Inhibition of GSK-3 affects the binding of NFκB p65 to its target gene promoters in CLL cells. (A) MEC1 cells were treated with 25 μmol/L AR-A014418 for 0, 12, and 24 hours, as indicated. Nuclear/cytosolic fractions were prepared, and 50 μg of nuclear and cytosolic proteins were separated by SDS-PAGE, transferred to PVDF membrane, and immunoblotted as indicated. (B-C) Binding of NFκB p65 to the promoters of its target genes XIAP and Bcl-2 was assayed with the use of chromatin immunoprecipitation (ChIP) in MEC1 CLL cells treated with 25 μmol/L AR-A014418 (ARA), 50 μmol/L Z-VAD-FMK, or AR-A014418 + Z-VAD-FMK for 12 hours. (D) Immunoprecipitated chromatin was analyzed by PCR for the binding of NFκB p65 to the promoters of its target genes XIAP and Bcl-2 in malignant B cells from 5 patients with CLL treated with 25 μmol/L AR-A014418 (ARA) for 12 hours.