Effects of 56 Fe 17+ , 12 C 6+ heavy-ion and 60 Co γ-ray irradiation in chromosome aberrations, cell cycle and apoptosis of lymphocytes

Abstract

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 to12C6+ , 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. Key words: 56Fe17+ ion beam; 12C6+ ion beam; 60Co γ-rays; Chromosome aberrations; Cell apoptosis