title: Analysis of p16(CDKN2A) methylation and HPV-16 infection in oral mucosal dysplasia.
abstract: OBJECTIVE
  The purpose of this study was to investigate the relationship between p16(CDKN2A) methylation and epithelial dysplasia (ED). We also evaluated the expressions of proteins related to methylation (DNMT3B and DNMT1). Finally, we tested whether HPV-16/18 or the dmt3b (C46359T) polymorphism is associated with p16(CDKN2A) methylation status.
  
  
  METHODS
  To test the hypothesis, a case-control study with 72 (control, n = 24; ED, n = 48) tissue samples from subjects was performed. Methylation-specific PCR, RFLP, and immunohistochemical analyses were performed to evaluate p16(CDKN2A) methylation status, dmt3b (C46359T) genotyping, and protein levels, respectively.
  
  
  RESULTS
  The methylation of p16(CDKN2A) and HPV-16 was associated with ED gradation (p = 0.001 and 0.002, respectively). In addition, most HPV-16-positive samples (77.8%) exhibited p16(CDKN2A) methylation; however, changes in DNMT3B and DNMT1 protein levels were not observed in HPV-positive samples. Neither HPV-18 nor the dmt3b polymorphism was associated with p16(CDKN2A) methylation.
  
  
  CONCLUSIONS
  There is an association between the presence of HPV-16 in ED and the occurrence of p16(CDKN2A) methylation. Both variables are also associated with ED development, but further studies are necessary to clarify if they operate independently and if they have any impact on OD malignization.
authors.affiliation: Department of Dentistry, Universidade Estadual de Montes Claros, Montes Claros, Brazil.
authors.forename: Thiago
authors.initials: T
authors.lastname: Fonseca-Silva
authors.forename: Lucyana Conceição
authors.initials: LC
authors.lastname: Farias
authors.forename: Claudio Marcelo
authors.initials: CM
authors.lastname: Cardoso
authors.forename: Ludmilla Regina de
authors.initials: LR
authors.lastname: Souza
authors.forename: Carlos Alberto de
authors.initials: CA
authors.lastname: Carvalho Fraga
authors.forename: Marcos Vinícius Macedo de
authors.initials: MV
authors.lastname: Oliveira
authors.forename: Lucas Oliveira
authors.initials: LO
authors.lastname: Barros
authors.forename: Lucas Rodrigues
authors.initials: LR
authors.lastname: Alves
authors.forename: Alfredo Maurício Batista
authors.initials: AM
authors.lastname: De-Paula
authors.forename: Luciano
authors.initials: L
authors.lastname: Marques-Silva
authors.forename: Ricardo Santiago
authors.initials: RS
authors.lastname: Gomez
authors.forename: André Luiz Sena
authors.initials: AL
authors.lastname: Guimarães
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D019175:DNA Methylation / Q000502:physiology*; D005260:Female; D019942:Genes, p16 / Q000502:physiology*; D005838:Genotype; D052162:Human papillomavirus 16 / Q000302:isolation & purification*; D052161:Human papillomavirus 18 / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008875:Middle Aged; D009061:Mouth Mucosa / Q000378:metabolism / Q000473:pathology*; D030361:Papillomavirus Infections / Q000235:genetics* / Q000821:virology