title: Loss of 5-hydroxymethylcytosine and TET2 in oral squamous cell carcinoma.
abstract: OBJECTIVE
  Epigenetic modifications, such as DNA methylation, are considered important in the regulation of target genes in cancer development. 5-Hydroxymethylcytosine (5hmC) was recently discovered to be related to the process of malignant transformation. The influence of DNA methylation in oral squamous cell carcinomas (OSCC) is not fully-understood. Therefore, the aim of the present study was to investigate the DNA methylation pattern in OSCC compared to healthy oral epithelium.
  
  
  METHODS
  Oral mucosal samples from patients with OSCC (n=15) and healthy mucosa (n=12) were analyzed using immunohistochemistry with antibodies against 5hmC, 5mC and ten-eleven-translocation-2 (TET2).
  
  
  RESULTS
  A significant decrease in 5hmC and TET2 expression was found in OSCC compared to healthy oral epithelium. In contrast, there was a significant increase in 5mC expression in OSCC compared to healthy epithelium.
  
  
  CONCLUSIONS
  Our results indicate that loss of 5hmC is an epigenetic event of OSCC.
authors.affiliation: Department of Oral and Maxillofacial Surgery, The Sahlgrenska Academy at University of Gothenburg, Box 450, SE 405 30 Göteborg, Sweden. goran.kjeller@odontologi.gu.se.
authors.forename: Fredrik
authors.initials: F
authors.lastname: Jäwert
authors.forename: Bengt
authors.initials: B
authors.lastname: Hasséus
authors.forename: Göran
authors.initials: G
authors.lastname: Kjeller
authors.forename: Bengt
authors.initials: B
authors.lastname: Magnusson
authors.forename: Lars
authors.initials: L
authors.lastname: Sand
authors.forename: Lena
authors.initials: L
authors.lastname: Larsson
mesh_terms: D044503:5-Methylcytosine / Q000031:analogs & derivatives; D002294:Carcinoma, Squamous Cell / Q000201:enzymology* / Q000235:genetics; D016022:Case-Control Studies; D003596:Cytosine / Q000031:analogs & derivatives* / Q000378:metabolism; D019175:DNA Methylation; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D049308:Dioxygenases; D044127:Epigenesis, Genetic; D015870:Gene Expression; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D009061:Mouth Mucosa / Q000378:metabolism; D009062:Mouth Neoplasms / Q000201:enzymology* / Q000235:genetics; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D004268:DNA-Binding Proteins; D011518:Proto-Oncogene Proteins; C011865:5-hydroxymethylcytosine; D044503:5-Methylcytosine; D003596:Cytosine; D049308:Dioxygenases; C541081:TET2 protein, human
keywords: 5-hydoxymethylcytosine; DNA methylation; Oral cancer; biological markers; ten-eleven-translocation 2