[Expression of G protein-coupled estrogen receptor and Gankyrin protein in ovarian endometriosis and 
its pathological significance].

OBJECTIVE: To examine the expression of G protein-coupled estrogen receptor (GPER) and Gankyrin in ovarian endometriosis (OEM) and to evaluate its clinicopathological significance. METHODS: Immunohistochemistry was conducted to determine the expression and distribution of GPER and Gankyrin in matched ectopic and eutopic endometrium of OEM and the normal endometrium. The association of these two proteins with the stages of OEM was also investigated. RESULTS: The positive rate for GPER protein in paired ectopic and eutopic endometrium of OEM and the normal endometrium were 63.6%, 51.5% and 21.2%, respectively. There was significant difference in matched ectopic and eutopic endometrium from OEM compared with the control endometrium (P0.0125). The positive rate for Gankyrin protein were 69.7%, 36.4% and 9.1%, respectively. Significant difference in Gankyrin protein was found between ectopic and eutopic endometrium of OEM, ectopic and normal endometrium or eutopic and normal endometrium (P<0.0125). Higher positive expression rate for GPER was also observed in eutopic endometrium from OEM during proliferative phase in comparison to secretory phase (P0.05). These two proteins were positively correlated with the revised American Society for Reproductive Medicine (rASRM) stages of OEM. Both of them were found to be significantly higher in advanced stages (III-IV) compared with those in early stages (I-II, P<0.05). Moreover, a significant positive correlation was found between GPER and Gankyrin proteins in ectopic endometrium of OEM (rs=0.640, P<0.01). CONCLUSION: GPER and Gankyrin might be involved in the pathogenesis of OEM, which could possibly facilitate the formation of ectopic lesions.