Figure 6. Autophagy regulates IFN1@-induced CASP8 dependent apoptosis. (A–C) K562 cells were treated with IFN1@ (1000 U/ml) for 48 h in the presence or absence of chloroquine (CQ, 100 μM). The expression and release of TNFSF10 was analyzed by western blot (A) and ELISA (B) respectively. In parallel, CASP8 activation (C) was assayed as described in Materials and Methods (n = 3, *p < 0.05). (D–F) Indicated K562 cells were treated with IFN1@ (1000 U/ml) for 48 h. Cleavage of BID (tBID) was analyzed by western blot (D). In parallel, mitochondrial membrane potential (Δψm) (E) and CASP9 activity (F) was assayed as described in Materials and Methods (n = 3, *p < 0.05). (G) K562 cells were transfected with indicated shRNA and then treated with IFN1@ (1000 U/ml) for 48 h. Apoptosis was analyzed by measuring annexin V-positive cells by flow cytometry (n = 3, *p < 0.05).