DNA methylation status of MutS genes in ameloblastoma

Author(s)

do Amaral-Silva, Gleyson Kleber ; Fontes Pereira, Thais dos Santos ; Rocha, Andre Caroli ; Linhares Almeida Mariz, Bruno Augusto ; Prado-Ribeiro, Ana Carolina ; Fonseca, Felipe Paiva ; Gomez, Ricardo Santiago ; Vargas, Pablo Agustin

• Document type: Journal article
• Source: ORAL DISEASES; v. 28, n. 7, p. 6-pg., 2021-04-30.

Abstract

Objectives Ameloblastoma is an odontogenic epithelial tumour with a low expression of mismatch repair system components. We aimed to investigate the methylation status of the genes MSH2, MSH3 and MSH6 (MutS group) in conventional ameloblastomas. Materials and Methods The ameloblastoma and dental follicle samples (n = 10 each) were collected from 20 different patients. Each ameloblastoma sample was sectioned into two fragments: one was paraffin-embedded while the other one, likewise the dental follicle samples, was fixed in RNAlater and frozen at -196 degrees C. All frozen samples were investigated for the MutS genes methylation levels, using the enzymatic restriction digestion and quantitative real-time PCR (qPCR) assay. The ameloblastoma paraffin-embedded samples were submitted to immunohistochemical reactions for MutS proteins detection and digitally quantification. Correlation analyses were performed between the immunohistochemical results and the respective gene methylation percentage. Results There are no significant differences between the MutS genes methylation levels in the ameloblastoma and the dental follicle. However, a strong negative correlation was found between MSH2 and MSH6 gene methylation status and their respective proteins expressions evaluated by immunohistochemistry. Conclusion Our results show that the genes methylations is in part responsible for decreasing the expression of MSH2 and MSH6 genes in ameloblastoma. (AU)

• FAPESP's process: 17/08995-2 - Epigenetic events in ameloblastomas: immuno-expression of DNMT1, DNMT3b and H3K9ac and hMutS promoters' methylation profile
• Grantee: Gleyson Kleber do Amaral Silva
• Support Opportunities: Scholarships in Brazil - Doctorate