DNA double-strand break repair defects in syndromes associated with acute radiation response: At least two different assays to predict intrinsic radiosensitivity?
DNA double-strand break repair defects in syndromes associated with acute radiation response: At least two different assays to predict intrinsic radiosensitivity?
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DOI：
10.1080/09553000701797039
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发表时间：
2008-02-01
影响因子：
2.6
通讯作者：
Foray, Nicolas
中科院分区：
文献类型：
--
作者：
Joubert, Aurelie;Zimmerman, Kristin M.;Foray, Nicolas
目的：与急性辐射反应相关的人类疾病是罕见的遗传性疾病，具有常见的临床和生物学特征，包括放射敏感性、基因组不稳定、染色体畸变和常见的免疫缺陷。为了确定哪些分子测定可以预测细胞放射敏感性（无论基因突变如何），在代表 8 种不同综合征的 40 个人类成纤维细胞中检查了细胞放射敏感性与未修复的 DNA 双链断裂 (DSB) 修复缺陷之间是否存在定量相关性。 材料和方法：多种技术，例如脉冲场凝胶电泳、质粒测定和使用抗 MRE11、MDC1、53BP1 和系统地应用了 H2AX、DNA-PK 的磷酸化形式。结果和结论：发现 2 Gy 下的存活分数与未修复的 DSB 的量成反比，无论基因突变和应用的测定如何。然而，没有任何一种检测能够区分人类放射敏感性的全部范围。特别是，H2AX 磷酸化形成的核灶不能很好地预测中等放射敏感性。我们的研究结果表明 DNA-PK 和 MRE11 的激活之间存在 ATM 依赖性相互作用。提出了根据细胞放射敏感性、对辐射的分子反应以及允许对其进行评估的功能测定对疾病进行分类。
Purpose: Human diseases associated with acute radiation responses are rare genetic disorders with common clinical and biological features including radiosensitivity, genomic instability, chromosomal aberrations, and frequently immunodeficiency. To determine what molecular assays are predictive of cellular radiosensitivity whatever the genes mutations, the existence of a quantitative correlation between cellular radiosensitivity and unrepaired DNA double-strand breaks (DSB) repair defects was examined in a collection of 40 human fibroblasts representing 8 different syndromes.Materials and methods: A number of techniques such as pulsed-field gel electrophoresis, plasmid assay and immunofluorescence with antibodies against MRE11, MDC1, 53BP1 and phosphorylated forms of H2AX, DNA-PK were applied systematically.Results and conclusions: Survival fraction at 2 Gy was found to be inversely proportional to the amount of unrepaired DSB, whatever the genes mutations and the assay applied. However, no single assay discriminates the full range of human radiosensitivity. Particularly, nuclear foci formed by the phosphorylation of H2AX do not predict well moderate radiosensitivities. Our findings suggest the existence of an ATM-dependent interplay between the activation of DNA-PK and MRE11. A classification of diseases according their cellular radiosensitivity, their molecular response to radiation and the functional assays permitting their evaluation is proposed.