Smoking and P53 polymorphism association with chromosomal aberration in lung cancer

Abstract

Tobacco exposure is the primary leading cause for cancer of the oral cavity, the airways and lung. The carcinogens in cigarette smoke have been linked as an environmental risk factor for causing genetic mutations in tumor suppressor, including TP53 (p53) which has been linked as a causative for occurrence and progression in lung cancer. The aim of the current case-control study is to assess the presence and frequency of chromosomal aberrations between smokers and non-smokers in case and control group. Further, analysis was also extended to include the p53 codon 72 Arg/Pro mutation analysis between the groups of study cohort. In methods, the case-control epidemiological study included a total of 100 cases and controls who were further categorized as smokers and non-smokers for analysis. Chromosomal aberration assay was done on peripheral blood lymphocytes and studied using Geimsa stain, while analysis of the p53 codon 72 Arg/Pro mutation was done by allele-specific polymerase chain reaction assay. The chromosomal aberration assessed include structural abnormalities like breaks, fragment, dysenteric and gaps, as well as numerical aneuploidies. Results showing the number of chromosomal aberrations was higher among smoker cases as compared to controls, and numerical aneuploidy was also detected only among this cohort. The mean of chromosomal aberrations observed between cases and controls and smokers as well as non-smokers was significant at p < 0.0001. In case of the p53 genotyping result, the frequency of the Arg/Arg allele was higher among controls as compared to cases and the difference significant at p < 0.005. Among female participants, the difference between Arg/Arg and Pro/Arg was also found to be significant between cases and controls. Combined analysis of the p53 codon 72 alleles and mean of chromosomal aberrations between cases and controls was found to be significant at p < 0.005. Our study found an association between risk of lung cancer as well as occurrence of chromosomal aberrations. In case of the p53 polymorphism, the significance was detected only among females. In Conclusion, the studied p53 variant and chromosomal aberration along with smoking has shown significant association with increased risk of lung cancer.