Increased acrolein-DNA adducts in buccal brushings of e-cigarette users

DNA adducts of acrolein were significantly greater in oral cells of 20 e-cigarette users sampled monthly for 3 months than in 20 non-users. This is the first identification of a carcinogen-DNA adduct in any tissue of an e-cigarette user. DNA adducts are central in the mechanism of carcinogenesis by genotoxic agents. We compared levels of a DNA adduct of acrolein, a genotoxic carcinogen found in e-cigarette vapor, in oral cell DNA of e-cigarette users and non-users of any tobacco or nicotine product. e-Cigarette users and non-users visited our clinic once monthly for 6 months, and oral brushings and urine samples were collected. For this study, we analyzed oral cell DNA adducts from three monthly visits in e-cigarette users and non-users as confirmed by urinary cyanoethyl mercapturic acid and total nicotine equivalents. DNA was isolated from the oral brushings and analyzed by a validated liquid chromatography-nanoelectrospray ionization-high resolution tandem mass spectrometry method for the acrolein DNA adduct 8R/S-3-(2'-deoxyribos-1'-yl)-5,6,7,8-tetrahydro-8-hydroxypyrimido[1,2-a]purine-10-(3H)-one (gamma-OH-Acr-dGuo). The median value of this DNA adduct in the e-cigarette users was 179 fmol/mu mol dGuo (range 5.0 - 793 fmol/mu mol dGuo) while that for non-users was 21.0 fmol/mu mol dGuo (range 5.0 - 539 fmol/mu mol dGuo), P = 0.001. These results demonstrate for the first time that e-cigarette users have elevated levels of a carcinogen-DNA adduct in their oral cells.