RNA interference-based hTERT gene silence induces apoptosis of colorectal cancer SW480 cells

Objective:To investigate the effect of RNA-mediated interference of hTERT (human telomerase reverse transcriptase) expression on the apoptosis of colorectal cancer cell line SW480. Methods:Small hairpin RNA (shRNA) targeting hTERT was synthesized and recombinant plasmid pGPU6/GFP/Neo-hTERT-shRNA (named hTERT-shRNA plasmid) containing hTERT-shRNA was constructed. SW480 cells were transfected with hTERT-shRNA plasmid by liposome method,and the expression of hTERT mRNA in SW480 cells was detected by RT-PCR analysis at different time points. The telomerase activity of SW480 cells was examined by TRAP-PCR-ELISA analysis. The ultrastructure of SW480 cells was examined by TEM (transparent electron microscope) 48 h after hTERT-shRNA transfection. Results:The inhibitory rate of hTERT mRNA expression in SW480 cells of hTERT-shRNA group was significantly higher than those of blank group,liposome group,and NC-shRNA group (75.0% vs 39.2%,33.3%,28.0%,P0.05). Telomerase activity in SW480 cells of hTERT-shRNA group was significantly decreased compared with those of blank group,liposome group,and NC-shRNA group (2.242±0.285 vs 2.756±0.089,2.693±0.225,2.691±0.120,P0.05). SW480 cells in hTERT-shRNA group showed smaller cell size,nuclear condensation,uneven aggregation of chromatin along the nuclear membrane,and increased vacuolization. Conclusion:RNA interference can effectively silence hTERT expression,reduce telomerase activity,and induce apoptosis of SW480 cells.