title: In vivo detection of a novel endogenous etheno-DNA adduct derived from arachidonic acid and the effects of antioxidants on its formation.
abstract: Previous studies showed that 7-(1',2'-dihydroxyheptyl)-substituted etheno DNA adducts are products of reactions with the epoxide of (E)-4-hydroxy-2-nonenal, an oxidation product of ω-6 polyunsaturated fatty acids (PUFAs). In this work, we report the detection of 7-(1',2'-dihydroxyheptyl)-1,N(6)-ethenodeoxyadenosine (DHHedA) in rodent and human tissues by two independent methods: a (32)P-postlabeling/HPLC method and an isotope dilution liquid chromatography-electrospray ionization-tandem mass spectrometry method, demonstrating for the first time that DHHedA is a background DNA lesion in vivo. We showed that DHHedA can be formed upon incubation of arachidonic acid with deoxyadenosine, supporting the notion that ω-6 PUFAs are the endogenous source of DHHedA formation. Because cyclic adducts are derived from the oxidation of PUFAs, we subsequently examined the effects of antioxidants, α-lipoic acid, Polyphenon E, and vitamin E, on the formation of DHHedA and γ-hydroxy-1,N(2)-propanodeoxyguanosine (γ-OHPdG), a widely studied acrolein-derived adduct arising from oxidized PUFAs, in the livers of Long Evans Cinnamon (LEC) rats. LEC rats are afflicted with elevated lipid peroxidation and prone to the development of hepatocellular carcinomas. The results showed that although the survival of LEC rats was increased significantly by α-lipoic acid, none of the antioxidants inhibited the formation of DHHedA, and only Polyphenon E decreased the formation of γ-OHPdG. In contrast, vitamin E caused a significant increase in the formation of both γ-OHPdG and DHHedA in the livers of LEC rats.
authors.affiliation: Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, District of Columbia 20057.
authors.forename: Ying
authors.initials: Y
authors.lastname: Fu
authors.affiliation: Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, District of Columbia 20057.
authors.forename: Raghu G
authors.initials: RG
authors.lastname: Nath
authors.affiliation: Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, District of Columbia 20057.
authors.forename: Marcin
authors.initials: M
authors.lastname: Dyba
authors.affiliation: Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, District of Columbia 20057.
authors.forename: Idalia M
authors.initials: IM
authors.lastname: Cruz
authors.affiliation: Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, District of Columbia 20057.
authors.forename: Sharanya R
authors.initials: SR
authors.lastname: Pondicherry
authors.affiliation: Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, District of Columbia 20057.
authors.forename: Aileen
authors.initials: A
authors.lastname: Fernandez
authors.affiliation: Department of Experimental Therapeutics, University of Texas, MD Anderson Cancer Center, Houston, Texas 77054.
authors.forename: Casey L
authors.initials: CL
authors.lastname: Schultz
authors.affiliation: Department of Experimental Therapeutics, University of Texas, MD Anderson Cancer Center, Houston, Texas 77054.
authors.forename: Peiying
authors.initials: P
authors.lastname: Yang
authors.affiliation: Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, District of Columbia 20057.
authors.forename: Jishen
authors.initials: J
authors.lastname: Pan
authors.affiliation: Department of Pharmacology, Penn State College of Medicine, Hershey, Pennsylvania 17033.
authors.forename: Dhimant
authors.initials: D
authors.lastname: Desai
authors.affiliation: Department of Pharmacology, Penn State College of Medicine, Hershey, Pennsylvania 17033.
authors.forename: Jacek
authors.initials: J
authors.lastname: Krzeminski
authors.affiliation: Department of Pharmacology, Penn State College of Medicine, Hershey, Pennsylvania 17033.
authors.forename: Shantu
authors.initials: S
authors.lastname: Amin
authors.affiliation: Department of Chemistry, Vanderbilt University, VU Station B 351822, Nashville, TN 37235.
authors.forename: Plamen P
authors.initials: PP
authors.lastname: Christov
authors.affiliation: Tea Solution, Hara Office Inc. Tokyo, Japan.
authors.forename: Yukihiko
authors.initials: Y
authors.lastname: Hara
authors.affiliation: Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, District of Columbia 20057.
authors.forename: Fung-Lung
authors.initials: FL
authors.lastname: Chung
mesh_terms: D000241:Adenosine / Q000031:analogs & derivatives* / Q000032:analysis / Q000096:biosynthesis; D000818:Animals; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D016718:Arachidonic Acid / Q000737:chemistry; D002392:Catechin / Q000031:analogs & derivatives / Q000494:pharmacology; D002853:Chromatography, Liquid; D018736:DNA Adducts / Q000032:analysis / Q000096:biosynthesis* / Q000737:chemistry; D003839:Deoxyadenosines / Q000032:analysis / Q000096:biosynthesis* / Q000737:chemistry; D003849:Deoxyguanosine / Q000031:analogs & derivatives* / Q000096:biosynthesis; D004852:Epoxy Compounds / Q000737:chemistry; D006801:Humans; D008099:Liver / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344; D020332:Rats, Inbred LEC; D017207:Rats, Sprague-Dawley; D021241:Spectrometry, Mass, Electrospray Ionization; D008063:Thioctic Acid / Q000494:pharmacology; D014810:Vitamin E / Q000494:pharmacology
chemical_list: C000597295:7-(1',2'-dihydroxyheptyl)-1,N6-ethenodeoxyadenosine; D000975:Antioxidants; D018736:DNA Adducts; D003839:Deoxyadenosines; D004852:Epoxy Compounds; C488128:alpha-hydroxypropanodeoxyguanosine; D014810:Vitamin E; D016718:Arachidonic Acid; D008063:Thioctic Acid; D002392:Catechin; D003849:Deoxyguanosine; D000241:Adenosine; C472086:polyphenon E
keywords: Antioxidants; DNA adduct; Free radicals; Isotope dilution liquid chromatography–electrospray ionization–tandem mass spectrometry; ω-6 polyunsaturated fatty acids