Baculoviral IAP Repeat Containing 6 (BIRC6) Is a Predictor of Prognosis in Prostate Cancer

BACKGROUND: Baculoviral IAP repeat containing 6 (BIRC6), a member of the inhibitors of apoptosis protein (IAP) family, has been reported to be correlated with oncogenesis. The aim of this study was to investigate the prognostic significance of BIRC6 in prostate cancer, as well as its effects on prostate cancer cell lines. MATERIAL/METHODS: BIRC6 protein expression was investigated in 112 prostate cancer tissues and 86 benign prostate disease tissues using immunohistochemistry. Overall survival was assessed by Kaplan-Meier analysis with log-rank test. To evaluate the prognostic significance of BIRC6, Cox regression models were applied. The effects of BIRC6 on human prostate cancer cells were confirmed via small interfering RNA. RESULTS: BIRC6 protein levels were significantly higher in prostate cancer tissues than that in benign prostate tissues (P<0.001). High BIRC6 expression was associated with advanced pathological stage (P=0.011) and positive metastasis (P=0.036). In addition, patients with high BIRC6 expression had worse survival than those with low expression (Log-rank test, P=0.002). Multivariate analysis demonstrated that BIRC6 expression was an independent prognostic factor for prostate cancer (HR=2.771, 95%CI=1.427–5.378, P=0.003). Furthermore, cell experiments suggested that BIRC6 knockdown inhibits cell proliferation and promote apoptosis (P<0.05 for all). CONCLUSIONS: Upregulated BIRC6 predicts aggressive clinical characteristics and poor prognosis in prostate cancer patients. BIRC6 can regulate prostate cancer cell proliferation and apoptosis, which may be a potential therapeutic target.