目的：探讨RNA干扰人端粒酶逆转录酶（human telomerase reverse transcriptase，hTERT）的表达对大肠癌细胞SW480凋亡的影响。方法：构建携带hTERT小发夹干扰RNA（small hairpin RNA，shRNA）的重组表达载体pGPU6/GFP/Neo-hTERT-shRNA（简称hTERT-shRNA质粒），脂质体法转染SW480细胞，RT-PCR法检测不同转染时间点SW480细胞中hTERT mRNA的表达。TRAP-PCR-ELISA法检测转染后48 h SW480细胞的端粒酶活性，透射电镜观察转染后48 h SW480细胞超微结构。结果：hTERT-shRNA质粒转染48 h时，hTERT-shRNA组SW480细胞hTERT mRNA表达的抑制率显著高于空白组、脂质体组、NC-shRNA组（75.0% vs 39.2%、33.3%、28.0%, P<0.05）。hTERT-shRNA转染组SW480细胞端粒酶活性显著低于空白组、脂质体组、NC-shRNA组（2.242±0.285 vs 2.756±0.089、 2.693±0.225、2.691±0.120，P<0.05）。hTERT-shRNA质粒转染后的SW480细胞体积明显缩小、细胞核固缩、染色质不均匀地沿核膜下聚集、空泡形成增多，出现典型的凋亡形态。结论：RNAi可有效沉默SW480细胞中hTERT的表达，降低SW480细胞端粒酶活性，诱导SW480细胞凋亡。

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%, P<0.05). 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, P<0.05). 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.

广西自然科学基金资助项目（No. 2010GXNSFA013238）；广西卫生厅重点课题（No. Z200971）