Telomeres are primarily controlled by a highly specialized DNA polymerase termed telomerase. Recent studies have demonstrated that introduction of the telomerase catalytic component (TERT) into telomerase-negative cells activates telomerase and extends cell life span, whereas mice lacking telomerase activity revealed impaired cell proliferation in some organs as well as reduced tumorigenesis. T...

The aim of the present study was to investigate the diagnostic efficacy of telomerase activity for discrimination of malignant and benign pleural effusions. Pleural effusions were collected from 109 consecutive patients in whom the diagnosis was confirmed with cytological and/or histological examinations. Cytological samples were classified as malignant (n=63) and benign (n=46). Telomerase acti...

OBJECTIVE Telomere length and telomerase activity are important indicators of cellular senescence and replicative ability. Loss of telomerase is associated with ageing and the development of osteoarthritis. Implantation of telomerase-positive cells, chondrocytes, or stem cells expressing a normal chondrocyte phenotype is desired for cartilage repair procedures. The objective of this study was t...

Telomerase is a reverse transcriptase that adds telomeric repeats to chromosomal ends. In most normal human somatic cells, telomerase is repressed and telomeres progressively shorten, leading to limited proliferative life-span. Telomerase reactivation is associated with cellular immortalization and is a frequent event during tumorigenesis. The telomerase ribonucleoprotein complex consists of tw...

BACKGROUND The activity of the ribonucleoprotein enzyme telomerase is not detected in normal somatic cells; thus, with each cell division, the ends of chromosomes consisting of the telomeric repeats TTAGGG progressively erode. The current model gaining support is that telomerase activity in germline and immortal cells maintains telomere length and thus compensates for the "end-replication probl...

AIMS To investigate the pattern of telomerase activity in hydatidiform mole as compared with normal placenta and choriocarcinoma, and to determine the prognostic significance of telomerase activity in hydatidiform mole. METHODS Telomerase activity in 35 cases of hydatidiform mole, 35 normal placentas, one choriocarcinoma sample, and two choriocarcinoma cell lines (JAR, JEG3) was determined us...

BACKGROUND AND OBJECTIVE Telomerase is the enzyme that stabilizes and elongates the telomeric ends of chromosomes. It is expressed in germline and malignant cells and absent in most human somatic cells. The selective expression of telomerase has thus been proposed to be a basis for the immortality of germline and malignant cells. Recently, telomerase activity has been observed in human bone mar...

Telomeres shortening, which leads to apoptosis, is prevented by telomerase adding small repeated segments of DNA to the telomeres. The telomerase level has been correlated with progression of several cancer types, including acute leukemia, breast, prostate, lung cancer and melanoma. Suppression of telomerase activity was found to reduce metastatic potential but could have serious side effects i...

To understand the molecular events for the proliferation of B cells, we studied the induction of telomerase activity in vitro after stimulation to B-cell antigen receptor (BCR) on human peripheral B cells. Although unstimulated purified B cells of tonsils and peripheral blood from healthy volunteers do not express detectable telomerase activity, anti-IgM beads induce telomerase activity in thes...

Stromal tumors of the gut (GISTs) have rarely been analyzed for genetic alterations. This study aimed at determining telomerase activity and the expression of the telomerase subunits human telomerase reverse transcriptase (hTRT) and human telomerase RNA (hTR) in GISTs and extragastrointestinal neurogenic or myogenic sarcomas. Telomerase activity was investigated using the telomeric repeat ampli...