Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
17
pubmed:dateCreated
2006-9-4
pubmed:abstractText
Eph receptor tyrosine kinases are involved in nervous system development. Eph ligands, termed ephrins, are transmembrane proteins that bind to Eph receptors, the mutual activation of which causes repulsive effects in reciprocally contacting cells. Previously, we showed that overexpression of EphB2 in glioma cells increases cell invasion. Here, expression profiles of ephrin-B family members were determined in four glioma cell lines and in invading glioblastoma cells collected by laser capture microdissection. Ephrin-B3 mRNA was up-regulated in migrating cells of four of four glioma cell lines (1.3- to 1.7-fold) and in invading tumor cells of eight of eight biopsy specimens (1.2- to 10.0-fold). Forced expression of ephrin-B3 in low expressor cell lines (U87, T98G) stimulated cell migration and invasion in vitro and ex vivo, concomitant with tyrosine phosphorylation of ephrin-B3. In high expressor cell lines (U251, SNB19), ephrin-B3 colocalized with Rac1 to lamellipodia of motile wild-type cells. Cells transfected with ephrin-B3 small interfering RNA (siRNA) showed significant morphologic change and decreased invasion in vitro and ex vivo. Depletion of endogenous ephrin-B3 expression abrogated the increase of migration and invasion induced by EphB2/Fc, indicating increased invasion is dependent on ephrin-B3 activation. Furthermore, using a Rac1-GTP pull-down assay, we showed that ephrin-B3 is associated with Rac1 activation. Reduction of Rac1 by siRNA negated the increased invasion by addition of EphB2/Fc. In human glioma specimens, ephrin-B3 expression and phosphorylation correlated with increasing tumor grade. Immunohistochemistry revealed robust staining for phosphorylated ephrin-B and ephrin-B3 in invading glioblastoma cells. These data show that ephrin-B3 expression and signaling through Rac1 are critically important to glioma invasion.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
1538-7445
pubmed:author
pubmed:issnType
Electronic
pubmed:day
1
pubmed:volume
66
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
8492-500
pubmed:meshHeading
pubmed-meshheading:16951161-Animals, pubmed-meshheading:16951161-Astrocytoma, pubmed-meshheading:16951161-Brain, pubmed-meshheading:16951161-Cell Line, Tumor, pubmed-meshheading:16951161-Cell Movement, pubmed-meshheading:16951161-DNA Primers, pubmed-meshheading:16951161-Ephrin-B3, pubmed-meshheading:16951161-Gene Expression Regulation, Neoplastic, pubmed-meshheading:16951161-Glioma, pubmed-meshheading:16951161-Humans, pubmed-meshheading:16951161-Immunohistochemistry, pubmed-meshheading:16951161-Ligands, pubmed-meshheading:16951161-Neoplasm Invasiveness, pubmed-meshheading:16951161-Phosphorylation, pubmed-meshheading:16951161-Plasmids, pubmed-meshheading:16951161-RNA, Small Interfering, pubmed-meshheading:16951161-Rats, pubmed-meshheading:16951161-Reverse Transcriptase Polymerase Chain Reaction, pubmed-meshheading:16951161-Transfection, pubmed-meshheading:16951161-Transplantation, Heterologous, pubmed-meshheading:16951161-rac1 GTP-Binding Protein
pubmed:year
2006
pubmed:articleTitle
Ephrin-B3 ligand promotes glioma invasion through activation of Rac1.
pubmed:affiliation
The Translational Genomics Research Institute, Phoenix, AZ 85004, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural