不同LET辐射对HepG2肝癌细胞的辐射敏感性与周期阻滞的影响

Radiosensitivity and cell cycle of HepG2 hepatoma cell line irradiated by ionizing radiation with different linear energy transfer

本工作研究不同LET射线辐照对HepG2肝癌细胞辐射敏感性、周期进程和凋亡的影响,为重离子治疗癌症的临床应用积累基础数据。以0、0.5、1、2、4、8Gy剂量的12C6+离子及X射线分别照射处于指数生长期的HepG2细胞,用克隆形成率测定细胞辐射敏感性,通过流式细胞术测定细胞DNA含量以确定各时相细胞的比例及细胞凋亡情况。实验结果显示,12C6+离子辐照所致的HepG2细胞存活率明显低于X射线。随着吸收剂量的增加和修复时间的延长,12C6+离子能导致更显著的细胞S期阻滞、G2/M期阻滞延迟和细胞凋亡。说明与X射线相比,12C6+离子辐照能更有效地杀伤HepG2肝癌细胞并诱导其凋亡。

In this paper, the effect of the ionizing radiation with different linear energy transfer on radiosensitivity, cell cycle alteration and the change of apoptosis in HepG2 hepatoma cell lines are studied to build up the base data for clinical therapy. Exponentially growing HepG2 cell lines are irradiated by ^12C^6＋ ions and X-ray at the doses of 0, 0.5, 1, 2, 4and 8Gy, respectivity. The radiosensitivity is assessed by means of the colony-forming assay. The DNA content, percentage of each cell-cycle phase and the apoptosis rate are obtained with the flow cytometry methods. The results indicate that compared with X-ray, the survival fraction of HepG2 hepatoma cells irradiated by ^12C^6＋ ions is evidently lower, the S phase arrest, G2/M phase arrest delay and the apoptosis in HepG2 cells irradiated by ^12C^6＋ ions are more prominent with the increase of dose and repaired time, thus suggesting that ^12C^6＋ ions can more effectively kill the HepG2 cells and induce apoptosis in the cells than X-ray.