Ovarian cancer and gonadotropins in vitro : New evidence in favor of independence

Backgrounds: The aim of this study was to investigate whether newly established epithelial ovarian carcinoma cell lines secrete inhibins, and whether their proliferative and secretory activity can be regulated by gonadotropins. Materials and methods: Three recently characterized human epithelial ovarian carcinoma cell lines were exposed to human choriongonadotropin hCG and follicle stimulating hormone FSH. Cell proliferation was determined by counting. Secretory activity of the cell lines was studied by analyzing inhibin A, inhibin B, inhibin pro-aC, estradiol, progesterone, testosterone, and CA 125 concentrations from the medium. The expression of gonadotropin receptors was studied by RT-PCR. Results: None of the cell lines were found to secrete any of the inhibins, progesterone or testosterone. Only UT-OC-4 cells secreted low levels of estradiol. Gonadotropin receptors were not expressed by any of the cell lines, and accordingly neither FSH nor hCG stimulated the growth of these cells. However, hCG had some dose dependent growth inhibitory effect on UT-OC-3. Passage 42 cells of UT-OC-3 secreted significantly more CA 125 than passages 8 cells (P= 0.000). Conclusions: The present results suggest that the carcinomatous epithelial cells of the ovary do not secrete inhibins. The serum inhibin levels previously detected in patients with epithelial ovarian carcinoma may therefore reflect an ovarian stromal response to carcinoma. The findings are also in favor of an independence of ovarian cancer of gonadotropins.