title: Mitogenic responsiveness of caprine mammary epithelial cells to endocrine and cytokine factors.
abstract: Mammary cell mitogenic responsiveness was evaluated with an established nontransformed caprine mammary epithelial cell line (CMEC). As expected, the cells responded to insulin-like growth factor 1 (IGF-1), insulin, and hydrocortisone with an increased number of cells after 3 and 5 d in culture. In combination, insulin and hydrocortisone augmented each other. A proliferation response was also observed for transforming growth factor-alpha (TGF-alpha), and epidermal growth factor (EGF), but not for fibroblast growth factor a (FGFa), FGFb, IGF-2, bovine somatotropin, or prolactin. Comparison of mitogenic potential for these growth factors with cells grown on plastic substratum indicated that hydrocortisone was most potent, followed by TGF-alpha in inducing a proliferative response measured by 3H-thymidine incorporation assay. Hydrocortisone augmented proliferation by 149% and TGF-alpha stimulated proliferation by 126% relative to the media control (p < 0.01). EGF, which binds to the same receptor as TGF-alpha in other species, induced a modest 35% increase in proliferation. Comparison of culture conditions with plastic, fibronectin, and type I collagen suggests that extracellular matrix/stroma influences the magnitude and effective concentration for cytokine-mediated growth response. Studies on responsiveness to ovarian steroids estradiol 17-beta (E2) and progesterone (P4) showed a modest proliferation response to E2 only in combination with triiodio-L-thyronine (T3), and no response to P4 or T3 either alone or in combination when grown on plastic.
authors.affiliation: Department of Pathobiology, University of Connecticut, Storrs 06269-3089, USA.
authors.forename: A G
authors.initials: AG
authors.lastname: Pantschenko
authors.forename: T J
authors.initials: TJ
authors.lastname: Yang
mesh_terms: D000818:Animals; D002417:Cattle; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D003094:Collagen / Q000378:metabolism; D004815:Epidermal Growth Factor / Q000494:pharmacology; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects; D005260:Female; D016220:Fibroblast Growth Factor 1 / Q000494:pharmacology; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology; D005353:Fibronectins / Q000378:metabolism; D006041:Goats; D013006:Growth Hormone / Q000494:pharmacology; D006854:Hydrocortisone / Q000494:pharmacology; D007328:Insulin / Q000494:pharmacology; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology; D007335:Insulin-Like Growth Factor II / Q000494:pharmacology; D008321:Mammary Glands, Animal / Q000166:cytology* / Q000187:drug effects; D010969:Plastics; D011388:Prolactin / Q000494:pharmacology; D016211:Transforming Growth Factor alpha / Q000494:pharmacology
chemical_list: D005353:Fibronectins; D007328:Insulin; D010969:Plastics; D016211:Transforming Growth Factor alpha; D016222:Fibroblast Growth Factor 2; D016220:Fibroblast Growth Factor 1; D004815:Epidermal Growth Factor; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II; D011388:Prolactin; D013006:Growth Hormone; D003094:Collagen; D006854:Hydrocortisone