PMID- 9525964 OWN - NLM STAT- MEDLINE DCOM- 19980507 LR - 20210209 IS - 0021-9258 (Print) IS - 0021-9258 (Linking) VI - 273 IP - 14 DP - 1998 Apr 3 TI - Binding of urokinase-type plasminogen activator to its receptor in MCF-7 cells activates extracellular signal-regulated kinase 1 and 2 which is required for increased cellular motility. PG - 8502-7 AB - Binding of urokinase-type plasminogen activator (uPA) to its receptor, uPAR, regulates cellular adhesion, migration, and tumor cell invasion. Some of these activities may reflect the ability of uPAR to initiate signal transduction even though this receptor is linked to the plasma membrane only by a glycosylphosphatidylinositol anchor. In this study, we demonstrated that single-chain uPA activates extracellular signal-regulated kinase 1 (ERK1) and ERK2 in MCF-7 breast cancer cells. Phosphorylation of ERK1 and ERK2 was increased 1 min after adding uPA and returned to baseline levels by 5 min. The amino-terminal fragment (ATF) of uPA, which binds to uPAR but lacks proteinase activity, also activated ERK1 and ERK2. Responses to uPA and ATF were eliminated when the cells were pretreated with PD098059, an inhibitor of mitogen-activated protein kinase kinase. uPA and ATF promoted the migration of MCF-7 cells across serum-coated Transwell membranes in vitro. Migration was increased 2.1 +/- 0.4-fold when uPA was added to the top chamber, 4. 8 +/- 0.8-fold when uPA was added to the bottom chamber, and 7.7 +/- 1.0-fold when uPA was added to both chambers. MCF-7 cells that were pulse-exposed to uPA for 30 min, and then washed to remove unbound ligand, demonstrated increased motility even though migration was allowed to occur for 24 h. PD098059 completely neutralized the effects of uPA on MCF-7 cellular motility, irrespective of whether the uPA was present for the entire motility assay or administered by pulse-exposure. These results demonstrate a novel, receptor-dependent signaling activity which is required for uPA-stimulated breast cancer cell migration. FAU - Nguyen, D H AU - Nguyen DH AD - Department of Biochemistry, University of Virginia Health Sciences Center, Charlottesville, Virginia 22908, USA. FAU - Hussaini, I M AU - Hussaini IM FAU - Gonias, S L AU - Gonias SL LA - eng GR - CA-53462/CA/NCI NIH HHS/United States PT - Journal Article PT - Research Support, U.S. Gov't, Non-P.H.S. PT - Research Support, U.S. Gov't, P.H.S. PL - United States TA - J Biol Chem JT - The Journal of biological chemistry JID - 2985121R RN - 0 (PLAUR protein, human) RN - 0 (Receptors, Cell Surface) RN - 0 (Receptors, Urokinase Plasminogen Activator) RN - EC 2.7.11.17 (Calcium-Calmodulin-Dependent Protein Kinases) RN - EC 2.7.11.24 (Mitogen-Activated Protein Kinase 1) RN - EC 2.7.11.24 (Mitogen-Activated Protein Kinase 3) RN - EC 2.7.11.24 (Mitogen-Activated Protein Kinases) RN - EC 3.4.21.73 (Urokinase-Type Plasminogen Activator) SB - IM MH - Calcium-Calmodulin-Dependent Protein Kinases/*metabolism MH - *Cell Movement MH - Enzyme Activation/drug effects MH - Female MH - Humans MH - Mitogen-Activated Protein Kinase 1 MH - Mitogen-Activated Protein Kinase 3 MH - *Mitogen-Activated Protein Kinases MH - Receptors, Cell Surface/*metabolism MH - Receptors, Urokinase Plasminogen Activator MH - Signal Transduction/*drug effects MH - Tumor Cells, Cultured MH - Urokinase-Type Plasminogen Activator/*metabolism/pharmacology EDAT- 1998/05/09 00:00 MHDA- 1998/05/09 00:01 CRDT- 1998/05/09 00:00 PHST- 1998/05/09 00:00 [pubmed] PHST- 1998/05/09 00:01 [medline] PHST- 1998/05/09 00:00 [entrez] AID - S0021-9258(18)52585-0 [pii] AID - 10.1074/jbc.273.14.8502 [doi] PST - ppublish SO - J Biol Chem. 1998 Apr 3;273(14):8502-7. doi: 10.1074/jbc.273.14.8502.