Downregulation of COPB2 by RNAi inhibits growth of human cholangiocellular carcinoma cells.

OBJECTIVE:The present study aimed to explore the contribution of COPB2 (coatomer subunit beta) towards the tumorigenesis of cholangiocellular carcinomas and to elucidate the underlying mechanism(s). MATERIALS AND METHODS:Expression of COPB2 mRNA by RBE and QBC939 cholangiocellular carcinoma cell lines was determined by qRT-PCR. We, then, silenced COPB2 expression in RBE cells by infection with a COPB2-siRNA lentivirus and measured the proliferation, cell-cycle distribution, and apoptosis of transduced cells. RESULTS:COPB2 was highly expressed in RBE and QBC939 cholangiocellular carcinoma cell lines. Infection with COPB2-siRNA lentivirus in RBE cells significantly decreased COPB2 expression. More so, silencing of COPB2 by COPB2-siRNA significantly suppressed the proliferation and promoted the apoptosis of RBE cells by arresting transduced cells in the G1 phase. CONCLUSIONS:Our results demonstrate that the COPB2 gene is highly expressed in cholangiocellular carcinoma cell lines, wherein knockdown inhibited the proliferation and promoted the arrest of cell-cycle progression and the apoptosis of cholangiocellular carcinomas. COPB2 may constitute an attractive target for therapeutic strategies against cholangiocellular cancers.