超微分割放疗与常规放疗对脑胶质瘤细胞的作用比较-第三军医大学学报.DOC

低剂量超微分割与常规分割放疗对脑胶质瘤细胞的生物学效应比较 陈媛媛1，汤金梁1，龙海霞2，李光辉2，许建平1（400037重庆第三军医大学新桥医院：1病理科2肿瘤科）各时间点彗星荧光图像的尾部DNA百分含量(TailDNA％)、尾长(TailLength)、尾距(TailMoment)均数(P0.05)。流式检测细胞凋亡(P0.01)。2组细胞周期分布无显著差异。结论 低剂量率超微分割放疗对脑胶质瘤细胞GL261可产生与常规分割等效的DNA损伤，但对细胞的杀伤作用强于常规分割照射。该现象可能与低剂量率超微分割照射胶质瘤细胞后有不同的DNA损伤修复机制有关。 [关键词]脑胶质瘤；超微分割放疗；凋亡；DNA损伤李光辉，E-mail:liguanghui_2000@；许建平，电话：（023E-mail:xujianping33@ Comparision of biological effects between ultra-microfractionated radiotherapy and conventional radiotherapy on glioma cells Chen Yuanyuan1, Tang jinliang1, Long Haixia2, Li Guanghui2, Xu Jianping1 (1Department of Pathology, Xinqiao Hospital, Third Military Medical University, Chongqing, 400037; 2Department of Oncology, Xinqiao Hospital, Third Military Medical University, Chongqing, 400037, China) [Abstract] Objective To compare ultra-microfractionated radiotherapy with conventional radiotherapy in effects on glioma cells. Methods The ultra-microfractionated radiotherapy (an interval of 3min for every 0.2Gy, the dose rate was 0.0667Gy/min) and conventional radiotherapy (the dose rate was 4-6Gy/min)were used to treat GL261 cells. On the 1st, 2nd and 3rd day after beginning of the treatment, the comet assay and flow cytometry were employed for detection of cell DNA damage, apoptosis and distribution of cell cycle. Results The comet assay showed that the ultra-microfractionated radiotherapy methods could cause similar cell DNA damage to the conventional one. The values comet TailDNA%, TailLength and TailMoment were not significantly different between the 2 groups (P 0.05) at different time phases. Flow cytometry showed that cell survival rate at different time phases was markedly lower in the ultra-microfractionated radiotherapy group than in the conventional radiotherapy group (P0.01). There were no remarkable differences in cell cycle distribution and growth curve between the 2 groups. Conclusion In glioma GL261 cells , ultra-microfractionated radiotherapy can cause similar cell DNA damage to