Different hormonal requirements for androgen-independent growth of normal and tumor epithelial cells from rat prostate

摘要: The proliferation of isolated normal prostate epithelial cells from rat and man is androgen-independent requires cholera toxin, insulin, dexamethasone, epidermal growth factor (EGF) one or more polypeptide factors that are concentrated in bovine neural tissue. active agents the tissue extract heparin-binding polypeptides (prostatropins), predominant form which has a molecular weight 17400 an acetylalanine at aminoterminus. Prostatropins supported half-maximal increase cell number 50 picomolar. primary serially-cultured androgen-responsive Dunning R3327 tumors was also androgen-independent, but exhibited dramatic alterations response to hormones stimulated proliferation. At low density, tumor-derived independent on by required insulin andeither EGFor prostatropin. presence either EGF prostatropin masked other factor. In absence EGF, purified prostatropins tumor 7 Endogenous production EGF-like prostatropin-like both suggested reduced requirement for high density. These results suggest anti-hormonal therapies against should be based intervention with activity (or insulin-like factors) simultaneous their homologues).