Synergistic Induction of Apoptosis in Primary B-CLL Cells after Treatment with Recombinant Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand and Histone Deacetylase Inhibitors
HDACi pretreatment leads to increased caspase activity and MMP loss with TRAIL administration. (a) B-CLL cells were cultured in the presence or absence of 2.5 M Oxam or 500 ng/ml TSA for 16 hours, followed by a 6 hours incubation with rhTRAIL (100 ng/ml). At that time, cells were harvested, and their caspase activity was determined as described in the Methods. (b) B-CLL cells were cultured in the presence or absence of 2.5 M Oxam or 500 ng/ml TSA for 16 hours, followed by a 6 hour incubation with or without rhTRAIL at 100 ng/ml. Mitochondrial membrane potential was assayed as described in the Methods. One experiment each, representative of more than 5 experiments using cells from different donors, is shown.