【摘要】 目的研究三氧化二砷（As₂O₃）对人脑胶质瘤SHG44细胞活性氧浓度及60Coγ射线照射联合As₂O₃对细胞DNA损伤中的影响。方法用2,7-二氢二氯荧光素（DCFH）标记细胞内活性氧（ROS）,激光共聚焦显微镜扫描检测细胞内荧光强度;用单细胞凝胶电泳法检测DNA彗星尾长及尾部DNA百分含量,比较As₂O₃、γ线照射单独及联合作用对细胞DNA的损伤程度。结果（1）As₂O₃可明显提高SHG44细胞内ROS水平,其ROS水平的改变随As2O3作用浓度的增加而升高。（2）60Coγ射线与As₂O₃联合作用诱导SHG44细胞DNA的损伤,其损伤程度随照射剂量的增加彗星尾长、尾部DNA百分比递增。两者联合作用后彗星尾长、尾部DNA百分比分别大于相应剂量的单独照射和As2O3组（P<0.01）。结论As2O3可明显抑制SHG44细胞的增殖,增强细胞的辐射敏感性,其抑制机制与诱导细胞内ROS水平提高具有相关性。更多还原

【Abstract】 Objective To study the effects of arsenic trioxide（As₂O₃） on the reactire oxygen species（ROS） level and of As₂O₃ combined with ⁶⁰Coγ rays on DNA damage of SHG44 human glioma cells.Methods The fluoresent probe 2,7-dichlorefluoresin（DCFH） was used to detect intracellular levels of ROS using laser scanning confocal microscopy（LSCM）.Single cell gel electrophoresis assay （SCGF） was used to detect SHG44 cells DNA damage.The index of DNA damage tail moment and percentage of tail of the comet were used to evaluate the extent of DNA damage.Results Compared with that of control group,the intracellular ROS level was significantly elevated when the cells were treated by As₂O₃.The DNA damage of SHG44 cells treated with ⁶⁰Coγ rays associated with As₂O₃ was significantly increased more than that with ⁶⁰Coγ rays or As₂O₃ alone（P<0.01）. Conclusion As₂O₃ could inhibit the growth of SHG44 cells and increase the radiosensitivity significantly,which might be correlated with the increase of ROS levels in the cells.更多还原