Influence of cigarette smoking on P53 gene mutations in bladder carcinomas

The aim of this study was to analyse the influence of cigarette smoking on bladder carcinomas.

98 cases of bladder cancers were examined by single strand conformation polymorphism analysis of exons 5 to 9, followed by DNA direct sequencing.

The incidence of p53 gene mutations was not significantly influenced by habitual smoking. However, the p53 mutation spectrum of current smokers differed significantly from the pattern for non-smokers and ex-smokers. Differences between the two populations included multiple mutations in the current-smokers and an absence in non- and ex-smokers (p<0.01), with the predominance of G:C to A:T transitions at CpG sites in non-smokers (60.0%) in comparison with current smokers (7.6%) (p<0.02). Moreover, G:C to T:A and G:C to C:G transversions were found solely in current smokers.

It would appear that, in current-smokers, the spectrum of p53 gene mutations is related to tobacco-smoke carcinogens and that the habit of smoking increases the extent of DNA damage.