Research Papers:

ABSTRACT

It has been reported that RNF2, a core member of the polycomb repressor complex 1 (PRC1) complex, is frequently overexpressed in several types of human cancers. However, abnormalities in RNF2 in ovarian carcinoma and its potential clinical/prognostic significance have not been elucidated. In this study, immunohistochemistry and fluorescence in situ hybridization were employed to examine the protein expression and amplification status of RNF2 in 30 normal ovaries, 30 ovarian cystadenomas, 40 borderline ovarian tumors and 170 ovarian carcinomas. Patient survival rate was evaluated using receiver-operator curve (ROC) analysis. Our result showed that overexpression of RNF2 was observed in none of the normal ovaries, in 7% of cystadenomas, in 15% of borderline tumors, and in 41% of ovarian carcinomas, respectively (P<0.01). In addition, amplification of RNF2 was detected in 12.3% of ovarian carcinomas. Correlation analysis demonstrated that overexpression of RNF2 in ovarian carcinomas was positively associated with increased cell proliferation, ascending histological grade, later pT/pN/pM and/or more advanced FIGO stages (P<0.05). In univariate survival analysis of the carcinoma cohorts, a significant association was observed between overexpression of RNF2 and shortened patient survival (mean 47.4 months versus 97.0 months, P<0.001). Importantly, multivariate analysis demonstrated that RNF2 expression was a significant independent prognostic factor for overall survival of the carcinoma patients (P=0.033). These findings provide evidence supporting that the overexpression of RNF2 might be a representation of a more aggressive cancer phenotype in ovarian carcinoma. Furthermore, RNF2 might serve as an independent biomarker indicative of poor prognosis in patients with ovarian carcinoma.