恶性脑胶质瘤U87细胞系肿瘤干细胞放疗敏感性的体外实验研究

目的探讨脑胶质瘤细胞系U87细胞及其肿瘤干细胞（CSCs）对体外放疗的敏感性。方法应用神经干细胞（NSCs）培养基分离培养形成细胞球克隆,检测细胞球细胞的NSCs特性。采用不同剂量放射线照射U87细胞及其CSCs,应用集落形成实验和生存曲线检测其生存情况。结果 U87细胞在NSCs培养基中形成悬浮的细胞球克隆,具有自我更新和多向分化能力,表达CD133、Nestin;两种细胞的存活率均随照射剂量增加而下降,且CSCs的存活率明显高于U87细胞（P〈0.01）。结论在体外条件下,CSCs的放射敏感性明显低于U87细胞,其可能是恶性脑胶质瘤放疗抵抗的主要原因。

Research on radiosensitivity of malignant glioma U87 cell line cancer stem cells in vitro

Objective Investigate radiosensitivity of glioma cell line U87 cells and cancer stem cells（CSCs） in vitro.Methods U87 cell was cultured in neural stem cells medium（NSCs-medium）,NSCs-medium was used to isolate spheres from primary cultured tumor cells derived from U87 cell line,and was identified as CSCs U87 cells.CSCs were irradiated by X-rays with different doses,respectively.Colony-forming experiment was used to detect cell survival,and survival curves were drafted,respectively.Results U87 cells formed suspension in serum-free stem cell medium and proliferated into the clonal sphere.The clonal spheres presented strong self-renewal and multipotency ability,and expressed specific marker CD133,Nestin.The cell survival curves showed that the survival rates decreased along with increased irradiation doses,and the ratios of cell clone formation in CSCs subpopulation was higher than in U87 cell significantly（P0.01）.Conclusion Radiosensitivity of CSCs is strikingly lower than that of U87 cells in vitro,which may be the culprit of malignant glioma radioresistance.