Department of Medicinal Chemistry and the Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota 55455, USA.
Chem Res Toxicol. 2010 Apr 19;23(4):808-12. doi: 10.1021/tx900439w.
1,3-Butadiene (BD) is an important industrial and environmental chemical classified as a human carcinogen on the basis of epidemiological evidence for an increased incidence of leukemia in workers occupationally exposed to BD and its carcinogenicity in laboratory rats and mice. BD is metabolically activated to epoxide intermediates that can react with nucleophilic sites of cellular biomolecules. Among these, 1,2,3,4-diepoxybutane (DEB) is considered the ultimate carcinogenic species of BD due to its potent genotoxicity and mutagenicity attributed to the ability to form DNA-DNA cross-links and exocyclic nucleoside adducts. DEB mutagenesis studies suggest that adducts formed at adenine bases may be critically important, as DEB induces large numbers of A --> T transversion mutations. We have recently identified two regioisomeric exocyclic DEB-dA adducts, 1,N(6)-(2-hydroxy-3-hydroxymethylpropan-1,3-diyl)-2'-deoxyadenosine (1,N(6)-gamma-HMHP-dA) and 1,N(6)-(1-hydroxymethyl-2-hydroxypropan-1,3-diyl)-2'-deoxyadenosine (1,N(6)-alpha-HMHP-dA) ( Seneviratne et al. ( ( 2010 ) Chem. Res. Toxicol. 23 , 118 - 133 ), which were detected in DEB-treated calf thymus DNA and in tissues of BD-exposed laboratory animals. In the present work, we describe a column switching HPLC-ESI(+)-MS/MS methodology for the quantitative analysis of 1,N(6)-HMHP-dA isomers in the DNA of laboratory mice exposed to BD by inhalation. On the basis of their exocyclic structure, which prevents normal Watson-Crick base pairing, these adducts could be responsible for mutations at the A:T base pairs observed following exposure to DEB.
1,3-丁二烯（BD）是一种重要的工业和环境化学品，根据流行病学证据，职业接触 BD 的工人白血病发病率增加，以及其在实验室大鼠和小鼠中的致癌性，将其归类为人类致癌物。BD 经代谢激活为环氧化物中间体，可与细胞生物分子的亲核位点反应。在这些中间产物中，1,2,3,4-二环氧丁烷（DEB）被认为是 BD 的最终致癌物质，因为它具有很强的遗传毒性和致突变性，归因于形成 DNA-DNA 交联和环外核苷加合物的能力。DEB 致突变研究表明，在腺嘌呤碱基形成的加合物可能是至关重要的，因为 DEB 诱导大量 A-T 颠换突变。我们最近鉴定了两种位置异构的环外 DEB-dA 加合物，1,N(6)-(2-羟基-3-羟甲基丙-1,3-二基)-2'-脱氧腺苷（1,N(6)-γ-HMHP-dA）和 1,N(6)-(1-羟甲基-2-羟基丙-1,3-二基）-2'-脱氧腺苷（1,N(6)-α-HMHP-dA）（ Seneviratne 等人，（2010）Chem. Res. Toxicol. 23,118-133），这些加合物在 DEB 处理的小牛胸腺 DNA 中以及 BD 暴露的实验动物组织中被检测到。在本工作中，我们描述了一种柱切换 HPLC-ESI(+)-MS/MS 方法，用于定量分析吸入 BD 的实验小鼠 DNA 中的 1,N(6)-HMHP-dA 异构体。基于它们的环外结构，这阻止了正常的 Watson-Crick 碱基配对，这些加合物可能是暴露于 DEB 后观察到的 A:T 碱基对突变的原因。
