5-Aza-CdR promotes partial MGMT demethylation and modifies expression of different genes in oral squamous cell carcinoma

Treatment strategies for oral squamous cell carcinoma (OSCC) vary, depending on the stage of diagnosis. Surgery and radiotherapy are options for localized lesions for stage I patients, whereas chemotherapy is the main treatment for metastatic OSCC. However, aggressive tumors can relapse, frequently causing death. In an attempt to address this, novel treatment protocols using drugs that alter the epigenetic profile have emerged as an alternative to control tumor growth and metastasis. Therefore, the objective in this study was to investigate the effect of the demethylating drug 5-aza-CdR in SCC9 OSCC cells. SCC9 cells were treated with 5-Aza-CdR at concentrations of 0.3 mu M and 2 mu M for 24 hours and 48 hours. DNA methylation of the MGMT, BRCA1, APC, c-MYC, and hTERT genes were investigated by using the methylation-specific high-resolution melting technique. Real time-polymerase chain reaction and quantitative polymerase chain reaction were performed to analyze gene expression. 5-Aza-CdR promoted demethylation of MGMT and modified the transcription of all analyzed genes. Curiously, 5-aza-CdR at the concentration of 0.3 mu M was more efficient than 2 mM in SCC9 cells. We observed that 5-aza-CdR led to MGMT demethylation, upregulated the transcription of 3 important tumor suppressor genes, and promoted the downregulation of c-Myc1275425432COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPnão tem2015/24749-