Figure 4. STAT1 and NFKB are required for IFN1@-induced BECN1 expression. (A and B) K562 cells were transfected with RELA shRNA for 48 h, and then treated with IFN1@ (1000 U/ml) for 24–72 h. Protein (A) and mRNA (B) levels of BECN1 were analyzed by western blot and real-time PCR, respectively. (C and D) K562 cells were transfected with STAT1 shRNA for 48 h, and then treated with IFN1@ (1000 U/ml) for 48–72 h. NFKB transcriptional activity was assayed by a luciferase reporter system (C). The indicated proteins were analyzed by western blot (D). (E) K562 cells were treated with IFN1@ (1000 U/ml) for 48 h, then cell lysates were prepared for immunoprecipitation (IP) as indicated. The resulting immune complexes and inputs were analyzed by western blotting (IB) as shown.