NMS-873

NMS-873 is a potent, selective allosteric VCP/p97 inhibitor with IC50 value of 30 nM.

Signaling Pathways >> Cell Cycle/DNA Damage >> p97

Research Areas >> Cancer

IC50: 30 nM[1]

NMS-873 has antiproliferative effect on a panel of tumor cell lines with IC50 values in the range of 0.08 μM to 2 μM. For HCT116 and HeLa cells, the IC50 values are 0.4 μM and 0.7 μM, respectively. NMS-873 reduces VCP sensitivity to trypsin digestion, preventing degradation of the linker-D2 domain. NMS-873 induces clear, dose-dependent accumulation of poly-Ub proteins and stabilization of cyclin E and Mcl-1 at doses consistent with its antiproliferative IC50 value[1].

The ATPase activity and the kinetic parameters of recombinant wild-type VCP and its mutants are evaluated by monitoring ADP formation in the reaction, using a modified NADH-coupled assay46. As ADP and NADH are ATP-competitive inhibitors of VCP ATPase activity, the standard protocol for the NADH-coupled assay is modified into a two-step procedure. In the first part, an ATP-regenerating system (40 U/mL pyruvate kinase and 3 mM phosphoenolpyruvate) recycles the ADP produced by VCP activity, keeps the substrate concentration constant (thus preventing product inhibition) and accumulates a stoichiometric amount of pyruvate. In the second part, the VCP enzymatic reaction is quenched with 30 mM EDTA and 250 μM NADH and stoichiometrically oxidized by 40 U/mL lactic dehydrogenase to reduce accumulated pyruvate. The decrease of NADH concentration is measured at 340 nm using a Tecan Safire 2 reader plate. The assay is performed in 96- or 384-well UV platesin a reaction buffer with 50 mM Hepes, pH 7.5, 0.2 mg/mL BSA, 10 mM MgCl2 and 2 mM DTT.

Cells are seeded at 1,600 cells per well in 384-well white clear-bottom plates. Twenty-four hours after seeding, cells are treated with the compounds (eight dilution points, in duplicate, for each compound) and incubated for an additional 72 h at 37°C under a 5% CO2 atmosphere. Cells are then lysed, and the ATP content in each well is determined using a thermostable firefly luciferase-based assay from Promega as a measure of cell viability. IC50 values are calculated using the percentage of growth of treated cells versus the untreated control.

[1]. Paola Magnaghi, et al. Covalent and allosteric inhibitors of the ATPATP ase VCP/p97 induce cancer cell death. Nat Chem Biol. 2013 Jul 28. doi: 10.1038/nchembio.1313.

CB-5083 | DBeQ | ML 240 | NMS-859