Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2006-4-24
pubmed:abstractText
Conjugated linoleic acids (CLAs), naturally occurring fatty acids in ruminant food products, have anti-tumorigenic and pro-apoptotic properties in animal as well as in vitro models of cancer. However, the cellular mechanism has not been fully understood. NAG-1 (non-steroidal anti-inflammatory drug-activated gene-1) is induced by several dietary compounds and belongs to a TGF-beta superfamily gene associated with pro-apoptotic and anti-tumorigenic activities. The present study was performed to elucidate the molecular mechanism by which CLA stimulates anti-tumorigenic activity in human colorectal cancer (CRC) cells. The trans-10, cis-12-CLA (t10,c12-CLA) repressed cell proliferation and induced apoptosis, whereas linoleic acid or c9,t11-CLA showed no effect on cell proliferation and apoptosis. We also found that t10,c12-CLA induced the expression of a pro-apoptotic gene, NAG-1, in human CRC cells. Inhibition of NAG-1 expression by small interference RNA (siRNA) results in repression of t10,c12-CLA-induced apoptosis. Microarray analysis using t10,c12-CLA-treated HCT-116 cells revealed that activating transcription factor 3 (ATF3) was induced and its expression was confirmed by western analysis. The t10,c12-CLA treatment followed by the overexpression of ATF3 increased NAG-1 promoter activity in HCT-116 cells. We further provide the evidence that t10,c12-CLA inhibited the phosphorylation of AKT and the blockage of GSK-3 by siRNA abolished t10,c12-CLA-induced ATF3 and NAG-1 expression. The current study demonstrates that t10,c12-CLA stimulates ATF3/NAG-1 expression and subsequently induces apoptosis in an isomer specific manner. These effects may be through inhibition of AKT/GSK-3beta pathway in human CRC cells.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0143-3334
pubmed:author
pubmed:issnType
Print
pubmed:volume
27
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
972-81
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Conjugated linoleic acid stimulates an anti-tumorigenic protein NAG-1 in an isomer specific manner.
pubmed:affiliation
Department of Pathobiology, College of Veterinary Medicine, University of Tennessee, Knoxville, TN 37996, USA.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural