拓扑替康对宫颈癌细胞系HeLa放射增敏作用的研究

目的:探讨拓扑替康对宫颈癌细胞系HeLa的放射增敏作用及其作用机制。方法:用MTT法和克隆形成分析实验检测拓扑替康对HeLa细胞放射增敏的影响,流式细胞仪检测细胞凋亡率及细胞周期。结果:放疗同时给予0.1、0.5、1.0、5.0μg/m l拓扑替康的放射增敏比分别为1.21、1.40、1.66、1.96;放疗同时及放疗后3h给予拓扑替康组增敏效果最佳,放疗前和放疗后6h以后给予拓扑替康组细胞生存分数与此差异有统计学意义(P<0.05);流式细胞仪检测单化组、单放组和增敏组放疗后24h和48h细胞凋亡率分别为:12.30%和17.00%,16.13%和21.90%,25.13%和34.43%;单放组和不同剂量拓扑替康增敏组G2/M期细胞比例增加。结论:拓扑替康对宫颈癌细胞系HeLa有放射增敏作用,且有剂量依赖性和用药时间选择性,其放射增敏机制可能与HeLa细胞放射后损伤性修复、细胞凋亡及G2/M期阻滞相关。

Radiosensitization effect of Topotecan on cervical carcinoma cell line HeLa

Objective:To investigate the radiosensitization effect and the mechanism of Topotecan on cervical carcinoma cell line HeLa.Methods:The radiosensitization effect of different doses and different treatment duration of Topotecan on HeLa cell line was evaluated by MTT test and clone formation essays.Apoptosis rate of defferent groups and cell cycles were calculated by flow cytometry.Results:Radiosensitization enhancement ratios of 0.1,0.5,1.0 and 5.0μg/ml Topotecan in combination with radiotherapy were 1.21,1.40,1.66 and 1.96,respectively.Additions of Topotecan simultaneously or 3 hours after radiotherapy achieve optimal radiosensitization effects and had significant differences with that when Topotecan could be added right before or 6 hours after radiotherapy(P<0.05).Apoptosis rates at 24 hours and 48 hours of the chemotherapy only group,the radiotherapy only group and the combination group by flow cytometry were 12.30% and 17.00%,16.13% and 21.90%,25.13% and 34.43%,respectively.Cells in G_2/M period increased in radiotherapy only group and different doses of Topotecan groups.Conclusion:Topotecan has radiosensitization effect on cervical carcinoma HeLa cells,which shows dose dependent and treatment duration dependent characteristic.This effect is probably caused by post-injury repair,apoptosis and G_2/M block of HeLa cells.