Increased steroid receptor RNA activator protein (SRAP) accompanied by decreased estrogen receptor-beta (ER-β) levels during the malignant transformation of endometriosis associated ovarian clear cell carcinoma

The modulating attributes of steroid receptor RNA activator protein (SRAP) on steroid receptors have been shown in some types of tumor cells. There is compelling evidence to suggest that this molecule may play a critical role in the development of the tumor. However, little has been reported on its expression in endometriosis associated ovarian clear cell carcinoma (EAOCCC). In order to investigate the role of SRAP and estrogen receptors (ERs) in EAOCCC, we have analyzed the distribution of these proteins in the malignant transformation tissues and endometrioma tissues by immunohistochemistry. Our results revealed that the positive ratio of ER-β expression was gradually reduced during the malignant transformation from endometriosis to atypical endometriosis to clear cell carcinoma. Conversely, during the process, a gradual increase in SRAP expression was observed. Furthermore, there is a negative relationship between the expressions of these two molecules. Overall an increase in SRAP and a reduction in ER-β expression might be associated with malignant transformation of EAOCCC.