Korean J Pathol.  2000 Aug;34(8):581-587.

Telomerase Activity and Expression of Telomerase RNA in Malignant Fibrous Histiocytoma

• Yoo J
• Kang SJ
• Kim BK

Abstract

Telomerase is an RNA-dependent DNA polymerase that synthesizes TTAGGG telomeric DNA onto chromosomal ends to compensate for sequence loss during replication. It has been detected in a variety of human malignancies, suggesting that such activity may play a role in the tumorigenic process. To determine whether telomerase is reactivated in malignant fibrous histiocytoma, 12 tissue samples with this tumor were analyzed for the telomerase activity by a radioactive PCR-based TRAP (telomeric repeat amplification protocol) assay. All of the tumors were further investigated for the expression of human telomerase RNA (hTR) by an in situ hybridization (ISH). Telomerase activity was detected in one (8.3%) sample. Expression of hTR was demonstrated in 7 (58.3%): one telomerase-positive and six telomerase-negatives. These data indicate that the reactivation of telomerase is an uncommon event and not an important factor involved in tumorigenesis in malignant fibrous histiocytoma. It is noteworthy that 50% of the patients with grade 2 tumors expressed hTR, suggesting that telomerase RNA may be useful as a marker for identifying tumor aggressiveness earlier than the conventional histopathologic grading scale.

Keyword

Telomerase activity; Telomerase RNA; Malignant fibrous histiocytoma

MeSH Terms

Carcinogenesis
DNA
Histiocytoma, Malignant Fibrous*
Humans
In Situ Hybridization
RNA*
RNA-Directed DNA Polymerase
Telomerase*
DNA
RNA
RNA-Directed DNA Polymerase
Telomerase