^(32)P持续照射对HeLa细胞周期影响规律的研究

Study on the characteristics of cell-cycle perturbation in Hela cell exposed to continuous β irradiation of ^(32)P

研究3 2 P照射体外培养HeLa细胞细胞周期影响特点 ,以探索肿瘤核素治疗放射生物学机制。采用人宫颈癌HeLa细胞系体外培养 ,制作3 2 P放射性贴片照射细胞 ,通过观察照射后细胞周期再分布 ,研究不同剂量、剂量率、照射时间细胞放射效应特点。结果表明 ,照射后G2期阻滞为剂量依赖性 ,但阻滞达峰值后 ,随照射时间延长 ,累积剂量增加阻滞程度不再增加 ,有坪值 ,其大小与剂量率有关 ;G2期阻滞峰值的时间均为 2 4h左右 ,2 4— 32h之后下降。结果提示 ,3 2 P放射性贴片照射HeLa细胞 ,照射后细胞表现为G2期阻滞 ,阻滞程度与剂量相关 ,G2期阻滞达峰值的时间与细胞周期内在属性相关 ,与剂量、照射时间无关。

In an attempt to understand radiobiological basis for targeted radiotherapy in oncology, the cell cycle perturbations have studied in Hela cell lines after exposed to different doses and dose-rate of 32 P radiation. Asynchronous Hela cells, cultured in vitro, were exposed to β radiation from radioactive filter papers (absorbed 32 P) which were put close under culture plate of growing monolayer of Hela cells. The characteristic radiation response to different dose, dose-rate and radiation time was evaluated through cell cycle perturbation studied by flow cytometry. Cell cycle status showed G2 phase blockage in a way of dose dependence, a plateau of G2 block can be recognized at about 24h. Interestingly, the G2 phase declined even though the accumulated doses increased as the time of radiation prolonged. This result suggested that the cell cycle progress could not be inhibited completely when exposed to continuous radiation, rather it seems to be controlled somehow by the nature of cell cycle itself for a certain cell line. G2 blockage, one of the major changes caused by β radiation, is dose-dependent, but the time reaching the plateau of G2 phase blockage is most likely related with the intrinsic nature of cell cycle.