56Fe17＋、12C6＋重离子束与60Coγ射线对人淋巴细胞染色体畸变、细胞周期和凋亡的影响

Effects of S6Fe17＋ , 12C6＋ heavy-ion and 60COγ -ray irradiation in chromosome aberrations, cell cycle and apoptosis of lymphocytes

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60Coγ射线分别照射人淋巴细胞系Peng—EBV，吸收剂量均为0、0．5和2．0Gy，56Fe17＋重离子束剂量率为0．26～0．55Gy／min，12C6＋重离子束剂量率为0．30～0．50Gy／min，γ射线照射剂量率为0．75Gy／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60Coγ射线照射后细胞畸变率与0Gy相比，差异有统计学意义（χ2=12．08～322．97，P〈0．05）。“双＋环”畸变率与0Gy相比，差异有统计学意义（χ2=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G，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、叮射线及。56Fe17＋重离子诱导的早期凋亡率依次降低。结论56Fe17＋、12C6＋离子束与60Coγ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＋离子束与叮射线的生物学效应与LET相关。

Objective To compare the radiation effects of 56Fe17＋ , 12C6＋ ion beams and 60Co γ- rays on chromosome aberrations, cell cycle arrest and apoptosis induction in lymphocytes. Methods Lymphocytes Peng-EBV cells were exposed to 56Fe17＋ , 12C6＋ ions and 60Co 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 tol2C6 ＋, 56Fe17 ＋ion beams and 60Co γ-rays（χ2 = 12.08 -322.9, P 〈0.05）, and the rate of ＂d ＋ r＂ distortion was significantly increased as well（ χ2 = 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 12C6＋, 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.