Estradiol formation from testosterone by continuously cultured human breast cancer cells.

摘要: Two human breast cancer cell lines (MCF-7 and MDA-MB-231) one line derived from normal (HBL-100) were examined for the presence of aromatase activity by determining amounts [3H]estradiol ([3(H]E2formed cultures incubated with [3H]testosterone. Aro-matase was demonstrable in both lines, but estradiol synthesis not observed HBL-100 cultures. The [3H]E2 content MCF-7 rose as a function incubation time substrate concentration. Furthermore, [3H[E2 formation this suppressed several known inhibitors placental aromatase. These observations represent first evidence that some continuously cultured cells, like tumors, are capable forming estrogen an extracellular precursor steroid. Cultured cells may provide model systems investigating relative importance intracellular regulation c...