Simultaneous Detectionof Multiple DNA Adducts inHuman Lung Samples by Isotope-Dilution UPLC-MS/MS

摘要

Recent studies have demonstrated that various DNA adducts can be detected in human tissues and fluids using liquid chromatography connected to tandem mass spectrometry (LC-MS/MS). However, the utility of a single DNA adduct as a biomarker in risk assessment is debatable because humans are exposed to many genotoxicants. We established a method to measure DNA adducts derived from 16 ubiquitous genotoxicants and developed an analytical technique for their simultaneous quantification by ultra performance liquid chromatography (UPLC)-MS/MS. Methods for the enrichment of the analytes from DNA hydrolysates and chromatographic separation preceding mass spectrometric analysis were optimized, and the resultant technique was used for the simultaneous analysis of the 16 DNA adducts in human lung biopsy specimens. Eleven adducts (formed by benzo[a]pyrene, 1-methylpyrene, 4-aminobiphenyl, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine, 1-methoxy-3-indolylmethylglucosinolate, 5-hydroxymethylfurfural, and malondialdehyde) were not detected in any tissue sample (limits ofdetection: 0.02–7.1 adducts/10⁸ nucleosides). 3,N⁴-etheno-2′-deoxycytidine and 1,N⁶-etheno-2′-deoxyadenosine, formed from2,3-epoxyaldehydes of endogenous lipid peroxidation products, werepresent in all subjects (16.9–115.3 and 27.2–179/10⁸ nucleosides, respectively). The same was true for N²-(trans-methylisoeugenol-3′-yl)-2′-deoxyguanosine,the major adduct of methyleugenol (1.7–23.7/10⁸ nucleosides).A minor adduct of methyleugenol and two adducts of furfuryl alcoholwere detected in several pulmonary specimens. Taken together, we developeda targeted approach for the simultaneous mass spectrometric analysesof 16 DNA adducts, which can be easily extended by adducts formedfrom other mutagens. The method allowed one to detect adducts of furfurylalcohol and methyleugenol in samples of human lung.