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

Abstract

Exfoliated mucosal cells were collected from the oral cavity of three groups at high risk for oral cancer: Indian betel nut chewers, Filipino inverted smokers (burning end of cigar in mouth) and Indian Khaini tobacco chewers. DNA was extracted from these samples, as well as from samples of exfoliated cells of Canadian non-smoking controls. DNA was analyzed for the presence of aromatic DNA adducts using ³² P-postlabel-ling analysis. Five chromatographically distinct adducts were found in samples from both the high risk groups and the nonsmoking controls. Individual adducts were detectable in ∼ 30–95% of samples, depending on the adduct and population group. Estimated levels of specific adducts ranged from non-detectable (prevalence relative to normal nucleotides < 1 x 10 ^-9 ) to occasionally > 1x 10 ^-7 . No adducts were found in high risk groups which did not also appear in control subjects.