Genotyping of the C>T allele of rs16906252, predictor of O16-methylguanine-DNA methyltransferase (MGMT) promoter methylation status, in erosive atrophic lesions of oral lichen planus.

BACKGROUND: DNA promoter methylation is usually an early stage in carcinogenesis process, including oral cancer. The purpose of this study was to investigate the association between T allele of specific single nucleotide polymorphism (SNP) C>T rs 16906252 and O16-methylguanine-DNA methyltransferase (MGMT) methylation as prospective biomarkers of malignant transformation in oral lichen planus (OLP), a chronic autoimmune mucocutaneous disease.

METHODS: This research is an observational, analytical case-control study where a total of 85 subjects (43 control individuals and 42 OLP patients) participated. The samples (mouthwashes) from all volunteers were analyzed, and DNA extraction was carried out. The genotyping of the rs 16906252 SNP in the MGMT gene was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Statistical analyses of Student t test and multiple logistic regressions were used.

RESULTS: C>T genotype in the control and OLP groups was detected in 2.3% and 19.0%, respectively. The presence of this genotype was associated with methylation of the MGMT gene. In fact, taking into account age and gender, subjects with C>T genotype were 10.5 (95% CI 1.03-106; P = 0.047) times more likely to methylate promoter region of the MGMT gene.

CONCLUSIONS: These findings indicate that C>T allele of rs 16906252, predictor of MGMT promoter methylation status, may be an important feature in the clinical prognosis of premalignant lesions of OLP, although this finding requires further clinical and laboratory investigation.