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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1996-7-17
pubmed:abstractText
The recent identification and cloning of mammalian transforming growth factor beta (TGFbeta) receptors permits further analysis of the importance of the TGFbeta family in intestinal biology. Expression of the type II TGFbeta receptor was examined in gastrointestinal cell lines and tissues. The 5.5 kb type II mRNA species was detected in poly-(A) mRNA isolated from the rat small bowel and colon. Northern blot analysis of RNA isolated from epithelial and non-epithelial small intestinal cell fractions showed the majority of receptor mRNA localized in the non-epithelial compartment. Immunohistochemical localization in the small intestine and colon supported the RNA findings; that is, expression was greatest in the lamina propria and muscularis. Staining was also detectable in the epithelium, where it was most prominent in the villus tip cells and absent in crypt cells. These findings mirror expression of TGFbeta in the epithelial compartment. The IEC-6, IPEC and RIE-1 cell lines, all of which are non-transformed, were growth inhibited by TGFbeta and expressed type II receptor mRNA and protein. By contrast, the ras-transfected RIE-1, HT-29, Caco-2 and SW-620 transformed lines were not growth inhibited by TGFbeta and all demonstrated a marked reduction in type II TGFbeta receptor mRNA expression and protein abundance by cross-linking. In conclusion, (i) colocalization of both ligand and receptor establishes the existence of potential autocrine and/or paracrine pathways for TGFbeta in the normal intestine and (ii) down-regulation of the type II TGFbeta receptor occurs in association with cellular transformation and may contribute to intestinal carcinogenesis.
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
17
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
989-95
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Type II TGF(beta) receptor expression in intestinal cell lines and in the intestinal tract.
pubmed:affiliation
Department of Pediatrics, Division of Gastroenterology and Nutrition, Vanderbilt University School of Medicine, Nashville, TN 37232-2576, USA.
pubmed:publicationType
Journal Article