Increased telomerase activity and hTERT expression in human salivary gland carcinomas

Abstract

Approximately 85% of human malignant tumors express increased levels of telomerase. The marked association of telomerase activity with malignant tissue provides strong evidence that telomerase activity is a significant marker for the diagnosis of cancer. In this study, telomerase activity was examined in 12 benign salivary gland tumors (8 pleomorphic adenomas and 4 adenolymphomas), 24 malignant tumors (15 mucoepidermoid carcinomas, 6 adenoid cystic carcinomas and 3 acinic cell carcinomas) and 6 non-neoplastic salivary glands. The mRNA expression of the human telomerase reverse transcriptase (hTERT) and additional telomeras-associated proteins (hTEP1, p23, Hsp90 and dyskerin) was also examined. Of the 24 malignant tumors, 15 revealed strong telomerase activity. The non-neoplastic salivary glands appeared to have a negative telomerase expression. Furthermore, telomerase activity was significantly higher in high-grade mucoepidermoid carcinomas compared to low-grade ones (Student's t-test, p<0.05). A significant correlation was found between telomerase activity and mRNA.