Qualitative and quantitative analysis of phosphorylated ATM foci induced by low-dose ionizing radiation
Qualitative and quantitative analysis of phosphorylated ATM foci induced by low-dose ionizing radiation
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DOI：
10.1667/rr3542.1
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发表时间：
2006-05-01
影响因子：
3.4
通讯作者：
Watanabe, M
中科院分区：
文献类型：
--
作者：
Suzuki, K;Okada, H;Watanabe, M
我们研究了在低剂量X射线照射下指数生长的正常人类二倍体细胞中磷酸化共济失调毛细血管扩张突变(ATM)灶的形成。照射后即刻即可检测到磷酸化的ATM病灶，且随着照射后时间的延长，病灶数目逐渐减少。磷酸化ATM焦点的动力学与磷酸化组蛋白H_2AX的动力学相似。我们发现，与组蛋白H_2AX的自发磷酸化焦点相比，ATM自发磷酸化的焦点更少。值得注意的是，在S期细胞中检测到大量的磷酸化组蛋白H_2AX焦点，而不是磷酸化的ATM焦点。病灶的诱导与剂量呈线性关系，剂量范围为10mGy1~1Gy.平均每灰度级的磷酸化ATM病灶数约为50个。病灶的平均大小与20mGy组和1Gy组相当，病灶消失的动力学没有显著差异，表明DNA双链断裂类似地被DNA损伤检查点识别并被修复，而不受剂量的影响。(C)2006年，由辐射研究学会提供。
We examined the formation of phosphorylated ataxia telangiectasia mutated (ATM) foci in exponentially growing normal human diploid cells exposed to low doses of X rays. Phosphorylated ATM foci were detected immediately after irradiation, and the number of foci decreased as the time after irradiation increased. The kinetics of phosphorylated ATM foci was comparable to that of phosphorylated histone H2AX. We found that there were fewer spontaneous phosphorylated ATM foci than that phosphorylated histone H2AX foci. Notably, significant numbers of phosphorylated histone H2AX foci, but not phosphorylated ATM foci, were detected in the S-phase cells. The induction of foci showed a linear dose-response relationship with doses ranging for 10 mGy to 1 Gy, and the average number of phosphorylated ATM foci per gray was approximately 50. The average size of the foci was comparable for the cells irradiated with 20 mGy and I Gy, and there was no significant difference in the kinetics of disappearance of foci, indicating that DNA double-strand breaks are similarly recognized by DNA damage checkpoints and are repaired irrespective of the dose. (c) 2006 by Radiation Research Society.