Effect of ethanol on proliferation and estrogen receptor-alpha expression in human breast cancer cells

There is substantial epidemiological evidence suggesting that alcohol consu mption is associated with increased risk for breast cancer. However, possib le biological mechanisms have not been clearly established. In the present studies, a direct effect of ethanol on the proliferation and intracellular content of cyclic AMP (cAMP) in two estrogen receptor-positive (ER+) and tw o estrogen receptor-negative (ER-) human breast cancer cell lines was exami ned. Treatment of ER+ human breast cancer cells (MCF-7 and ZR75.1) with eth anol at concentrations between 10 and 100 mM was associated with increased cell numbers compared to controls. The ER alpha content and the amount of i ntracellular cAMP also increased in ER+ cells exposed to ethanol, compared to controls. On the other hand, ethanol treatment did not increase cell pro liferation or cAMP levels in the ER- (BT-20 and MDA-MB-231) human breast ca ncer cells. Therefore, ethanol added at physiologically relevant concentrat ions to ER+ human breast cancer cell cultures can enhance cell proliferatio n and increase the content of ER alpha. (C) 2001 Elsevier Science Ireland L td. All rights reserved.