Abstract: X-ray Radiosensitivity of Brain Glioma Stem Cells and U251 CellsRuitai FAN1, Junqi LIU1, Hongzhi ZHANG2, Chenlei GE1, Yong HU1, Fangxia GUAN3, Bo YANG4Correspondence to: Ruitai FAN, E-mail: 14528968@qq.com1Department of Radiation Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China2Department of Hematologic Medicine, Huaihe Hospital Affiliated to He'nan University, Kaifeng 475000, China3Department of Bioengineering, Zhengzhou University, Zhengzhou 450052, China4Department of Neurosurgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, ChinaAbstract Objective: To study the radiosensitivity of brain glioma stem cells and U251 glioma cells to X-rays at different doses.Methods: Glioma tumor spheres were separated and cultured from glioma tissues, and glioma stem cells were obtained throughCD133 immunomagnetic bead separation. After radiation was administered to the glioma stem cells and U251 glioma cells at differentdoses, the radiosensitivity of these cells was detected by colony formation assays. Results: As the X-ray dose increased, the survivalrate of the two cell lines decreased. However, the survival rate of glioma stem cells was significantly higher than that of U251 cells (t = -3.71, P < 0.01 ). The experimental data were fitted according to the formula: SF = exp ( -αD-βD2 ), and α / β values of the tumorstem cells and U251 cells were 3.57 and 7.15, respectively. Conclusion: Glioma stem cells have a stronger resistance to radiation thanU251 glioma cells.Keywords Glioma stem cell; U251 Glioma cell line; CD133 Immunomagnetic beads; Radiosensitivity