Linked Life Data

17721077

Source:http://linkedlifedata.com/resource/pubmed/id/17721077

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
16
pubmed:dateCreated
2007-8-29
pubmed:abstractText
Levels of p27(Kip1), a key negative regulator of the cell cycle, are often decreased in cancer. In most cancers, levels of p27(Kip1) mRNA are unchanged and increased proteolysis of the p27(Kip1) protein is thought to be the primary mechanism for its downregulation. Here we show that p27(Kip1) protein levels are also downregulated by microRNAs in cancer cells. We used RNA interference to reduce Dicer levels in human glioblastoma cell lines and found that this caused an increase in p27(Kip1) levels and a decrease in cell proliferation. When the coding sequence for the 3'UTR of the p27(Kip1) mRNA was inserted downstream of a luciferase reporter gene, Dicer depletion also enhanced expression of the reporter gene product. The microRNA target site software TargetScan predicts that the 3'UTR of p27(Kip1) mRNA contains multiple sites for microRNAs. These include two sites for microRNA 221 and 222, which have been shown to be upregulated in glioblastoma relative to adjacent normal brain tissue. The genes for microRNA 221 and microRNA 222 occupy adjacent sites on the X chromosome; their expression appears to be coregulated and they also appear to have the same target specificity. Antagonism of either microRNA 221 or 222 in glioblastoma cells also caused an increase in p27(Kip1) levels and enhanced expression of the luciferase reporter gene fused to the p27(Kip1) 3'UTR. These data show that p27(Kip1) is a direct target for microRNAs 221 and 222, and suggest a role for these microRNAs in promoting the aggressive growth of human glioblastoma.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
1551-4005
pubmed:author
pubmed:issnType
Electronic
pubmed:day
15
pubmed:volume
6
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2005-9
pubmed:dateRevised
2009-9-9
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Regulation of p27Kip1 by miRNA 221/222 in glioblastoma.
pubmed:affiliation
Ottawa Health Research Institute, Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't