Defective cell migration in an ovarian cancer cell line is associated with impaired urokinase-induced tyrosine phosphorylation.
The urokinase receptor (u-PAR), a protein anchored to cell membrane by a glycosyl phosphatidylinositol, plays a central role in cancer cell invasion and metastasis by binding urokinase plasminogen activator (u-PA), thereby facilitating plasminogen activation. Plasmin can promote cell migration either directly or by activating metalloproteinases that degrade some of the components of the extra cellular matrix. However, the IGR-OV1-Adria cell line contains the u-PAR but does not migrate even in the presence of exogenous u-PA, although the parental IGR-OV1 cell line migrates normally in the presence of u-PA. We therefore investigated the role of cell signalling for u-PA induced cell locomotion. We show that cell migration induced by u-PA-u-PAR complex is always associated with tyrosine kinase activation for the following reasons: (1) the blockade of the u-PAR by a chimeric molecule (albumin-ATF) inhibits not only the u-PA-induced cell migration, but also the signalling in IGR-OV1 line; (2) the binding of u-PA to u-PAR on non-migrating IGR-OV1-Adria cells was not associated with tyrosine kinase activation; (3) the inhibition of tyrosine kinase also blocked cell migration of IGR-OV1. Therefore tyrosine kinase activation seems to be essential for the u-PA-induced cell locomotion possibly by the formation of a complex u-PAR-u-PA with a protein whose transmembrane domain can ensure cell signalling. Thus, IGR-OV1 and IGR-OV1-Adria cell lines represent a good model for the analysis of the mechanism of u-PA-u-PAR-induced cell locomotion.
Mirshahi
S S
SS
Laboratoire Sainte Marie, Hôtel Dieu, Parvis de Notre Dame, Paris, France.
Lounes
K C
KC
Lu
H
H
Pujade-Lauraine
E
E
Mishal
Z
Z
Bénard
J
J
Bernadou
A
A
Soria
C
C
Soria
J
J
D015153:Blotting, Western; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005341:Fibrinolysin / Q000378:metabolism; D017261:Glycosylphosphatidylinositols / Q000502:physiology; D006801:Humans; D007150:Immunohistochemistry; D018613:Microscopy, Confocal; D010051:Ovarian Neoplasms; D010766:Phosphorylation; D019000:Phosphotyrosine / Q000378:metabolism*; D017395:Plasminogen Activator Inhibitor 1 / Q000032:analysis; D011956:Receptors, Cell Surface / Q000378:metabolism*; D055293:Receptors, Urokinase Plasminogen Activator; D015398:Signal Transduction; D014407:Tumor Cells, Cultured; D014568:Urokinase-Type Plasminogen Activator / Q000378:metabolism / Q000494:pharmacology*
D017261:Glycosylphosphatidylinositols; C524898:PLAUR protein, human; D017395:Plasminogen Activator Inhibitor 1; D011956:Receptors, Cell Surface; D055293:Receptors, Urokinase Plasminogen Activator; D019000:Phosphotyrosine; D005341:Fibrinolysin; D014568:Urokinase-Type Plasminogen Activator