Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1995-2-16
pubmed:abstractText
Gastrin is transcriptionally responsive to EGF stimulation (Merchant et al., 1991, Mol. Cell. Biol., 11:2686-2696). Consequently, we hypothesized that previously recognized gastrin autocrine loops (Hoosein et al., 1990, Exp. Cell. Res., 186:15-21), might be controlled by autocrine TGF alpha in human colon carcinoma cells. Therefore, we examined the interaction between these two autocrine growth factors in two colon carcinoma cell lines which utilize TGF alpha. The FET cell line requires exogenous TGF alpha/EGF for optimal growth and has a classical TGF alpha autocrine loop which is disrupted by TGF alpha or epidermal growth factor receptor (EGFr) antibodies. The HCT 116 cell line is not dependent on exogenous TGF alpha/EGF and exhibits a nonclassical TGF alpha autocrine loop which is not disrupted by neutralizing antibodies to either TGF alpha itself or the EGFr. Basal gastrin mRNA production is significantly higher in HCT 116 than FET as measured by RNase protection assay. In the FET cells, exogenous EGF stimulates gastrin mRNA production but not in HCT 116. When the TGF alpha autocrine loop in HCT 116 is disrupted by constitutive expression of antisense TGF alpha mRNA, the gastrin mRNA level is significantly repressed. In xenografts derived from these antisense clones, TGF alpha reverted to high expression, and the gastrin mRNA level was again increased. This interaction between the strong TGF alpha loop in HCT 116 and the gastrin autocrine loop may confer a growth advantage to these colon cells. Such interactions between growth factors may promote enhanced tumorigenicity to transformed cells with these strong, nonclassical autocrine loops.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0021-9541
pubmed:author
pubmed:issnType
Print
pubmed:volume
162
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
256-65
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Regulation of autocrine gastrin expression by the TGF alpha autocrine loop.
pubmed:affiliation
Department of Pharmacology, Baylor College of Medicine, Houston, Texas 77030.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.