Bcl-2 and p53 are the most relevant proteins in apoptosis and tumor development. Telomerase functions in the maintenance of telomeres and is indispensable for immortalization. Bcl-2 was reported as a direct modulator of telomerase activity, and a correlation between p53 and telomerase activity was reported. The aim of this study was to determine the relationships between Bcl-2, p53, and telomer...

Using three different differentiation agents (1alpha, 25 dihydroxyvitamin D3, all-trans-retinoic acid, and Am80), down-regulation of telomerase activity was found to be a common response during the monocytic or granulocytic differentiation of human acute myeloblastic leukemia cell line 60 (HL60) cells. Rapid down-regulation of telomerase transcription occurred during early differentiation of HL...

Using the sensitive telomeric repeat amplification protocol assay, we detected telomerase activity in 26 of 35 (74.3%) renal cell carcinomas analyzed. Subdivision of the tumors according to telomerase activity did not reveal an obvious association between the presence of telomerase activity and histomorphological stage, grade, tumor size, or DNA ploidy. Furthermore, no association was found bet...

Telomerase, the enzyme that maintains the ends of linear eukaryotic chromosomes, is active in human germ cells and in a majority of tumor tissues and immortalized cell lines. In contrast, most mature somatic cells and tissues contain low or undetectable telomerase activity, implying a stringent negative regulatory control mechanism. We report here that telomerase activity is dramatically inhibi...

Telomeres, which are important for maintaining chromosome integrity and functions, shorten with each cell division. Telomerase, responsible for telomere synthesis, is expressed in approximately 90% of human tumor cells but seldom in normal somatic cells. This study evaluated the hypothesis that simultaneous shortening of telomeres and inhibition of telomerase results in synergistic and tumor-se...

Telomerase is a ribonucleoprotein that maintains telomere length and whose activity is associated with escape from cellular senescence. Telomerase activity has been found in germline, immortalized, and malignant tumor cells. Using a modified PCR-based assay for telomerase activity, 26 of 35 (80%) primary, fresh, head and neck squamous cell cancer specimens and 3 of 6 head and neck squamous dysp...

Telomerase activity is present in >90% of all tumors and appears to be regulated by the phosphatidylinositol 3-kinase signaling pathway. Here we demonstrate that Akt is not involved in the signaling cascade for telomerase regulation in ovarian surface epithelial cells. However, we showed that c-Jun NH2-kinase induces telomerase activity, that inhibition of JNK by JIP abrogates telomerase activi...

Activation of telomerase seems to be a prerequisite for immortalization and is found in permanent cell lines and most malignant tumors. Normal somatic cells are generally telomerase negative, except for bone marrow stem cells. Weak activity is also present in peripheral blood cells. In the present study strong telomerase activity was demonstrated in vivo in normal mature cells of the immune sys...

There is a close relationship between telomeres-telomerase and age-related disease. Human telomerase reverse transcriptase (hTERT) is both the catalytic component of human telomerase and the rate-limiting determinant of telomerase activity. Its transcriptional regulation is the primary mode of control of telomerase activity. It is critical to find the proteins interacting with hTERT for explori...

Telomeres, the ends of linear chromosomes, safeguard against genome instability. The enzyme responsible for extension of the telomere 3' terminus is the ribonucleoprotein telomerase. Whereas telomerase activity can be reconstituted in vitro with only the telomerase RNA (hTR) and telomerase reverse transcriptase (TERT), additional components are required in vivo for enzyme assembly, stability an...