Influence of RNA Interference Caspase-3 Gene on HEK 293 Cell Apoptosis Induced by Cadmium

Objective To study the influence of RNA interference Caspase-3 gene on apoptosis of transformed human embryonic kidney 293 cells induced by cadmium in vitro. Methods Transformed human embryonic kidney 293 cell were treated with siRNA for 36 h. The treated cells were incubated with 40 μmol/L CdCl2 for 12-24 h and the cells viability were measured with methyl thiazolyl tetrazolium(MTT) assay. In addition,the expression of caspase-3 gene in 293 cells was detected by the methods of reverse transcription polymerase chain reaction (RT-PCR) and Western-blot analysis,and the occurrence of apoptosis was determined by flowcytometry with Annexin-V and propidium iodide (PI) double labeling method. Results The results of RT-PCR and Western-blot analysis revealed that in incubated cells with 40 μmol/L cadmium 12 h,the expression of Caspase-3 mRNA and 20 kDa protein significantly increased when compared with controls(n=4,P0.01). The apoptosis rate enhanced significantly in incubated cells with 40 μmol/L cadmium for 24 h(n=4,P0.01). RNA interference inhibited the expression of Caspase-3 gene mRNA and 20 kDa protein and decreased the apoptosis rate induced by cadmium. Conclusion RNA interference Caspase-3 gene could significantly inhibit the apoptosis rate induced by cadmium. It was suggested that Caspase-3 gene could play a central role in cadmium-induced cell apoptosis.