Immunolocalization of nuclear transcription factors, DAX-1 and Ad4BP/SF-1, in human common epithelial ovarian tumors: Correlations with StAR and steroidogenic enzymes in epithelial ovarian carcinoma

Intratumoral steroidogenesis is considered to play important roles in the biologic behavior of common epithelial ovarian carcinoma. Recent studies have demonstrated the important roles of Ad4BP/SF-1 and DAX-1 in regulation of steroidogenesis. In this study, we evaluated DAX-1, Ad4BP/SF-1, StAR, and steroidogenic enzyme expressions and their correlations in epithelial ovarian carcinomas to evaluate the possible roles of these factors in regulation of intratumoral steroid metabolism and/or production. Immunolocalization of DAX-1, Ad4BP/SF-1, StAR, and steroidogenic enzymes were examined in 90 epithelial ovarian carcinomas. mRNA expression of these proteins was evaluated using real-time polymerase chain reaction (PCR) in 23 cases for further characterization. DAX-1 and Ad4BP/SF-1 immunoreactivity was detected predominately in the nuclei of tumor cells, whereas that of StAR and steroidogenic enzymes was present in the cytoplasm. We detected a significant positive correlation between StAR and steroidogenic enzymes immunoreactivity and Ad4BP/SF-1 and statistically inversed correlation with DAX-1. A positive statistical correlation was detected between intratumoral stromal Ad4BP/SF-1 immunoreactivity and clinicopathologic parameters of carcinoma patients. Results of real-time PCR analysis were correlated with those of immunohistochemical studies. The status of intratumoral DAX-1, Ad4BP/SF-1, and StAR and steroidogenic enzymes in epithelial cells and intratumoral stromal cells of epithelial ovarian carcinoma may contribute in the progression and/or aggressiveness of these tumors.