Effects of selective estrogen receptor modulators and genistein on the expression of ERalpha/beta and COX-1/2 in ovarectomized mouse uteri.

This study was performed to examine the effects of selective estrogen receptor modulators [tamoxifen (TAM) and toremifene (TOR)] and pure anti-estrogen, ICI-182780 (ICI, Faslodex) and soybean isoflavone, genistein (GE) on the expression of estrogen-stimulated c-fos/jun, ERalpha/beta and COX-1/2 in the uteri of ovarectomized mice. TAM, TOR, ICI and GE treatment significantly decreased the levels of estradiol (E2)-induced c-fos. ICI and GE treatment significantly decreased the levels of E2-induced c-jun and ERalpha expressions. High doses of TOR treatment significantly increased the E2-induced ERbeta expression. In contrast, ICI and GE treatment significantly decreased the levels of E,-induced COX-2 expression, thus suggesting that TOR and GE might prevent E2-related endometrial carcinogenesis.