The difference in LET and ion species dependence for induction of initially measured and non-rejoined chromatin breaks in normal human fibroblasts
The difference in LET and ion species dependence for induction of initially measured and non-rejoined chromatin breaks in normal human fibroblasts
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DOI：
10.1667/rr1279.1
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发表时间：
2008-08-01
影响因子：
3.4
通讯作者：
Okayasu, Ryuichi
中科院分区：
文献类型：
--
作者：
Tsuruoka, Chizuru;Suzuki, Masao;Okayasu, Ryuichi
我们研究了在正常人成纤维细胞中，用不同重离子（如碳、氖、硅和铁）在正常人成纤维细胞中，在辐照后立即测量的初始测量断裂和辐照后 24 小时（37 摄氏度）后测量的非重新连接断裂诱导染色质断裂的 LET 和离子种类依赖性，这些重离子是由国家放射科学研究所 (NIRS) 的千叶重离子医疗加速器 (HIMAC) 产生的。使用过早染色体缩合（PCC）将染色质断裂测量为过多数量的过早缩合染色体片段。结果表明，最初测量的染色质断裂的每个细胞每 Gy 的过量碎片数量取决于 13.3 至 113.1 keV/μm 范围内的 LET，但不取决于离子种类。另一方面，辐照后孵育 24 小时后检测到的未重新连接的染色质断裂数量明显取决于 LET 和离子种类。在最初测量的断裂的横截面中没有观察到显着差异，但在碳、氖、硅和铁离子之间的非重新连接断裂的横截面中观察到统计学显着差异。这表明生物效应中的 LET 依赖性结构反映在修复过程的生物后果中。 (C) 2008 年，辐射研究学会。
We studied the LET and ion species dependence of the induction of chromatin breaks measured immediately after irradiation as initially measured breaks and after 24 h postirradiation incubation (37 degrees C) as non-rejoined breaks in normal human fibroblasts with different heavy ions, such as carbon, neon, silicon and iron, generated by the Heavy Ion Medical Accelerator in Chiba (HIMAC) at the National Institute of Radiological Science (NIRS). Chromatin breaks were measured as an excess number of fragments of prematurely condensed chromosomes using premature chromosome condensation (PCC). The results showed that the number of excess fragments per cell per Gy for initially measured chromatin breaks was dependent on LET in the range from 13.3 to 113.1 keV/mu m but was not dependent on ion species. On the other hand, the number of non-rejoined chromatin breaks detected after 24 h postirradiation incubation was clearly dependent on both LET and ion species. No significant difference was observed in the cross section for initially measured breaks, but a statistically significant difference was observed in the cross section for non-rejoined breaks among carbon, neon, silicon and iron ions. This suggests that the LET-dependent structure in the biological effects is reflected in biological consequences of repair processes. (C) 2008 by Radiation Research Society.