Detection of O6-methyldeoxyguanosine in human placental DNA.
A monoclonal antibody specific for O6-methyldeoxyguanosine (O6-MedGuo) was developed. When used in a competitive enzyme-linked immunosorbent assay, 50% inhibition of binding was achieved with 0.51 pmol O6-MedGuo. When the competitive enzyme-linked immunosorbent assay was coupled with high-performance liquid chromatography, 2 mg of DNA could be analyzed giving a lower limit of detection of 0.5 mumol O6-MedGuo/mol deoxyguanosine. This assay was used to test for O6-MedGuo in DNA from placentas of smoking and nonsmoking women. Two of 10 DNA samples from smoking women and three of 10 from nonsmoking women had detectable concentrations of O6-MedGuo. Concentrations ranged from 0.6 to 1.6 mumol O6-MedGuo/mol deoxyguanosine. Activity of O6-alkylguanine DNA alkyltransferase was also measured. There was no apparent relationship between O6-alkylguanine DNA alkyltransferase activity and O6-MedGuo concentrations in the 20 subjects, nor did mean O6-alkylguanine DNA alkyltransferase activity differ between the two groups. Although no apparent relationship between smoking history and O6-MedGuo concentration was found in this preliminary study, this is the first report of a structurally identified DNA adduct in human placenta.
Foiles
P G
PG
Division of Chemical Carcinogenesis, Naylor Dana Institute for Disease Prevention, Valhalla, New York 10595.
Miglietta
L M
LM
Akerkar
S A
SA
Everson
R B
RB
Hecht
S S
SS
D000911:Antibodies, Monoclonal; D004247:DNA / Q000032:analysis*; D003849:Deoxyguanosine / Q000031:analogs & derivatives* / Q000032:analysis; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D010920:Placenta / Q000032:analysis*; D012907:Smoking
D000911:Antibodies, Monoclonal; D004247:DNA; C015558:O(6)-methyl-2'-deoxyguanosine; D003849:Deoxyguanosine