hTERT对HeLa细胞放疗后细胞周期的影响  

Study of effects of telomerase activity on cell proliferation and chemosensitivity in HeLa cells.

作　　者：奚玲[1] 吴鹏[1] 朱涛[1] 王常玉[1] 王世宣[1] 马丁[1] 

机构地区：[1]华中科技大学同济医学院妇产科,武汉430030

出　　处：《现代妇产科进展》2006年第4期272-275,共4页Progress in Obstetrics and Gynecology

基　　金：国家自然科学基金(30271358);97-3基金(2002CB513100)资助课题

摘　　要：目的:研究端粒酶逆转录酶(hTERT)对HeLa细胞放疗后细胞周期的影响。方法:将野生型端粒酶逆转录酶(WT-hTERT)、端粒酶逆转录酶显性负突变体(DN-hTERT)和对照质粒(pBABE)电转染于HeLa细胞中,RT-PCR法检测hTERT表达,TRAP-ELISA检测HeLa细胞端粒酶活性改变,Southern-B lot检测端粒长度改变,各转染组细胞分别经5Gy和10Gy60Co照射,流式细胞仪检测其在照射后0、24、48和72h细胞周期分布和凋亡的情况。结果:转染DN-hTERT后,HeLa细胞端粒酶活性下降,端粒长度显著缩短,而转染WT-hTERT后,HeLa细胞端粒酶活性增强,端粒长度较对照组长;各转染组细胞周期分布相似,经60Co照射24h后,各组细胞G2M峰均升高,并随照射剂量增加得更明显,其中WT-hTERT组G2M峰最高,而DN-hTERT组G2M峰最低,60Co照射48h后各组细胞亚G1峰均升高,其中WT-hTERT组最低,而DN-hTERT组最高,对照组和DN-hTERT组G2M阻滞进一步增加,G1峰下降,而WT-hTERT组G2M下降,G1峰升高。结论:DN-hTERT能抑制HeLa细胞端粒酶活性,进而缩短其端粒长度,增强其对放射线的敏感性,而WT-hTERT通过增强G2M阻滞率促进损伤细胞修复。Objective：To investigate the effects of human telomerase transcriptase on cell cycle in HeLa cells after radiation treatment. Methods：WT-hTERT, DN-hTERT and control plasmid were electroperated into HeLa cells. RT-PCR and TRAP-ELISA were used to verify the transfestion efficiency. Telomere length was determined by southernblot. The three transfected cell lines were exposed to 5Gy and 10Gy radiation respectively. Cell cycle growth distribution and apoptosis rates were examined at 24h,48h and 72h after radition by flow cytometery. Results：DN-hTERT inhibited telomerase activity and resulted in shortened telomere length in He- La cells while WT-hTERT had the opposite effects. The cell cycle distribution was similar in the three transfecants after transfection. Twenty-four post radiation GzM peak increased in a dose dependant manner. The G2M peak increased the highest in WT-hTERT transfected HeLa cells and the lowest in DN-hTERT transfected HeLa cells. Fourty-eight post radiation the subG1 peak increased,hightest in DT-hTERT transfected HeLa cells and lowest in WT-hTERT transfected HeLa cells. Meanwhile the G2M arrest kept increasing and G1 peak decreased in DN-hTERT and vector transfected HeLa cells. On the contrary, G2M peak decreased and Gt peak decreased in WT-hTERT transfected HeLa cells. Condusions： DN-hTERT can decrease telomerase activity,lead to telomere loss and thus increase radiosensitivity in HeLa cells. WT-hTERT enhances G2M arrest and cell repair capability after damage by radiation.

关 键 词：端粒酶 人端粒酶逆转录酶 细胞凋亡 细胞周期 放射增敏 

分 类 号：R730.55[医药卫生—肿瘤]