Cyclin-Dependent Kinase Inhibitor P1446A Induces Apoptosis in a JNK/p38 MAPK-Dependent Manner in Chronic Lymphocytic Leukemia B-Cells
Fig 5
P1446A induces NOXA and cooperates with ABT-737 to reverse apoptosis resistance.
(A-B) CLL cells from 6 individual patients were incubated with the indicated doses of P1446A for 6 hours with or without 20 μM SP600125. Total RNA was isolated from CD19+ CLL B-cells, reverse-transcribed and subjected to real-time PCR with the indicated probes (in duplicates). Results were normalized to 18S levels. Data are the mean ± SE. (C) CLL cells (N = 3) were incubated with 20 μM SP600125 or vehicle control for 1 hour and then with 1 μM P1446A for 6 hours. Whole-cell protein lysates were subjected to immunoblotting. (D) CLL cells (N = 6) were co-cultured with CD40L-expressing stroma for 24 hours and subsequently incubated with the indicated doses of P1446A and ABT-737 or vehicle control for 24 hours. Apoptosis was determined by Annexin V and 7-AAD staining within the CD19+ subset of cells. **—p<0.01 vs. control.