Estrogen receptor activation in relation to previous estrogen treatment in carcinoma corporis uteri heterotransplanted into nude mice

Abstract

The interaction between estradiol and its receptor in human endometrial adenocarcinoma was investigated in a human tumor-nude mice model. Estradiol treatment was found to activate estrogen receptor (ER), estimated through the measurement of ER in the nuclear fraction. The receptor activation in the tumors was significantly higher in tumors previously treated with estradiol than in previously non-treated tumors. The activation seems also to be dependent on the estrogen dose. We concluded, that previous influence of estradiol may change the sensitivity of estrogen receptor positive tumors for its hormone, and therefore the measurement of the receptor content alone does not seem to be a sufficient marker for the prediction of the receptor activation process.