numerous ductal structures with defined lumens were present. Phenotypically, these ductal structures were completely surrounded by a thickened basement membrane that was strongly immunoreactive for laminin. Like their in vivo biliary cell counterparts, the epithelial cells comprising these ductal structures in culture also exhibited strong immunocytochemical staining reactions for cytokeratins 8 and 19, for glutathione S-transferase pi 7, and for luminal gamma-glutamyl transpeptidase, but they did not express immunoreactive albumin or alpha-fetoprotein. Occasional epithelial cells of the ductal structures, when examined in 10-day-old primary gel culture, showed strong nuclear staining for incorporated 5-bromo-2'deoxyuridine, indicating active cell proliferation. Our results support the development of a novel biliary epithelial cell culture model that has the potential of serving as a powerful tool for investigation of factors that regulate hyperplastic bile ductular morphogenesis, cell proliferation, and polarized cell functions in a structural form in vitro that mimics that of hyperplastic bile ductules induced in vivo.

Topics: Animals; Bile Ducts; Biomarkers; Cattle; Cell Culture Techniques; Cell Division; Cell Nucleus; Cell Polarity; Cell Separation; Cells, Cultured; Collagen; Epidermal Growth Factor; Epithelial Cells; Epithelium; Fibronectins; gamma-Glutamyltransferase; Glutathione Transferase; Hyperplasia; Immunohistochemistry; Keratins; Laminin; Liver; Male; Models, Biological; Rats; Rats, Inbred F344; Time Factors

Chronic metabolic acidosis induces both hyperplastic and hypertrophic renal growth and is associated with progressive loss of renal function. These studies examine the direct effect of media acidification on the growth of rabbit proximal tubule cells in primary culture. The results demonstrate that media acidification has a direct antiproliferative (hypoplastic) effect on both quiescent and mitogen-stimulated [epidermal growth factor (EGF)-stimulated] cells and does not induce hypertrophy. This direct antiproliferative effect of acid is associated with inhibition of EGF-induced phosphorylation of the retinoblastoma protein (pRB), which maintains pRB activity and inhibits cell cycle progression from G1 to S phase. Transforming growth factor-beta (TGF-beta) alone has an antiproliferative effect in these cells. TGF-beta converts EGF-induced hyperplasia to hypertrophy and inhibits EGF-induced pRB phosphorylation. Media acidification inhibits both the antiproliferative effect of TGF-beta and the ability of TGF-beta to convert EGF-induced hyperplasia to hypertrophy. This activity is associated with inhibition of TGF-beta-mediated retention of pRB in the active, hypophosphorylated state. These results demonstrate that metabolic acidosis has a direct growth-suppressive effect on renal epithelial cells but inhibits the growth-suppressive effects of TGF-beta. Inhibition of the antiproliferative effect of cytokines, such as TGF-beta, may be responsible for acidosis-induced hyperplasia in vivo.

Topics: Animals; Cell Division; Cells, Cultured; Culture Media; Epidermal Growth Factor; Growth Inhibitors; Hydrogen-Ion Concentration; Hyperplasia; Hypertrophy; Kidney Tubules, Proximal; Phosphorylation; Rabbits; Retinoblastoma Protein; Transforming Growth Factor beta

The recent conjugation of the potent ribosome-inactivating protein saporin (SAP) with basic fibroblast growth factor (FGF2) to form recombinant (r)FGF2-SAP permits increased selectivity of this mitoxin for cells exhibiting upregulated FGF receptors. Systemic administration of rFGF-SAP in therapeutic doses, however, may be associated with significant liver toxicity. In this blinded study, we used a local boundary layer infusion approach to increase local drug concentration while minimizing the risk of side effects. Six dogs underwent bilateral carotid endarterectomies. Expanded polytetrafluoroethylene infusion devices, blindly primed with rFGF2-SAP to one artery or vehicle to the contralateral vessel, were anastomosed proximal to the injured segments so that each animal served as its own control. rFGF2-SAP (2 microgram/kg/day) or vehicle (5 microl/hr) was continuously delivered for 14 days from an osmotic reservoir, through the wall of the graft infusion device. Euthanasia was carried out at 14 days and the processed arteries were blindly analyzed for intimal thickening and cellular proliferation. All dogs survived until sacrifice with no clinical side effects. Liver function tests at euthanasia were not significantly altered when compared to baseline values. Intimal area in rFGF2-SAP-treated vessels averaged 0.31 +/- 0.10 mm2 versus 0.57 +/- 0.24 mm2 in the control segments (P = 0.02), a relative reduction of 46%. Cell proliferation, however, was not significantly different at 14 days postendarterectomy (2.40 +/- 1.31% vs 2.39 +/- 0.45%). From this study it can be concluded that locally delivered rFGF2-SAP reduces intimal hyperplasia and that the boundary layer infusion strategy is an effective means for delivering high local drug concentration while minimizing systemic drug effects.

Topics: Amino Acid Sequence; Animals; Antibody Formation; Cell Division; Dogs; Epidermal Growth Factor; Hyperplasia; Immunotoxins; Male; Molecular Sequence Data; Muscle, Smooth, Vascular; N-Glycosyl Hydrolases; Plant Proteins; Recombinant Proteins; Ribosome Inactivating Proteins, Type 1; Saporins

In this study, we determined in vivo morphologic effects of continuous intravenous infusion of recombinant human epidermal growth factor (EGF) in adult Wistar rats. The EGF used consisted of the amino acid residues 1-48 of the human 53-amino-acid EGF molecule, purified from transfected Escherichia coli. Doses of 25, 100, or 250 micrograms/kg body weight were administered using Harvard digital syringe infusion pumps for 4 weeks. At necropsy, the submandibular salivary glands, Harderian glands, liver, kidneys (females only), and ovaries were enlarged and urinary bladders were thickened in 100- and 250-micrograms/kg rats. Numerous tissues of the 100- and 250-micrograms/kg rats contained hyperplastic epithelial cells, and selected organs also had mesenchymal cell proliferation. Epithelial proliferation was most pronounced in the trachea, nasal cavity, nasolacrimal duct, tongue, stomach, small intestine, large intestine, urinary tract, salivary gland ducts, and Harderian gland. Periportal hepatocytes were hypertrophic, correlating with increased liver weight. In addition, mesenchymal cell proliferation was evident in the gastric mucosa lamina propria and in heart valves in 100- and 250-micrograms/kg rats. Increased ovarian weight correlated with increased number and size of corpora lutea and an increased incidence of luteal cysts. Continuous systemic exposure of adult Wistar rats to high doses of EGF resulted in generalized epithelial hyperplasia and tissue-selective mesenchymal proliferation.

Topics: Amino Acid Sequence; Animals; Body Weight; Cell Count; Digestive System; Epidermal Growth Factor; Female; Gastrins; Humans; Hyperplasia; Infusions, Intravenous; Male; Molecular Sequence Data; Organ Size; Rats; Rats, Wistar; Recombinant Proteins; Respiratory System; Urogenital System

The expression of cripto, a member of the epidermal growth factor (EGF) family, was examined by immunohistochemistry in benign lesions and carcinomas of the gall bladder. Cripto expression was detected in 6 (67 percent) of 9 hyperplasias, 4 (58 percent) of 7 adenomas, and 89 (68 percent) of 132 adenocarcinomas of the gall bladder. The degree of cripto expression was not correlated with depth of tumour invasion, tumour stage or patient prognosis. The incidence of cases with cripto expression was significantly higher in papillary and well-differentiated adenocarcinomas (positive 73 percent; strongly positive 38 percent) than in moderately and poorly differentiated adenocarcinomas (positive 54 percent; strongly positive 17 percent) (P < 0.05). These results suggest that cripto expression may not relate to progression in gall bladder carcinomas, but may be associated with tumour differentiation.

Topics: Adenocarcinoma; Adenoma; Epidermal Growth Factor; Gallbladder; Gallbladder Neoplasms; Gene Amplification; Gene Rearrangement; GPI-Linked Proteins; Humans; Hyperplasia; Immunohistochemistry; Intercellular Signaling Peptides and Proteins; Membrane Glycoproteins; Neoplasm Proteins

The topical application of recombinant growth factors such as epidermal growth factor, platelet-derived growth factor-BB homodimer (rPDGF-BB), keratinocyte growth factor (rKGF), and neu differentiation factor has resulted in significant acceleration of healing in several animal models of wound repair. In this study, we established highly reproducible and quantifiable full and deep partial thickness porcine burn models in which burns were escharectomized 4 or 5 days postburn and covered with an occlusive dressing to replicate the standard treatment in human burn patients. We then applied these growth factors to assess their efficacy on several parameters of wound repair: extracellular matrix and granulation tissue production, percent reepithelialization, and new epithelial area. In full thickness burns, only rPDGF-BB and the combination of rPDGF-BB and rKGF induced significant changes in burn repair. rPDGF-BB induced marked extracellular matrix and granulation tissue production (P = 0.013) such that the burn defect was filled within several days of escharectomy, but had no effect on new epithelial area or reepithelialization. The combination of rPDGF-BB and rKGF in full thickness burns resulted in a highly significant increase in extracellular matrix and granulation tissue area (P = 0.0009) and a significant increase in new epithelial area (P = 0.007), but had no effect on reepithelialization. In deep partial thickness burns, rKGF induced the most consistent changes. Daily application of rKGF induced a highly significant increase in new epithelial area (P < 0.0001) but induced only a modest increase in reepithelialization (83.7% rKGF-treated versus 70.2% control; P = 0.016) 12 days postburn. rKGF also doubled the number of fully reepithelialized burns (P = 0.02) at 13 days postburn, at least partially because of marked stimulation of both epidermal and follicular proliferation as assessed by proliferating cell nuclear antigen expression. In situ hybridization for KGFR in porcine burns revealed strong expression of KGFR on hair follicles and basal epidermis, confirming direct rKGF action on follicular as well as epidermal keratinocytes. Although the epithelial proliferation induced by rKGF resulted in marked neoepidermal psoriasiform hyperplasia with exaggerated rete ridges and neoepidermal and follicular maturation as assessed by expression of cytokeratin 10, a marker of keratinocyte terminal differentiation was not delayed and appeared to be accelerated i

Topics: Administration, Topical; Animals; Becaplermin; Burns; Cell Division; Epidermal Growth Factor; Epithelium; Fibroblast Growth Factor 10; Fibroblast Growth Factor 7; Fibroblast Growth Factors; Glycoproteins; Growth Substances; Hyperplasia; In Situ Hybridization; Integrins; Keratinocytes; Neuregulins; Platelet-Derived Growth Factor; Proto-Oncogene Proteins c-sis; Psoriasis; Recombinant Proteins; Swine; Wound Healing

Epidermal growth factor (EGF) is present in large amounts in the urine, but the effects of systemically administered EGF on the urinary tract have not been described previously. In the present paper, we describe a potent growth induction of EGF on the urinary tract. Goettingen minipigs were treated with solvent (n = 5), EGF 30 micrograms/kg/day (n = 6) for 4 weeks, or EGF 30 micrograms/kg/day for 5 weeks followed by 3 weeks of recovery (n = 5). The ureters and bladders were examined by routine histology and electron microscopy and were immunostained for proliferating cell nuclear antigen. Four weeks of EGF treatment increased the median cross sectional area of the ureter fourfold with growth of all wall layers. The urothelium was widened from 5 cell layers in the controls to 10 in the EGF-treated animals. Proliferating cell nuclear antigen immunostaining revealed an increased mitotic activity in the basal zone of the urothelium. In the luminal zone, glycoconjugates accumulated in goblet cells, in cells with intracytoplasmic lumina, and beneath the luminal cell membrane in the umbrella cells. Our studies present a new experimental approach to growth induction of the urinary tract. The findings implicate the EGF system in regulating urothelial growth and glycoconjugate biosynthesis.

Topics: Animals; Epidermal Growth Factor; Epithelium; Female; Glycoconjugates; Humans; Hyperplasia; Injections, Subcutaneous; Male; Proliferating Cell Nuclear Antigen; Swine; Swine, Miniature; Ureter

Smooth muscle cell accumulation is a key feature of restenosis that may be inhibited by the delivery of receptor-targeted cytotoxins. DAB389EGF is a recombinant fusion protein in which the receptor-binding domain of diphtheria toxin has been replaced by human epidermal growth factor (EGF). We investigated the effectiveness of DAB389EGF to inhibit neointimal hyperplasia in the balloon-injured rat carotid artery. Incubation of rat carotid arteries with 125I-labeled EGF revealed extensive EGF binding sites in the neointima of balloon-injured arteries. Sixty rats subsequently received either saline or DAB389EGF (total dose, 0.15 mg) delivered immediately following balloon injury either systemically, via 14-day continuous osmotic pump infusion, or locally, via 30-minute intraluminal incubation. The effect of both treatment strategies was measured 2 weeks after injury by cross-sectional morphometric analysis of intimal area, the ratio of intimal/medial area (I/M), and the percent luminal narrowing (%LN). In addition, proliferative activity was assessed by immunostaining for the presence of the proliferating cell nuclear antigen (PCNA). Compared with controls, systemic delivery of fusion toxin significantly reduced intimal area, I/M, and %LN by 40%, 40%, and 29%, respectively. However, these rats exhibited 2% weight loss, indicating mild systemic toxicity. Local, intraluminal administration of DAB389EGF yielded a more pronounced reduction in intimal area, I/M, and %LN by 74%, 79%, and 72%, respectively. This inhibitory effect was preserved at 3 weeks postinjury, and PCNA immunostaining of locally treated arteries revealed a virtual absence of proliferative activity in the neointima and media at this timepoint. In contrast to systemically treated rats, rats receiving fusion toxin locally gained weight at a rate similar to controls, indicating avoidance of systemic toxicity. We conclude that DAB389EGF is a potent inhibitor of neointimal hyperplasia in vivo and that whereas an inhibitory effect may be achieved by systemic delivery, local delivery appears to be more potent, avoids systemic toxicity, and thus represents a feasible strategy to preempt restenosis.

Topics: Animals; Diphtheria Toxin; Epidermal Growth Factor; ErbB Receptors; Hyperplasia; Male; Muscle, Smooth, Vascular; Proliferating Cell Nuclear Antigen; Rats; Rats, Sprague-Dawley; Recombinant Fusion Proteins

Epidermal growth factor (EGF) is an important factor for maintaining the esophageal functional integrity. Goettingen minipigs were treated with either placebo or subcutaneous EGF (30 micrograms/kg/day) for four weeks. Wistar rats were treated with either placebo or subcutaneous EGF (150 micrograms/kg/day) for four weeks. At sacrifice, esophageal samples were obtained for histology, immunochemistry, and lectin characterization. In pigs, the thickness of the esophageal epithelium was almost doubled in the EGF-treated animals. Characterization with lectins revealed a normal pattern of differentiation. Subcutaneously administered EGF was visualized on cells located basally in the esophageal epithelium. In rats, EGF-treatment increased the esophageal volume of the epithelium, the lamina propria of the mucosa, and the submucosa. In conclusion, systemic EGF challenge induces growth of the esophageal epithelium with an unaltered pattern of differentiation. This supports previous studies demonstrating a beneficial effects of systemic EGF-treatment on sclerotherapy-induced esophageal damage.

Topics: Animals; Cell Differentiation; Epidermal Growth Factor; Epithelium; Esophagus; Female; Hyperplasia; Lectins; Male; Rats; Rats, Wistar; Swine; Swine, Miniature; Time Factors

Epidermal growth factor (EGF) receptor hyperstimulation induced by systemically administered EGF or by the development of transgenic mice overexpressing transforming growth factor alpha (TGF alpha) or other EGF-related ligands is known to induce various effects, such as acceleration of developmental processes like incisor eruption, inhibition of gastric acid secretion, morphologic changes in the pancreas resembling pancreatitis, and malignancies in mammary glands and the liver. The present investigation was initiated to explore the effects of systemic EGF administration to the mature organism in a species with greater anatomic resemblance to humans than rodents.. Eleven Goettingen Minipigs underwent 4 weeks of treatment either with placebo (n = 5) or human recombinant EGF 30 micrograms/kg/day (n = 6) administered subcutaneously. At the end of Week 4, the animals were sacrificed, autopsy was performed, and tissue samples were collected for histologic examination.. EGF treatment caused macroscopic enlargement of the ureters, kidney, and heart. The ureters increased 4-fold in cross sectional area due to growth of all wall layers. The urothelium was hyperplastic with intracellular accumulations of material staining with Periodic acid-Schiff. Similar but less pronounced changes were found in the pancreas, lungs, salivary glands and esophagus.. The most important observation of the present study is that systemic treatment with EGF for 4 weeks induces considerable growth to the urinary tract. We suggest new biologic effects of the EGF family in promoting growth of the urinary tract and in stimulating epithelial glycoconjugate biosynthesis in the urothelium and excretory ducts of the pancreas.

Topics: Animals; Digestive System; Epidermal Growth Factor; Female; Glycoconjugates; Hyperplasia; Lung; Male; Pancreas; Salivary Glands; Swine; Urinary Tract

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

Little is known about the impact of acute proximal tubular injury and dysfunction on the distal nephron.. Selective necrosis of the kidney proximal convoluted tubule (PCT) was induced in rats by subcutaneous injection of the aminoglycoside gentamicin during 2 days. Damage and repair were measured until complete morphologic recovery after 10 days. Special attention was given to structural and biochemical alterations in the distal nephron.. In control animals, cellular turnover, measured by immunohistochemical staining for proliferating cell nuclear antigen, was higher in distal than in proximal tubules. After injury, the strongly increased cell proliferation in regenerating necrotic PCT was preceded by an equally important proliferation in the distal tubules of the cortex and outer stripe of the outer medulla in the absence of necrosis but displaying enhanced apoptosis. Yet, epithelial vimentin expression was restricted to regenerating PCT. A temporary loss in the amount of immunostainable epidermal growth factor in the distal nephron was paralleled by a similar reduction in Tamm- Horsfall protein and transferrin receptor staining and in peanut and Helix pomatia lectin binding. Furthermore, the epithelial area/nucleus in the cortical distal tubules was increased by 71%, 6 days after the onset of acute renal failure; this hypertrophic condition was confirmed ultrastructurally. After full recovery of the PCT, a second burst in proliferative activity occurred in the hypertrophic distal segments in the absence of apoptosis. In the regenerated PCT, an excess cell number was accompanied by increased apoptotic activity.. Development of distal tubular hypertrophy after PCT necrosis may be a compensatory response to a transient loss of proximal tubular function. The early reduction in staining for epidermal growth factor and other distal tubular markers in the presence of apoptosis and hyperplasia indicates transient phenotypic simplification and implies that renal epidermal growth factor is unlikely to control PCT regeneration.

Topics: Animals; Apoptosis; Cell Division; Epidermal Growth Factor; Female; Gentamicins; Hyperplasia; Hypertrophy; Immunoenzyme Techniques; Kidney Tubules, Distal; Kidney Tubules, Proximal; Membrane Glycoproteins; Mucoproteins; Nuclear Proteins; Proliferating Cell Nuclear Antigen; Rats; Rats, Wistar; Receptors, Transferrin; Uromodulin; Vimentin

A transgenic mouse line (EGF/Tag) has been established in which expression of SV40 T-antigen is directed by a 5.5 kb fragment of the 5'-flanking region of the mouse epidermal growth factor (EGF) gene. Of the two principal sites of EGF expression in mice, submaxillary gland and kidney, T-antigen mRNA and protein were detected in the former but not in the latter tissue of the EGF/Tag animals. T-antigen expression in the submaxillary gland was restricted to the EGF-producing cells of the granular convoluted tubules, and the oncoprotein induced hyperplasia of these cells. T-antigen levels were markedly higher in the submaxillary glands of male compared with female transgenic mice, suggesting that expression of the transgene was androgen-regulated, like the endogenous EGF gene. These results indicate that the 5.5 kb fragment upstream of the mouse EGF gene contains the DNA enhancer elements required for hormonally regulated expression in the submaxillary gland. Since the hyperplastic submaxillary glands of the EGF/Tag mice continue to synthesize EGF, these glands provide a tissue source from which it may prove possible to establish EGF-secreting cell lines for further in vitro studies of the mechanisms regulating expression of the EGF gene.

Topics: Androgens; Animals; Antigens, Polyomavirus Transforming; Enhancer Elements, Genetic; Epidermal Growth Factor; Female; Gastric Mucosa; Gene Expression Regulation; Genes, Synthetic; Hyperplasia; Male; Mice; Mice, Transgenic; Organ Specificity; Promoter Regions, Genetic; Prostate; Recombinant Fusion Proteins; Submandibular Gland

Epidermal growth factor (EGF) was administered by chronic subcutaneous or intracolonic infusion into normal adult rats to determine the effect on colonic growth. Subcutaneous infusion of 200 micrograms EGF/kg/day for 7 days increased the cross-sectional mass and protein content of the muscularis and mucosal layers of the proximal colon, with the distal colon showing less response. In the mucosa, subcutaneous EGF induced proportional increments in the number of cells per crypt, and in the number of cells positively labelled for PCNA, while maintaining a normal crypt growth fraction. In contrast, an 8-fold higher dose of EGF administered intraluminally had no effect on colonic mucosal or muscularis growth. This lack of bioactivity was unlikely to reflect rapid luminal degradation as radiolabelled EGF remained stable in the colonic lumen for at least 4 h. The results demonstrate that the normal adult colon is responsive to subcutaneously delivered EGF, particularly the proximal colon, whereas EGF may not be active on the normal colon when presented from the luminal direction.

Topics: Animals; Colon; Drug Administration Routes; Epidermal Growth Factor; Hyperplasia; Hypertrophy; Infusions, Parenteral; Intestinal Mucosa; Male; Muscle, Smooth; Organ Size; Rats; Rats, Sprague-Dawley; Recombinant Proteins

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

Hyperplastic polyps are common benign lesions of uncertain histogenesis, which occur in the colon in populations at risk for colorectal carcinoma. They contain neutral/MUC1 gene-related mucin which in turn is closely associated with the trefoil-peptide pS2, a major component of the ulcer-associated cell lineage, previously termed pseudopyloric metaplasia. We have examined 17 hyperplastic polyps for expression of the trefoil-peptides pS2 and human spasmolytic polypeptide by in situ hybridization and immunohistochemistry, as well as by using antisera to epidermal growth factor/urogastrone and its receptor and to epitopes of the product of the MUC1 gene to characterize any further similarity between these lesions and the ulcer-associated cell lineage and thus help elucidate the nature of the lesions. Our investigations show both human spasmolytic polypeptide and pS2 messenger RNA within the polyps, whereas only pS2 peptide could be demonstrated immunohistochemically. Epidermal growth factor/urogastrone, its receptor, and antisera to the MUC1 gene also showed widespread staining of these polyps. We suggest that hyperplastic polyps are formed of a lineage that both synthesizes and secretes trefoil-peptides and the MUC1 mucin and that hyperplastic polyps may be related to the phenotypically similar ulceration-associated cell lineage.

Topics: Cell Line; Colonic Polyps; Epidermal Growth Factor; ErbB Receptors; Humans; Hyperplasia; Immunohistochemistry; In Situ Hybridization; Intercellular Signaling Peptides and Proteins; Membrane Glycoproteins; Mucin-1; Mucins; Muscle Proteins; Neoplasm Proteins; Neuropeptides; Peptic Ulcer; Peptides; Phenotype; Proteins; RNA, Messenger; Staining and Labeling; Tissue Distribution; Trefoil Factor-1; Trefoil Factor-2; Trefoil Factor-3; Tumor Suppressor Proteins

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 time course for the increases in soluble renal epidermal growth factor (EGF) after ischemia has been established. These elevated levels of EGF have been compared with the degree of tissue injury as well as the extent of cell proliferation in the recovering tissue. Levels of soluble immunoreactive EGF (irEGF) in control animals were 9.74 +/- 1.1 ng/g wet wt (n = 4-8 for all values) and rose to 83.9 +/- 30 ng/g within 12 h after injury. Soluble irEGF content peaked at 88.8 +/- 15 ng/g at 24 h postinjury and returned to control values by 72 h. We previously reported that trypsin digestion of crude renal membranes (CRM) generates rat EGF that is indistinguishable from that isolated from the submandibular gland. Initial levels of trypsin-releasable membrane-associated irEGF were 439 +/- 26 ng/g. These levels fell to 46.6 +/- 9.6 ng/g at 48 h after injury. The total renal EGF demonstrated an 80% decline 48 h after injury but returned to 50% of the initial values after 72 h representing significant new synthesis of EGF-containing proteins between 48 and 72 h postinjury. Immunohistochemical staining of kidney paraffin sections for EGF immunoreactivity demonstrated staining intensities that paralleled the amount of irEGF in the trypsin-digested CRM fraction, suggesting that the membrane-associated irEGF is the predominant form detected by this technique. Regenerative hyperplasia subsequent to tubular insult was monitored by immunostaining nuclei of S phase cells after pulse labeling with the thymidine analogue 5-bromo-2'-deoxyuridine. Cell proliferation was particularly prominent in the outer stripe of outer medulla of kidneys exposed to ischemia and reached a maximum (19-fold higher than the baseline value) 48 h after reperfusion. Renal cell turnover returned to control values by day 7. The observation that the peak in soluble EGF levels (24 h) precedes the peak in tubular regeneration (48 h) by 24 h is consistent with the hypothesis that EGF is one of the mitogenic signals triggering regenerative hyperplasia after renal injury.

Topics: Acute Kidney Injury; Animals; Epidermal Growth Factor; Hyperplasia; Immunohistochemistry; Ischemia; Kidney; Kidney Tubules; Male; Necrosis; Rats; Rats, Sprague-Dawley; Regeneration; Renal Circulation

The effects of removal of the submandibular gland (sialoadenectomy) and administration of human urinary epidermal growth factor on the 9,10-dimethyl-1,2-benzanthracene-induced tumor formation were investigated with the use of a hamster cheek pouch model. Syrian hamsters were treated with 0.5% 9,10-dimethyl-1,2-benzanthracene for 6 weeks. Thereafter hamsters in group 1 underwent a sham operation and those in groups 2 and 3 underwent a sialoadenectomy. Subsequently, hamsters in groups 1 and 2 were given 0.9% sodium chloride and group 3 received the human urinary epidermal growth factor at a dose of 0.25 mg/kg body weight subcutaneously three times a week for 8 weeks. Sixteen weeks after the start of the experiment, the mean number of tumors that were less than 3-mm in diameter in groups 1 and 3 was significantly greater than that in group 2 (p < 0.05). The overall incidence and mean number of all carcinomas irrespective of size showed no differences among the experimental groups. These results indicate that epidermal growth factor synthesized in the submandibular gland may enhance the induction of cheek pouch tumor.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Carcinogens; Carcinoma, Squamous Cell; Cricetinae; Epidermal Growth Factor; Hyperplasia; Male; Mesocricetus; Mouth Neoplasms; Papilloma; Submandibular Gland

Salivary mesenchyme is a potent stimulator of mammary epithelial hyperplasia and carcinogen-induced tumor formation in vivo. We have utilized a three-dimensional collagen gel culture system, which mimics the in vivo growth environment, to identify growth stimulatory molecules produced by salivary mesenchyme cells. In this report we describe the development and characteristics of salivary mesenchyme cell lines, and we present further evidence that these cells produce growth factor(s) which could account for the effect by interacting with epidermal growth factor (EGF) receptors on primary mouse mammary epithelial cells isolated from midpregnant mice. Using a receptor assay with isolated cell membranes, we characterized [125I]-EGF binding to mammary epithelial cells cultured within collagen gels. Scatchard analysis revealed one class of high affinity EGF receptors with a Kd ranging from 8.3 x 10(-11) M on day one to 5.1 x 10(-11) M on day 10 of the culture period. Addition of 10 ng/ml purified EGF to the culture medium progressively up-regulated the expression of EGF receptors during a 10-day culture period. Scatchard analysis showed that the increase in specific [125I]-EGF binding was due predominantly to an increase in EGF receptor number. We also demonstrated that conditioned medium collected from salivary mesenchyme cells competed effectively for EGF receptor sites on mammary epithelial cells, and chronic exposure to conditioned medium up-regulated EGF receptor expression. Thus, EGF-related growth factor(s) released by salivary mesenchyme cells may induce hyperplasia of adjacent mammary epithelium in vivo, both by directly activating EGF receptors, and by provoking long term up-regulation of EGF receptors.

Topics: Animals; Cells, Cultured; Collagen; Culture Media, Conditioned; Epidermal Growth Factor; Epithelium; ErbB Receptors; Gels; Hyperplasia; Mammary Glands, Animal; Mesoderm; Mice; Salivary Glands; Up-Regulation

This study was undertaken to investigate the effect of epidermal growth factor (EGF) on the rat small intestinal mucosa by three different routes of administration. Four-week-old rats were fed elemental diet for 4 weeks and were administered EGF either subcutaneously, intraluminally or intraperitoneally with mini-osmotic pumps for a week. Intraperitoneal administration of EGF resulted in a significant increase of mucosal wet weight, mucosal content of protein and DNA, villus height, crypt depth and crypt cell production rate. Intraluminal or subcutaneous administration of EGF tended to increase those morphological and proliferative parameters, but did not cause any significant change. We conclude that EGF caused the hyperplasia of the small intestine of rats maintained on oral elemental diet and that this trophic effect was clearly shown by the intraperitoneal route of administration, rather than by the intraluminal route. These results suggest that EGF receptors located in the basal portion of crypt cells play a more important role than those located in the microvillous membrane.

Topics: Amine Oxidase (Copper-Containing); Animals; Epidermal Growth Factor; ErbB Receptors; Food, Formulated; Hyperplasia; Ileum; Infusions, Parenteral; Injections, Intraperitoneal; Injections, Subcutaneous; Intestinal Mucosa; Jejunum; Male; Ornithine Decarboxylase; Rats; Rats, Wistar

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

Administration of the autonomic antagonists atropine (1 mg/kg body wt), propranolol (2 mg/kg body wt), and phenoxybenzamine (2 mg/kg body wt) before the dietary change from all liquid to solid chow prevented an increase in uptake of [3H]thymidine into DNA of rat parotid gland associated with this dietary change. Administration of either the cholinergic antagonist alone or the adrenergic antagonists alone produced partial inhibition. The effects of complete autonomic blockade were not reversed when nerve growth factor (NGF) or epidermal growth factor (EGF) was given immediately after administration of antagonists. The effects of complete autonomic blockade were similar to those seen with surgical removal of the autonomic nerves to the parotid. The increased levels of beta 1-4-galactosyltransferase seen with the dietary change were not evident in rats given both muscarinic and adrenergic antagonists before the change to solid food nor did NGF or EGF reverse these inhibitory effects. Histological observation showed that the surgically denervated gland was morphologically less homogenous than the gland of rats given the antagonists and had infiltrating connective tissue. Nonetheless, with the reduced acinar cell pool, the [3H]thymidine uptake of the denervated parotid and that of antagonist-injected animals was similar.

Topics: Animals; Atropine; Autonomic Nervous System; Denervation; Diet; Epidermal Growth Factor; Female; Hyperplasia; N-Acetyllactosamine Synthase; Nerve Growth Factors; Parotid Gland; Phenoxybenzamine; Propranolol; Rats; Thymidine

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

The effect of anti-epidermal growth factor (EGF) antibody on the compensatory renal growth including hyperplasia and hypertrophy was investigated. The antibody used in this study blocked the stimulatory effect of EGF on the DNA synthesis of cultured rat hepatocytes. When this antibody was injected into mice intravenously after unilateral nephrectomy, the labeling index of the renal cortical tubular cells decreased significantly at the second day after uninephrectomy, but the antibody caused no decrease in remaining kidney weight. Immunohistochemical study revealed that injected anti-mouse EGF rabbit IgG was positively stained at the renal cortical tubular cells. EGF would thus appear importantly essential to compensatory renal hyperplasia.

Topics: Animals; Antibodies; Cell Division; Cells, Cultured; DNA; Epidermal Growth Factor; Hyperplasia; Hypertrophy; Immunization, Passive; Immunohistochemistry; Kidney; Liver; Male; Mice; Nephrectomy; Organ Size; Rats

Chronic injections of epidermal growth factor (EGF) or the beta-adrenergic receptor agonist isoprenaline resulted in rat parotid gland hypertrophy and hyperplasia. Introduction of a polyclonal antibody to EGF or the EGF-receptor (EGF-R) caused a specific retardation of acinar cell proliferation when injected along with the growth factor. Meanwhile, only the antibody to EGF-R caused a dose-dependent retardation of proliferation on co-administration with isoprenaline both in vivo and in vitro. The antibody injected alone had no effect on cell growth. When cells were incubated in the presence of EGF, plasma membranes from isoprenaline-treated and control animals showed phosphorylation of the EGF-R tyrosine moieties and transient increases in membrane-associated phospholipase C gamma. Isoprenaline did not stimulate phosphorylation of the EGF-R in isolated plasma membranes. However, activation of the phosphotyrosine-signalling pathway could be duplicated by incubating isoprenaline-treated acinar cells, but not control cells, with bovine galactosyltransferase. Immunopurified EGF-R demonstrated variations in reactivity with two different lectins after treatment of the cells with the beta-agonist as well as increased galactosyltransferase substrate capacity in vitro. In addition, incubation of intact acinar cells and isolated plasma-membrane fractions from isoprenaline-treated rats with UDP-[14C]galactose resulted in an increased incorporation of label into the EGF-R. The results suggest that the carbohydrate moiety of the EGF-R has been altered in isoprenaline-treated animals allowing galactosyltransferase now to recognize this receptor. This interaction may in part mediate proliferation of parotid acinar cells. Indeed, we have previously shown that an antibody to galactosyltransferase is capable of blocking isoprenaline-mediated acinar cell proliferation in vivo [Humphreys-Beher, Schneyer, Kidd & Marchase (1987) J. Biol. Chem. 262, 11706-11713].

Topics: Animals; Antibodies; Antibodies, Monoclonal; Cell Division; Cell Line; Cell Membrane; DNA Replication; Electrophoresis, Polyacrylamide Gel; Epidermal Growth Factor; ErbB Receptors; Female; Galactosyltransferases; Humans; Hyperplasia; Hypertrophy; Immunoblotting; Isoproterenol; Membrane Glycoproteins; Models, Biological; Molecular Weight; Parotid Gland; Rats; Rats, Inbred Strains; Uridine Diphosphate Galactose

epsilon(gamma-Glutamyl)lysine isodipeptide, the end-product of proteolytic digestion of proteins cross-linked by transglutaminase, was detected in culture fluid of neonatal rat hepatocytes and plasma of adult rats. The concentration of the isodipeptide was significantly increased in both when high rate of apoptosis with phagocytosis of dying hepatocytes was produced either by epidermal growth factor in the culture or by lead nitrate-induced hyperplasia with subsequent involution in rats. Specific induction of tissue transglutaminase and the consequent formation of highly cross-linked protein envelopes in apoptotic cells have been previously demonstrated by us in both systems.

Topics: Animals; Animals, Newborn; Cell Survival; Cells, Cultured; Dipeptides; Epidermal Growth Factor; Hyperplasia; Lead; Liver; Male; Nitrates; Phagocytosis; Rats; Rats, Inbred Strains; Transglutaminases

We previously demonstrated that the specific component of rat urine designated as Fraction I (Fr.I), which has been known to enhance carcinogenesis in the rat urinary bladder, contains epidermal growth factor (EGF) and transferrin (TF). The present study was designed to determine whether EGF or TF is responsible for the tumor-enhancing effect of Fr.I. The heterotopically transplanted rat urinary bladder (HTB), which has been developed in our laboratory, was used for the study. Fr.I was prepared from normal rat urine by a method published previously. Fr.I deficient in EGF or TF was prepared by passing this fraction through an Affi-Gel Hz column coupled with anti-rat EGF or TF antibodies, respectively. EGF and TF eluted from the column (designated as eluted EGF and eluted TF) were also tested for tumor-enhancing activity. Fr.I passed through the column coupled with nonimmune rabbit IgG served as control (Fr.I column control). After initiation of carcinogenesis in HTBs by instillation of a single dose of 0.25 mg of N-methyl-N-nitrosourea, test materials were administered into these HTBs once a week for 30 weeks. The results showed that removal of EGF significantly reduced the tumor-enhancing effect of Fr.I (P less than 0.001 as compared to that of the Fr.I column control) and that eluted EGF by itself significantly enhanced the carcinogenesis as compared to that of the vehicle control (P less than 0.006). Removal of TF from Fr.I also reduced the tumor-enhancing effect of Fr.I (P less than 0.01). However, removal of both EGF and TF from Fr.I did not enhance the inhibitory effect demonstrated by the Fr.I which was deficient in EGF. Likewise, combined use of TF and EGF did not exceed the tumor-promoting effect of EGF. The results indicate that EGF in Fr.I may play a significant role in the promotion of bladder carcinogenesis by urine.

Topics: Animals; Carcinoma, Transitional Cell; Drug Synergism; Epidermal Growth Factor; Hyperplasia; Male; Rats; Rats, Inbred F344; Transferrin; Urinary Bladder; Urinary Bladder Neoplasms

This report describes the development of hyperplasia of both the thymus and the peripheral T-cell system with advancing age in the Buffalo rat. Buffalo/Mna rats do not show age-related thymic involution, but rather develop thymic hyperplasia with advancing age. This thymic growth is expansile and there is no infiltration of the surrounding tissues. Because the enlarging thymus occupies the thoracic cavity, most of the rats die of respiratory failure by the age of 24 months. Thymic enlargement is due to primary hyperplasia of cortical epithelial cells and the large number of proliferating lymphocytes. The hyperplastic epithelial cells are bizarre in shape and strongly positive when stained with Th-3 monoclonal antibody (MoAb), anti-thymosin antibody and anti-EGF antibody, but negative with Th-4 MoAb. The patterns of distribution of CD-5+, CD-4+ and CD-8+ lymphocytes within the hyperplastic thymus are similar to those seen in young rats of other species. The high level of T-cell emigration from the thymus to the periphery appears to persist throughout life, since the percentage of normal splenic T-cells also increase with advancing age and exceed 70% of the total by 24 months of age. This thymic enlargement with abnormal hyperplasia of cortical epithelial cells can be prevented by hypophysectomy.

Topics: Aging; Animals; Antibodies, Monoclonal; Epidermal Growth Factor; Epithelium; Female; Hyperplasia; Immunologic Techniques; Leukocyte Count; Male; Organ Size; Rats; Rats, Inbred BUF; Rats, Inbred Strains; Spleen; T-Lymphocytes; Thymosin; Thymus Gland

Several physiological parameters were examined for inducing acinar cell proliferation and corresponding increased expression of beta 1-4 galactosyltransferase. In this study, dietary changes causing acinar cell proliferation included the following: the introduction of animals to a liquid diet (causing gland atrophy) followed by re-introduction of solid chow, gustatory stimulation provided by the introduction of 0.5% citric acid to animal drinking water, and removal of the submandibular gland with subsequent reliance on the parotid gland for saliva protein and fluid. Alterations in growth factor levels were produced by injecting animals with a chronic (three-day) regimen of either nerve growth factor (NGF) or epidermal growth factor (EGF). In all cases of acinar cell proliferation in vivo, generated by the above treatments, cell-surface galactosyltransferase was detected along with the unique expression of a 4.5-kb proliferation-associated mRNA. Parotid gland proliferation could be blocked in all cases by the injection of the galactosyltransferase specific modifier protein, alpha-lactalbumin. Propranolol, a beta-adrenergic receptor antagonist, blocked proliferation in all cases except EGF treatment. EGF-induced proliferation could, however, be prevented if the animals were treated with monoclonal antibody to EGF receptor or with the galactosyltransferase modifier alpha-lactalbumin. As a comparison, human parotid tissue samples obtained from neoplastic pleomorphic adenomas, muco-epidermoid carcinoma, adenoid cystic carcinoma, and a bulimia patient were analyzed for galactosyltransferase expression by Northern blot of mRNA and plasma membrane isolation. Elevated levels of galactosyltransferase were found in all neoplastic tissue preparations as well as in the bulimia sample. Amylase synthesis was reduced in samples compared with surrounding normal tissue from the same patient. In vitro cell culturing of pleomorphic adenoma cells in the presence of galactosyltransferase modifier alpha-lactalbumin and substrate UDP-galactose inhibited proliferation in a dose-dependent fashion. Southern blot analysis of DNA from neoplastic parotid cells showed an alteration in chromosomal gene structure for the galactosyltransferase activator cDNA from the adenoid cystic carcinoma. These results for induced acinar cell proliferation as well as human neoplastic pathologies suggest a direct role for cell surface beta 1-4 galactosyltransferase in signaling growth. Furthermore, the

Topics: Animals; Bulimia; Cell Division; Epidermal Growth Factor; Galactosyltransferases; Humans; Hyperplasia; Hypertrophy; Lactalbumin; Membrane Proteins; Nerve Growth Factors; Parotid Gland; Parotid Neoplasms; Propranolol; Rats

The etiology of adenomas in the stomach and duodenum in patients with familial adenomatous polyposis (FAP) is unknown. In this study the plasma concentration of epidermal growth factor (EGF), and other gastrointestinal polypeptides with a possible trophic effect on the gastrointestinal mucosa, was unchanged before and after meal stimulation. In 3 of 7 patients an increased EGF immunoreactivity was found in duodenal adenomas. This study has not indicated that regulatory peptides are involved in development of duodenal polyps in FAP, but suggests further studies to determine the role of EGF in FAP.

Topics: Adenoma; Adenomatous Polyposis Coli; Adult; Duodenal Neoplasms; Epidermal Growth Factor; Female; Gastrointestinal Hormones; Humans; Hyperplasia; Intestinal Mucosa; Intestinal Polyps; Male; Middle Aged; Peptides

The in vivo effects of epidermal growth factor (EGF) on pancreatic growth and digestive enzyme concentrations were compared with the actions of the pancreatic secretagogue caerulein in the adult rat. EGF (10 micrograms/kg BW) did not alter pancreatic weight or protein content. However, this concentration of EGF inhibited [3H]thymidine incorporation into DNA by 44%, decreased DNA content by 20%, and increased the concentrations of amylase, chymotrypsinogen, and protein by 106%, 232%, and 42%, respectively. Pancreatic acini prepared from EGF-treated rats exhibited a characteristic secretory response to caerulein that was superimposable to that obtained in acini from saline-treated rats. In both groups of acini half-maximal and maximal stimulation of amylase release occurred at approximately 5 pM and 50 pM caerulein, respectively. In contrast to EGF, caerulein (1 microgram/kg BW) increased pancreatic weight by 29% and protein content by 59%, and enhanced [3H]thymidine incorporation into DNA by 70%. Although caerulein increased the concentrations of pancreatic amylase and chymotrypsinogen by 38% and 297%, respectively, pancreatic acini prepared from caerulein-treated rats were less sensitive to the actions of caerulein in vitro when compared with acini from control rats. Indeed, the EC50 was shift from 4.8 pM to 9.8 pM after 4 days of treatment. EGF potentiated the actions of caerulein on pancreatic weight, protein content, and chymotrypsinogen concentration, and prevented the caerulein-induced alteration in the secretory responsiveness of the acinar cell. Conversely, caerulein reversed the inhibitory effect of EGF on thymidine incorporation. These findings suggest that EGF may modulate the trophic effects of certain gastrointestinal hormones, and may participate in the regulation of pancreatic exocrine function in vivo.

Topics: Amylases; Animals; Cell Division; Ceruletide; Chymotrypsin; DNA Replication; Epidermal Growth Factor; Hyperplasia; Hypertrophy; Male; Organ Size; Pancreas; Rats; Rats, Inbred Strains; Reference Values

The production of EGF and EGF-like polypeptides in the normal intestinal mucosa and during 1,2-dimethylhydrazine (DMH)-induced carcinogenesis and postresection regeneration was studied in albino rats using chromatographic separation of acid-ethanol extracts. Fractions after gel filtration on Biogel P-60 with subsequent reverse-phase high performance liquid chromatography in acetonitrile gradient were tested in radioreceptor assay for competition with EGF. It has been established that intestinal tumours induced by DMH and regenerating intestinal mucosa have amplified production of EGF--alpha-TGF and related proteins of high molecular weight (approx. 30; 45-55; 120 kD) with the EGF-competitive activity. It is supposed that the high molecular weight EGF-competitive material represents nonprocessed forms of EGF and/or alpha-TGF which are accumulated in rapidly proliferating low-differentiated cells due to the intensified expression of their genes.

Topics: 1,2-Dimethylhydrazine; Animals; Carcinogens; Chromatography, High Pressure Liquid; Dimethylhydrazines; Epidermal Growth Factor; Hyperplasia; Intestinal Mucosa; Intestinal Neoplasms; Intestine, Small; Male; Methylhydrazines; Molecular Weight; Peptide Biosynthesis; Peptides; Rats; Regeneration; Time Factors

Duodenal adenomas are a frequent extracolonic manifestation in patients with familial polyposis coli (FPC). Epidermal growth factor (EGF), a polypeptide that stimulates cellular growth and differentiation, is localized in Paneth cells in the small intestine. In two patients with FPC, we found EGF immunoreactivity in duodenal adenomas. Numerous EGF immunoreactive Paneth cells were localized, not as usually, in the bottom of the crypts, but scattered along the crypts alone or in clusters. We do not know whether EGF is involved in the development of duodenal polyps in FPC patients, or whether the present findings represent secondary changes in duodenal polyps.

Topics: Adenoma; Adenomatous Polyposis Coli; Adult; Duodenal Neoplasms; Duodenum; Epidermal Growth Factor; Female; Humans; Hyperplasia; Intestinal Mucosa; Intestinal Polyps; Male; Neoplasms, Multiple Primary

Prostatic epithelium proliferates in a defined medium consisting of basal medium RPMI1640 containing transferring (1 microgram/ml), EGF (10 ng/ml), and insulin (3.7 micrograms/ml or 0.1 IU/ml). Although neither dexamethasone nor retinyl acetate affected the proliferation of prostatic epithelium in RPMI1640 containing transferrin alone, they modify the mitogenic effect of EGF and insulin. Dexamethasone at 10(-10) M or retinyl acetate at about 3 X 10(-9) M inhibits proliferation stimulated by EGF. Higher concentrations of dexamethasone (10(-8) - 10(-6) M) or retinyl acetate (3 X 10(-8) - 10(-7) M) enhance the mitogenic activity of EGF. Dexamethasone had a similar effect in the presence of insulin. However, retinyl acetate stimulated, but did not significantly inhibit, proliferation in the presence of insulin. These results suggest that both dexamethasone and retinyl acetate, and possibly other glucocorticoids and retinoids, may regulate the proliferation of prostate epithelium by a dose-dependent modification of the activity of insulin and EGF.

Topics: Aged; Cell Division; Culture Media; Dexamethasone; Diterpenes; Dose-Response Relationship, Drug; Drug Interactions; Epidermal Growth Factor; Epithelium; Humans; Hyperplasia; Insulin; Insulin Antagonists; Male; Middle Aged; Prostate; Retinyl Esters; Vitamin A

The effect of the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) and other diterpene derivatives on the binding of epidermal growth factor (EGF) to primary cultures of mouse epidermal cells was studied. 125I-EGF was used to study the specific binding of the growth factor to monolayer cultures of mouse epidermal cells grown under low-calcium culture conditions (0.06 mM Ca2+). Under these growth conditions, nonspecific binding did not exceed 10%. Initially, TPA decreased the binding of 125I-EGF to cells. However, when cells were incubated continuously in TPA plus EGF (0.25 ng/ml) for 19 hr, there was more EGF bound to the TPA-treated cells than to control cells. This phenomenon was not observed at high (5 ng/mg) EGF concentrations. Scatchard analysis of specific 125I-EGF binding at 4 degrees after a 1-hr pretreatment of the cells with TPA at 37 degrees converted a curvilinear plot to a linear plot. TPA induced a 25% decrease in the number of receptors per cell and eliminated binding of EGF to a class of high-affinity receptors. Preincubation of cells in TPA at 37 degrees for up to 13 hr followed by Scatchard analysis at 4 degrees showed that the curvilinear plot was restored and that the effects of TPA were partially reversible. TPA did not alter the rate at which bound EGF was degraded. However, at low EGF concentrations, TPA reduced the amount of EGF that was metabolized. The greater amount of EGF bound to TPA-treated cells over controls after long-term incubation was due to the presence of larger amounts of whole EGF in the media of TPA-treated cells at a time when the cells have regained their ability to bind EGF. A series of diterpene derivatives of different abilities to act as tumor promoters and hyperplasia-inducing agents were tested for their ability to influence EGF binding. The abilities of members of this series to decrease EGF binding and prevent degradation of EGF correlated more with their potentials to induce hyperplasia than with their tumor-promoting potentials. The ability of these diterpene derivatives to induced DNA synthesis with EGF synergistically may depend on the transient sparing of the EGF from degradation and subsequent binding of the spared EGF.

Topics: Animals; Calcium; Cells, Cultured; Epidermal Growth Factor; Hyperplasia; Mice; Peptides; Phorbol Esters; Phorbols; Skin; Temperature; Tetradecanoylphorbol Acetate

Topics: Animals; Epidermal Growth Factor; Hyperplasia; Hypertrophy; Incisor; Isoproterenol; Mice; Peptides; Submandibular Gland; Tooth Extraction