摘要目的 比较56Fe17+、12C6+重离子束与60Coγ射线对人淋巴细胞染色体畸变、周期、凋亡的影响.方法56Fe17+、12C6+重离子束和60 Coγ射线分别照射人淋巴细胞系Peng-EBV,吸收剂量均为0、0.5和2.0 Gy,56Fe17+重离子束剂量率为0.26 ～0.55 Gy/min,12C6+重离子束剂量率为0.30 ～0.50 Gy/min,γ射线照射剂量率为0.75 Gy/min.研究不同射线对染色体细胞畸变率、“双+环”畸变率的影响.利用流式细胞仪检测细胞周期和细胞凋亡.结果12C6+、56Fe17+重离子与60 Coγ射线照射后细胞畸变率与0 Gy相比,差异有统计学意义(x2=12.08～322.97,P＜0.05).“双+环”畸变率与0 Gy相比,差异有统计学意义(x2=4.06 ～205.37,P＜0.05).其中,12C6+重离子束诱导的细胞畸变率和“双+环”畸变率最高,其次是56Fe17+重离子束,而且二者均高于60Coγ射线.56Fe17+、12C6+离子束与60Coγ射线均能诱导人淋巴细胞发生明显的G2期阻滞,差异有统计学意义(t=-80.9～0.17,P＜0.05),12C6+重离子、γ射线及56Fe17+重离子诱导的G2期阻滞程度依次降低.56Fe17+、12C6+离子束与60Coγ射线均能促进细胞凋亡,差异有统计学意义(t=-22.65 ～ 0.87,P＜0.05),12C6+重离子、γ射线及56Fe17+重离子诱导的早期凋亡率依次降低.结论 56Fe17+、12C6+离子束与60 Co γ射线均能诱导人淋巴细胞发生明显的染色体畸变、G2期阻滞及细胞凋亡.12C6+离子束诱导的染色体畸变、周期阻滞和凋亡程度最高.56Fe17+、12C6+离子束与γ射线的生物学效应与LET相关.

abstractsObjective To compare the radiation effects of 56Fe17+,12C6+ ion beams and 60Ci γ-rays on chromosome aberrations,cell cycle arrest and apoptosis induction in lymphocytes.Methods Lymphocytes Peng-EBV cells were exposed to 56 Fe17+,12C6+ ions and 60Ci γ-rays with different dose (0,0.5,2.0 Gy) at dose rates of 0.26-0.55,0.30-0.50 and 0.75 Gy/min,respectively.Chromosome aberration and " d + r" distortion rate was assayed,and cell apoptosis and cell cycle were analyzed by flow cytometry.Results The percentage of cells with chromosome aberration increased significantly after exposure to12C6+,56Fe17+ ion beams and 60Co γ-rays(x2 =12.08-322.9,P ＜0.05),and the rate of " d + r" distortion was significantly increased as well (x2 =4.06-205.37,P ＜ 0.05).The chromosome aberration rate and "d + r" distortion rateinduced by 56Fe17+ and 12C6+ ion beams were higher than that of γ-rays,especially 12C6 + irradiation.The G2 phase arrest(t =-80.9-0.17,P ＜ 0.05) and cell apoptosis (t =-22.65-0.87,P ＜ 0.05) were significantly induced by each irradiation in an order of 12 C6 +,γ-rays and 56Fe17+ ions from high to low.Conclusions Associated with the LET values,12C6+,56Fe17+ ionbeams and 60Co γ-rays could induce chromosome aberrations,G2 phase arrest and apoptosis in human lymphocytes,where 12C6+ ion beam irradiation was much more effective.