Cooperativity between the Ras-ERK and Rho-Rho kinase pathways in urokinase-type plasminogen activator-stimulated cell migration.
Binding of the urokinase-type plasminogen activator (uPA) to its receptor activates diverse cell signaling pathways. How these signals are integrated so that cell physiology is altered remains unclear. In this study, we demonstrated that migration of MCF-7 breast cancer cells and HT-1080 fibrosarcoma cells on serum-coated surfaces is stimulated by agents that activate ERK, including uPA, epidermal growth factor, and constitutively active MEK1. The promigratory activity of these agents was entirely blocked not only by the MEK-specific antagonist PD098059, but also by antagonists of the Rho-Rho kinase pathway, including Y-27632 and dominant-negative RhoA (RhoA-N19). uPA did not significantly increase the level of GTP-bound RhoA, suggesting that the constitutive activity of the Rho-Rho kinase pathway may be sufficient to support ERK-stimulated cell migration. Paradoxically, Y-27632 and RhoA-N19 increased ERK phosphorylation in MCF-7 cells, providing further evidence that ERK activation alone does not promote cell migration when Rho kinase is antagonized. When MCF-7 cell migration was stimulated by ERK-independent processes such as expression of the beta(3) integrin subunit or changing the substratum to type I collagen, Y-27632 and RhoA-N19 failed to inhibit the response. This study supports a model in which the Ras-ERK and Rho-Rho kinase pathways cooperate to promote cell migration. Neutralizing either pathway is sufficient to block the response to agents that stimulate cell migration by activating ERK.
Jo
Minji
M
Department of Pathology, University of Virginia School of Medicine, Charlottesville, Virginia 22908, USA.
Thomas
Keena S
KS
Somlyo
Avril V
AV
Somlyo
Andrew P
AP
Gonias
Steven L
SL
D000577:Amides / Q000494:pharmacology; D002460:Cell Line; D002465:Cell Movement; D003094:Collagen / Q000378:metabolism; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D048049:Extracellular Signal-Regulated MAP Kinases; D005419:Flavonoids / Q000494:pharmacology; D006160:Guanosine Triphosphate / Q000378:metabolism; D006801:Humans; D048369:MAP Kinase Kinase 1; D020930:MAP Kinase Kinase Kinases / Q000378:metabolism*; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D010766:Phosphorylation; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011725:Pyridines / Q000494:pharmacology; D013997:Time Factors; D014407:Tumor Cells, Cultured; D014568:Urokinase-Type Plasminogen Activator / Q000378:metabolism*; D018631:ras Proteins / Q000378:metabolism*; D020741:rho GTP-Binding Proteins / Q000378:metabolism*
D000577:Amides; D004791:Enzyme Inhibitors; D005419:Flavonoids; D011725:Pyridines; C108830:Y 27632; D006160:Guanosine Triphosphate; D003094:Collagen; D017346:Protein Serine-Threonine Kinases; D048049:Extracellular Signal-Regulated MAP Kinases; D020928:Mitogen-Activated Protein Kinases; D020930:MAP Kinase Kinase Kinases; C089319:Ras-dependent mitogen-activated protein kinase kinase kinase; D048369:MAP Kinase Kinase 1; C482125:MAP2K1 protein, human; D020929:Mitogen-Activated Protein Kinase Kinases; D014568:Urokinase-Type Plasminogen Activator; D018631:ras Proteins; D020741:rho GTP-Binding Proteins; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one