epidermal-growth-factor and Myoepithelioma

During tumor development, benign neoplastic cells are influenced by the expression of cytokines, growth factors, and proteases present in the tumor microenvironment. Epidermal growth factor (EGF) is the most studied growth factor and is considered important for cell proliferation and migration. Metalloproteinases (MMPs) are also involved in tumor progression. The present study aimed to analyze the proliferation, viability and migration index of pleomorphic adenoma myoepithelial cells, in addition to the secretion of MMPs with EGF supplementation. Benign myoepithelial cells were cultured with two different EGF doses (5 and 10 ng/ml), and the influence of EGF on cell proliferation and viability, using trypan blue and MTT assays, respectively, after 24, 48, and 72 h, was evaluated. To analyze cellular morphology, hematoxylin-eosin staining and indirect immunofluorescence using the anti-vimentin antibody, was performed. In vitro migration assays were performed in Transwell chambers with an 8-μm pore covered with Matrigel and supplemented with 5 or 10 ng/ml of EGF, after 96 h. After 4 days of cell culture, ELISA was performed to determine the MMP-2 and MMP-13 levels. One-way analysis of variance (ANOVA) with post hoc Tukey test was applied, with a significance level of 0.05. The results revealed that EGF influences myoepithelial cell morphology, without alteration of proliferation and viability. The migration assay showed that EGF increased the mean index from 16 % in the control group to 40 and 76 % for 5 and 10 ng/ml of EGF, respectively. ELISA revealed that when the cells were supplemented with either of the EGF doses, an increase in MMP-2 levels was observed when compared with the control group (C). This study concludes that EGF aids in the production of MMP-2, which favors the dissolution of the basement membrane, contributing to cell migration and tumor progression, hence permitting contact between the myoepithelial cells and stroma.

Topics: Adenoma, Pleomorphic; Cell Movement; Cell Proliferation; Cell Shape; Epidermal Growth Factor; Epithelial Cells; Humans; Matrix Metalloproteinase 13; Matrix Metalloproteinase 2; Myoepithelioma; Salivary Gland Neoplasms; Signal Transduction; Tumor Cells, Cultured

Myoepithelial cells in situ and in vitro exert important paracrine effects on carcinoma cells which are mediated by high expression of extracellular matrix molecules, proteinase inhibitors and angiogenic inhibitors. Myoepithelial xenografts (human matrix secreting (HMS)-X, HMS-3X and HMS-4X) established from benign human salivary gland and breast myoepithelial tumors accumulate an abundant extracellular matrix which can be extracted with 6 M urea and 2 M guanidinium hydrochloride to form a gel at 25-37 degrees C. This gel, termed Humatrix, exhibits different biochemical and biological properties than the conventional non-human matrical gels in existence, i.e. Matrigel and Vitrogen 100. Whereas Matrigel consists mainly of basement membrane molecules, e.g. laminin, type IV collagen and heparan sulfate proteoglycan, and Vitrogen 100 consists mainly of non-basement membrane molecules, e.g. type I and type III collagen, Humatrix contains significant amounts of both basement membrane and non-basement membrane molecules, including large amounts of chondroitin sulfate proteoglycan. Like Matrigel, Humatrix contains bound growth factors, including epidermal growth factor (EGF) and insulin-like growth factor-I (IGF-I); unlike Matrigel, which contains predominantly significant quantities of bound proteinases, including tissue-type plasminogen activator (tPA), matrix metalloproteinase (MMP)-2 and MMP-9, and angiogenic factors, including basic fibroblast growth factor (bFGF) and transforming growth factor (TGF)-beta, Humatrix contains predominantly bound proteinase inhibitors such as protease nexin II (PN-II) and alpha1-antitrypsin and angiogenic inhibitors such as thrombospondin-1. Humatrix selectively stimulates the growth and tumorigenicity of human myoepithelial cell lines but inhibits invasion, angiogenesis and metastasis of other non-myoepithelial malignant cell lines. Because of its myoepithelial origin Humatrix represents a more natural source of extracellular matrix molecules and bound factors that carcinoma cells encounter in vivo.

Topics: Animals; Blotting, Western; Collagen; Drug Combinations; Epidermal Growth Factor; Extracellular Matrix; Humans; Insulin-Like Growth Factor I; Laminin; Mice; Mice, Inbred C57BL; Myoepithelioma; Neoplasm Invasiveness; Neovascularization, Pathologic; Proteoglycans; Rabbits; Sarcoma, Experimental; Transplantation, Heterologous; Tumor Cells, Cultured