Influence of telomerase activity on bone and soft tissue tumors
Telomerase is a ribonucleoprotein enzyme that maintains the protective structures at the ends of eukaryotic chromosomes, called telomeres. Telomerase activity was observed and correlated with aggressiveness in different neoplasms such as breast, prostate, blood and brain cancers, among others. To investigate whether telomerase activity is an index of aggressiveness in bone and soft tissue lesions of the extremities, 66 biopsy samples from our tissue bank were studied. These samples included 43 high-grade sarcomas, 9 aggressive benign tumors and 14 totally benign lesions. The samples were collected from patients homogeneously treated at the Rizzoli Orthopaedic Institute with a follow-up ranging from 4 to 11 years (median, 7 years). A non-radioactive polymerase chain reaction-based enzyme-linked immunosorbent assay was used for the study. All tumors investigated were positive for telomerase activity. Among benign lesions, only 2 aneurysmal bone cysts showed higher telomerase activity than the cut-off point, whereas all the other benign lesions had lower activity. Our results indicate that high levels of telomerase activity in bone and soft tissue lesions correlate with more aggressive clinical behavior in patients treated with surgery alone. An interesting inverse correlation between telomerase activity and occurrence of pulmonary metastasis was detected in osteosarcoma patients treated with chemotherapy. A parallel increase of telomerase activity and malignancy was observed in the adipose and cartilagineous tissue lesions. Our data suggest that telomerase activity could be considered a marker of tumor aggressiveness for bone and soft tissue lesions. The results obtained in osteosarcoma samples suggest that low levels of telomerase activity may be predictive of the prognosis and should influence the therapeutic protocol.