Fig. 4.

ROS generated by SAHA induces caspase-mediated cleavage of HSP90. a K562 cells were untreated or treated with 20 mM of NAC for 1 h, followed by treatment with SAHA (5 μM) for 6 and 24 h. The cells were incubated with 10 μM fluorescent probe DCF-DA for 20 min and visualized using fluorescence microscopy. Scale bar: 40 μM. b K562 cells were untreated or treated with indicated doses of NAC for 1 h, followed by treatment with SAHA (5 μM) for 24 h. c K562 cells were treated with the indicated dose of H₂O₂ for 24 h. d K562 cells were untreated or treated with indicated doses of z-VAD-fmk for 1 h, followed by treatment with H₂O₂ (5 mM) for 24 h. The cell lysates were subjected to Western blot analysis