Mechanism of induction of apoptosis by siRNA targeting hTERT in HeLa cells

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.