OVEREXPRESSION AND AMPLIFICATION OF C-MYC AND C-Ha-RAS ONCOGENES IN PLEOMORPHIC SALIVARY ADENOMA

Twenty-seven samples of pleomorphic salivary adenoma (PSA) were examined for expression and structure of c-myc, c-Ha-ras, e-erbB-2, c-sis oncogenes by RNA dot blot, DNA dot blot and Southern blot hybridization. Eighteen of 25 PSA showed 5.02±4.74 fold overexpression of c-myc oncogene, 6 of 19 PSA had 4.91±3.87 fold overexpression of c-Ha-ras oncogene. Two of 16 PSA were found to have overexpression of c-erbB-2 oncogene. In addition, 7 of 10 PSA and 1 of 9 PSA were detected to have c-myc and c-erbB-2 oncogene amplification respectively. However, no rearrangement, amplification or overexpression of c-sis gene was found. We also discussed various clinicopathological parameters of PSA, whichhowever, had no significant correlation with expression of c-myc or c-Ha-ras oncogene. Our results indicate that activation of c-myc, c-Ha-ras and their combination may play an important role in the pathogenesis of PSA.