Genotoxic chemicals act by causing DNA damage, which, if left unrepaired, can have deleterious consequences for cell survival. DNA damage response (DDR) gets activated to repair or mitigate the effects of DNA damage. Histone H2AX and H3 phosphorylation biomarkers (γ-H2AX and p-H3) have attracted great attention as they play pivotal roles in the DDR. Simultaneous quantitation of γ-H2AX and p-H3 in exposed cells may monitor the toxicity of genotoxic chemicals and to some extent reflect the subsequent DDR process. Reported here is the first comprehensive characterization of distinct orchestration and dynamic processes on cellular γ-H2AX and p-H3 for two major types of genotoxic chemicals, clastogens and aneugens, by stable isotope dilution-liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS). We find that clastogens significantly induce an increase in γ-H2AX and a decrease in p-H3; aneugens have no obvious effect on γ-H2AX, whereas induce either an increase or a decrease in p-H3. In addition, the specific profiles of clastogens and aneugens affecting DNA damage may be dynamically observed, which in turn provides insights into the processes involving DNA damage repair as well as transcription. Taken together, these results suggest that robust LC-MS/MS analysis of γ-H2AX and p-H3 can not only quantitatively differentiate mechanistic information on clastogens and aneugens but also dynamically present the detail profiles of DNA damage and repair processes.

中文翻译：

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质谱分析揭示了两种主要类型的遗传毒性化学品的 γ-H2AX 和 p-H3 的不同编排和动态过程。

基因毒性化学物质通过引起 DNA 损伤起作用，如果不加以修复，会对细胞存活产生有害后果。DNA 损伤反应 (DDR) 被激活以修复或减轻 DNA 损伤的影响。组蛋白 H2AX 和 H3 磷酸化生物标志物（γ-H2AX 和 p-H3）在 DDR 中发挥着关键作用，因此引起了极大的关注。同时定量暴露细胞中的 γ-H2AX 和 p-H3 可以监测基因毒性化学物质的毒性，并在一定程度上反映随后的 DDR 过程。此处报告的是通过稳定同位素稀释-液相色谱-串联质谱 (ID-LC-质谱/质谱）。我们发现断裂素显着诱导γ-H2AX 增加和p-H3 减少；aneugens 对 γ-H2AX 没有明显影响，而诱导 p-H3 增加或减少。此外，可以动态观察影响 DNA 损伤的断裂素和异基因的特定谱，这反过来又提供了对涉及 DNA 损伤修复和转录过程的见解。综上所述，这些结果表明，对 γ-H2AX 和 p-H3 进行稳健的 LC-MS/MS 分析不仅可以定量区分关于断裂原和去毛素的机械信息，而且还可以动态呈现 DNA 损伤和修复过程的详细信息。可以动态观察影响 DNA 损伤的断裂素和异基因的特定谱，这反过来又提供了对涉及 DNA 损伤修复和转录的过程的见解。综上所述，这些结果表明，对 γ-H2AX 和 p-H3 进行稳健的 LC-MS/MS 分析不仅可以定量区分关于断裂原和去毛素的机械信息，而且还可以动态呈现 DNA 损伤和修复过程的详细信息。可以动态观察影响 DNA 损伤的断裂素和异基因的特定谱，这反过来又提供了对涉及 DNA 损伤修复和转录的过程的见解。综上所述，这些结果表明，对 γ-H2AX 和 p-H3 进行稳健的 LC-MS/MS 分析不仅可以定量区分关于断裂原和去毛素的机械信息，而且还可以动态呈现 DNA 损伤和修复过程的详细信息。