Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2000-10-2
pubmed:abstractText
Telomeres are specialized nucleoprotein complexes that serve as protective caps of linear eukaryotic chromosomes. Loss of telomere function is associated with rampant genetic instability and loss of cellular viability and renewal potential. The telomere also participates in processes of chromosomal repair, as evidenced by the 'capture' or de novo synthesis of telomere repeats at double-stranded breaks and by the capacity of yeast telomeres to serve as repositories of essential components of the DNA repair machinery, particularly those involved in non-homologous end-joining (NHEJ). Here we used the telomerase-deficient mouse, null for the essential telomerase RNA gene (Terc), to assess the role of telomerase and telomere function on the cellular and organismal response to ionizing radiation. Although the loss of telomerase activity per se had no discernable impact on the response to ionizing radiation, the emergence of telomere dysfunction in late-generation Terc-/- mice imparted a radiosensitivity syndrome associated with accelerated mortality. On the cellular level, the gastrointestinal crypt stem cells and primary thymocytes showed increased rates of apoptosis, and mouse embryonic fibroblasts (MEFs) showed diminished dose-dependent clonogenic survival. The radiosensitivity of telomere dysfunctional cells correlated with delayed DNA break repair kinetics, persistent chromosomal breaks and cytogenetic profiles characterized by complex chromosomal aberrations and massive fragmentation. Our findings establish a intimate relationship between functionally intact telomeres and the genomic, cellular and organismal response to ionizing radiation.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
1061-4036
pubmed:author
pubmed:issnType
Print
pubmed:volume
26
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
85-8
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:10973255-Animals, pubmed-meshheading:10973255-Apoptosis, pubmed-meshheading:10973255-Cell Nucleus, pubmed-meshheading:10973255-Cell Survival, pubmed-meshheading:10973255-Chromosome Aberrations, pubmed-meshheading:10973255-Chromosomes, pubmed-meshheading:10973255-DNA Fragmentation, pubmed-meshheading:10973255-DNA Repair, pubmed-meshheading:10973255-Dose-Response Relationship, Radiation, pubmed-meshheading:10973255-Fibroblasts, pubmed-meshheading:10973255-Genotype, pubmed-meshheading:10973255-In Situ Nick-End Labeling, pubmed-meshheading:10973255-Kinetics, pubmed-meshheading:10973255-Mice, pubmed-meshheading:10973255-Mice, Transgenic, pubmed-meshheading:10973255-Models, Genetic, pubmed-meshheading:10973255-Radiation, Ionizing, pubmed-meshheading:10973255-Radiation Tolerance, pubmed-meshheading:10973255-Telomere, pubmed-meshheading:10973255-Thymus Gland, pubmed-meshheading:10973255-Time Factors
pubmed:year
2000
pubmed:articleTitle
Telomere dysfunction impairs DNA repair and enhances sensitivity to ionizing radiation.
pubmed:affiliation
Department of Adult Oncology, Dana Farber Cancer Institute, Boston, Massachusetts, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't