Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2007-1-11
pubmed:abstractText
Transforming growth factor (TGF)-beta-dependent apoptosis is important in the elimination of damaged or abnormal cells from normal tissues in vivo. Previously, we have shown that TGF-beta inhibits the growth of rat intestinal epithelial (RIE)-1 cells. However, RIE-1 cells are relatively resistant to TGF-beta-induced apoptosis due to a low endogenous Smad3-to-Akt ratio. Overexpression of Smad3 sensitizes RIE-1 cells (RIE-1/Smad3) to TGF-beta-induced apoptosis by altering the Smad3-to-Akt ratio in favor of apoptosis. In this study, we utilized a genomic approach to identify potential downstream target genes that are regulated by TGF-beta/Smad3. Total RNA samples were analyzed using Affymetrix oligonucleotide microarrays. We found that TGF-beta regulated 518 probe sets corresponding to its target genes. Interestingly, among the known apoptotic genes included in the microarray analyses, only caspase-3 was induced, which was confirmed by real-time RT-PCR. Furthermore, TGF-beta activated caspase-3 through protein cleavage. Upstream of caspase-3, TGF-beta induced mitochondrial depolarization, cytochrome c release, and cleavage of caspase-9, which suggests that the intrinsic apoptotic pathway mediates TGF-beta-induced apoptosis in RIE-1/Smad3 cells.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0193-1857
pubmed:author
pubmed:issnType
Print
pubmed:volume
292
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
G28-38
pubmed:dateRevised
2007-12-3
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Identification of apoptotic genes mediating TGF-beta/Smad3-induced cell death in intestinal epithelial cells using a genomic approach.
pubmed:affiliation
Department of Surgery, University of Texas Medical Branch, 301 University Blvd., Galveston, TX 77555-0737, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural