32P-Postlabelling analysis of aromatic DNA adducts in human oral mucosal cells

Exfoliated mucosal cells were collected from the oral cavityof three groups at high risk for oral cancer: Indian betel nutchewers, Filipino inverted smokers (burning end of cigar inmouth) and Indian Khaini tobacco chewers. DNA was extractedfrom these samples, as well as from samples of exfoliated cellsof Canadian non-smoking controls. DNA was analyzed for the presenceof aromatic DNA adducts using ³²P-postlabel-ling analysis. Fivechromatographically distinct adducts were found in samples fromboth the high risk groups and the nonsmoking controls. Individualadducts were detectable in 30–95% of samples, dependingon the adduct and population group. Estimated levels of specificadducts ranged from non-detectable (prevalence relative to normalnucleotides < 1 x 10^-9) to occasionally > 1x 10^-7. Noadducts were found in high risk groups which did not also appearin control subjects.