Cloning and expression of hamster telomerase catalytic subunit cDNA

Topical application of 7,12-dimethylbenz(a)anthracene induces tumors in the hamster cheek pouch. Telomerase activity is increased in the cancer tissue s if compared to normal adjacent tissues in both human and hamster oral can cer. In order to achieve a probe and to investigate the putative role of te lomerase in oral carcinogenesis using the hamster cheek pouch model, we hav e cloned the cDNA encoding the hamster telomerase catalytic subunit (hamTER T). The hamster TERT cDNA encoded 1128 amino acids and shared 64% amino aci d identity with human TERT and 80% with murine TERT. As noted with human TE RT which express several alternatively spliced mRNAs, we have also detected one alternatively spliced hamTERT mRNA in hamster cancer cells. Transient transfection of hamTERT cDNA in a retroviral expression vector reconstitute d telomerase activity in the telomerase negative human lung fibroblast IMR9 0 cells.