Upregulation of Abelson interactor protein 1 predicts tumor progression and poor outcome in epithelial ovarian cancer.

Abelson interactor protein 1 (Abi1) is a key regulator of actin reorganization and lamellipodia formation. Because of its role in cell migration, Abi1 has been implicated in tumor progression. In the present study, we investigated the role of Abi1 in epithelial ovarian cancer (EOC) by analyzing its expression and correlation with clinicopathological and survival data. We evaluated the expression of Abi1 in 223 paraffin-embedded EOC specimens by immunohistochemistry and 46 frozen EOC samples by Western blot and real-time reverse transcription polymerase chain reaction analysis. Results showed that Abi1 protein and mRNA expression was significantly higher in EOC tissue compared with noncancerous tumors and normal ovaries (P < .05). Moreover, high level of Abi1 expression was significantly correlated with advanced stage, high grade, elevated Ca-125 level, and suboptimal surgical debulking (P < .05). By Western blot analysis, Abi1 was expressed in highly invasive cells compared with weakly invasive cells (P < .05). Immunofluorescence was performed to demonstrate Abi1 expression in SKOV3 cells. Additionally, upregulation of Abi1 significantly correlated with shorter survival (P < .05). Most importantly, multivariate analysis showed that Abi1 overexpression is an independent prognostic factor, complementary to clinical stage and residual tumor size. In conclusion, our findings suggest that Abi1 acts as a tumor-promoting gene in EOC progression, which may lead to unfavorable prognosis. Abi1 may serve as a potential effective prognostic marker for EOC.