Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
Pt 3
pubmed:dateCreated
2008-1-24
pubmed:abstractText
EPHA2 receptor tyrosine kinase is overexpressed in several human cancer types and promotes malignancy. However, the mechanisms by which EPHA2 promotes tumor progression are not completely understood. Here we report that overexpression of a wild-type EPHA2, but not a signaling-defective cytoplasmic truncation mutant (DeltaC), in human mammary epithelial cells weakens E-cadherin-mediated cell-cell adhesion. Interestingly, the total level of cadherins and the composition of the adherens junction complexes were not affected, nor was the tyrosine phosphorylation of the cadherin complex components changed. By contrast, RhoA GTPase activity was significantly affected by modulating the EPHA2 activity in MCF-10A cells. Treatment with a ROCK kinase inhibitor rescued cell-cell adhesion defects in EPHA2-overexpressing cells, whereas expression of constitutively activated Rho disrupted adherens junctions in DeltaC-expressing cells. EPHA2-dependent Rho activation and destabilization of adherens junctions appeared to be regulated via a signaling pathway involving Src kinase, low molecular weight phosphotyrosine phosphatase (LMW-PTP) and p190 RhoGAP. EPHA2 interacted with both Src and LMW-PTP, and the interactions increased in EPHA2-overexpressing cells. In addition, LMW-PTP phosphatase activity was elevated, and this elevation was accompanied by a decrease in tyrosine phosphorylation of p190 RhoGAP and destabilization of cell-cell adhesion. Expression of either a dominant negative LMW-PTP mutant, C12S, or a wild-type p190 RhoGAP rescued adhesion defects in EPHA2-overexpressing cells. Together, these data suggest that EPHA2 promotes tumor malignancy through a mechanism involving RhoA-dependent destabilization of adherens junctions.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/ARHGAP35 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/Cadherins, http://linkedlifedata.com/resource/pubmed/chemical/Catenins, http://linkedlifedata.com/resource/pubmed/chemical/Guanine Nucleotide Exchange Factors, http://linkedlifedata.com/resource/pubmed/chemical/Protein Tyrosine Phosphatases, http://linkedlifedata.com/resource/pubmed/chemical/RHOA protein, human, http://linkedlifedata.com/resource/pubmed/chemical/Receptor, EphA2, http://linkedlifedata.com/resource/pubmed/chemical/Recombinant Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Repressor Proteins, http://linkedlifedata.com/resource/pubmed/chemical/rhoA GTP-Binding Protein, http://linkedlifedata.com/resource/pubmed/chemical/src-Family Kinases
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0021-9533
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
121
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
358-68
pubmed:dateRevised
2011-9-27
pubmed:meshHeading
pubmed-meshheading:18198190-Adherens Junctions, pubmed-meshheading:18198190-Cadherins, pubmed-meshheading:18198190-Catenins, pubmed-meshheading:18198190-Cell Adhesion, pubmed-meshheading:18198190-Cell Line, pubmed-meshheading:18198190-Female, pubmed-meshheading:18198190-Gene Expression, pubmed-meshheading:18198190-Guanine Nucleotide Exchange Factors, pubmed-meshheading:18198190-Humans, pubmed-meshheading:18198190-Models, Biological, pubmed-meshheading:18198190-Mutation, pubmed-meshheading:18198190-Phosphorylation, pubmed-meshheading:18198190-Protein Tyrosine Phosphatases, pubmed-meshheading:18198190-Receptor, EphA2, pubmed-meshheading:18198190-Recombinant Proteins, pubmed-meshheading:18198190-Repressor Proteins, pubmed-meshheading:18198190-Sequence Deletion, pubmed-meshheading:18198190-Signal Transduction, pubmed-meshheading:18198190-rhoA GTP-Binding Protein, pubmed-meshheading:18198190-src-Family Kinases
pubmed:year
2008
pubmed:articleTitle
Overexpression of EPHA2 receptor destabilizes adherens junctions via a RhoA-dependent mechanism.
pubmed:affiliation
Department of Cancer Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, N.I.H., Extramural