Abstract
We investigated the clinical significance of regulated in development and DNA damage response (REDD1) and p-AKT expression in human ovarian cancer (OC), explored the correlation of KRAS mutations with REDD1 expression, and assessed the therapeutic relevance of REDD1 in OC. We collected and immunohistochemically analyzed 118 formalin-fixed paraffin-embedded tumor tissue samples (100 primary OC and 18 borderline tumors) and 14 normal fallopian tubes, for REDD1 and p-AKT expression. Direct DNA sequencing for KRAS mutations and quantitative real-time polymerase chain reaction for detecting REDD1 mRNA expression were performed. REDD1 and p-AKT expressions were significantly higher in serous adenocarcinoma than other histological types, and this increase positively correlated with late-stage disease. REDD1 expression correlated with ascites formation, while p-AKT expression correlated with higher histological grade and chemoresistance. Kaplan Meier survival analysis showed significantly reduced disease-free survival (DFS) and overall survival (OS) in OC patients with both REDD1 and p-AKT overexpression. Patients with KRAS mutations had a longer DFS and OS. However, KRAS mutation and REDD1 over-expression was not correlated. Together, REDD1 and p-AKT over-expression may serve as a prognostic biomarker in OC, but KRAS mutations and REDD1 protein over-expression were not correlated in OC. We believe that with increasing knowledge of the role of REDD1 in cell migration, invasion, and proliferation pathways, the potential of REDD1 as a therapeutic target in OC may be uncovered.