| Inactivation of p53 function in cultured human mammary epithelial cells turns the telomere-length dependent senescence barrier from agonescence into crisis. | |
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MedLine Citation:
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PMID: 17671422 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Cultured human mammary epithelial cells (HMEC) encounter two distinct barriers to indefinite growth. The first barrier, originally termed selection, can be overcome through loss of expression of the cyclin-dependent kinase inhibitor p16(INK4A). The resultant p16-, p53+ post-selection HMEC encounter a second barrier, termed agonescence, associated with critically shortened telomeres and widespread chromosomal aberrations. Although some cell death is present at agonescence, the majority of the population retains long-term viability. We now show that abrogation of p53 function in post-selection HMEC inactivates cell cycle checkpoints and changes the mostly viable agonescence barrier into a crisis-like barrier with massive cell death. In contrast, inactivation of p53 does not affect the ability of HMEC to overcome the first barrier. These data indicate that agonescence and crisis represent two different forms of a telomere-length dependent proliferation barrier. Altogether, our data suggest a modified model of HMEC senescence barriers. We propose that the first barrier is Rb-mediated and largely or completely independent of telomere length. This barrier is now being termed stasis, for stress-associated senescence. The second barrier (agonescence or crisis) results from ongoing telomere erosion leading to critically short telomeres and telomere dysfunction. |
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Authors:
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James C Garbe; Charles R Holst; Ekaterina Bassett; Thea Tlsty; Martha R Stampfer |
Publication Detail:
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Type: Journal Article Date: 2007-05-30 |
Journal Detail:
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Title: Cell cycle (Georgetown, Tex.) Volume: 6 ISSN: 1551-4005 ISO Abbreviation: Cell Cycle Publication Date: 2007 Aug |
Date Detail:
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Created Date: 2007-08-17 Completed Date: 2007-09-26 Revised Date: - |
Medline Journal Info:
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Nlm Unique ID: 101137841 Medline TA: Cell Cycle Country: United States |
Other Details:
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Languages: eng Pagination: 1927-36 Citation Subset: IM |
Affiliation:
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Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Cell Aging
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physiology* Cell Death Cell Line Cell Proliferation Cell Shape DNA Damage / genetics Epithelial Cells / cytology*, metabolism* Humans Mammary Glands, Human / cytology* Telomere / genetics* Tumor Suppressor Protein p53 / genetics, metabolism* |
| Chemical | |
Reg. No./Substance:
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0/Tumor Suppressor Protein p53 |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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