Kopp Benjamin, Dario Morgane, Zalko Daniel, Audebert Marc
Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRA, ENVT, INP-Purpan, UPS, Toulouse, France.
Environmental and Occupational Health and Safety, Toxicology of Contaminants Unit, French Agency for Food, Fougères, France.
Environ Mol Mutagen. 2018 Jul;59(6):516-528. doi: 10.1002/em.22197. Epub 2018 Apr 18.
One major challenge for in vitro genotoxicology is the determination of the genotoxic mode of action of tested compounds. The quantification of the phosphorylation of the histones H3 (pH3) and H2AX (γH2AX) allows an efficient discrimination between aneugenic and clastogenic compounds. However, these two biomarkers do not permit to deduct the specific mechanisms involved in the action of clastogenic compounds. The aim of this study was to investigate other possible cellular biomarkers allowing differentiating clastogenic properties. For this purpose, we analyzed γH2AX and pH3 plus six other biomarkers involved in the DNA damage signaling pathway in HepG2 cells treated with nine clastogens exhibiting different mechanisms of action, as well as one aneugen. All compounds were tested at various concentrations and with kinetics of 2, 6, 24 and 48 hr. Our results demonstrate the activation of the investigated biomarkers by the tested compounds in a time and concentration dependent manner. Notably, we observed for some nondirect genotoxic clastogens, notably dNTPs pool imbalance inducers, a different kinetic of DNA damage induction compared with direct genotoxins (oxidative stress). However, no specific biomarker signature of mechanisms of clastogenic action could be specified. Multiparametric analysis demonstrates a strong correlation between γH2AX and p-p53(S15) for clastogen compounds. Environ. Mol. Mutagen. 59:516-528, 2018. © 2018 Wiley Periodicals, Inc.
体外遗传毒理学面临的一个主要挑战是确定受试化合物的遗传毒性作用模式。组蛋白H3（pH3）和H2AX（γH2AX）磷酸化的定量分析有助于有效区分非整倍体诱导剂和染色体断裂剂。然而，这两种生物标志物无法推断出染色体断裂剂作用所涉及的具体机制。本研究的目的是研究其他可能的细胞生物标志物，以区分染色体断裂特性。为此，我们分析了γH2AX和pH3以及参与DNA损伤信号通路的其他六种生物标志物，这些标志物来自用九种具有不同作用机制的染色体断裂剂以及一种非整倍体诱导剂处理的HepG2细胞。所有化合物均在不同浓度下进行测试，作用时间分别为2、6、24和48小时。我们的结果表明，受试化合物以时间和浓度依赖性方式激活了所研究的生物标志物。值得注意的是，我们观察到一些非直接遗传毒性染色体断裂剂，特别是dNTP库失衡诱导剂，与直接遗传毒素（氧化应激）相比，其DNA损伤诱导动力学不同。然而，无法确定染色体断裂作用机制的特定生物标志物特征。多参数分析表明，对于染色体断裂剂化合物，γH2AX和p-p53（S15）之间存在很强的相关性。《环境与分子突变》，2018年，第59卷，第516 - 528页。© 2018威利期刊公司。
