title: LC-MS/MS simultaneous quantitation of 2-hydroxyethylated, oxidative, and unmodified DNA nucleosides in DNA isolated from tissues of mice after exposure to ethylene oxide.
abstract: 2-Hydroxyethylated and oxidative DNA nucleosides (DNA adduct biomarkers), such as O6-(2-hydroxyethyl)-2'-deoxyguanosine (O6HEdG), N6-(2-hydroxyethyl)-2'-deoxyadenosine (N6HEdA), 1-(2-hydroxyethyl)-2'-deoxyadenosine (N1HEdA), and 8-hydroxy-2'-deoxyguanosine (8-OHdG), N2,3-etheno-2'-deoxyguanosine (N2,3-ethenodG), α-methyl-γ-hydroxy-1,N2-propano-2'-deoxyguanosine (CrotondG), are important proposed biomarkers for exploring the genotoxicity mechanism of ethylene oxide (EO) in vivo. A liquid chromatography-tandem mass spectrometric method was developed for the simultaneous determination of O6HEdG, N6HEdA, N1HEdA, 8-OHdG, CrotondG, and N2,3-ethenodG together with regular 2'-deoxyguanosine (dG), and 2'-deoxyadenosine (dA) nucleosides in the DNA extracted from mouse lung tissues for the assessment of exposure to EO after inhalation. The lower limits of quantitation for 8-OHdG, CrotondG, N2,3-EthenodG, O6HEdG, N1HEdA, N6HEdA, dG, and dA were 0.025, 0.00125, 0.025, 0.00125, 0.025, 0.01, 2342, and 2500ng/mL, respectively. The linearity of the calibration curves for all analytes were >0.989. The intra-day assay precision relative standard deviation (RSD) values for quality control (QC) samples for all analytes were ≤13.5% with accuracy values ranging from 86.5% to 111%. The inter-day assay precision (RSD) values for all analytes were ≤18.8% with accuracy values ranging from 87.9% to 119%. This method was used for simultaneous determination of the levels of 8-OHdG, CrotondG, N2,3-EthenodG, O6HEdG, dG, N1HEdA, N6HEdA, and dA in DNA enzymatic hydrolysates from DNA extracted from mouse lung after 12 weeks' inhalation exposure to EO at atmospheric concentrations of 0, 100, and 200ppm. Overall, N2,3-ethenodG was not detected in any samples. 8-OHdG, CrotondG, dG, and dA were all quantifiable in all samples. O6HEdG, N1HEdA, and N6HEdA were quantifiable in most samples and the ratio of the corresponding adduct versus their corresponding DNA base (dG or dA) [×10 (e6)] was increased as the EO exposure concentration increased.
authors.affiliation: Toxicology and Environmental Research & Consulting, The Dow Chemical Company, 1803 Building, Midland, MI 48674, USA. Electronic address: fzzhang@dow.com.
authors.forename: Fagen
authors.initials: F
authors.lastname: Zhang
authors.affiliation: Toxicology and Environmental Research & Consulting, The Dow Chemical Company, 1803 Building, Midland, MI 48674, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Bartels
authors.affiliation: Toxicology and Environmental Research & Consulting, The Dow Chemical Company, 1803 Building, Midland, MI 48674, USA.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: LeBaron
authors.affiliation: Toxicology and Environmental Research & Consulting, The Dow Chemical Company, 1803 Building, Midland, MI 48674, USA.
authors.forename: Melissa R
authors.initials: MR
authors.lastname: Schisler
authors.affiliation: Toxicology and Environmental Research & Consulting, The Dow Chemical Company, 1803 Building, Midland, MI 48674, USA.
authors.forename: Yo-Chan
authors.initials: YC
authors.lastname: Jeong
authors.affiliation: Toxicology and Environmental Research & Consulting, The Dow Chemical Company, 1803 Building, Midland, MI 48674, USA.
authors.forename: B Bhaskar
authors.initials: BB
authors.lastname: Gollapudi
authors.affiliation: Toxicology and Environmental Research & Consulting, Dow Europe GmbH Horgen, Switzerland.
authors.forename: Nigel P
authors.initials: NP
authors.lastname: Moore
mesh_terms: D000818:Animals; D002853:Chromatography, Liquid; D004247:DNA / Q000032:analysis* / Q000737:chemistry*; D005027:Ethylene Oxide / Q000494:pharmacology*; D008297:Male; D051379:Mice; D009705:Nucleosides / Q000032:analysis* / Q000737:chemistry*; D053719:Tandem Mass Spectrometry
chemical_list: D009705:Nucleosides; D004247:DNA; D005027:Ethylene Oxide
keywords: 2-Hydroxyethylated and oxidative DNA nucleoside biomarkers; Ethylene oxide; Liquid chromatography tandem mass spectrometry; Simultaneous quantitation