(A) The effect of AMPK activators on JNK activation. A375 cells were incubated in the absence or presence of A77 1726 (200 μM), oligomycin (10 μM), or metformin (5 mM) for 16 hr. Cells were harvested and analyzed with the antibodies against phospho-JNK, phospho-Jun, p62 and actin. (B) A375 cells were incubated in the absence or presence of A77 1726 (200 μM) and/or compound C (CC) (1 μM) for 16 hr. Cell lysates were prepared and analyzed for ULK and AMPK phosphorylation, and for LC3 and actin expression by Western blot. (C) A375 cells were transfected with S6K1 siRNA. After incubation for 48 hr, the cells were harvested and analyzed for Jun, JNK, p62, and actin expression. (D) A375 cells were treated with the indicated concentrations of PF-4708671 for 16 hr. Cells were harvested and analyzed for Jun, JNK, p62, and actin expression.