Urinary excretion of 3,N4-etheno-2'-deoxycytidine in humans as a biomarker of oxidative stress: association with cigarette smoking.
Smokers are known to have elevated levels of lipid peroxidation, a form of oxidative stress. Etheno DNA adduct formation can originate from endogenous lipid peroxidation or from exogenous exposure of carcinogens. Using a modified stable isotope dilution GC/negative ion chemical ionization/MS assay originally developed for urinary 3,N(4)-ethenocytosine (epsilonCyt), the nucleoside 3,N(4)-etheno-2'-deoxycytidine (epsilondCyd) was detected for the first time in human urine. The presence of epsilondCyd in human urine was confirmed by LC/electrospray ionization/tandem MS. Concentrations of epsilondCyd in the 24 h urine samples from healthy individuals not occupationally exposed to industrial chemicals were in the range between 0 and 0.80 nM. A statistically significant correlation was established between cigarette smoking and urinary excretion of epsilondCyd after being adjusted for creatinine (p = 0.004). Furthermore, the urinary total antioxidant capacity was found to correlate inversely with the epsilondCyd levels (r = -0.50, p = 0.02). The results indicate that urinary epsilondCyd may provide a valuable noninvasive biomarker for oxidative DNA damage.
Chen
Hauh-Jyun Candy
HJ
Department of Chemistry and Biochemistry, National Chung Cheng University, 160 San-Hsing, Ming-Hsiung, Chia-Yi 62142, Taiwan. chehjc@ccunix.ccu.edu.tw
Wu
Chan-Fu
CF
Hong
Chia-Liang
CL
Chang
Chia-Ming
CM
D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000652:urine; D003596:Cytosine / Q000031:analogs & derivatives* / Q000652:urine*; D018736:DNA Adducts / Q000652:urine*; D004249:DNA Damage; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology; D012907:Smoking / Q000009:adverse effects / Q000652:urine*; D021241:Spectrometry, Mass, Electrospray Ionization
D015415:Biomarkers; D018736:DNA Adducts; C051143:3,N(4)-ethanocytosine; D003596:Cytosine