NF-κB inhibition sensitizes ML-1, OCI AML2 and OCI AML3 to TRAIL-induced apoptosis. (A-C) AML cells were pre-treated with 2, 5 or 7.5 μM BMS-345541 for 15 h followed by a treatment with 10 ng/mL (ML-1) or 250 ng/mL TRAIL (OCI AML2 and OCI AML3) for 24 h. Induction of cell death was measured by Annexin V staining. Data shown are mean ± S.E.M. (A) ML-1; (B) OCI AML2; (C) OCI AML3; (D) OCI AML2 cells were treated with 5 μM BMS-345541 for 0, 4, 6, 8 or 10 h after which cell lysates were harvested and analyzed for c-FLIP and XIAP expression by Western blotting. Expression of actin was detected to serve as a loading control.