title: Targeting multiple conformations leads to small molecule inhibitors of the uPAR·uPA protein-protein interaction that block cancer cell invasion.
abstract: Interaction of the urokinase receptor (uPAR) with its binding partners such as the urokinase-type plasminogen activator (uPA) at the cell surface triggers a series of proteolytic and signaling events that promote invasion and metastasis. Here, we report the discovery of a small molecule (IPR-456) and its derivatives that inhibit the tight uPAR·uPA protein-protein interaction. IPR-456 was discovered by virtual screening against multiple conformations of uPAR sampled from explicit-solvent molecular dynamics simulations. Biochemical characterization reveal that the compound binds to uPAR with submicromolar affinity (K(d) = 310 nM) and inhibits the tight protein-protein interaction with an IC(50) of 10 μM. Free energy calculations based on explicit-solvent molecular dynamics simulations suggested the importance of a carboxylate moiety on IPR-456, which was confirmed by the activity of several derivatives including IPR-803. Immunofluorescence imaging showed that IPR-456 inhibited uPA binding to uPAR of breast MDA-MB-231 tumor cells with an IC(50) of 8 μM. The compounds blocked MDA-MB-231 cell invasion, but IPR-456 showed little effect on MDA-MB-231 migration and no effect on adhesion, suggesting that uPAR mediates these processes through its other binding partners.
authors.affiliation: Department of Biochemistry and Molecular Biology, Stark Neuroscience Research Institute, Indiana University Cancer Center, Indianapolis, Indiana 46202, United States.
authors.forename: May
authors.initials: M
authors.lastname: Khanna
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
authors.forename: Inha
authors.initials: I
authors.lastname: Jo
authors.forename: W Eric
authors.initials: WE
authors.lastname: Knabe
authors.forename: Sarah M
authors.initials: SM
authors.lastname: Wilson
authors.forename: Liwei
authors.initials: L
authors.lastname: Li
authors.forename: Khuchtumur
authors.initials: K
authors.lastname: Bum-Erdene
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: George
authors.initials: G
authors.lastname: W Sledge
authors.forename: Rajesh
authors.initials: R
authors.lastname: Khanna
authors.forename: Samy O
authors.initials: SO
authors.lastname: Meroueh
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology*; D001565:Benzoates / Q000737:chemistry / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology*; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D055808:Drug Discovery; D004354:Drug Screening Assays, Antitumor; D005260:Female; D006801:Humans; D008968:Molecular Conformation / Q000187:drug effects; D008970:Molecular Weight; D009361:Neoplasm Invasiveness / Q000473:pathology / Q000517:prevention & control*; D010880:Piperidines / Q000737:chemistry / Q000494:pharmacology*; D011485:Protein Binding / Q000187:drug effects; D055293:Receptors, Urokinase Plasminogen Activator / Q000737:chemistry / Q000378:metabolism*; D013329:Structure-Activity Relationship; D014568:Urokinase-Type Plasminogen Activator / Q000737:chemistry / Q000378:metabolism*
chemical_list: C571689:2-((3-(3,5-dimethylpiperidin-1-yl)-6-oxo-6H-anthra(1,9-cd)isoxazol-5-yl)amino)benzoic acid; D000970:Antineoplastic Agents; D001565:Benzoates; D010880:Piperidines; D055293:Receptors, Urokinase Plasminogen Activator; D014568:Urokinase-Type Plasminogen Activator