Introduction: Telomerase is a ribonucleoprotein that adds TTA GGG nucleotide repeated into the ends of eukaryotic chromosomes to maintain their integrity. Most of the normal somatic cells do not express telomerase while telomerase is expressed in the vast majority of malignant tumor cells. Contradictory and limited data have been reported concerning the telomerase expression in soft-tissue sarcomas. The current study evaluates telomerase expression in a single histologic type of a high-grade soft-tissue sarcoma.

Materials and Methods: A non-radioactive in situ hybridization (ISH) method was used to study the expression of the RNA component of human telomerase in 55 paraffin embedded archives tissue samples of patients who were diagnosed with synovial sarcoma, the diagnosis of which was based on morphologic, immunohistochemical, and cytogenetic characteristics. The intensity and distribution of telomerase RNA was scored by two different investigators. Intensity was graded as weak, moderate, or intensive. These parameters were further correlated to the oncologic status of the patient.

Results: The majority of the investigated specimens demonstrated moderate to intensive telomerase RNA intensity with a diffuse distribution throughout the specimen. A positive correlation was found between telomerase intensity and progression of the underlying disease.

Conclusions: Results of the current series suggest that upregulating of telomerase expression may play a role in the pathogenesis and biological activity of synovial sarcoma. This upregulation as detected by ISH assay may be a useful prognostic tool in the evaluation of these patients.