title: Evaluation of the methylation profile of exfoliated cell samples from patients with head and neck squamous cell carcinoma.
abstract: BACKGROUND
  Silencing of tumor suppressor genes plays a vital role in head and neck carcinogenesis. The purposes of this study were to determine the methylation profile of exfoliated tumors cells collected from patients with head and neck squamous cell carcinoma (HNSCC) and to evaluate its prognostic significance.
  
  
  METHODS
  The methylation profile and level of a 20-gene panel were evaluated by quantitative methylation-specific polymerase chain reaction (qMSP) in exfoliated tumor cell samples from 96 patients with HNSCC.
  
  
  RESULTS
  CCNA1 (60.4%), DCC (54.2%), and TIMP3 (35.4%) were frequently methylated in these samples. Patients with exfoliated tumors cells positive for DCC methylation showed a trend toward a lower local recurrence-free survival.
  
  
  CONCLUSIONS
  These findings indicate that a low invasive method could be used to access the methylation profile of exfoliated cells from patients with HNSCC. Moreover, our data provide evidence that hypermethylation of DCC could be useful as prognostic indicator for this malignancy.
authors.affiliation: Laboratório de Biologia Molecular do Câncer, Departamento de Ciências Biológicas, Universidade Federal de São Paulo, São Paulo, Brazil.
authors.forename: Ana Luiza Bomfim
authors.initials: AL
authors.lastname: Longo
authors.forename: Marianna M
authors.initials: MM
authors.lastname: Rettori
authors.forename: Ana Carolina
authors.initials: AC
authors.lastname: de Carvalho
authors.forename: Luiz Paulo
authors.initials: LP
authors.lastname: Kowalski
authors.forename: Andre Lopes
authors.initials: AL
authors.lastname: Carvalho
authors.forename: Andre Luiz
authors.initials: AL
authors.lastname: Vettore
mesh_terms: D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000235:genetics* / Q000401:mortality / Q000473:pathology; D015331:Cohort Studies; D056750:Cyclin A1 / Q000235:genetics; D019175:DNA Methylation; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D016163:Genes, DCC / Q000235:genetics; D016147:Genes, Tumor Suppressor; D006258:Head and Neck Neoplasms / Q000235:genetics* / Q000401:mortality / Q000473:pathology; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011446:Prospective Studies; D018570:Risk Assessment; D000077195:Squamous Cell Carcinoma of Head and Neck; D018709:Statistics, Nonparametric; D015996:Survival Rate; D019717:Tissue Inhibitor of Metalloproteinase-3 / Q000235:genetics; D014407:Tumor Cells, Cultured
chemical_list: C503745:CCNA1 protein, human; D056750:Cyclin A1; D019717:Tissue Inhibitor of Metalloproteinase-3
keywords: exfoliated cell; head and neck squamous cell carcinoma (HNSCC); methylation; qMSP