An association between BPDE-like DNA adduct levels and P53 genemutation in pterygium

[摘要] Purpose: A previous report of ours noted that not only p53 proteinoverexpression, but also p53 gene mutation. were indeed detected inpterygium. BaP 7,8-diol 9,10-epoxide (BPDE), an ultimate metabolite ofBaP, attacks deoxyguanosine to form a BPDE-N2-dG adduct resulting in p53mutations. The relationship between BPDE-like DNA adduct levels andabnormal p53 has not been clear in pterygium. Therefore, BPDE-like DNAadduct, p53 protein expression and p53 gene mutation were examined inthis study to provide more molecular evidence to understand the cause ofp53 gene mutation in pterygium.Methods: In this study, immunohistochemical staining, using amonoclonal antibody (DO7) against p53 and a polyclonal antibody againstBPDE-like DNA adducts, was performed on 73 pterygial specimens. DNAsamples for p53 mutation analysis were extracted from epithelial cellsand then subjected to DNA sequencing for the determination of mutationsin exons 4, 5, 6, 7, and 8 of the p53 gene.Results: BPDE-like DNA adducts were detected in 36.1% (26/73)pterygium samples. No correlation between adduct levels and p53 proteinexpression was found in these samples. Additionally, the p53 genemutation and p53 mutation pattern also did not correlate with BPDE-likeDNA adduct levels.Conclusions: Our data provides evidence that BPDE-like DNA adductsare indeed detected in pterygium samples, and they are only minorcontributors to the abnormal p53 gene.

[学科分类] 生物化学/生物物理