Association of polymorphism in P16 and myeloperoxidase genes with susceptibility to oral lesions in North Indian population

Abstract Background Expression of P16 and MPO (myeloperoxidase) has been proposed as a marker for malignant transformation. In MPO , a G/A polymorphism at 463 bp upstream of the transcription start site of the enzyme has functional outcome, where G allele results in higher level of MPO expression than A allele. Protein P16 , a key regulator in cell cycle, is also commonly associated with cancer. SNP of P16 exon3 (C540G) has been found to be linked with tumor aggressiveness. Objective The study aimed to investigate SNP of P16 C540G and myeloperoxidase ( MPO ) −463G/A for their potential association in oral lesions with risk to oral squamous cell carcinoma (OSCC). Methods In this hospital based case control study, single nucleotide polymorphism in P16 and MPO genes was studied by polymerase chain reaction (PCR) followed by restriction fragment length polymorphism (RFLP) method in patients of oral lesions or OSCC and compared with age matched healthy controls. The test group consisted of 226 patients from both rural and urban areas whereas the control group had 103 individuals who did not show a history of oral lesions or OSCC. Genotype and allele frequencies were analyzed by chi-square test and strength of associations by odds ratio with 95% confidence intervals. Results This case–control study demonstrates that people having P16 C540G carrier genotypes 540 (CG/GG) were found to be protected from the development of leukoplakia (P = 0.004, MPO gene was found to be not associated with the risk of oral lesions (P = 0.8351, OR = 0.5667, 95% CI = 0.0968–3.3168). Conclusion Our results suggest that single nucleotide polymorphisms in P16 genes may affect the susceptibility to oral lesions; while genotype of MPO showed no association with the development of oral lesions.