Abstract:Objective: To investigate the molecular mechanism of survivin regulaion of the apoptosis-related signaling in human cholangiocarcinoma cells. Methods: The siRNA targeting survivin gene and nontargeting control siRNA were constructed, and human cholangiocarcinoma QBC939 cells were divided into three groups that were survivin targeting siRNA transfection group, control siRNA transfection group and untransfection group, respectively. After transfection, the surviving expression in the QBC939 cells, QBC939/siRNA (–) and QBC939/siRNA (+) cells was determined by Western blot to identify the interference effect, and then, the apoptosis rate, capase-3 activity, and expression of caspase-3, caspase-9 and procaspase-9 in the QBC939 cells of above three statuses were detected by flow-cytometry, capase activity detection kit and Western blot, respectively. Results: The protein expression level of survivin in the QBC939/siRNA (+) cells was significantly decreased (P<0.05), and there was no obvious alteration in the QBC939/siRNA (–) cells compared with the untransfected QBC939 cells (P>0.05). Compared with the untransfected QBC939 cells, the QBC939/ siRNA (+) cells presented enhanced apoptosis, increased caspase-3 activity, and upregulated expression level of caspase-3 and caspase-9, but downregulted expression level of procaspase-9 (all P<0.05). In each of the above indexes, the differences between the QBC939/siRNA (–) cells and untransfected QBC939 cells had no statistical significance (all P>0.05). Conclusion: In cholangiocarcinoma cells, apoptosis inhibition by survivin is possibly due to the inactivation of caspase-3 and caspase-9 via procaspase-9 activation.