Effect of PI-3K inhibition on apoptosis in B-CLL cells.
B-CLL cells (1 × 106 cells/mL) were incubated in the absence or presence of LY294002 (10 μM) for 24 hours before the indicated tests were performed. (A) Annexin/PI staining revealed an increase in apoptotic cells (right panel) compared with medium control (left panel); 1 representative experiment of 24 is shown. (B) The proapoptotic effect was demonstrated in 24 of 24 different CLL samples. (C) A representative example of dose-response data as measured by annexin/PI staining is shown. As demonstrated in panel D, apoptosis was confirmed by measuring the mitochondrial membrane potential (Δψ); PI-3K inhibition resulted in an increase of Δψ-negative, apoptotic cells. The same experiment was repeated 9 times with similar results. Peripheral B cells of healthy donors (n = 5) were resistant to the proapoptotic effect of the PI-3K inhibitor (E).
