although pyrimethamine (tindurin™) appears to be effective in the prevention and treatment of some infectious diseases, very little information exists on its unpredictable properties. we design this study to evaluate its anti-tumoral effect on a model of cell line. methods: the cytotoxic influence of pyrimethamine on prostate cell line was investigated using an in vitro colometric assay. the po...

Telomerase is a specialized reverse transcriptase consisting of both RNA and protein components. Previous characterization of yeast telomerase function in vivo identified four EST (for ever shorter telomeres) genes that, when mutated, result in the phenotypes expected for a defect in telomerase. Consistent with this genetic prediction, the EST2 gene has recently been shown to encode the catalyt...

Telomerase activity has been detected in many human immortal cells lines and in tumor tissues, whereas it is generally absent from primary cell strains and from many tumor adjacent tissue samples. With the recently cloned human telomerase RNA (hTR), we used Northern analysis to follow the levels of hTR in primary, precrisis, and immortalized cells. It was surprising that the amount of hTR was h...

Telomerase is a ribonucleoprotein comprising telomerase RNA and associated proteins. The formation of the telomerase holoenzyme takes place in the Cajal body (CB), a subnuclear domain that participates in the formation of ribonucleoproteins. CBs also contribute to the delivery of telomerase to telomeres. The protein WRAP53 is enriched within the CB and is instrumental for the targeting of telom...

Telomerase is a ribonucleoprotein that synthesizes telomeric DNA on chromosomal ends. Telomerase activation has been seen in many immortal cell lines and cancers. Telomerase activity was analyzed in prostate carcinoma; in coexistent prostatic intraepithelial neoplasia (PIN), benign prostatic hyperplasia (BPH), atrophy and normal tissue; and in benign prostate glands. Telomerase activity was det...

Telomere length maintenance is essential for cellular immortalization, and thus tumorigenesis. Most human tumors and immortal cell lines maintain their telomeric DNA via the activity of a specialized reverse transcriptase, telomerase. Stabilization of telomeric repeat tracts may also be achieved through a telomerase-independent mechanism, referred to as alternative lengthening of telomeres (ALT...

Telomerase is a ribonucleoprotein enzyme that functions to maintain telomeres, the terminal DNA that protects chromosomal integrity, regulating cellular replicative life span. Telomerase is not expressed in most normal human somatic cells but is active in stabilizing telomeres of certain self-renewing cell populations and most malignant cells, making the enzyme an appealing target for anticance...

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...

Exosomes are small (30-100nm) vesicles secreted from all cell types serving as inter-cell communicators and affecting biological processes in "recipient" cells upon their uptake. The current study demonstrates for the first time that hTERT mRNA, the transcript of the enzyme telomerase, is shuttled from cancer cells via exosomes into telomerase negative fibroblasts, where it is translated into a...

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...