title: Induction of epidermal growth factor-related polypeptides by 17 beta-estradiol in MCF-7 human breast cancer cells.
abstract: MCF-7 human breast cancer cells release polypeptides related to insulin-like growth factor-I (IGF-I) and epidermal growth factor (EGF) into serum-free culture medium (CM). Treatment of MCF-7 cells with 17 beta-estradiol, which is required in vivo for MCF-7 tumor growth in the nude mouse and stimulates the MCF-7 growth rate in vitro, resulted in selectively enhanced growth factor activities in CM. Autostimulatory growth-promoting activity was elevated at least 2-fold, and EGF-like polypeptides were elevated 5-fold but IGF-I immunoreactivity was not elevated. Several species of estrogen-induced receptor-reactive EGF-like polypeptides, suggestive of high molecular weight transforming growth factor alpha, were detected after gel exclusion chromatography of CM extracted with 1 M acetic acid. A 30,000 mol wt peak of EGF receptor competing activity comigrated with a peak of autostimulatory and fibroblast-transforming activity. It is possible that estradiol stimulation of MCF-7 growth and/or tumor formation may depend on induction of EGF-related polypeptide growth factors. EGF-I- and EGF-related polypeptides may act together as autocrine or paracrine growth factors in breast cancer.
mesh_terms: D001943:Breast Neoplasms / Q000378:metabolism*; D002460:Cell Line; D003470:Culture Media; D004247:DNA / Q000378:metabolism; D004815:Epidermal Growth Factor / Q000096:biosynthesis*; D066246:ErbB Receptors; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D006801:Humans; D007328:Insulin / Q000494:pharmacology; D007334:Insulin-Like Growth Factor I / Q000096:biosynthesis; D011863:Radioimmunoassay; D011956:Receptors, Cell Surface / Q000378:metabolism
chemical_list: D003470:Culture Media; D007328:Insulin; D011956:Receptors, Cell Surface; D004958:Estradiol; D004815:Epidermal Growth Factor; D007334:Insulin-Like Growth Factor I; D004247:DNA; D066246:ErbB Receptors