CD44 interaction with c-Src kinase promotes cortactin-mediated cytoskeleton function and hyaluronic acid-dependent ovarian tumor cell migration.
In this study we have demonstrated that both CD44 (the hyaluronan (HA) receptor) and c-Src kinase are expressed in human ovarian tumor cells (SK-OV-3.ipl cell line), and that these two proteins are physically associated as a complex in vivo. Using a recombinant cytoplasmic domain of CD44 and an in vitro binding assay, we have detected a specific interaction between CD44 and c-Src kinase. Furthermore, the binding of HA to SK-OV-3.ipl cells promotes c-Src kinase recruitment to CD44 and stimulates c-Src kinase activity, which, in turn, increases tyrosine phosphorylation of the cytoskeletal protein, cortactin. Subsequently, tyrosine phosphorylation of cortactin attenuates its ability to cross-link filamentous actin in vitro. In addition, transfection of SK-OV-3.ipl cells with a dominant active form of c-Src (Y527F)cDNA promotes CD44 and c-Src association with cortactin in membrane projections, and stimulates HA-dependent/CD44-specific ovarian tumor cell migration. Finally, overexpression of a dominant-negative mutant of c-Src kinase (K295R) in SK-OV-3.ipl cells impairs the tumor cell-specific phenotype. Taken together, these findings strongly suggest that CD44 interaction with c-Src kinase plays a pivotal role in initiating cortactin-regulated cytoskeleton function and HA-dependent tumor cell migration, which may be required for human ovarian cancer progression.
Bourguignon
L Y
LY
Department of Cell Biology and Anatomy, School of Medicine, University of Miami, Florida 33101, USA. lbourgui@med.miami.edu
Zhu
H
H
Shao
L
L
Chen
Y W
YW
D000818:Animals; D002465:Cell Movement; D003001:Cloning, Molecular; D051356:Cortactin; D003599:Cytoskeleton / Q000378:metabolism*; D018076:DNA, Complementary / Q000378:metabolism; D005260:Female; D005799:Genes, Dominant; D006801:Humans; D018960:Hyaluronan Receptors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D006820:Hyaluronic Acid / Q000494:pharmacology*; D015151:Immunoblotting; D008840:Microfilament Proteins / Q000378:metabolism*; D008856:Microscopy, Fluorescence; D009154:Mutation; D010051:Ovarian Neoplasms / Q000378:metabolism*; D010641:Phenotype; D010766:Phosphorylation; D010957:Plasmids / Q000378:metabolism; D011233:Precipitin Tests; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D016392:Proto-Oncogene Proteins pp60(c-src) / Q000378:metabolism*; D051381:Rats; D011994:Recombinant Proteins / Q000378:metabolism; D013997:Time Factors; D014162:Transfection; D014407:Tumor Cells, Cultured; D014443:Tyrosine / Q000378:metabolism
C495868:CTTN protein, human; D051356:Cortactin; C495870:Cttn protein, rat; D018076:DNA, Complementary; D018960:Hyaluronan Receptors; D008840:Microfilament Proteins; D011994:Recombinant Proteins; D014443:Tyrosine; D006820:Hyaluronic Acid; D016392:Proto-Oncogene Proteins pp60(c-src)