Steroid metabolism by human mammary carcinoma.

The ability of human mammary tumors to convert 7alpha 3H-testerone to estrogens was examined in order to determine whether this bore any relationship to estrogen receptor and steroid sulfurylation levels; such levels being indicative of hormone dependency. In 8 out of 9 tumors, formation of estradiol-17beta from testosterone was demonstrated. Those tumors showing the lowest conversion of testosterone to estradiol-17beta possessed the highest levels of dehydroepiandrosterone sulfotransferase which lends support to data implicating sulfurylation in the regulation of steroid metabolism in human tumors. All tumors activated sulfate to adenosine-3'-phospho-5'-phosphosulfate and the concentrations were significantly correlated withe the recorded levels of dehydroepiandrosterone sulfate. Estrogen receptor levels did not show any obvious relationship to the other parameters.