Overexpression of oxidored-nitro domain containing protein 1 induces growth inhibition and apoptosis in human prostate cancer PC3 cells.

Previous studies have reported that oxidored-nitro domain containing protein 1 (NOR1) is a novel tumor suppressor gene identified in various types of cancer, such as nasopharyngeal carcinoma and cervical cancer. Recent studies have shown that NOR1 expression is lower in prostate cancer compared with normal prostate tissue. However, the specific function and exact mechanism of NOR1 in prostate cancer remains to be clarified. The present study aimed to investigate the function and mechanism of NOR1 in prostate cancer PC3 cells. DU145 and PC3 cells were transduced with a vector and cell viability, proliferation and apoptosis were determined. As predicted, NOR1 overexpression significantly inhibited growth and apoptosis in PC3 cells. NOR1 overexpression decreased the expression of the anti-apoptotic genes Bcl-2 and Bcl-xl and increased the level of the pro-apoptotic genes Bax and Bak in PC3 cells. Further investigation demonstrated that NOR1 overexpression activates caspase-3. Silencing of NOR1 did not inhibit growth or induce apoptosis in PC3 cells. Moreover, NOR1 inhibited proliferation and induced apoptosis via the activation of MAPK. The overexpression of NOR1 significantly inhibited tumor growth in PC3 tumor-bearing nude mice. The results suggest that the upregulated NOR1 expression was able to inhibit the progression of prostate cancer. Thus, NOR1 may be an ideal target for the treatment of prostate cancer.