DNMT3B (C46359T) polymorphisms and immunoexpression of DNMT3b and DNMT1 proteins in oral lichen planus.

OBJECTIVE To investigate the DNMT3B (C46359T) polymorphism and immunoexpression of DNMT3b and DNMT1 in oral lichen planus (OLP) compared to a control group. METHODS We aimed to investigate the DNMT3B (C46359T) polymorphism and immunoexpression of DNMT3b and DNMT1 in OLP (n = 32), comparing it with oral mucosa (control; n = 24). The DNMT3B (C46359T) polymorphism was analyzed using the RFLP-PCR and DNMT1, and DNMT3a proteins were identified using immunohistochemistry. We also compared the DNMT3B expression in OLP and oral inflammatory fibrous hyperplasia (OIFH), another oral inflammatory disease. Differences between the groups were determined by specific statistical analyses. RESULTS The CT genotype of DNMT3B was associated with OLP development (p = 0.012). Increased expression of DNMT3B and DNMT1 was observed in OLP compared to the control group (p = 0.014 and p = 0.001, respectively). A significant increase in DNMT3B protein levels was observed in the genotype CT in DNMT3B (C46359T) polymorphisms (p = 0.045). No DNMT3B expression differences between OLP and OIFH were observed. CONCLUSIONS Our data show that the DNMT3B (C46359T) polymorphism is associated with OLP development. Furthermore, increased expression of the enzyme DNMT3B, an epigenetic-associated protein, is present in OLP.