Can an autocrine loop explain sex-hormone-dependent tumor growth? A brief overview.
Sex hormones and their related compounds have been known to regulate the target cell growth positively or negatively in the receptor-dependent manner. The molecular mechanism of these complicated events, especially sex hormone-dependent growth enhancement, has been studied extensively. In MCF-7 cells, estrogen-induced autocrine loop has been demonstrated to play the important role for estrogen-dependent growth. Androgen has been also found to promote the growth of SC-3 cell through the induction of an autocrine growth factor (FGF 8). The blockade of FGF 8 activity resulted in a complete inhibition of androgen-dependent growth of SC-3 cells, suggesting that FGF 8 acts as an essential component of androgen-dependent growth. However, the constitutional expression of FGF 8 failed to convert SC-3 cells from an androgen-dependent to an androgen-independent phenotype. These observations would suggest that sex hormone-induced autocrine loop is an obligatory but not sufficient component for the growth of sex hormone-dependent tumor.
Sato
B
B
Third Department of Internal Medicine, Nissay Hospital, Osaka, Japan.
D000728:Androgens / Q000378:metabolism; D000818:Animals; D018931:Antineoplastic Agents, Hormonal / Q000494:pharmacology; D019898:Autocrine Communication; D020847:Estrogen Receptor Modulators / Q000494:pharmacology; D004967:Estrogens / Q000378:metabolism; D005260:Female; D051524:Fibroblast Growth Factor 8; D005346:Fibroblast Growth Factors / Q000378:metabolism; D012739:Gonadal Steroid Hormones / Q000378:metabolism*; D006801:Humans; D008297:Male; D009363:Neoplasm Proteins / Q000378:metabolism; D009374:Neoplasms, Experimental / Q000378:metabolism; D009376:Neoplasms, Hormone-Dependent / Q000188:drug therapy / Q000378:metabolism*; D013629:Tamoxifen / Q000494:pharmacology
D000728:Androgens; D018931:Antineoplastic Agents, Hormonal; D020847:Estrogen Receptor Modulators; D004967:Estrogens; C496456:FGF8 protein, human; D012739:Gonadal Steroid Hormones; D009363:Neoplasm Proteins; D013629:Tamoxifen; D051524:Fibroblast Growth Factor 8; D005346:Fibroblast Growth Factors