Objective:To investigate the molecular mechanism of induction of apoptosis by siRNA targeting human telomerase reverse transcriptase(hTERT)in HeLa Cells.Methods:HeLa cells were transfected with siRNAs by liposome method.RT-PCR was used to examine mRNA levels of hTERT in HeLa cells.Microarray assay was adopted to explore the transcriptional profiling of apoptosis associated genes.The protein levels of hTERT,TRAIL,Bcl-2,and cytoplasm Cyt C were detected by Western Blotting.The apoptosis rate was determined by flow cytometry using PI staining.Relative activity of Caspase-3 and Caspase-8 was measured by colorimetric assay.Results:The siRNA targeting hTERT suppressed the expression of hTERT gene significantly.Forty-eight hours after transfection,the expression level of TRAIL was increased,the expression level of Bcl-2 was decreased,the releasing of Cyt C was enhanced,the activation of Caspase-3 was increased and the apoptosis rate was increased.Conclusion:hTERT-siRNA induces apoptosis of HeLa cells via activating mitochondrial signal transduction pathway.