Effect of XIAP siRNA on Growth Inhibition and Apoptotic Cell Death Induced by TRAIL in Colon Cancer Cells

Objective To investigate the effect of XIAP siRNA on TRAIL induced apoptotic cell death in colon cancer cell line SW620. Methods SW620 cells were transfected by XIAP siRNA or negative control,followed by TRAIL treatment.The expression of XIAP,cell growth inhibtion and Caspase-3 activity were determined by Western blot,MTT assay and fluorescent Caspase-3 assay,respectively.The expression of cleaved PARP was measured by Western blot. Results The XIAP protein expression was significantly downregulated by transfection with XIAP siRNA.Compared with mock control and negative siRNA control,the XIAP siRNA significantly enhanced growth inhibition,Caspase-3 activation and PARP cleavage of SW620 cells treated by TRAIL in the concentrations of 10,100 and 1 000 ng/ml. Conclusion XIAP siRNA significantly enhanced TRAIL mediated apoptotic cell death of colon cancer cell line SW620.