PAR-1 Activation by Metalloproteinase-1 (MMP-1)

Abstract

Matrix metalloproteases (MMPs) play many important roles in normal and pathological remodeling processes including atherothrombotic disease, inflammation, angiogenesis and cancer. This invention relates to the activation of protease-activated receptor-1 (PAR-1) by endogenous platelet MMP-1 collagenase on the surface of platelets. Exposure of platelets to fibrillar collagen converts the surface-bound pro-MMP-1 zymogen to active MMP-1, which promotes aggregation through PAR-1. MMP-1 is shown to cleave the PAR-1 extracellular domain at a novel site, which then strongly activates Rho-GTP signaling pathways, cell shape change and motility, and MAPK signaling. Blockade of MMP-PAR1 suppresses thrombogenesis under arterial flow conditions and inhibited thrombosis in animals. These studies provide a link between matrix-dependent activation of metalloproteases and platelet-G protein signaling and identify MMP-1/PAR-1 as a new target for the treatment and prevention of arterial thrombosis and other thrombotic diseases.

1 - 87 . (canceled) 
     
     
         88 . A method of treating a cancer in a patient, said method comprising administering to a patient diagnosed with or at substantial risk of developing a cancer a therapeutically effective amount of an agent that substantially inhibits said patient's protease-activated receptor-1 (PAR-1) signaling activity that results from a proteolytic cleavage by matrix metalloprotease-1 (MMP-1) between aspartic acid at position 39 (D39) and proline at position 40 (P40) of said patient's protease-activated receptor-1 (PAR-1). 
     
     
         89 . The method of  claim 88 , wherein said agent comprises a pepducin lipopeptide of a PAR family member. 
     
     
         90 . The method of  claim 89 , wherein said pepducin lipopeptide of a PAR family member comprises a PAR-1 pepducin lipopeptide. 
     
     
         91 . The method of  claim 90 , wherein said PAR-1 pepducin lipopeptide is selected from the group consisting of P1i3pal-7, P1i3pal-12, P1i3pal-12S, P1i3pal-10S, P1i1pal-11, P1i2pal-7, P1i2pal-11, P1i2pal-16, P1i2pal-21, P1i4pal13 and P1i4pal13R. 
     
     
         92 . The method of  claim 88 , wherein said agent is administered through a means selected from the group consisting of intravenous (I.V.) injection, subcutaneous injection, intramuscular injection, oral ingestion, nasal, topical, rectal, vaginal and parenteral intake. 
     
     
         93 . The method of  claim 88 , wherein said agent is formulated with a pharmaceutically acceptable excipient, carrier or diluent. 
     
     
         94 . The method of  claim 88 , further comprising administering to said patient a second agent that inhibits the tissue-factor-initiated hemostatic pathway. 
     
     
         95 . The method of  claim 94 , wherein said second agent inhibits an activity selected from the group consisting of thromboxane-signaling in platelets, ADP-signaling in platelets, PAR-1's enzymatic activity, and thrombin-dependent activation of PAR-1. 
     
     
         96 . The method of  claim 94 , wherein said second agent is selected from the group consisting of anti-platelet drugs, anticoagulant drugs, and thrombolytic drugs. 
     
     
         97 . The method of  claim 94 , wherein said second agent is selected from the group consisting of thienopyridines, prostaglandin analogs, COX inhibitors, vitamin K antagonists, glycoprotein IIB/IIIA inhibitors and thrombin inhibitors. 
     
     
         98 . The method of  claim 94 , wherein said second agent is selected from the group consisting of aspirin, clopidogrel, ticlopidine, prasugrel, heparin, abciximab, eptifibatid, tirofiban and bivalirudin.