Genetic Variations in Indian Tobacco consumers to Oral Cancer

Genetic Variations in Indian Tobacco consumers to Oral Cancer

Objectives:

Oral squamous cell carcinoma is one of the most commonly occuring cancers in India. The incidence of oral cancer is strongly associated with use of tobacco. Studies have suggested that genetic susceptibility plays an important role in the risk for squamous cell carcinoma.

The present study aimed at evaluating the risk factor related to poly aromatic hydrocarbons and nitrosamines in oral squamous cell carcinoma (OSCC) and tobacco associated habit (TAH) and control samples through allelic variation of CYP1A1 gene at exon 7 and 3' UTR of the gene.

Methods:

45 blood samples in the three categories were chosen, 15 representing each category (15=OSCC, 15=TAH and 15=controls) were analysed for genetic polymorphisms in CYP1A1 gene and its risk susceptibility to oral squamous cell carcinoma to tobacco habits. High molecular weight DNA was isolated from samples and in vitro amplification was achieved through PCR and two genetic polymorphisms were studied.

Results:

Exon 7 polymorphism on CYP1A1 gene, demonstrated only genotype Class 1 (A/A) and Class 2 (A/G). However, Class 3 (G/G) was not observed. Class 2 heterozygotic genotype was significantly higher in OSCC and TAH when compared with control samples. MSP1 RFLP at 3'VTR on CYP1A1 gene showed only genotypeA (m1/m1) and genotype B (m1/m2) and genotype C (m2/m2) was not seen.

Conclusion:

The results of this study show that individual with class 2 (Ile/Val) genotype and type B (m1/m2) are at a higher risk for oral squamous cell carcinoma with a less tobacco dose and that the individual difference in genetic make up plays