title: Characterization of the Major Purine and Pyrimidine Adducts Formed after Incubations of 1-Chloro-3-buten-2-one with Single-/Double-Stranded DNA and Human Cells.
abstract: We have previously shown that 1-chloro-3-buten-2-one (CBO), a potential reactive metabolite of 1,3-butadiene (BD), exhibits potent cytotoxicity and genotoxicity that have been attributed in part to its reactivity toward DNA. In an effort to identify the DNA adducts of CBO, we characterized the CBO reactions with 2'-deoxyguanosine (dG), 2'-deoxycytidine (dC), and 2'-deoxyadenosine (dA) under in vitro physiological conditions (pH 7.4, 37 °C). In the present study, we investigated the CBO reaction with 2'-deoxythymidine (dT) and compared the rate constants of the reactions of CBO with dA, dC, dG, and dT at both individual- and mixed-nucleosides levels. We also investigated the reactions of CBO with single- and double-stranded DNA using HPLC with UV detection after adducts were released by either acid or enzymatic hydrolysis of DNA. Consistent with the results from the nucleoside reactions and the rate constant experiments, 1,N6-(1-hydroxy-1-chloromethylpropan-1,3-diyl)adenine (A-2D) was identified as the major DNA adduct detected after acid hydrolysis, followed by N7-(4-chloro-3-oxobutyl)guanine (CG-2H) and a small amount of 1,N6-(1-hydroxy-1-hydroxymethylpropan-1,3-diyl)adenine (A-1D). After enzymatic hydrolysis, 1,N6-(1-hydroxy-1-hydroxymethylpropan-1,3-diyl)-2'-dexoyadenosine (dA-1), 3,N4-(1-hydroxy-1-hydroxymethylpropan-1,3-diyl)-2'-deoxycytidine (dC-1/2), and 1,N2-(3-hydroxy-3-hydroxymethylpropan-1,3-diyl)-2'-dexoyguanosine (CG-1) were detected, with dA-1 being the major product, followed by dC-1/2. When a nontoxic concentration of CBO (1 μM) was incubated with HepG2 cells, no adducts could be detected by LC-MS. However, pretreatment of cells with l-buthionine sulfoximine to deplete GSH levels allowed A-2D to be consistently detected in cellular DNA. These results may contribute to a better understanding of the role of the DNA adducts in CBO genotoxicity and mutagenicity. It also suggests that A-2D could be developed as a biomarker of CBO formation after BD exposure in vivo.
authors.affiliation: Institute of Environmental Pollution and Health, School of Environmental and Chemical Engineering, Shanghai University , Shanghai 200444, China.
authors.forename: Ling-Yan
authors.initials: LY
authors.lastname: Liu
authors.affiliation: Institute of Environmental Pollution and Health, School of Environmental and Chemical Engineering, Shanghai University , Shanghai 200444, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Zheng
authors.affiliation: East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences , Shanghai 200090, China.
authors.forename: Cong
authors.initials: C
authors.lastname: Kong
authors.affiliation: Institute of Environmental Pollution and Health, School of Environmental and Chemical Engineering, Shanghai University , Shanghai 200444, China.
authors.forename: Jing
authors.initials: J
authors.lastname: An
authors.affiliation: Institute of Environmental Pollution and Health, School of Environmental and Chemical Engineering, Shanghai University , Shanghai 200444, China.
authors.forename: Ying-Xin
authors.initials: YX
authors.lastname: Yu
authors.affiliation: Institute of Environmental Pollution and Health, School of Environmental and Chemical Engineering, Shanghai University , Shanghai 200444, China.
authors.forename: Xin-Yu
authors.identifier: 0000-0003-3472-8393
authors.initials: XY
authors.lastname: Zhang
authors.affiliation: Department of Comparative Biosciences and the Molecular and Environmental Toxicology Center, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States.
authors.forename: Adnan A
authors.initials: AA
authors.lastname: Elfarra
mesh_terms: D002074:Butanones / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D004247:DNA / Q000737:chemistry*; D018736:DNA Adducts / Q000737:chemistry*; D004277:DNA, Single-Stranded / Q000737:chemistry*; D006801:Humans; D011687:Purines / Q000032:analysis* / Q000737:chemistry; D011743:Pyrimidines / Q000032:analysis* / Q000737:chemistry; D013050:Spectrometry, Fluorescence
chemical_list: C580717:1-chloro-3-buten-2-one; D002074:Butanones; D018736:DNA Adducts; D004277:DNA, Single-Stranded; D011687:Purines; D011743:Pyrimidines; D004247:DNA