Fig. 7.

NH-23-C2 is a potent and selective inhibitor of endogenous caspase-2. Top panel: Caspase-2 activation. a Caspase activation and protein processing pattern in HCT116 cells stimulated with reversine in the presence of various concentrations of NH-23-C2. b Processing of MDM-2 protein in HCT116 cells stimulated with reversine (1 μM, 24 h) in the presence of various concentration of caspase-2 inhibitors (NH-23-C2 and Ac-23-C2) and a broad-spectrum caspase inhibitor, zVAD-fmk. c Caspase-2 inhibition in HCT116 cells expressed as IC₅₀ for three inhibitors: NH-23-C2, Ac-23-C2, and zVAD-fmk. Bottom panel: Caspases-3/-8 activation. d Caspase activation and protein processing pattern in HCT116 cells undergoing TRAIL-mediated apoptosis. e PARP processing and caspase-3 activation in TRAIL-stimulated HCT116 cells in the presence of various concentrations of NH-23-C2, Ac-23-C2, and zVAD-fmk. f zVAD-fmk, but not NH-23-C2 or Ac-23-C2, inhibits apoptosis in TRAIL-stimulated HCT116 cells; fl—full length, cl—cleaved form