Synergistic Activity of Carfilzomib and Panobinostat in Multiple Myeloma Cells via Modulation of ROS Generation and ERK1/2

Figure 3

Concomitant treatment with carfilzomib and LBH589 synergistically resulted in mitochondrial injury and caspase activation. (a) RPMI 8226 cells were treated with carfilzomib (40 nM) and/or LBH589 (4 nM) for 24 h (upper panel) or 48 h (low panel), after which JC-1 staining was performed. ΔΨm was assessed by flow cytometry. Only JC-1 green positive (lower right quadrant) cells were analyzed for the loss of ΔΨm. The loss of ΔΨm (24 h) in Cont., LBH589, CFZ, and LBH589 + CFZ group was 5.3% ± 2.1%, 16.3% ± 2.9%, 20.3% ± 4.0%, and 35.0% ± 3.0, respectively. The value (48 h) was 12.2% ± 3.5%, 20.8% ± 3.1%, 40.1% ± 4.6%, and 62.4% ± 5.0, respectively. versus control group; . (b) RPMI 8226 cells were treated with carfilzomib (40 nM) and/or LBH589 (4 nM) for 24 h. Then, caspase-9 (p51) and cleaved caspase-8 (p43/41, p18), caspase-9 (p39/37), and caspase-3 (p19/17) were monitored by Western blot analysis. Cont., control. CFZ, carfilzomib.

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