Figure 1.

Initial in vitro drug screening study of chloroquine on patient-derived AML cells and UCB mononuclear cells. Cells were treated with chloroquine for six days before 3H-thymidine was added to cultures for an additional 22 h of incubation, before proliferation (nuclear incorporation) was determined by liquid scintillation counting. (A) Acute myeloid leukemia (AML) cells derived from 17 patients were treated with chloroquine at six different concentrations (2.5, 5, 10, 25, 50, and 100 µM), and (B) Umbilical cord blood (UCB) mononuclear cells from four donors were treated with chloroquine at five different concentrations (2.5, 5, 10, 25, and 50 µM). Detectable incorporation was defined as >1000 counts per minute (cpm). Results are shown as the percent proliferation of chloroquine-treated cultures compared to their respective untreated control cultures (set to 100%). At lower concentrations (2.5 and 5 µM) there was a varied sensitivity towards chloroquine, but at higher concentrations (10–100 µM) all samples showed decreased proliferation compared to untreated controls, * = p-value < 0.05, ** = p-value < 0.01, *** = p-value < 0.0001, Kruskal–Wallis, Dunn’s post-hoc test. (C) The figure shows the overall mean cell proliferation with SD, for all 17 AML patients (solid line) and four UCB donors (stippled line). There were no significant differences between the anti-proliferative effects of chloroquine on AML compared to UCB cells.