Dizdaroglu Miral, Jaruga Pawel, Birincioglu Mustafa, Rodriguez Henry
Chemical Science and Technology Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899-8311, USA.
Free Radic Biol Med. 2002 Jun 1;32(11):1102-15. doi: 10.1016/s0891-5849(02)00826-2.
Free radicals are produced in cells by cellular metabolism and by exogenous agents. These species react with biomolecules in cells, including DNA. The resulting damage to DNA, which is also called oxidative damage to DNA, is implicated in mutagenesis, carcinogenesis, and aging. Mechanisms of damage involve abstractions and addition reactions by free radicals leading to carbon-centered sugar radicals and OH- or H-adduct radicals of heterocyclic bases. Further reactions of these radicals yield numerous products. Various analytical techniques exist for the measurement of oxidative damage to DNA. Techniques that employ gas chromatography (GC) or liquid chromatography (LC) with mass spectrometry (MS) simultaneously measure numerous products, and provide positive identification and accurate quantification. The measurement of multiple products avoids misleading conclusions that might be drawn from the measurement of a single product, because product levels vary depending on reaction conditions and the redox status of cells. In the past, GC/MS was used for the measurement of modified sugar and bases, and DNA-protein cross-links. Recently, methodologies using LC/tandem MS (LC/MS/MS) and LC/MS techniques were introduced for the measurement of modified nucleosides. Artifacts might occur with the use of any of the measurement techniques. The use of proper experimental conditions might avoid artifactual formation of products in DNA. This article reviews mechanistic aspects of oxidative damage to DNA and recent developments in the measurement of this type of damage using chromatographic and mass spectrometric techniques.
自由基由细胞代谢和外源性物质在细胞内产生。这些物质与细胞内的生物分子发生反应，包括DNA。由此对DNA造成的损伤，也称为DNA氧化损伤，与诱变、致癌和衰老有关。损伤机制涉及自由基的提取和加成反应，导致以碳为中心的糖自由基以及杂环碱基的OH-或H-加合物自由基。这些自由基的进一步反应产生大量产物。存在多种用于测量DNA氧化损伤的分析技术。采用气相色谱（GC）或液相色谱（LC）与质谱（MS）联用的技术可同时测量多种产物，并提供阳性鉴定和准确定量。测量多种产物可避免因测量单一产物而得出的误导性结论，因为产物水平会因反应条件和细胞的氧化还原状态而有所不同。过去，GC/MS用于测量修饰的糖和碱基以及DNA-蛋白质交联。最近，引入了使用液相色谱/串联质谱（LC/MS/MS）和液相色谱/质谱（LC/MS）技术来测量修饰核苷。使用任何测量技术都可能出现假象。使用适当的实验条件可能避免DNA中产物的假象形成。本文综述了DNA氧化损伤的机制方面以及使用色谱和质谱技术测量此类损伤的最新进展。
