INDUCTION OF PROSTATE-SPECIFIC ANTIGEN PRODUCTION BY STEROIDS AND TAMOXIFEN IN BREAST-CANCER CELL-LINES

We demonstrate that the steroid hormone receptor-positive breast carci noma cell lines T-47D and MCF-7 can be induced by androgens, progestin s, mineralocorticosteroids, glucocorticosteroids, and antiestrogens, t o produce prostate specific antigen (PSA). Estrogens failed to induce such stimulation in both cell lines and, in addition, were able to blo ck the induction by androgens in the cell line T-47D. These data suppo rt and extend our previous report on PSA production by breast tumors a nd describe an in vitro system which can be used to study the phenomen on for possible application in prognosis and design of new therapy.