Immunohistochemical Expression of De novo Methyltransferases (DNMT3A and DNMT3B) in Ameloblastoma and Odontogenic Cysts

Abstract

BackgroundAmeloblastoma (AME), radicular cyst (RC), dentigerous cyst (DC), and odontogenic keratocyst (OKC) are the most frequently occurring odontogenic lesions. De novo DNA methylation takes place by the action of DNA methyl transferases (DNMT) 3A and 3B. Epigenetic studies revealing the expression of methyltransferases in odontogenic cysts and tumors are sparse and miss the relevance of the expression to clinical outcomes. This study examined the expression of DNMT3A and DNMT3B in the most common odontogenic cysts and AME and linked the expression to clinical variables.MethodsImmunohistochemical staining was performed on 75 paraffin- embedded tissue sections, 15 of each of NOM, RC, DC, OKC, and AME. The immunopositive epithelial cells were counted, statistically analyzed, and correlated to clinical features.ResultsDNMT3A was more highly expressed in odontogenic cysts than DNMT3B while the expression was the highest in AME with no significant difference between both markers. DNMT3A correlated significantly with disrupted cortical integrity in RC (p<0.001) and AME (p=0.038), besides, male gender (p=0.001) and multilocularity (p=0.001) in OKC. DNMT3B was only highly expressed in DC in females (p=0.031).ConclusionDNMT3A has more prevailing action in de novo methylation of RC, DC, and OKC than DNMT3B. It might have a role in the excessive growth of RC and the aggressiveness of AME and OKC.