title: Prognostic value of the DNMTs mRNA expression and genetic polymorphisms on the clinical outcome in oral cancer patients.
abstract: OBJECTIVE
  Although the importance of the epigenetic changes in tumors, including oral squamous cell carcinomas (OSCCs), is now becoming apparent, the mechanisms that trigger or cause aberrant DNA methylation in cancer are still unrevealed. DNA methylation is regulated by a family of enzymes, DNA methyltransferases (DNMTs). DNMT gene expression analysis, as well as genetic polymorphisms, has not been previously evaluated in OSCC.
  
  
  METHODS
  In 65 OSCC patients, SYBR Green real-time PCR method was assessed for relative quantification of DNMT1, DNMT3A, and DNMT3B mRNAs, normalized to TATA-binding protein (TBP) mRNA. The expression levels of all three genes were dichotomized as high or low, with a twofold change of normalized mRNA expression used as the cutoff value. Polymorphisms in DNMT1 (rs2228612) and DNMT3B (rs406193) were analyzed in 99 OSCCs by TaqMan SNPs genotyping assays.
  
  
  RESULTS
  DNMT1, DNMT3A, and DNMT3B were overexpressed in 36.9, 26, and 23 % of the OSCC patients, respectively. DNMT1 overexpression was significantly associated with the overall survival, p = 0.029, and relapse-free survival of OSCC patients, p = 0.003. Patients with DNMT1 overexpression, as an independent prognostic factor, had a 2.385 times higher risk to relapse than those with lower expression. The DNMT1 A201G gene polymorphism was associated with a reduced overall survival in OSCC patients, p = 0.036.
  
  
  CONCLUSIONS
  Our results suggest that DNMT1 could play an important role in modulating OSCC patient survival.
  
  
  CONCLUSIONS
  DNMT gene expression could be a potential prognostic marker that might lead to an improvement in diagnosis, prognosis, and prospective use of epigenetic-targeted therapy of OSCC.
authors.affiliation: Faculty of Medicine, Military Medical Academy, University of Defense, Belgrade, Serbia. gogasupic@sezampro.rs.|Institute for Medical Research, Military Medical Academy, Crnotravska 17, Belgrade, 11002, Serbia. gogasupic@sezampro.rs.
authors.forename: Gordana
authors.initials: G
authors.lastname: Supic
authors.affiliation: Faculty of Medicine, Military Medical Academy, University of Defense, Belgrade, Serbia.|Clinic for Maxillofacial Surgery, Military Medical Academy, Belgrade, Serbia.
authors.forename: Ruzica
authors.initials: R
authors.lastname: Kozomara
authors.affiliation: Institute for Medical Research, Military Medical Academy, Crnotravska 17, Belgrade, 11002, Serbia.|Faculty of Biology, University of Belgrade, Belgrade, Serbia.
authors.forename: Katarina
authors.initials: K
authors.lastname: Zeljic
authors.affiliation: Faculty of Medicine, Military Medical Academy, University of Defense, Belgrade, Serbia.|Clinic for Maxillofacial Surgery, Military Medical Academy, Belgrade, Serbia.
authors.forename: Nebojsa
authors.initials: N
authors.lastname: Jovic
authors.affiliation: Faculty of Medicine, Military Medical Academy, University of Defense, Belgrade, Serbia.|Institute for Medical Research, Military Medical Academy, Crnotravska 17, Belgrade, 11002, Serbia.
authors.forename: Zvonko
authors.initials: Z
authors.lastname: Magic
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000235:genetics*; D000076123:DNA (Cytosine-5-)-Methyltransferase 1 / Q000235:genetics*; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000235:genetics*; D019175:DNA Methylation; D000090205:DNA Methyltransferase 3A; D044127:Epigenesis, Genetic; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D011379:Prognosis; D012333:RNA, Messenger / Q000235:genetics; D012307:Risk Factors; D015996:Survival Rate; D000097584:DNA Methyltransferase 3B
chemical_list: D000076123:DNA (Cytosine-5-)-Methyltransferase 1; D004248:DNA (Cytosine-5-)-Methyltransferases; D000090205:DNA Methyltransferase 3A; D012333:RNA, Messenger; D000097584:DNA Methyltransferase 3B; C000717967:DNMT3A protein, human; C000619380:DNMT1 protein, human
keywords: DNMT1; DNMT3A; DNMT3B; Oral cancer; Overall survival; Overexpression; Polymorphism; Relapse-free survival; mRNA