Virtual screening targeting the urokinase receptor, biochemical and cell-based studies, synthesis, pharmacokinetic characterization, and effect on breast tumor metastasis

Virtual screening targeting the urokinase receptor (uPAR) led to (±)-3-(benzo[d][1,3]dioxol-5-yl)-N-(benzo[d][1,3]dioxol-5-ylmethyl) -4-phenylbutan-1-amine 1 (IPR-1) and N-(3,5-dimethylphenyl)-1-(4- isopropylphenyl)-5-(piperidin-4-yl)-1H-pyrazole-4-carboxamide 3 (IPR-69). Synthesis of an analogue of 1, namely, 2 (IPR-9), and 3 led to breast MDA-MB-231 invasion, migration and adhesion assays with IC ₅₀ near 30 μM. Both compounds blocked angiogenesis with IC ₅₀ of 3 μM. Compounds 2 and 3 inhibited cell growth with IC ₅₀ of 6 and 18 μM and induced apoptosis. Biochemical assays revealed leadlike properties for 3, but not 2. Compound 3 administered orally reached peak concentration of nearly 40 μM with a half-life of about 2 h. In NOD-SCID mice inoculated with breast TMD-231 cells in their mammary fat pads, compound 3 showed a 20% reduction in tumor volumes and less extensive metastasis was observed for the treated mice. The suitable pharmacokinetic properties of 3 and the encouraging preliminary results in metastasis make it an ideal starting point for next generation compounds.