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: May Khanna, Fang Wang, Inha Jo, W Eric Knabe, Sarah M Wilson, Liwei Li, Khuchtumur Bum-Erdene, Jing Li, George W Sledge, Rajesh Khanna, Samy O Meroueh
• Journal: ACS chemical biology (ACS Chem Biol) Vol. 6 Issue 11 Pg. 1232-43 (Nov 18 2011) ISSN: 1554-8937 [Electronic] United States
• PMID: 21875078 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• 2-((3-(3,5-dimethylpiperidin-1-yl)-6-oxo-6H-anthra(1,9-cd)isoxazol-5-yl)amino)benzoic acid
• Antineoplastic Agents
• Benzoates
• Piperidines
• Receptors, Urokinase Plasminogen Activator
• Urokinase-Type Plasminogen Activator

Topics

• Antineoplastic Agents (chemistry, pharmacology)
• Benzoates (chemistry, pharmacology)
• Breast Neoplasms (drug therapy, metabolism, pathology)
• Cell Line, Tumor
• Cell Movement (drug effects)
• Drug Discovery
• Drug Screening Assays, Antitumor
• Female
• Humans
• Molecular Conformation (drug effects)
• Molecular Weight
• Neoplasm Invasiveness (pathology, prevention & control)
• Piperidines (chemistry, pharmacology)
• Protein Binding (drug effects)
• Receptors, Urokinase Plasminogen Activator (chemistry, metabolism)
• Structure-Activity Relationship
• Urokinase-Type Plasminogen Activator (chemistry, metabolism)