Linked Life Data

18219184

Source:http://linkedlifedata.com/resource/pubmed/id/18219184

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2008-3-27
pubmed:abstractText
Replicative senescence is a fundamental feature in normal human diploid cells and results from dysfunctional telomeres at the Hayflick cell division limit. Ionizing radiation (IR) prematurely induces the same phenotypes as replicative senescence prior to the Hayflick limit. This process is known as stress-induced premature senescence (SIPS). Since the cell cycle is irreversibly arrested in SIPS-induced cells, even if they are stimulated by various growth factors, it is thought that SIPS is a form of cell death, irreversibly eliminating replicating cells. IR-induced-focus formation of DNA repair proteins, a marker of DNA damage, is detected in SIPS as well as replicative senescent cells. Furthermore, both processes persistently induce cell cycle checkpoint mechanisms, indicating DNA damage created by ionizing radiation induces SIPS in normal cells, possibly by the same mechanisms as those occurring in replicative senescence. Interestingly, IR induces SIPS not only in normal cells, but also in tumor cells. Due to the expression of telomerase in tumor cells, telomere-dependent replicative senescence does not occur. However, SIPS is induced under certain conditions after IR exposure. Thus, cell death triggered by IR can be attributed to apoptosis or SIPS in tumor cells. However, metabolic function remains intact in SIPS-induced cancer cells, and recent studies show that senescence eliminate cells undergoing SIPS secrete various kinds of factors outside the cell, changing the microenvironment. Evidence using co-culture systems containing normal senescent stromal cells and epithelial tumor cells show that factors secreted from senescent stroma cells promote the growth of tumor epithelial cells both in vitro and in vivo. Thus, regulation of factors secreted from SIPS-induced stromal cells, as well as tumor cells, may affect radiotherapy.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0449-3060
pubmed:author
pubmed:issnType
Print
pubmed:volume
49
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
105-12
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Stress-induced premature senescence (SIPS)--influence of SIPS on radiotherapy.
pubmed:affiliation
Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Review