Backgroud: Telomerase activity, mainly regulated by the human telomerase reverse transcriptase (hTERT) gene, plays critical roles in tumor growth and progression through the maintenance of telomere length and structure. Telomerase is elevated in most malignant tumors as well as in breast cancer, the ubiquitous expression of telomerase makes it a promising target for cancer therapy. With the goa...

A previously reported highly sensitive assay for measuring telomerase activity on cell and tissue extracts indicates that most human tumor tissues, but not cells adjacent to tumors, have detectable telomerase activity. Although this assay has provided a significant amount of information about the presence or absence of telomerase activity, it does not indicate whether all cells within a tumor h...

Telomere shortening occurs when cells divide, both in vitro and in vivo. On the other hand, telomerase is able to maintain telomere length in cells by adding TTAGGG repeats to the ends of telomeres. However, the interrelationships existing among telomere length, telomerase activity and growth in vertebrates remain to be clarified. In the present study we measured telomere length (terminal restr...

Telomerase activity is frequently associated with the malignant phenotype, and it can be considered an almost ubiquitous tumor marker. In this study, we evaluated telomerase activity in telomerase-positive human tumor cell lines exposed in vitro to antineoplastic agents. The results show that drug-induced cell killing of tumor cells is associated with a decline in detectable telomerase activity...

Telomerase activity has been detected in >85% of all malignant human cancers, including 90% of prostate carcinomas. Using a well-characterized experimental prostate cancer system, we have found that telomerase activity is notably increased (>10-fold) during tumorigenic conversion. Expression profiles of the telomerase components (hTR and hTERT) revealed no substantive changes, which suggests a ...

Progressive loss of the telomeric ends of chromosomes caused by the semi-conservative mechanism of DNA replication is an important timing mechanism which controls the number of cells doubling. Telomerase is an enzyme which elongates one chain of the telomeric DNA and compensates for its shortening during replication. Therefore, telomerase activity serves as a proliferation marker. Telomerase ac...

The activation of telomerase and stabilization of telomeres are thought to be required for cellular immortality and oncogenesis. Three major components of human telomerase--human telomerase RNA (hTERC), telomerase-associated protein (TEP1), and human telomerase catalytic subunit (hTERT)-have recently been identified. However, the roles played by these subunits in the regulation of telomerase ac...

PURPOSE Telomerase activity appears to play a crucial role in the development of many tumors. More than 80% of all malignant human tumors show an increased telomerase activity. However, conflicting results have been reported about telomerase activity in sarcomas. The aim of the study was to obtain more information about telomerase activity in sarcomas based on a large number of cases. METHODS...

Telomerase activity appears to be associated with cell immortalization and malignant progression. Understanding how telomerase activity is regulated in vivo is important not only for understanding the molecular biology of telomerase but also for the potential clinical application of anticancer drugs. This study evaluated telomerase activity and quantified the expression of human telomerase reve...

Telomerase, a ribonucleoprotein, is responsible for maintaining the telomere length and therefore promoting genomic integrity, proliferation, and lifespan. In addition, telomerase protects the mitochondria from oxidative stress and confers resistance to apoptosis, suggesting its possible importance for the surviving of non-mitotic, highly active cells such as neurons. We previously demonstrated...