Fig. 4: QC enhances the cytotoxicity of AraC in primary ALL cells but fails to prolong the survival of secondary recipients.

A Schematic presentation of experimental design. B QC reduces leukemia burden in primary recipients. Percentage of human cells in the bone marrow of mice transplanted with four ALL patient samples were determined by flow cytometry 1-month post-transplant (ALL2: V, n = 10; n = 8 for all other groups). C, D QC prolongs the survival of primary recipients. Survival of recipients transplanted with ALL2 (C) or ALL5 (D) cells were monitored and plotted by the Kaplan–Meier method (ALL2: Ctr, n = 8; V, n = 9; AraC; n = 10; QC, n = 8; AraC + QC, n = 9; ALL5: Ctr, n = 8; V, n = 9; AraC, n = 8; QC, n = 12; AraC + QC, n = 12). Median survival of C: Vehicle (35 days); AraC (52 days); QC (42.5 days); and AraC+QC (70 days). Median survival of D: Vehicle (32 days); AraC (55 days); QC (47 days); and AraC+QC (65 days). E, F QC fails to improve survival of secondary transplanted recipients. hCD45⁺ cells from the primary recipients of the same donor (C, D) were sorted and pooled, and transplanted into sublethally irradiated NSGS mice. Survival of recipients transplanted with ALL2 (E) or ALL5 (F) cells were monitored and plotted by the Kaplan–Meier method (ALL2: Ctr, n = 10; V, n = 12; AraC, n = 12; QC, n = 12; AraC + QC, n = 12; ALL5: Ctr, n = 10; V, n = 12; AraC, n = 13; QC, n = 12; AraC + QC, n = 12). V, Vehicle; A, AraC; QC: Quinacrine; A + QC, AraC + Quinacrine. Median survival of E: Vehicle (25 days); AraC (52 days); QC (37.5 days); and AraC+QC (57.5 days). Median survival of F: Vehicle (25 days); AraC (52 days); QC (35 days); and AraC+QC (55 days). Statistics were performed in the indicated groups: two-sided paired t test (parametric). Animal survival data were analyzed by Gehan–Breslow–Wilcoxon test; p values are indicated in Source Data files (*p < 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001).