The direct proliferative stimulus of dehydroepiandrosterone on MCF7 breastcancer cells is potentiated by overexpression of aromatase

In women after menopause aromatization of adrenal androgens represents the main source of estrogens, which may promote the development of hormone-depe ndent breast tumor. Several studies have attempted to determine the cell ty pe within carcinomas that is responsible for 'in situ' estrogen biosynthesi s and whether the amount produced may sustain relevant biological effects. Here we show P450arom mRNA and protein expression together with immunocytoc hemical localization of aromatase in the epithelial MCF7 breast cancer cell line. Moreover, we demonstrate that the enhanced aromatization of dehydroe piandrosterone in aromatase transfected MCF7 cells confers biological advan tages such as proliferative stimulation similar to that induced by estradio l. Our results suggest that aromatase inhibitors may be particularly effect ive in the treatment of hormone-dependent breast cancer disease in postmeno pausal women. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.