RESEARCH ARTICLE Overexpression of BIRC6 Is a Predictor of Prognosis for Colorectal Cancer

Background and Objective Inhibitors of apoptosis proteins (IAPs) have been well investigated in human cancers, where they are frequently overexpressed and associated with poor prognosis. Here we ex-plored the role of baculoviral IAP repeat containing 6 (BIRC6), a member of IAPs, in human colorectal cancer (CRC). Methods We usedWestern blotting and immunohistochemistry to examine BIRC6 expression in 7 CRC cell lines and 126 CRC clinical samples. We determined the biological significance of BIRC6 in CRC cell lines by a lentivirus-mediated silencing method. Results We reported that BIRC6 was overexpressed in CRC cell lines and clinical CRC tissues. BIRC6 overexpression was correlated with tumor size and invasion depth of CRC. BIRC6 overexpression is associated with worse overall survival (OS) (P = 0.001) and shorter dis-ease-free survival (DFS) (P = 0.010). BIRC6 knockdown inhibited cell proliferation, arrested cell cycle at S phase, downregulated cyclin A2, B1, D1 and E1 levels, and sensitized CRC cells to chemotherapy in vitro and in vivo. Conclusions Taken together, these data suggests that BIRC6 overexpression is a predictor of poor prog-nosis in colorectal cancer and BIRC6 could be a potential target of CRC therapy