Suppression of mTOR activity by AMPK activators in BCR-ABL–expressing cells. (A) K562 cells were treated with either AICAR or metformin, as indicated. Equal amounts of protein were resolved by SDS-PAGE and immunoblotted with an antibody against the Ser79 phosphorylated form of ACC. The same blot was stripped and reprobed with an anti-ACC antibody, as indicated. (B) K562 cells were treated with either AICAR or metformin for 24 hours. Equal amounts of protein were resolved by SDS-PAGE and immunoblotted with the indicated antibodies. (C) BV173 or BV173R cells were treated with AICAR, metformin, or imatinib mesylate for 24 hours as indicated. Equal amounts of protein were resolved by SDS-PAGE and immunoblotted with the indicated antibodies.