Replication stress induces micronuclei comprising of aggregated DNA double-strand breaks.
Replication stress induces micronuclei comprising of aggregated DNA double-strand breaks.
复制标题
复制应激诱导由聚集的 DNA 双链断裂组成的微核
DOI：
10.1371/journal.pone.0018618
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发表时间：
2011-04-15
期刊：
影响因子：
3.7
通讯作者：
Shao C
中科院分区：
文献类型：
--
作者：
Xu B;Sun Z;Liu Z;Guo H;Liu Q;Jiang H;Zou Y;Gong Y;Tischfield JA;Shao C
背景 哺乳动物细胞中的微核（MN）是基因组不稳定性和基因毒性暴露的可靠生物标志物。 MN 升高常见于具有内在基因组不稳定性的细胞和暴露于基因毒性剂的正常细胞中。 DNA 双链断裂的标志是 H2AX 丝氨酸 139 处的磷酸化 (γ-H2AX)。 MN 的一个子类包含大量且均匀的 γ-H2AX 信号。本研究测试了复制应激是否可以诱导这种 MN 亚类。主要发现 我们观察到，很大一部分 MN（从 20% 到近 50%）显示出 γ-H2AX 抗体的均匀染色，γ-H2AX 是 DNA 双链断裂 (DSB) 的标记。这种微核被命名为 MN-γ–H2AX (+)。我们发现，这种 MN 可以由已知会导致 DNA 复制应激和 S 期停滞的化学物质诱导。羟基脲、阿菲迪霉素和胸苷均可显着诱导 MN-γ–H2AX (+)，MN-γ–H2AX (+) 形成于 S 期，似乎源自 DSB 的聚集。 MN-γ–H2AX (−)，缺乏均匀 γ-H2AX 信号的 MN，在倍数变化方面被诱导程度较小。抑制微管解体的紫杉醇仅诱导 MN-γ–H2AX (−)。在由于细胞周期调节剂 CUL4B 耗尽而经历 S 期延长的细胞中，MN-γ–H2AX (+) 的频率也显着增加，但 MN-γ–H2AX (−) 的频率没有显着增加。 RNA 干扰消除复制蛋白 A1 (RPA1) 导致 MN-γ–H2AX (+) 和 MN-γ–H2AX (−) 升高。结论/意义 MN 的一个亚类 MN-γ–H2AX (+) 可以优先由复制应激诱导。根据 MN 的 γ-H2AX 状态对 MN 进行分类可以提供对内在基因组不稳定性和各种环境遗传毒物的更精细的评估。
Background Micronuclei (MN) in mammalian cells serve as a reliable biomarker of genomic instability and genotoxic exposure. Elevation of MN is commonly observed in cells bearing intrinsic genomic instability and in normal cells exposed to genotoxic agents. DNA double-strand breaks are marked by phosphorylation of H2AX at serine 139 (γ-H2AX). One subclass of MN contains massive and uniform γ-H2AX signals. This study tested whether this subclass of MN can be induced by replication stress. Principal Findings We observed that a large proportion of MN, from 20% to nearly 50%, showed uniform staining by antibodies against γ-H2AX, a marker of DNA double-strand breaks (DSBs). Such micronuclei were designated as MN-γ–H2AX (+). We showed that such MN can be induced by chemicals that are known to cause DNA replication stress and S phase arrest. Hydroxyurea, aphidicolin and thymidine could all significantly induce MN-γ–H2AX (+), which were formed during S phase and appeared to be derived from aggregation of DSBs. MN-γ–H2AX (−), MN that were devoid of uniform γ-H2AX signals, were induced to a lesser extent in terms of fold change. Paclitaxel, which inhibits the disassembly of microtubules, only induced MN-γ–H2AX (−). The frequency of MN-γ–H2AX (+), but not that of MN-γ–H2AX (−), was also significantly increased in cells that experience S phase prolongation due to depletion of cell cycle regulator CUL4B. Depletion of replication protein A1 (RPA1) by RNA interference resulted in an elevation of both MN-γ–H2AX (+) and MN-γ–H2AX (−). Conclusions/Significance A subclass of MN, MN-γ–H2AX (+), can be preferentially induced by replication stress. Classification of MN according to their γ-H2AX status may provide a more refined evaluation of intrinsic genomic instabilities and the various environmental genotoxicants.
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影响因子：
3.5
作者：
Bolderson, E;Scorah, J;Meuth, M
通讯作者：
Meuth, M
影响因子：
3.7
作者：
Kurose, A;Tanaka, T;Darzynkiewicz, Z
通讯作者：
Darzynkiewicz, Z
DOI：
10.1073/pnas.0830918100
发表时间：
2003-04-29
影响因子：
11.1
作者：
Rothkamm, K;Löbrich, M
通讯作者：
Löbrich, M
影响因子：
9.2
作者：
Paull, TT;Rogakou, EP;Bonner, WM
通讯作者：
Bonner, WM
DOI：
10.1002/cyto.990130711
发表时间：
1992-01-01
期刊：
CYTOMETRY
影响因子：
--
作者：
GRAWE, J;ZETTERBERG, G;AMNEUS, H
通讯作者：
AMNEUS, H