单次照射剂量增加对K562细胞损伤和细胞周期的影响

The study of cell damage and cell cycle arrest after high single dose irradiation in K562 cells

目的观察评价K562细胞在不同剂量单次照射后的损伤方式和进程。方法取对数生长期K562细胞分别给予0～20 Gy 6 MV-X线照射,并于照射后不同时间收集细胞,采用ANNEX IN-V/PI双染色法流式细胞仪检测细胞凋亡百分率变化,PI单染色法流式细胞仪检测细胞周期阻滞情况,得出不同照射剂量和时间对K562细胞的杀伤作用方式,以及细胞对损伤进行修复的能力。结果随照射剂量的增加细胞凋亡率增加,细胞周期分布从短暂的S期阻滞到持续的G2/M期阻滞,细胞自我修复能力减低。结论单次大剂量照射对细胞杀伤作用增强,损伤方式仍是凋亡,且不能被修复。

Objective To observe the type of cell damage and repair induced by 6 MV-X ray with different single dose irradiation in K562 cell lines. Methods K562 cells were exposed to 6 MV X-ray of 0 -20 Gy respectively. Cell apoptosis and cell cycle progression were detected by flow cytometry （FCM） after staining with FITC-ANNEXIN V/PI or only PI at the time point of 2 h,24 h and 48 h after irradiation. The type of cell damage and the ability of cell repair caused by different dose of irradiation were analyzed. Results The percentage of cell apoptosis was increased （P 〈 0.05 ） with an irreversible G2/M phase cell cycle arrest after high-dose irradiation. Conclusions Lethal damage of K562 cells was observed by high-dose X-ray irradiation. The type of damage is apoptosis which could not be repaired.