Fig. 3

PTC-209 inhibits colony formation and induces apoptosis in myeloma cells. a Treatment with PTC-209 significantly inhibited colony formation of KMS-12-BM and OPM-2 cells. Images are representative for three independent experiments. Induction of apoptosis was verified by annexin V/7-AAD staining (b), quantification of cleaved PARP by ELISA (c) and analysis of the mitochondrial membrane potential by JC-1 assay (d) 72 and 24 h post PTC-209 treatment, respectively. e Rapid induction (5 h) of NOXA expression was observed in all MM cell lines tested, followed by a decrease in MCL-1 protein levels 20 h post treatment analysed by intracellular staining using flow cytometry (f). Histograms are representative for three independent experiments. ***P < 0.001, **P < 0.01 and *P < 0.05 vs DMSO control