Steroidogenic acute regulatory protein (StAR), P450 side-chain cleavage
enzyme (P450scc) and
3 beta-hydroxysteroid dehydrogenase enzyme (3beta-HSD) are all involved in the transport of
cholesterol and production of
progesterone. In situ production of sex
steroids including
progesterone have been considered to play important roles in pathogenesis and/or development of common
epithelial ovarian carcinomas. In this study, StAR, P450scc, and 3beta-HSD were immunolocalized in 100 cases of ovarian
carcinoma and results were then correlated with clinicopathological and prognostic parameters of individual patients including status of
progesterone receptor (PR) in
tumor cells. Results of immunohistochemistry were further characterized by real-time PCR analysis in 20 cases of
epithelial ovarian carcinomas in which frozen tissues were available for examination. StAR, P450scc, and 3beta-HSD immunoreactivity was detected predominately in the cytoplasm of
carcinoma cells. Results of real-time PCR analysis were correlated with those of immunohistochemical studies. StAR, P450scc, and 3beta-HSD H scores demonstrated significant inversed statistical correlation with FIGO stage, residual size of the
tumor, and Ki67 LI. A positive statistically significant correlation was detected between StAR H score and PR-B LI. Multivariate statistical analysis demonstrated that the status of intratumoral StAR, FIGO stage, and
residual tumor size all turned out to be independent prognostic factors for the clinical outcome of the patient. The presence of StAR, a
cholesterol transporter for steroidogenesis in human
epithelial ovarian carcinoma, may reflect the ability of these
tumors to produce
progesterone in situ that could influence
biological behavior of these
tumors, especially through
progesterone dependent inhibition of
tumor cell proliferation.