Contribution of Decreased Expression of Ku70 to Enhanced Radiosensitivity by Sodium Butyrate in Glio

• 作 者: Yuhui LI Hongxia ZHOU Enming XING Meera Dassarath Jinghua REN Xiaorong DONG Hongli LIU Kunyu YANG Gang WU
• 机 构: Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology
• 出 处: 华中科技大学学报（医学）（英德文版）
• 发表日期: 2011年3期
• 关键词: sodium butyrate radiosensitivity Ku70 DNA double-strand breaks γ-H2AX

The present study investigated the enhanced radiosensitivity of U-251 cells induced by sodium butyrate (NaB) and its possible mechanisms.Increased radiosensitivity of U251 cells was examined by clonogenic cell survival assays.The expression of Ku70 mRNA and protein was detected by using RT-PCR and West blotting respectively.γ-H2AX foci were measured at different time points after ionizing irradiation alone or combined with NaB treatment.The results showed that cell survival rate was significantly reduced,both D0 and Dq values were decreased (D0:1.43 Gy vs.1.76 Gy; Dq:1.22 Gy vs.2.05 Gy) after the combined treatment as compared with irradiation alone,and sensitivity enhancing ratio (SER) reached 1.23.The average number ofγ-H2AX foci per cell receiving the combined treatment was significantly increased at different time points,and the expression levels of Ku70mRNA and protein were suppressed by NaB in a dose-dependent manner.It was concluded that enhanced radiosensitivity induced by NaB involves an inhibited expression of Ku70 and an increase in γ-H2AX foci,which suggests decreased ability in DSB repair.