Cytosol and nuclear estrogen and progestin receptors and 17 beta‐hydroxysteroid dehydrogenase activity in non‐diseased tissue and in benign and malignant tumors of the human ovary
Authors: Vierikko P. , Kauppila A. , Vihko R. 
Published: February 2007

Significant but low concentrations (mean 8 fmol/mg cy‐tosol protein) of cytosol estrogen receptors were found in 57% of non‐diseased ovarian tissues, and higher concentrations (mean 211) of cytosol progestin receptors in all these tissues. An approximately similar distribution was found for the presence of nuclear female sex steroid receptors; the mean concentrations were 159 and 1149 sites/ cell, for estrogen and progestin receptors, respectively. There were no major differences in these parameters between pre‐ and postmenopausal non‐diseased ovaries. The activities of ovarian 17 beta‐hydroxysteroid dehydro‐genase (17‐HSD) did not display correlations between circulating progesterone concentrations in pre‐ or postmenopausal women with non‐diseased ovaries. The majority of benign epithelial tumors contained significant concentrations of cytosol estrogen receptors, and all showed cytosol progestin receptors. The concentration of estrogen receptors was identical to that seen in non‐diseased ovaries (mean 9 fmol/mg cytosol protein), whereas that of progestin receptor was significantly lower (mean 95). Nuclear female sex steroid receptors were measured in all benign tumors, and their concentrations were significantly higher than in normal ovaries (440 and 3218 sites/cell for estrogen and progestin receptors, respectively). No difference in 17‐HSD activities were detected between normal ovaries and benign tumors.

In malignant ovarian tumors, the picture was different from that found in normal ovarian tissues and benign tumors. Cytosol estrogen receptor was found in 89% of malignant epithelial tumors, and its concentration was significantly higher (mean 64 fmol/mg cytosol protein). Cytosol progestin receptor was found in 91%, and its concentration (mean 75) was significantly lower than in normal ovarian tissue or benign ovarian tumors. Nuclear female sex steroid receptor concentrations were intermediate beween those seen in non‐diseased ovaries an in benign tumors. 17‐HSD activity was significantly lower than in other tissue categories studied. In the small group (16) of non‐epithelial ovarian carcinomas cytosol estrogen receptors were not found, whereas the results of other measurements did not display any coherent picture.

Breast and endometrial carcinoma metastatic to the ovary showed receptor patterns which were typical of the primary tumors.

When the different clinical stages (I‐IV) of malignant epithelial ovarian tumors were compared, 17‐HSD activity was significantly higher in the least advanced clinical stage (I), whereas no significant differences were found in the other parameters measured.

In epithelial ovarian carcinomas, and separately in the serous and mucinous subgroups, there was a decrease in cytosol progestin receptor concentrations, and a tendency towards increased cytosol estrogen receptor concentrations, with resultant significant increases in cytosol estro‐gen/progestin receptor ratios, in the most anaplastic tumors compared with the more differentiated ones.

The present results show that tumor formation, whether benign or malignant, in the human ovary is associated with a number of changes in the parameters related to female sex steroid action in this tissue.