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Updated: Aug 13, 2026
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Techniques to Induce and Quantify Cellular Senescence
Published on: May 1, 2017
Smurf2 up-regulation activates telomere-dependent senescence
1Department of Genetics, Stanford University School of Medicine, Stanford, California 94305-5120, USA.
Genes & Development
|December 3, 2004
Summary
Telomere shortening triggers Smurf2, an E3 ubiquitin ligase, causing replicative senescence in human cells. This finding identifies Smurf2 as the first gene both activated by telomere attrition and capable of inducing cellular senescence.
Area of Science:
- Cell Biology
- Molecular Biology
- Genetics
Background:
- Replicative senescence, driven by telomere shortening, limits cell proliferation, contributing to aging and tumor suppression.
- The molecular mechanisms linking telomere attrition to senescence are not fully understood.
Purpose of the Study:
- To identify genes up-regulated by telomere attrition that can induce senescence.
- To investigate the role of Smurf2 in telomere-mediated senescence.
Main Methods:
- Analysis of Smurf2 expression in human fibroblasts undergoing telomere attrition.
- Induction of senescence in early passage fibroblasts by adventitious Smurf2 production.
- Assessment of senescence markers, including proliferation, morphology, gene expression, and pathway activation (Rb, p53, p21).
Main Results:
- Up-regulation of Smurf2 is a specific consequence of telomere attrition in human fibroblasts.
- Physiological levels of Smurf2 induce a senescence phenotype, including proliferative arrest and characteristic cellular alterations.
- Smurf2-induced senescence occurs independently of DNA damage and stress responses, requires a novel function distinct from its E3 ligase activity, and involves the Rb and p53 pathways, but not p21.
Conclusions:
- Smurf2 is the first identified gene that is both up-regulated by telomere attrition and sufficient to induce replicative senescence.
- Smurf2 plays a critical role in the cellular senescence pathway triggered by telomere shortening.
- This discovery offers new insights into the fundamental processes of cellular aging and cancer prevention.
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