title: Increased levels of the acetaldehyde-derived DNA adduct N 2-ethyldeoxyguanosine in oral mucosa DNA from Rhesus monkeys exposed to alcohol.
abstract: Alcohol is a human carcinogen. A causal link has been established between alcohol drinking and cancers of the upper aerodigestive tract, colon, liver and breast. Despite this established association, the underlying mechanisms of alcohol-induced carcinogenesis remain unclear. Various mechanisms may come into play depending on the type of cancer; however, convincing evidence supports the concept that ethanol's major metabolite acetaldehyde may play a major role. Acetaldehyde can react with DNA forming adducts which can serve as biomarkers of carcinogen exposure and potentially of cancer risk. The major DNA adduct formed from this reaction is N (2)-ethylidenedeoxyguanosine, which can be quantified as its reduced form N (2)-ethyl-dG by LC-ESI-MS/MS. To investigate the potential use of N (2)-ethyl-dG as a biomarker of alcohol-induced DNA damage, we quantified this adduct in DNA from the oral, oesophageal and mammary gland tissues from rhesus monkeys exposed to alcohol drinking over their lifetimes and compared it to controls. N (2)-Ethyl-dG levels were significantly higher in the oral mucosa DNA of the exposed animals. Levels of the DNA adduct measured in the oesophageal mucosa of exposed animals were not significantly different from controls. A correlation between the levels measured in the oral and oesophageal DNA, however, was observed, suggesting a common source of formation of the DNA adducts. N (2) -Ethyl-dG was measured in mammary gland DNA from a small cohort of female animals, but no difference was observed between exposed animals and controls. These results support the hypothesis that acetaldehyde induces DNA damage in the oral mucosa of alcohol-exposed animals and that it may play role in the alcohol-induced carcinogenic process. The decrease of N (2)-ethyl-dG levels in exposed tissues further removed from the mouth also suggests a role of alcohol metabolism in the oral cavity, which may be considered separately from ethanol liver metabolism in the investigation of ethanol-related cancer risk.
authors.forename: Silvia
authors.initials: S
authors.lastname: Balbo
authors.affiliation: Division of Neuroscience, Oregon National Primate Research Center, Oregon Health & Science University, 505 NW 185th Avenue, Beaverton, OR 97006, USA.
authors.forename: Rita Cervera
authors.initials: RC
authors.lastname: Juanes
authors.forename: Samir
authors.initials: S
authors.lastname: Khariwala
authors.affiliation: Department of Computer Science, Baylor University, One Bear Place #97356, Waco, TX 76798, USA and.
authors.forename: Erich J
authors.initials: EJ
authors.lastname: Baker
authors.affiliation: Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157, USA.
authors.forename: James B
authors.initials: JB
authors.lastname: Daunais
authors.affiliation: Division of Neuroscience, Oregon National Primate Research Center, Oregon Health & Science University, 505 NW 185th Avenue, Beaverton, OR 97006, USA.
authors.forename: Kathleen A
authors.initials: KA
authors.lastname: Grant
mesh_terms: D000079:Acetaldehyde / Q000494:pharmacology / Q000633:toxicity*; D000428:Alcohol Drinking / Q000009:adverse effects*; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D018736:DNA Adducts / Q000032:analysis*; D004249:DNA Damage; D003849:Deoxyguanosine / Q000031:analogs & derivatives* / Q000032:analysis*; D000071041:Esophageal Mucosa / Q000737:chemistry / Q000187:drug effects; D005260:Female; D008253:Macaca mulatta; D008297:Male; D008321:Mammary Glands, Animal / Q000737:chemistry / Q000187:drug effects; D009061:Mouth Mucosa / Q000737:chemistry / Q000187:drug effects*; D053719:Tandem Mass Spectrometry
chemical_list: D018736:DNA Adducts; C492934:N2-ethyl-2'-deoxyguanosine; D003849:Deoxyguanosine; D000079:Acetaldehyde