RESUMO
The Ras/RAF/MEK/ERK1/2 pathway is important in the control of growth signals, differentiation and cell survival. Over-expression and activation of this pathway have been reported in different types of cancer. This study analyses the promoter methylation and RNA expression profiles of ERK and RAF1 genes with risk of oral squamous cell carcinoma (OSCC) along with the promoter methylation status of ERK and RAF1 genes using a methylation-specific polymerase chain reaction (MS-PCR) in 86 paraffin-wax embedded samples of OSCC and 68 normal control tissues. Furthermore, ERK and RAF1 expression was analysed in 19 cases and 20 normal samples by real-time reverse transcription PCR. Frequency of promoter methylation was detected for ERK (93.02% and 6.98%) and RAF1 (95.35% and 4.65%) genes in cases and controls, respectively. Messenger RNA (mRNA) expression analysis indicated statistically significant difference between cases and controls for ERK (P < 0.002) and RAF1 (P < 0.006). The authors believe that this is the first report to show that expression of ERK and RAF1 is involved in risk of OSCC.