Rsf-1 overexpression in human prostate cancer, implication as a prognostic marker.

Rsf-1 (HBXAP) was recently reported to be overexpressed in various cancers and associated with the malignant behavior of cancer cells. However, the expression of Rsf-1 and its clinical significance in human prostate cancer have not been reported. In the present study, we analyzed the expression pattern of Rsf-1 in human prostate cancer tissues and found that Rsf-1 was overexpressed in 45 % of prostate cancer specimens. There was a significant association between Rsf-1 overexpression and tumor stage (p=0.0039) and preoperative PSA level (p=0.015). Furthermore, Rsf-1 overexpression correlated with poor biomedical recurrence-free survival in prostate cancer patients (p<0.001). Rsf-1 overexpression could serve as an independent predictor for poor recurrence-free survival (p=0.012). In addition, small interfering RNA (siRNA) knockdown in DU145 cells with high endogenous Rsf-1 expression decrease cell proliferation, colony formation, and invasion. In conclusion, Rsf-1 is overexpressed in human prostate cancers and serves as a novel prognostic marker. Rsf-1 contributes to prostate cancer cell growth and invasion, which makes it a candidate therapeutic target.