Cancer Biomarkers and Prevention Group, Biocentre, University of Leicester, University Road, Leicester LE1 7RH, UK.
Rapid Commun Mass Spectrom. 2010 Aug 30;24(16):2329-40. doi: 10.1002/rcm.4645.
Human exposure to polycyclic aromatic hydrocarbons (PAHs) from sources such as industrial or urban air pollution, tobacco smoke and cooked food is not confined to a single compound, but instead to mixtures of different PAHs. The interaction of different PAHs may lead to additive, synergistic or antagonistic effects in terms of DNA adduct formation and carcinogenic activity resulting from changes in metabolic activation to reactive intermediates and DNA repair. The development of a targeted DNA adductomic approach using liquid chromatography/tandem mass spectrometry (LC/MS/MS) incorporating software-based peak picking and integration for the assessment of exposure to mixtures of PAHs is described. For method development PAH-modified DNA samples were obtained by reaction of the anti-dihydrodiol epoxide metabolites of benzo[a]pyrene, benzo[b]fluoranthene, dibenzo[a,l]pyrene (DB[a,l]P) and dibenz[a,h]anthracene with calf thymus DNA in vitro and enzymatically hydrolysed to 2'-deoxynucleosides. Positive LC/electrospray ionisation (ESI)-MS/MS collision-induced dissociation product ion spectra data showed that the majority of adducts displayed a common fragmentation for the neutral loss of 116 u (2'-deoxyribose) resulting in a major product ion derived from the adducted base. The exception was the DB[a,l]P dihydrodiol epoxide adduct of 2'-deoxyadenosine which resulted in major product ions derived from the PAH moiety being detected. Specific detection of mixtures of PAH-adducted 2'-deoxynucleosides was achieved using online column-switching LC/MS/MS in conjunction with selected reaction monitoring (SRM) of the M+H to M+H-116 transition plus product ions derived from the PAH moiety for improved sensitivity of detection and a comparison was made to detection by constant neutral loss scanning. In conclusion, different PAH DNA adducts were detected by employing SRM M+H-116 transitions or constant neutral loss scanning. However, for improved sensitivity of detection optimised SRM transitions relating to the PAH moiety product ions are required for certain PAH DNA adducts for the development of targeted DNA adductomic methods.
人接触多环芳烃（PAHs）的来源，如工业或城市空气污染、烟草烟雾和熟食，不仅限于单一化合物，而是不同 PAHs 的混合物。不同 PAHs 的相互作用可能导致 DNA 加合物形成和致癌活性的相加、协同或拮抗效应，这是由于代谢激活到反应性中间体和 DNA 修复的变化。描述了一种使用液相色谱/串联质谱（LC/MS/MS）结合基于软件的峰选择和整合的靶向 DNA 加合物组学方法，用于评估多环芳烃混合物的暴露情况。为了开发方法，通过苯并[a]芘、苯并[b]荧蒽、二苯并[a,l]芘（DB[a,l]P）和二苯并[a,h]蒽的反式二氢二醇环氧化物代谢物与小牛胸腺 DNA 在体外反应，然后酶解为 2'-脱氧核苷，获得了 PAH 修饰的 DNA 样品。正 LC/电喷雾电离（ESI）-MS/MS 碰撞诱导解离产物离子谱数据表明，大多数加合物显示出共同的碎片，中性损失 116 u（2'-脱氧核糖），导致来自加合物碱基的主要产物离子。例外的是 2'-脱氧腺苷的 DB[a,l]P 反式二氢二醇环氧化物加合物，检测到主要产物离子来自 PAH 部分。通过在线柱切换 LC/MS/MS 与选择反应监测（SRM）相结合，实现了 PAH 加合物 2'-脱氧核苷混合物的特异性检测，即[M+H]+到[M+H-116]+的转变加上来自 PAH 部分的产物离子，以提高检测灵敏度，并与恒定中性损失扫描进行了比较。总之，通过采用 SRM [M+H-116]+转变或恒定中性损失扫描，检测到不同的 PAH DNA 加合物。然而，对于某些 PAH DNA 加合物，为了提高检测灵敏度，需要优化与 PAH 部分产物离子相关的 SRM 转变，以开发靶向 DNA 加合物组学方法。
