【作者】 李平；

【导师】 陆雪官；

【作者基本信息】 苏州大学 ， 肿瘤学， 2013， 硕士

【摘要】 目的：探讨由CD133标记的脑胶质瘤干细胞（CD133阳性细胞）与非脑胶质瘤干细胞（CD133阴性细胞）辐射后DNA双链断裂损伤及修复的差异，从而研究影响脑胶质瘤干细胞放射敏感性的可能因素。方法：选择人脑胶质瘤U87、U251细胞系，采用免疫流式分选技术分选出CD133+、CD133-细胞；采用中性彗星实验检测4Gy X射线垂直照射后0.5h、6h、24hDNA双链断裂情况；间接免疫荧光技术检测照射后0.5h、6h、24h Rad51荧光灶的表达情况。结果：U87细胞分选后CD133+、CD133-细胞及U251细胞分选后CD133+、CD133-细胞在0Gy条件下彗星尾力距均无明显差异（t=1.67，P=0.171；t=1.80，P=0.147）；4Gy照射后0.5h两种细胞系分选出的CD133+、CD133-细胞彗星尾力距均显著升高，但两种细胞亚型间差异均无统计学意义（t=1.44，P=0.224；t=1.09，P=0.339）；6、24h U87细胞分选出的CD133+细胞彗星尾力距下降程度大于CD133-细胞（t=5.31，P=0.006；t=8.09，P=0.001）， U251细胞分选出的CD133+细胞尾力距下降程度亦大于CD133-细胞（t=16.81，P=0.000；t=14.53，P=0.000）。U87细胞分选后CD133+、CD133-细胞及U251细胞分选后CD133+、CD133-细胞在0Gy条件下均有Rad51荧光灶的表达，但CD133+、CD133-细胞间表达率差异无统计学意义（t=2.41，P=0.074；t=0.44，P=0.681）；4Gy照射后0.5h两种细胞系分选出的CD133+、CD133-细胞Rad51灶表达率均明显上升，但CD133+、CD133-细胞间无明显差异（t=1.12，P=0.265；t=2.50，P=0.067）；6、24h U87细胞分选出的CD133-细胞相较CD133+细胞Rad51荧光灶表达率下降（t=22.88，P=0.000；t=12.43，P=0.000），U251细胞分选出的CD133-细胞Rad51荧光灶表达率亦下降（t=14.06，P=0.000；t=17.69，P=0.000）。结论：人脑胶质瘤干细胞CD133+细胞照射后损伤修复能力高于非脑胶质瘤干细胞CD133-细胞，这可能是影响人脑胶质瘤干细胞放射敏感性的一个因素。更多还原

【Abstract】 Objective: To explore the differences of DNA double-strand breaks (DSBs) breakrepair after irradiation between CD133-positive (CD133+) glioma stem cells andCD133-negative (CD133-) non-stem cells in vitro, to investigate the possiblie influencingfactors of glioma stem cells radiosensitivityMethods: CD133+and CD133-cells were isolated from glioma U87and U251celllines by flow cytometry sorter system. The radiation-induced DSB repair of CD133+andCD133-cells was determined by the neutral comet assay, immunofluorescence of Rad51foci at0.5h,6h,24h after irradiation.Results: For glioma U87and U251cell lines, the tailmoment between CD133+cellsand CD133-cells had no difference at0Gy (t=1.67, P=0.171; t=1.80, P=0.147),0.5h afterirradiation, the tailmoment both increased, but had no difference for CD133+cells andCD133-cells(t=1.44, P=0.224; t=1.09, P=0.339); at6and24h after irradiation, thetailmoment of CD133+cells isolated from glioma U87cell lines was lower than CD133-cells (t=5.31, P=0.006; t=8.09, P=0.001). The results were similar for glioma U251celllines (t=16.81, P=0.000; t=14.53, P=0.000). The expression of Rad51foci betweenCD133+and CD133-cells were no significant difference at0Gy (t=2.41, P=0.074; t=0.44,P=0.681).0.5h after irradiation, the expression of Rad51foci both increased, but had nodifference for CD133+cells and CD133-cells(t=1.12, P=0.265; t=2.50, P=0.067). Theexpression of Rad51foci was reduced on CD133-cells isolated from U87at6and24hafter irradiation compared to CD133+cells(t=22.88, P=0.000; t=12.43, P=0.000). Thesimilar results also were found at glioma U251cell lines (t=14.06, P=0.000; t=17.69,P=0.000). Conclusions: The DSB repair capacity of glioma stem cells is more powerful thannon-stem cells. It is a probable mechanism that glioma stem cells are more radioresistivethan glioma non-stem cells.更多还原