title: Methylation of P16, P21, P27, RB1 and P53 genes in odontogenic keratocysts.
abstract: BACKGROUND
  Odontogenic keratocyst (OKC) is a benign neoplasm with an aggressive clinical behavior and a high recurrence rate. Although epigenetic alterations have been reported in different tumors, these events were not investigated in OKC yet. The aim of this study was to investigate the presence of methylation in P16, P21, P27, P53 and RB1 genes in OKC tumors.
  
  
  METHODS
  Methylation-specific polymerase chain reaction (MSP) was used to evaluate the presence of methylation in 10 samples of OKCs, 10 samples of dental follicles and six samples of normal mucosa.
  
  
  RESULTS
  The methylation status of the P16 gene was similar among the three groups. In P21 gene, 30% of OKCs were methylated while no methylation could be detected in the other groups. High frequency of P27 methylation (90%) was observed in dental follicles, however, some OKC lesions (10%) and normal mucosa samples (33%) were also methylated. Concerning the RB1 gene, positive results were detected only in dental follicles (40%). No positive result was observed considering P53 gene.
  
  
  CONCLUSIONS
  Our data show methylation of the promoter of P21 gene in OKCs. In addition, methylation of the P27 and RB1 genes are commonly found in dental follicles. Further studies are necessary to determine the functional relevance of these alterations.
authors.affiliation: Laboratory of Molecular Biology, Department of Oral Surgery and Pathology, School of Dentistry, Universidade Federal de Minas Gerais, Minas Gerais, Brazil.
authors.forename: Paula Rocha
authors.initials: PR
authors.lastname: Moreira
authors.forename: Mariana Moreira
authors.initials: MM
authors.lastname: Guimarães
authors.forename: André Luiz Sena
authors.initials: AL
authors.lastname: Guimarães
authors.forename: Marina Gonçalves
authors.initials: MG
authors.lastname: Diniz
authors.forename: Carolina Cavaliéri
authors.initials: CC
authors.lastname: Gomes
authors.forename: João Artur Ricieri
authors.initials: JA
authors.lastname: Brito
authors.forename: Ricardo Santiago
authors.initials: RS
authors.lastname: Gomez
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000235:genetics; D050760:Cyclin-Dependent Kinase Inhibitor p27 / Q000235:genetics; D019175:DNA Methylation / Q000235:genetics*; D003795:Dental Sac / Q000378:metabolism; D044127:Epigenesis, Genetic / Q000235:genetics; D005260:Female; D016147:Genes, Tumor Suppressor; D019942:Genes, p16; D016158:Genes, p53; D006801:Humans; D008297:Male; D009061:Mouth Mucosa / Q000378:metabolism; D009807:Odontogenic Cysts / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics; D016160:Retinoblastoma Protein / Q000235:genetics; D055815:Young Adult
chemical_list: C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016160:Retinoblastoma Protein; D050760:Cyclin-Dependent Kinase Inhibitor p27