RESUMO
Inexpensive forms of tobacco are widely used in developing countries such as India. We have evaluated genotoxicity endpoints (chromosome aberrations, micronucleus frequency, comet assay) and polymorphisms of the XRCC1 and p53 genes among smokers and smokeless tobacco (SLT) users in rural Tamilnadu, South India. Cytogenetic, DNA damage and SNP analyses were performed on peripheral blood samples; micronucleus frequency was measured in peripheral blood and buccal mucosa exfoliated cells. Both categories of tobacco users had elevated levels of genotoxic damage. SNP analysis of tobacco users revealed that 17% carry the XRCC1 gln399gln genotype and 19% carry the p53 pro72pro genotype. Both genotypes are associated with increased risk of cancer.
Assuntos
Dano ao DNA , Proteínas de Ligação a DNA , Neoplasias , Fumar , Tabaco sem Fumaça/efeitos adversos , Proteína Supressora de Tumor p53 , Adolescente , Adulto , Idoso , Células Sanguíneas/metabolismo , Células Sanguíneas/patologia , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Feminino , Genótipo , Humanos , Índia , Masculino , Pessoa de Meia-Idade , Mucosa Bucal/metabolismo , Mucosa Bucal/patologia , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias/patologia , Polimorfismo de Nucleotídeo Único , Fatores de Risco , Fumar/efeitos adversos , Fumar/genética , Fumar/metabolismo , Fumar/patologia , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Proteína 1 Complementadora Cruzada de Reparo de Raio-XRESUMO
India has a long history of tobacco, which includes chewing tobacco and smoking tobacco in various forms. Initially, the smokeless tobacco chewing habit was seen among the majority of the farmers who cultivated tobacco; but in recent years, smokeless tobacco is available in many forms and is cheaper as well and hence it is widely being used among literate and illiterate people. The subjects of our study are living in hilly regions of Yerkaud in Salem district, South India. Most of the inhabitants of our study area are illiterate and more particularly they are unaware of the health effects due to tobacco use. Recent epidemiological reports have strongly indicated the association of cancer risk with usage of smokeless tobacco. The prime aim of our study is to evaluate the genotoxic effects of tobacco use by analysing the cytogenetic end points such as chromosome aberrations in peripheral blood and micronucleus in peripheral blood and buccal cells. About 85 smokeless tobacco users were enrolled for the study and same numbers of age- and sex-matched nontobacco users were also enrolled to serve as controls. The result of our study revealed that tobacco users displayed varied levels of elevated chromosomal damage and micronucleated cells than nontobacco users. The variation in the extent of genetic damage was dependent on the duration of the tobacco use. In conclusion, this study might be helpful in creating awareness on the hazards of the smokeless tobacco products among the global population as a whole for those who chose such products as a cheap alternative to tobacco smoke.
