中文摘要：

目的：研究人肝癌细胞接受不同剂量或时间的6MV-X线照射后,对细胞凋亡和周期进程的影响。方法：用流式细胞术检测6MV-X线照射4Gy后不同时间以及不同剂量6MV-X线照射后24h HepG2和PLC/PRF/5两种细胞的细胞凋亡和周期分布状况。结果：4Gy 6MV-X线照射后24h,HepG2细胞凋亡率高于PLC/PRF/5细胞,分别为（7.61±0.77）%和（5.63±0.87）%（P〈0.05）,且随时间和剂量增加,差异越显著;HepG2细胞受4Gy照射后12h,G0/G1期比例下降,为（40.56±1.59）%,后逐渐上升,G2/M期比例增高,为（13.28±1.02）%,随后逐渐下降;2-6Gy照射24h后,G0/G1期比例逐渐上升,G2/M期比例逐渐下降;PLC/PRF/5细胞G2/M期比例在照射后24h阻滞最明显（22.11±1.48）%,后逐渐降低,随照射剂量增加而增大。结论：2-6Gy 6MV-X线照射可诱导HepG2与PLC/PRF/5细胞凋亡,并改变周期进程,HepG2细胞发生G1和G2期阻滞,PLC/PRF/5发生G2期阻滞。

英文摘要：

Objective：To evaluate effects of radiotherapy on apoprosis and cell cycle in human hepatoma cell line.Methods：Using flow cytometry to determine cell cycle distribution of HepG2 and PLC / PRF /5 cells from 0-24 h after exposure to 4Gy 6MV X-ray and at the 24 thh after exposure 0-6Gy.Results：24h after exposed of 4Gy 6MV X-ray to HepG2 and PLC / PRF /5 cells,and cell survival rates of HepG2 and PLC / PRF /5 cells were（7.61 ± 0.77） %and（5.63 ± 0.87） %（ P〈0.05）,the discrepancy were gradually increased as the time or dosage increased.After HepG2 cells were exposed to 4Gy 6MV X-ray,the percentage of G0/ G1 cells decreased to（40.56 ± 1.59） %,and then,it augmented with prolonged time.But G2/ M cells were reverse.After PLC / PRF /5 cells were exposed to 4Gy6 MV X-ray,the percentage of G2/ M cells augmented to（22.11 ± 1.48） %,and it decreased with prolonged time.The percentage of G2/ M cells increased with irradiated dose from 0-6Gy after PLC / PRF /5 cells were exposed to6 MV X-ray and at the 24^th h.Conclusion：Irradiation could induce the apoptosis of human hepatoma cell line.The cell cycle progression of HepG2 and PLC / PRF /5 cell lines could be changed by 6MV X-ray with the doses of 2-6Gy.X-irradiation could induce G1 and G2arrest in HepG2 cells,G2 arrest in PLC / PRF /5 cells.