Alkyl and vinyl halides are of interest because of their high volumes of production, extensive human exposure, and known genotoxicity and carcinogenicity. Continuing studies are directed toward bifunctional electrophiles in this group (including oxidation products) and the related compound butadiene diepoxide, an oxidation product of another commodity chemical (1,3-butadiene). The proposed studies are focused on thiol- dependent activation mechanisms of 1,2-dibromoethane (ethylene dibromide) and butadiene diepoxide, particularly by glutathione (GSH) transferases (GSTs) and the DNA repair protein O6-alkylguanine DNA- alkyltransferase (AGT). The first Specific Aim involves the characterization of mechanisms of mutation of DNA-AGT crosslinks derived from 1,2-dibromoethane and butadiene diepoxide. Further characterization of crosslinks other than the N7-guanyl ones will be done, and a major hypothesis is that peptides derived from AGT are the mutagenic adducts. The second Specific Aim involves the GSH conjugate of butadiene diepoxide and the hypothesis that this is a prominent electrophilic species involved in DNA alkylation and genotoxicity of butadiene diepoxide (as opposed to a detoxication product). An approach is also proposed to evaluate the AGT and GST pathways for these chemicals in rodents in vivo. The third Specific Aim utilizes a new chemical approach to the synthesis of DNA adducts with unstable glycosidic bonds, including several derived from alkyl and vinyl halides, especially N7-(2-oxoethyl)-guanine, S-[N7-(2-guanylethyl)]glutathione, and N2,3-etheno(5)guanine. Our hypothesis is that these adducts are miscoding. The miscoding potentials of these and other unstable adducts will be evaluated with several microbial and human DNA polymerases, and comparisons will be made. Collectively these studies should provide new mechanistic insight into the toxicity and carcinogenicity of these adducts and important information that may alter paradigms in risk assessment.

Public Health Relevance

We propose a research plan that should produce valuable information related to 1,2-dibromo- and 1,2- dichloroethane, butadiene, and other bis-electrophiles or chemicals that can produce bis-electrophiles, which have practical significance in human health considerations. The work with peptides linked to DNA has basic mechanistic importance and fills a scientific need. The new approaches we propose to study involve labile DNA adducts that should allow us to address several long-standing questions about mutagenesis.

Agency
National Institute of Health (NIH)
Institute
National Institute of Environmental Health Sciences (NIEHS)
Type
Research Project (R01)
Project #
5R01ES010546-12
Application #
8294640
Study Section
Cancer Etiology Study Section (CE)
Program Officer
Carlin, Danielle J
Project Start
2001-06-09
Project End
2016-03-31
Budget Start
2012-05-01
Budget End
2013-03-31
Support Year
12
Fiscal Year
2012
Total Cost
$419,480
Indirect Cost
$144,480
Name
Vanderbilt University Medical Center
Department
Biochemistry
Type
Schools of Medicine
DUNS #
004413456
City
Nashville
State
TN
Country
United States
Zip Code
37212
Chowdhury, Goutam; Shibata, Norio; Yamazaki, Hiroshi et al. (2014) Human cytochrome P450 oxidation of 5-hydroxythalidomide and pomalidomide, an amino analogue of thalidomide. Chem Res Toxicol 27:147-56
Cho, Sung-Hee; Guengerich, F Peter (2013) In vivo roles of conjugation with glutathione and O6-alkylguanine DNA-alkyltransferase in the mutagenicity of the bis-electrophiles 1,2-dibromoethane and 1,2,3,4-diepoxybutane in mice. Chem Res Toxicol 26:1765-74
Cho, Sung-Hee; Guengerich, F Peter (2013) Replication past the butadiene diepoxide-derived DNA adduct S-[4-(N(6)-deoxyadenosinyl)-2,3-dihydroxybutyl]glutathione by DNA polymerases. Chem Res Toxicol 26:1005-13
Zhao, Linlin; Christov, Plamen P; Kozekov, Ivan D et al. (2012) Replication of N2,3-ethenoguanine by DNA polymerases. Angew Chem Int Ed Engl 51:5466-9
Cho, Sung-Hee; Guengerich, F Peter (2012) Conjugation of butadiene diepoxide with glutathione yields DNA adducts in vitro and in vivo. Chem Res Toxicol 25:706-12
Rendic, Slobodan; Guengerich, F Peter (2012) Contributions of human enzymes in carcinogen metabolism. Chem Res Toxicol 25:1316-83
Guengerich, F Peter (2011) Mechanisms of drug toxicity and relevance to pharmaceutical development. Drug Metab Pharmacokinet 26:3-14
Chowdhury, Goutam; Guengerich, F Peter (2011) Liquid chromatography-mass spectrometry analysis of DNA polymerase reaction products. Curr Protoc Nucleic Acid Chem Chapter 7:Unit 7.16.1-11
Chowdhury, Goutam; Murayama, Norie; Okada, Yusuke et al. (2010) Human liver microsomal cytochrome P450 3A enzymes involved in thalidomide 5-hydroxylation and formation of a glutathione conjugate. Chem Res Toxicol 23:1018-24
Loecken, Elisabeth M; Dasari, Surendra; Hill, Salisha et al. (2009) The bis-electrophile diepoxybutane cross-links DNA to human histones but does not result in enhanced mutagenesis in recombinant systems. Chem Res Toxicol 22:1069-76

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