Figure 7

Sensitivity to DRB-induced apoptosis in primary AML sample. (A) Differential effect of DRB against tumour versus non-malignant cells. Total nucleated cells separated from the bone marrow of an AML patient were kept in medium alone or containing 10–60 μM DRB, harvested at 24, 48 and 72 hr and analysed by flow cytometry after stainig with anti-CD45 antibody and PI. Blast cells (unbroken line) were selected based on CD45/SSC parameters. Non-malignant cells (broken line) were selected by exclusion of blast cells and debris. Viability of tumour versus non-malignant cells differed in a statistically significant way (p < 0.005 with the test of independence at all doses analysed). (B) DRB treatment induces apoptosis in primary AML cells. Left panel: AML cells were kept for 24 hr in medium alone or containing 10–100 μM DRB, harvested and stained with anti-active caspase-3 antibody (left panel) or annexin V and PI (right panel). Histograms show the percentage of active caspase-3⁺ cells (mean ± S.D. of two independent experiments) and PI- annexin V+ cells.