AML1-ETO is not degraded by autophagy. Kasumi-1 cells were treated with the indicated concentrations of (A) VPA or (B) vorinostat for 16 hours in the presence or absence of Baf or CQ. Cell lysates were prepared for immunoblotting, and the blots were probed with the indicated antibodies. Representative blots are shown. (Right) The relative band intensities of AML1-ETO and cleaved PARP at 1.5 mM VPA and 1 μM vorinostat were normalized to glyceraldehyde-3-phosphate dehydrogenase (GAPDH). (C) Kasumi-1 cells transfected with siRNA oligoes against Atg7 and Ulk1 were treated with VPA for 16 hours, and degradation of long-lived proteins was quantified. The VPA-induced degradation of long-lived proteins in cells transfected with siAtg7 or siUlk1 was compared with the VPA-induced protein degradation in siCtrl-transfected cells to demonstrate inhibition of autophagy. (D-E) Cells transfected as in C were treated with VPA at the indicated concentrations for the last 16 hours, and total cell lysates were prepared for immunoblotting. AML1-ETO was detected by an ETO-specific antibody. (E) The relative band intensities of AML1-ETO at 1.5 mM VPA were normalized to GAPDH. (F) VPA- or vorinostat-induced degradation of AML1-ETO is inhibited by caspase-inhibitor. Kasumi-1 cells were treated with zVAD-fmk (20 µM) for 30 minutes before addition of the indicated concentrations of VPA or vorinostat, and the incubation was continued for 16 hours. Total cell lysates were prepared for immunoblotting, and the blots were probed with antibodies against ETO and GAPDH. All bars show mean values ± SEM quantified from ≥3 independent experiments. *P < .05; **P < .01.