GA101 induces lysosomal swelling and burst and cell death is blocked by cytoD and concA. (A) Before incubation with RXL, G, or GXL, 3T40L CLL cells were pretreated with 1μM cytoD, 100nM concA, or 200nM bafA. After 24 hours, cell death was analyzed by measuring MitoTracker signal by flow cytometry. Averaged results from 8 CLL patients are presented as percentage cell death (mean ± SEM). (B) Top: Histograms showing LysoTracker signal in CD40-stimulated CLL cells in medium after 2 and 6 hours of incubation with GA101 in the presence (light gray line) and absence (black line) of concA. Unstained control is shown in shaded gray. In the right upper corner the individual Geomean of LysoTracker (LT) of every sample is shown. Bottom: After 1, 2, 4, and 6 hours of incubation with GA101, CD40-stimulated CLL cells were labeled with LysoTracker and the signal was analyzed by flow cytometry. *.01 < P < .05; ***P < .001.