Telomerase Activation in Malignant Bone Tumors

Background: Telomerase is a ribonucleoprotein that can reconstitute the ends (telomeres) of chromosomes after cell division and thus circumvent the cumulative damage that occurs during mitotic cycles of cells. A unique association has been established between telomerase activity and neoplastic transformation and cellular immortalization. The measurement of telomerase activity has also been considered to be a diagnostic marker for human malignant tumors; however, little is known about the status of telomerase activity in malignant bone tumors. Methods and Results: Thirty-five human bone sarcomas and adjacent noncancerous tissues were subjected for the first time by the modified telomeric repeat amplification protocol (TRAP)-silver staining assay for telomerase activity. The results showed that telomerase activity was present in 82.9% (29/35) of malignant bone tumors. Twenty-two of 26 (84.6%) osteosarcomas, 3 of 5 (60%) chondrosarcomas, 2 of 2 (100%) malignant fibrous histiocytomas, and 2 of 2 (100%) rhabdomyosarcomas contained telomerase activity. In contrast, there was no telomerase activity in 19 adjacent noncancerous tissues. Conclusions: The findings suggest that telomerase might play an important role in the development of malignant bone tumors. The detection of telomerase in malignant bone tumors may have value in increasing the accuracy of diagnosis of malignant bone tumors.