Telomeres, the ends of eukaryotic chromosomes, play a central role in the control of cellular senescence and organismal ageing and need to be protected in order to avoid being recognised as damaged DNA and activate DNA damage response pathways. Dysfunctional telomeres arise from critically short telomeres or altered telomere structures, which ultimately lead to replicative cellular senescence and chromosome instability: both hallmarks of ageing. The observation that telomeres are transcribed led to the discovery that telomeric transcripts play important roles in chromosome end protection and genome stability maintenance. Recent evidence indicates that particular long non-coding (nc)RNAs transcribed at telomeres, namely TElomeric Repeat-containing RNA (TERRA) and telomeric damage-induced long ncRNAs (tdilncRNA), play key roles in age-related pathways by actively orchestrating the mechanisms known to regulate telomere length, chromosome end protection and DNA damage signalling. Here, we provide a comprehensive overview of the telomere transcriptome, outlining how it functions as a regulatory platform with essential functions in safeguarding telomere integrity and stability. We next review emerging antisense oligonucleotides therapeutic strategies that target telomeric ncRNAs and discuss their potential for ameliorating ageing and age-related diseases. Altogether, this review provides insights on the biological relevance of telomere transcription mechanisms in human ageing physiology and pathology.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.arr.2020.101115 | DOI Listing |
World J Methodol
December 2024
Department of Biology, St. Francis College, Brooklyn, NY 11201, United States.
In this Editorial review, we would like to focus on a very recent discovery showing the global autosomal gene regulation by Y- and inactivated X-chromosomal transcription factors, zinc finger gene on the Y chromosome (ZFY) and zinc finger protein X-linked (ZFX). ZFX and ZFY are both zinc-finger proteins that encode general transcription factors abundant in hematopoietic and embryonic stem cells. Although both proteins are homologs, interestingly, the regulation of self-renewal by these transcriptional factors is almost exclusive to ZFX.
View Article and Find Full Text PDFLife Sci
December 2024
Department of Pharmacology, School of Pharmacy, Nantong University, Nantong 226001, China. Electronic address:
Aims: High telomerase activity has been detected in over 85 % of tumors, with the activation of hTERT being the most crucial mechanism for re-establishing telomerase activity. Activation of hTERT maintains telomere length in cells, enabling cancer cells to proliferate indefinitely. Nevertheless, the specific mechanism of telomerase activation in non-small cell lung cancer (NSCLC) remains unclear, and post-transcriptional regulation of hTERT could be a potential activation mechanism.
View Article and Find Full Text PDFFEBS Lett
December 2024
Department of Biochemistry and Molecular Biology, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, USA.
Genome maintenance is essential for the integrity of the genetic blueprint, of which only a small fraction is transcribed in higher eukaryotes. DNA lesions occurring in the transcribed genome trigger transcription pausing and transcription-coupled DNA repair. There are two major transcription-coupled DNA repair pathways.
View Article and Find Full Text PDFClin Epigenetics
December 2024
Third Department of Internal Medicine, Kansai Medical University, 2-5-1 Shin-Machi, Hirakata, Osaka, 573-1010, Japan.
Interaction between host genotoxic changes and mucosa-associated microbiome (MAM) dysbiosis may have a role in various digestive cancers. We investigated MAM in Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC) progression sequence and its association with host genotoxic changes. 16S rRNA gene sequencing was performed in three different groups of biopsies from nonneoplastic BE from patients without cancer (N, normal group; n = 47) and with EAC (ADJ, adjacent group; n = 27).
View Article and Find Full Text PDFBMC Genomics
December 2024
Department of Chemistry & Biochemistry, University of Colorado Colorado Springs, Colorado Springs, CO, 80918, USA.
Background: Organization of the eukaryotic genome is essential for proper function, including gene expression. In metazoans, chromatin loops and Topologically Associated Domains (TADs) organize genes into transcription factories, while chromosomes occupy nuclear territories in which silent heterochromatin is compartmentalized at the nuclear periphery and active euchromatin localizes to the nucleus center. A similar hierarchical organization occurs in the fungus Neurospora crassa where its seven chromosomes form a Rabl conformation typified by heterochromatic centromeres and telomeres independently clustering at the nuclear membrane, while interspersed heterochromatic loci aggregate across Megabases of linear genomic distance to loop chromatin in TAD-like structures.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!