Background: The reactivation of the telomerase seems to be an important step in the carcinogenesis of most human cancer types. Cell clones, which express this enzyme, get the ability of indefinite proliferation, means become immortal.
Methods: In this study, 80 patients with squamous cell carcinomas (SSC) in oral cavity, oropharynx, hypopharynx and larynx were recorded prospectively concerning a possible correlation of telomerase activity and clinical and prognostic factors. Telomerase activity was analysed by a modified telomeric repeat amplification protocol (TRAP) assay.
Results: In 75% of the tumour tissues the telomerase was demonstrated independently of the localization of the tumour. The known clinical prognostic factors did not show any correlation to the expression rate of the telomerase activity in the tumour tissues. Also, reactivated telomerase did not affect the tumour-dependent survival. Only the number of lymph node metastases was in tendency higher in patients with telomerase-positive tumours. The number and timeframe of local and regional recurrences was not influenced by the telomerase status.
Conclusions: Although telomerase seems to be an important part of the carcinogenesis of SCC our data show that the reactivation of telomerase in tumour tissue did not have any prognostic significance for these tumours. The tendency that tumours with active telomerase developed lymph node metastases in a higher number should be evaluated by further enlarged studies for its clinical relevance.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1111/j.1600-0714.2004.00232.x | DOI Listing |
Mol Biol Rep
January 2025
Department of Integrative Biology, School of Bio-Sciences and Technology, Vellore Institute of Technology, Vellore, Tamil Nadu, 632014, India.
Telomerase, constituted by the dynamic duo of telomerase reverse transcriptase (TERT), the catalytic entity, and an integral RNA component (TERC), is predominantly suppressed in differentiated human cells due to postnatal transcriptional repression of the TERT gene. Dysregulation of telomerase significantly contributes to cancer development via telomere-dependent and independent mechanisms. Telomerase activity is often elevated in advanced cancers, with TERT reactivation and upregulation of TERC observed in early tumorigenesis.
View Article and Find Full Text PDFCancers (Basel)
January 2025
Department of Molecular Biosciences, University of South Florida, 4202 East Fowler Avenue, ISA2015, Tampa, FL 33620, USA.
Background/objectives: As cells divide, telomeres shorten through a phenomenon known as telomere attrition, which leads to unavoidable senescence of cells. Unprotected DNA exponentially increases the odds of mutations, which can evolve into premature aging disorders and tumorigenesis. There has been growing academic and clinical interest in exploring this duality and developing optimal therapeutic strategies to combat telomere attrition in aging and cellular immortality in cancer.
View Article and Find Full Text PDFCancer Res Commun
January 2025
Charité, Berlin, Germany.
Telomerase is reactivated by genomic TERT rearrangements in ~30% of diagnosed high-risk neuroblastomas. Dismal patient prognosis results if the RAS/MAPK/ALK signaling transduction network also harbors mutations. We present a liquid biopsy-based monitoring strategy for this particularly vulnerable pediatric patient subgroup, for whom real-time molecular diagnostic tools are limited to date.
View Article and Find Full Text PDFCell Rep
December 2024
Institute for Research on Cancer and Aging of Nice (IRCAN), CNRS UMR7284, INSERM U1081, Université Côte d'Azur, 06107 Nice, France; Instituto Gulbenkian de Ciência, 2780-156 Oeiras, Portugal. Electronic address:
Most cancers re-activate telomerase to maintain telomere length and thus acquire immortality. Activating telomerase promoter mutations are found in many cancers, including melanoma. However, it is unclear when and if telomerase is strictly required during tumorigenesis.
View Article and Find Full Text PDFMol Genet Genomics
December 2024
Department of Medical Genetics, School of Medicine, Iranshahr University of Medical Sciences, Iranshahr, Iran.
Telomeres, which are situated at the terminal ends of chromosomes, undergo a reduction in length with each cellular division, ultimately reaching a critical threshold that triggers cellular senescence. Cancer cells circumvent this senescence by utilizing telomere maintenance mechanisms (TMMs) that grant them a form of immortality. These mechanisms can be categorized into two primary processes: the reactivation of telomerase reverse transcriptase and the alternative lengthening of telomeres (ALT) pathway, which is dependent on homologous recombination (HR).
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!