重离子辐射对体外支气管上皮细胞的失活效应

Heavy Ion Radiation Induced Inactivation of Human Bronchial Epithelial Cells.

目的观察Ｌｉ、Ｃ、Ｆ三种重离子辐射诱发的细胞失活效应。方法用中国原子能科学院核物理研究所的ＨＩ１３串列加速器产生的Ｌｉ（Ｚ＝３，ＬＥＴ＝１００ｋｅＶ／μｍ）、Ｃ（Ｚ＝６，ＬＥＴ＝３００ｋｅＶ／μｍ）、Ｆ（Ｚ＝９，ＬＥＴ＝１０００ｋｅＶ／μｍ）三种离子束以０．５～６．０Ｇｙ剂量设计值照射人支气管上皮细胞系（ＢＥＡＳ－２Ｂ），以１０００个细胞／瓶接种，计算存活分数。结果三种重离子照射细胞后的细胞存活分数与照射剂量呈指数负相关关系，存活分数（ＳＦ，无量纲）与剂量（Ｄ，Ｇｙ）关系的拟合方程分别为Ｓ＝ＥＸＰ（－Ｄ／１．２８）（Ｌｉ），Ｓ＝ＥＸＰ（－Ｄ／１．１８）（Ｃ），Ｓ＝ＥＸＰ（－Ｄ／２．０９）（Ｆ）；辐射敏感参数Ｄ０为１．２８、１．１８、２．０９Ｇｙ，呈单击单靶模型。以６０Ｃｏγ射线的Ｄ０为参比，Ｌｉ、Ｃ及Ｆ离子的相对生物效应值相继是２．５４、２．６７和１．５５。失活截面（σｉ）分别为１２．５、４０．６、７６．５μｍ２。结论Ｌｉ、Ｃ、Ｆ对体外细胞的失活效应大于６０Ｃｏγ射线，细胞失活至少需要一次以上的离子打击。

s: Objective To observe the cell inactivating effects of Li,C and F ions. Method Li(Z=3),C(Z=6) and F(Z=9) ion beams,with LETs of 100 keV/μm,300 keV/μm and 1000 keV/μm,respectively were produced by HI 13 tandem accelerator at the Department of Nuclear Physics,China Institute of Atomic Energy.The human bronchial epithelium cell line(BEAS-2B) was irradiated with the designed doses ranging from 0.5 Gy to 6.0 Gy. After irradiation,the cells were cultured at 1000/flask and the survival fractions were calculated. Result The cell survival fraction (SF,non unit) have negative exponential relations with dose(D,Gy) as shown by the fitted equations:SF=EXP(-D/1.28)(Li);SF=EXP(-D/1.18)(C);SF=EXP(-D/2.09)(F),respectively. The sensitive parameters(D 0,Gy) of radiation were D 0=1.28; D 0=1.18;D 0=2.09,respectively.The patterns of cell survival were fitted to single target model. The relative biological effectiveness (RBE) for Li,C and F ions were 2.54,2.67,1.55,repectively,compared with D 0 of γ ray irradiation.The inactivation cross sections for these ions were 12.5,40.6 and 76.5μm 2 respectively. Conclusion The effectiveness of radiation induced by heavy ions of Li,C and F was more serious than that of 60 Co γ ray,and more than one particle traversal are needed to kill a cell on the average.