Quantification of Hemoglobin and White Blood Cell DNA Adducts of the Tobacco Carcinogens 2-Amino-9H-pyrido[2,3-b]indole and 4-Aminobiphenyl Formed in Humans by Nanoflow Liquid Chromatography/Ion Trap Multistage Mass Spectrometry
CHEMICAL RESEARCH IN TOXICOLOGY(2017)
摘要
Aromatic amines covalently bound to hemoglobin (Hb) as sulfinamide adducts at the cysteine 93 residue of the Hb beta chain have set-tea as biomarkers to assess exposure to this class of human carcinogens for the past 30 years. In this study, we report that 2-amino-9H-pyrido[2,3-b]indole (A alpha C), an abundant carcinogenic heterocyclic, aromatic amine formed in tobacco smoke,,and charred cooked meats, also reacts with Hb to form a sulfinamide adduct. A novel nanoflow liquid chromatography/ion trap multistage mass spectrometry (nanoLC-IT/MS3) method was established to assess exposure to A alpha C and the tobacco-associated bladder carcinogen 4-aminobiphenyl (4-ABP) through their Hb sulfinamide adducts. Following mild acid hydrolysis of Hb in vitro, the liberated A alpha C and 4-ABP were derivatized with acetic anhydride to form the N-acetylated amines, which were measured by nanoLC-IT/MS3. The limits of quantification (LOQ) for A alpha C- and 4-ABP-Hb sulfinamide adducts were <= 7.1 pg/g Hb. In a pilot study, the mean level of Hb sulfinamide adducts of A alpha C and 4-ABP were, respectively; 3.4-fold and 4.8-fold higher in smokers (>20,cigarettes/day) than nonsmokers. In contrast, the major DNA adducts of 4-ABP, N-(2'-deoxyguanosin-8-yl)-4-aminobiphenyl, and A alpha C, N-(2'-deoxyguanpsin-8-yl)-2-amino-9H-pyrido[2,3-b]indole, were below the LOQ (3 adducts per 109 bases) in white blood cell (WBC) DNA of smokers and nonsmokers. These findings reaffirm that tobacco smoke is a major source of exposure to A alpha C. Hb sulfinamide adducts are suitable biomarkers to biomonitor 4-ABP and A alpha C; however, neither carcinogen binds to DNA in WBC, even in heavy smokers; at levels sufficient for biomonitoring.
更多查看译文
AI 理解论文
溯源树
样例
生成溯源树,研究论文发展脉络
Chat Paper
正在生成论文摘要