RESUMO
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. CONCLUSION: 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.
Assuntos
Carcinoma de Células Escamosas/genética , Metilação de DNA , Genes Supressores de Tumor , Neoplasias de Cabeça e Pescoço/genética , Idoso , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/patologia , Estudos de Coortes , Ciclina A1/genética , Intervalo Livre de Doença , Feminino , Seguimentos , Genes DCC/genética , Neoplasias de Cabeça e Pescoço/mortalidade , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Estudos Prospectivos , Medição de Risco , Carcinoma de Células Escamosas de Cabeça e Pescoço , Estatísticas não Paramétricas , Taxa de Sobrevida , Inibidor Tecidual de Metaloproteinase-3/genética , Células Tumorais CultivadasRESUMO
BACKGROUND: Hypermethylation in the promoter regions is associated with the suppression of gene expression and has been considered a potential molecular marker for several tumor types, including head and neck squamous cell carcinomas (HNSCC). METHODS: To evaluate the gene hypermethylation profile as a prognostic marker, this retrospective study used a QMSP approach to determine the methylation status of 19 genes in 70 HNSCC patients. RESULTS: The methylation profile analysis of primary HNSCC revealed that genes CCNA1, DAPK, MGMT, TIMP3 and SFRP1 were frequently hypermethylated, with high specificity and sensitivity. TIMP3 and CCNA1 hypermethylation was significantly associated with lower rates of second primary tumor-free survival (p = 0.007 and p = 0.001; log-rank test, respectively). CONCLUSION: This study, for the first time, presents CCNA1 and TIMP3 hypermethylation as a helpful tool to identify HNSCC subjects at risk of developing second primary carcinomas.
