Induction of autophagy by proteasome inhibitors in ovarian cancer cells. A, SKOV3, OVCAR3 or A2870 cells were treated with vehicle or 5 μM of MG132 for 24 h, and the formation of acidic vacuoles were analyzed using AO staining. B, SKOV3, OVCAR3 or A2870 cells were treated with the indicated concentrations of MG132 for 24 h, Western blot analysis was performed to investigate LC3 transition. C, OVCAR3 were treated with vehicle, BZ, Epox, Lacta or MG132 in the absence or presence of bafiloymycin A1 for 24 h, and LC3 transition was measured using Western blot analysis. D, OVCAR3 were transfected with a scramble shRNA or shRNA specific against Atg7 (shAtg7) for 24 h, then treated with 5 μM of MG132 for additional 24 h, and Western blot was performed.