Ding Wei, Bishop Michelle E, Lyn-Cook Lascelles E, Davis Kelly J, Manjanatha Mugimane G
Division of Genetic and Molecular Toxicology, US FDA/National Center for Toxicological Research;
Division of Genetic and Molecular Toxicology, US FDA/National Center for Toxicological Research.
J Vis Exp. 2016 May 4(111):53833. doi: 10.3791/53833.
Unrepaired DNA damage can lead to genetic instability, which in turn may enhance cancer development. Therefore, identifying potential DNA damaging agents is important for protecting public health. The in vivo alkaline comet assay, which detects DNA damage as strand breaks, is especially relevant for assessing the genotoxic hazards of xenobiotics, as its responses reflect the in vivo absorption, tissue distribution, metabolism and excretion (ADME) of chemicals, as well as DNA repair process. Compared to other in vivo DNA damage assays, the assay is rapid, sensitive, visual and inexpensive, and, by converting oxidative DNA damage into strand breaks using specific repair enzymes, the assay can measure oxidative DNA damage in an efficient and relatively artifact-free manner. Measurement of DNA damage with the comet assay can be performed using both acute and subchronic toxicology study designs, and by integrating the comet assay with other toxicological assessments, the assay addresses animal welfare requirements by making maximum use of animal resources. Another major advantage of the assays is that they only require a small amount of cells, and the cells do not have to be derived from proliferating cell populations. The assays also can be performed with a variety of human samples obtained from clinically or occupationally exposed individuals.
未修复的DNA损伤会导致基因不稳定，进而可能促进癌症发展。因此，识别潜在的DNA损伤剂对于保护公众健康至关重要。体内碱性彗星试验通过检测DNA链断裂来检测DNA损伤，对于评估外源性物质的遗传毒性危害尤为重要，因为其反应反映了化学物质的体内吸收、组织分布、代谢和排泄（ADME）以及DNA修复过程。与其他体内DNA损伤试验相比，该试验快速、灵敏、直观且成本低廉，并且通过使用特定的修复酶将氧化性DNA损伤转化为链断裂，该试验能够以高效且相对无假象的方式测量氧化性DNA损伤。彗星试验测量DNA损伤可采用急性和亚慢性毒理学研究设计，并且通过将彗星试验与其他毒理学评估相结合，该试验通过最大限度地利用动物资源满足了动物福利要求。该试验的另一个主要优点是只需要少量细胞，而且细胞不必来自增殖细胞群体。该试验也可以用从临床或职业暴露个体获得的各种人类样本进行。
