Fig. 3: QC enhances AraC cytotoxicity in primary ALL cells in vitro but has no effect on L-LTC-ICs.

A Schematic presentation of short-term culture (STC) and long-term culture (LTC) of primary ALL cells. B QC enhances AraC cytotoxicity in primary ALL cells in culture. Percentage of ALL cell survival after treatment was determined using counting beads and normalized to the Vehicle control. Results are means ± SEM of two independent experiments (n = 6). C QC increases the apoptotic effect of AraC on ALL cells in vitro. Apoptosis of eight ALL samples 1 week after treatment was measured by Flow Cytometry using Annexin V/7AAD staining. Results are means ± SEM of three independent experiments (Vehicle: ALL1, 5, 7, 8, n = 7; ALL2, 3, 4, 6, n = 8; AraC, QC, AraC + QC, n = 6 for all groups). D QC does not increase the effect of AraC on ALL long-term culture-initiating cells (LTC-ICs). Eight ALL samples were subjected to 1 week of treatments with the indicated regimens, 4 weeks of LTC in a limiting dilution assay (LTC-LDA), and 2 weeks of culture in methylcellulose, followed by determination of the L-LTC-IC frequencies. V, Vehicle; A, AraC; QC: Quinacrine; A + QC, AraC + Quinacrine. Results are means ± SEM of three independent experiments (n = 6). Statistics were performed in the indicated groups: two-tailed, paired t test (parametric); p values are indicated in Source Data files (*p < 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001).