U251胶质瘤干细胞抗辐射性能研究

Redioresistence of glioma stem cell in U251 cell line

目的从U251细胞株中分离胶质瘤干细胞并探讨胶质瘤干细胞的抗辐射性能。方法应用无血清培养基悬浮培养法从U251细胞株中分离鉴定胶质瘤干细胞，X线辐射处理72h后，噻唑蓝（MTT）比色法检测细胞活性，流式细胞仪及免疫荧光染色法检测辐射前后CD133和三磷酸腺苷结合盒转运体成员2（ABCG2）的表达。结果U251细胞株中经过无血清培养可以得到悬浮生长的胶质瘤细胞球，具有较强的自我更新和增殖能力；在细胞球中，有3．17％的细胞表达CD133，1．17％表达ABCG2；9Gy辐射处理72h后，CD133表达阳性率上升到13．24％，ABCG2表达阳性率上升到8．76％；辐射处理后，细胞活性随辐射剂量增大而显著下降（P〈0．05）。结论悬浮培养法得到的肿瘤细胞球有小部分是胶质瘤干细胞；X线辐射处理后，细胞活性随辐射剂量增大而显著下降；胶质瘤干细胞表现出更强的抗辐射损伤性能。

Objective To explore the radioresistence of glioma stem cell iso-lated from U251 cell line. Methods U251 cells were cultured in serum-free DMEM/F12 medium, There were forming U251 brain tumor spheres, In order to observe the characteristic of the cell of tumor spheres, the cell of tumor spheres were identifyed by immunohistochemistry and were irradiated by X- rays with different doses, The activ-ity of cell were measured by methyl thiazol tetrazolium （MTT） , the marker CD133 and ABCG2 were measured by Flow cytometer. Results Some U251 glioma cells have the capacity to self-renew and generate free-floating brain tumor spheres; CD133 ＋ cells were 3.17% and ABCG2 ＋ cells were 1.17% in tumur sphere, After 9Gy irradiated, CD133 ＋ ceils increased to13.24% and ABC-G2 ＋ ceils were 8.76% ; After ir-radiated, the activity of cells decreased obviously. Conclusion Glioma stem cell can achieve by cultured in serum-free medium and Glioma stem cell show more radioresistance than glioma cell.