中文摘要：

选取对数生长期人肺癌细胞A549接受0-6．0Gy碳离子照射，用克隆形成法检测细胞的存活率；并于照射后12和24h收集细胞，用流式细胞术检测细胞周期各时相的细胞百分比，观察不同剂量碳离子辐照对A549细胞周期进程的影响。结果显示：0～6．0Gy碳离子照射后细胞存活率显著下降；照射后12h细胞发生G0／G1期阻滞，而照射后24h，1．0Gy照射组细胞在G0／G1期阻滞，2．0～6．0Gy照射组细胞在G2／M期阻滞。上述结果表明，在A549细胞接受碳离子照射后的12和24h内，1．0Gy照射可持续激活细胞G1期检查点，而2．0～6．0Gy碳离子照射后其细胞周期进程是随时间变化的。

英文摘要：

To investigate the effects of cell-cycle progression of A549 cell induced by ^12C^6＋ ion irradiation at different doses, the survival fractions of the A549 cells were determined by colony-forming assay; cell cycles were analyzed by FACS at 12 h or 24 h after irradiation. The results showed that the percentage of survival in the A549 cells decreased with irradiation doses. Compared with control group, the percentage of the cells in G0/G1 phase significantly increased at 12 h after irradiation with different doses of 12C6＋ ions. However, at 24 h after irradiation the percentage of the cells in G0/G1 phase significantly increased with 1.0 Gy ^12C^6＋ions, while the cells showed increasing percentage in G2/M phase with 2.0, 4.0 or 6.0 Gy ^12C^6＋ ions. The results suggested that G1 cell cycle checkpoint was activated in 12-24 h after irradiation with 1.0 Gy ;zC6＋ ions, but after irradiation with 2.0=-6.0 Gy ^12C^6＋ ions, the cell-cycle progression of the A549 cells changed with time.