title: Oxidative DNA damage estimated by plasma 8-hydroxydeoxyguanosine (8-OHdG): influence of 4, 4'-methylenebis (2-chloroaniline) exposure and smoking.
abstract: Oxidative DNA damage may play an important role in the human carcinogenic process. Recently, we reported a case of bladder cancer among 4, 4'-methylenebis (2-chloroaniline) (MBOCA)-exposed workers. By measuring the plasma level of 8-hydroxydeoxyguanosine (8-OHdG), we investigated the association between oxidative DNA damage and MBOCA exposure. In addition, we examined the effects of different confounders on the plasma level of 8-OHdG. We undertook a cross-sectional survey at four MBOCA-producing factories in Taiwan (158 subjects). Plasma 8-OHdG levels and urinary MBOCA concentrations were measured by liquid chromatography coupled with tandem mass spectrometry (LC/MS/MS). Personal characteristics were collected by questionnaire. The workers were classified according to their job titles as exposed (n=57) or unexposed (n=101) groups as well as classified according to urinary MBOCA levels as high urinary MBOCA (>20 microg/g creatinine) (n=45) or low urinary MBOCA (n=108) groups. Neither the MBOCA-exposed workers nor the high urinary MBOCA workers had a significant increase in the mean plasma 8-OHdG level, even after adjustment for potential confounders. Age and gender were significantly positively correlated with plasma 8-OHdG levels. Smokers among high urinary MBOCA workers also had significantly higher 8-OHdG levels than non-smokers among high urinary MBOCA workers. Our study provides evidence that smoking rather than MBOCA exposure induces elevation of plasma 8-OHdG levels among workers exposed to MBOCA, indicating that oxidative DNA damage does not play an important role in the carcinogenic processes of MBOCA.
authors.affiliation: Division of Urology, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taiwan.
authors.forename: Hong-I
authors.initials: HI
authors.lastname: Chen
authors.forename: Saou-Hsing
authors.initials: SH
authors.lastname: Liou
authors.forename: Shu-Fen
authors.initials: SF
authors.lastname: Ho
authors.forename: Kuen-Yuh
authors.initials: KY
authors.lastname: Wu
authors.forename: Chien-Wen
authors.initials: CW
authors.lastname: Sun
authors.forename: Ming-Fong
authors.initials: MF
authors.lastname: Chen
authors.forename: Li-Chuan
authors.initials: LC
authors.lastname: Cheng
authors.forename: Tung-Sheng
authors.initials: TS
authors.lastname: Shih
authors.forename: Ching-Hui
authors.initials: CH
authors.lastname: Loh
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000328:Adult; D017677:Age Distribution; D000395:Air Pollutants, Occupational / Q000032:analysis / Q000633:toxicity; D000428:Alcohol Drinking / Q000453:epidemiology; D015415:Biomarkers / Q000097:blood / Q000652:urine; D015992:Body Mass Index; D002853:Chromatography, Liquid; D015986:Confounding Factors, Epidemiologic; D003430:Cross-Sectional Studies; D004249:DNA Damage / Q000187:drug effects / Q000502:physiology*; D003849:Deoxyguanosine / Q000031:analogs & derivatives* / Q000097:blood; D004305:Dose-Response Relationship, Drug; D006801:Humans; D016014:Linear Models; D008297:Male; D008753:Methylenebis(chloroaniline) / Q000032:analysis / Q000633:toxicity*; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects* / Q000032:analysis; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology*; D017678:Sex Distribution; D012907:Smoking / Q000009:adverse effects* / Q000453:epidemiology; D011795:Surveys and Questionnaires; D013624:Taiwan / Q000453:epidemiology
chemical_list: D000395:Air Pollutants, Occupational; D015415:Biomarkers; D008753:Methylenebis(chloroaniline); D000080242:8-Hydroxy-2'-Deoxyguanosine; D003849:Deoxyguanosine