HeLa cell cultures were used as model systems for small interfering RNA (siRNA) induced knockdown of mRNA expression of the human telomerase catalytic subunit, telomerase reverse transcriptase (hTERT). Four 21-bp siRNAs targeting different sites of the hTERT mRNA were designed, and the siRNA molecules produced by a T7 transcription system in vitro. In transient transfection assays on HeLa cells...

Functional human telomerase complexes are minimally composed of the human telomerase RNA (hTR) and a catalytic subunit (human telomerase reverse transcriptase [hTERT]) containing reverse transcriptase (RT)-like motifs. The N terminus of TERT proteins is unique to the telomerase family and has been implicated in catalysis, telomerase RNA binding, and telomerase multimerization, and conserved mot...

Human telomerase gene hTERT is important for cancer and aging. hTERT promoter is regulated by multiple transcription factors (TFs) and its activity is dependent on the chromatin environment. However, it remains unsolved how the interplay between TFs and chromatin environment controls hTERT transcription. In this study, we employed the recombinase-mediated BAC targeting and BAC recombineering te...

Activation of telomerase is one of the rate-limiting steps in human cell immortalization and carcinogenesis Human telomerase is composed of at least two protein subunits and an RNA component. Regulation of expression of the catalytic subunit, human telomerase reverse transcriptase (hTERT), is suggested as the major determinant of the enzymatic activity. We report here the cloning and characteri...

BACKGROUND & OBJECTIVE The expression of human telomerase reverse transcriptase (hTERT) is positively correlated to the activity of telomerase. Alternative splicing exists in the transcription of hTERT and special splicing patterns may change during tumor progression. This study was to reveal the changes of hTERT alterative splicing pattern in gastric carcinogenesis. METHODS Three alternative...

With granulosa and theca cells, the ovaries are responsible for producing oocytes and secreting sex steroids such as estrogen and progesterone. Endoplasmic reticulum stress (ERS) plays an important role in follicle atresia and embryo implantation. In this study, goat granulosa cells were isolated from medium-sized (4-6 mm) healthy follicles. Primary granulosa cells were immortalized by transfec...

The human telomerase reverse transcriptase hTERT is highly expressed in undifferentiated embryonic cells and silenced in the majority of somatic cells. To investigate the mechanisms of hTERT silencing, we have developed a novel reporter using a bacterial artificial chromosome (BAC) that contained the entire hTERT gene and its neighboring loci, hCRR9 and hXtrp2. Firefly and Renilla luciferases w...

OBJECTIVES To evaluate the effect of antineoplastic agents on the expression of human telomerase reverse transcriptase (hTERT) splice variants in MCF-7 cells. DESIGN AND METHODS We have developed a luminometric hybridization assay for hTERT beta plus transcript. MCF-7 cells were isolated before and after treatment with antineoplastic agents. A combination of nested RT-PCR and the developed lu...

Sustained cell proliferation requires telomerase to maintain functional telomeres that are essential for chromosome integrity and protection. Although nuclear import of telomerase transcriptase (hTERT) is required for telomerase activity to elongate telomeres in vivo, the molecular mechanism regulating nuclear localization of hTERT is unclear. We have identified a bipartite nuclear localization...

Transfection of the human telomerase reverse transcriptase (hTERT) gene has been shown to increase cell proliferation and enhance tissue repair. In the present study, hTERT was transfected into rat Schwann cells. A rat model of acute spinal cord injury was established by the modified free-falling method. Retrovirus PLXSN was injected at the site of spinal cord injury as a vector to mediate hTER...