The growth of many malignant solid tumors is critically dependent on the proliferation of new vessels to supply the rapidly dividing cells with oxygen and nutrients. Recognition that inhibition of tumor angiogenesis leads to regression of these malignancies and controls metastatic spread in animals has led to a major effort to control cancer by targeting its vasculature. The urokinase receptor (uPAR) is not only highly expressed on malignant cells, but plays a critical role in regulating cell migration and adhesion of cell-associated proteolytic activity, which are all essential for angiogenesis. Recently, we have identified a new anti-angiogenic molecule, cleaved high molecular weight kininogen (HKa). We have shown that HKa binds to domain 2/3 of uPAR on endothelial cells and competes for occupancy with a major adhesive protein, vitronectin. HKa, when bound, also facilitates the binding and activation of PK to kallikrein, which cleaves pro-urokinase to urokinase by plasma kallikrein, and the subsequent enhancement of the formation of cell-associated plasmin from plasminogen. We now hypothesize that HKa-uPAR interactions may be critical in the control of angiogenesis, and that specific peptide sequences would be inhibitors of tumor angiogenesis. We will therefore study the binding of HKa to uPAR using both transfected cells and surface plasmon resonance with an emphasis on establishing which domains and subdomains of HKa are the sites of binding. We will use monoclonal antibodies, recombinant fragments (deletion mutants) and synthetic peptides derived from molecular homology models of domains 3 and 5 of HKa based on the crystal and NMR structures to identify the exact sequences responsible for HKa binding to urokinase. We will then test the effects of these polypeptides on four of the in vitro components of angiogenesis, namely, endothelial adhesion, migration, proliferation and cell surface-mediated proteolysis. Preliminary studies show that at nanomolar concentrations, deletion mutants or synthetic peptides derived from HKa inhibit migration of endothelial cells to vitronectin and endothelial cell proliferation. These studies will be extended using site-directed mutagenesis and optimized cyclic peptides to identify the minimum sequences. We will select the most potent peptides and test them in vivo on basic fibroblast growth factor stimulated chicken egg chorioallantoic membrane (CAM), where domain 5 at 30 nM inhibits angiogenesis, as well as tumor cells growing on the CAM. We will then test the polypeptides on human tumor cells which can grow in immunologically deficient mice. Finally, we will test these new anti-angiogenic peptides for their ability to prevent cancer growth metastasis in the Lewis lung tumor model. We expect that these studies will identify biologically active peptides which can serve as lead compounds in designing peptidomimetic angiogenic inhibitors.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
1R01CA083121-01
Application #
2907333
Study Section
Special Emphasis Panel (ZCA1-SRRB-3 (M1))
Program Officer
Jhappan, Chamelli
Project Start
1999-07-01
Project End
2004-04-30
Budget Start
1999-07-01
Budget End
2000-04-30
Support Year
1
Fiscal Year
1999
Total Cost
Indirect Cost
Name
Temple University
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
City
Philadelphia
State
PA
Country
United States
Zip Code
19122
Armstead, William M; Riley, John; Cines, Douglas B et al. (2014) PAI-1-derived peptide EEIIMD prevents hypoxia/ischemia-induced aggravation of endothelin- and thromboxane-induced cerebrovasoconstriction. Neurocrit Care 20:111-8
Armstead, William M; Bohman, Leif-Erik; Riley, John et al. (2013) tPA-S(481)A prevents impairment of cerebrovascular autoregulation by endogenous tPA after traumatic brain injury by upregulating p38 MAPK and inhibiting ET-1. J Neurotrauma 30:1898-907
Armstead, William M; Ganguly, Kumkum; Riley, John et al. (2012) RBC-coupled tPA Prevents Whereas tPA Aggravates JNK MAPK-Mediated Impairment of ATP- and Ca-Sensitive K Channel-Mediated Cerebrovasodilation After Cerebral Photothrombosis. Transl Stroke Res 3:114-21
Armstead, William M; Riley, John; Yarovoi, Serge et al. (2012) tPA-S481A prevents neurotoxicity of endogenous tPA in traumatic brain injury. J Neurotrauma 29:1794-802
Armstead, William M; Riley, John; Cines, Douglas B et al. (2012) Combination therapy with glucagon and a novel plasminogen activator inhibitor-1-derived peptide enhances protection against impaired cerebrovasodilation during hypotension after traumatic brain injury through inhibition of ERK and JNK MAPK. Neurol Res 34:530-7
Armstead, William M; Riley, John; Cines, Douglas B et al. (2011) tPA contributes to impairment of ATP and Ca sensitive K channel mediated cerebrovasodilation after hypoxia/ischemia through upregulation of ERK MAPK. Brain Res 1376:88-93
Armstead, William M; Kiessling, J Willis; Riley, John et al. (2011) tPA contributes to impaired NMDA cerebrovasodilation after traumatic brain injury through activation of JNK MAPK. Neurol Res 33:726-33
Armstead, William M; Kiessling, J Willis; Cines, Douglas B et al. (2011) Glucagon protects against impaired NMDA-mediated cerebrovasodilation and cerebral autoregulation during hypotension after brain injury by activating cAMP protein kinase A and inhibiting upregulation of tPA. J Neurotrauma 28:451-7
Armstead, William M; Ganguly, Kumkum; Riley, John et al. (2011) Red blood cell-coupled tissue plasminogen activator prevents impairment of cerebral vasodilatory responses through inhibition of c-Jun-N-terminal kinase and potentiation of p38 mitogen-activated protein kinase after cerebral photothrombosis in the newborn Pediatr Crit Care Med 12:e369-75
Armstead, William M; Riley, John; Kiessling, J Willis et al. (2010) PAI-1-derived peptide EEIIMD prevents impairment of cerebrovasodilation by augmenting p38 MAPK upregulation after cerebral hypoxia/ischemia. Am J Physiol Heart Circ Physiol 299:H76-80

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