Fig. 7.

PLC inhibition suppresses BIRD-2-induced cell death in a subset of primary CLL patient cells. (a-d) Results from flow cytometry analysis of Annexin V-FITC/7-AAD-stained CLL patient samples treated for 2 h with 30 µM BIRD-2 with or without U73122 pre-treatment. For each CLL sample, the individual bar graph, plotting the apoptotic fraction (%) measured in untreated cells (black bar), cells treated with BIRD-2 (dark gray bar), U73122 (gray bar) or a combination of U73122 and BIRD-2 (light gray bar), is shown. The lowest U73122 concentration for which an effect could be observed was used (0.1/0.5/2.5 µM; see Supplemental Table 1). The CLL samples were stratified in 4 categories, according to the CI calculated for the combined treatment of U73122 and BIRD-2 and according to their sensitivity towards U73122: (a) CI > 1.2 & cell death U73122 < 10%; (b) CI > 1.2 and cell death U73122 > 10%; (c) 0.8 ≤ CI ≤ 1.2; (d) CI < 0.8. At the bottom of each panel, the ∆ apoptotic fraction (%), which corresponds to the difference in apoptotic fraction between the BIRD-2-treated and the control condition, and between the BIRD-2 + U73122-treated and the U73122-treated conditions, is shown for each CLL sample belonging to that category. In the dot plots, each CLL sample is represented with a different color, which is shown in the titles of the individual bar graphs. Statistically significant differences were determined using a one-tailed paired t-test (**P < 0.01)