N2-Ethyldeoxyguanosine as a Potential Biomarker for Assessing Effects of Alcohol Consumption on DNA
Cancer Epidemiology Biomarkers & Prevention 17, 3026-3032, November 1, 2008
Head and neck cancers are causally related to alcohol consumption,
but the underlying mechanisms are unclear. Ethanol is metabolized
to acetaldehyde, an experimental carcinogen. Quantitation of
the major DNA adduct of acetaldehyde,
N2-ethylidenedeoxyguanosine,
in human tissues could help to elucidate the mechanism of alcohol
carcinogenicity.
We applied a quantitative method for the analysis
of this adduct, measured as the NaBH
3CN reduction product
N2-ethyldeoxyguanosine
(
N2-ethyl-dGuo) by liquid chromatography-electrospray ionization-tandem
mass spectrometry-selected reaction monitoring, on DNA (0.04
± 0.03 mg) isolated from blood collected from control
subjects recruited from two studies conducted in different areas
of Europe between 1999 and 2005. The group selected from the
first study (
n = 127) included alcohol drinkers and abstainers
while the group from the second study (
n = 50) included only
heavy drinkers.
N2-ethyl-dGuo was detected in all DNA samples.
After adjusting for potential confounders, in the first study,
drinkers showed a higher level of
N2-ethyl-dGuo (5,270 ±
8,770 fmol/µmol dGuo) compared with nondrinkers (2,690
± 3040 fmol/µmol dGuo;
P = 0.04). A significant
trend according to dose was observed in both studies (
P = 0.02
and 0.04, respectively). Taking into account the amount of alcohol
consumption, adduct levels were higher in younger compared with
older subjects (
P = 0.01), whereas no differences were observed
comparing men with women.
These results show the feasibility
of quantifying
N2-ethyl-dGuo in small-volume blood samples and
are consistent with the hypothesis that ethanol contributes
to carcinogenesis through DNA adducts formation.
Read Full AbstractRequest Reprint E-Mail: boffetta@iarc.fr___________________________________________________