Fig. 7
EG leukemogenic dependency on cytokines can be targeted by inhibiting signal transduction and survival pathways. A In vitro experimental design: FL and CB EG in vitro selected cells were treated with DMSO, Venetoclax (0.1 µM), Trametinib (0.1 µM) or the combination of both. Cells were counted every 24 h after treatment and cell death was measured at 48 h. B Cumulative number of FL EG (left panel) and CB EG (right panel) cells during 96 h control in presence of the inhibitors. Mean ± SEM of 3 biological replicates is shown. C Relative percentage of apoptotic (AnnV+) cells at 48 h of treatment. Mean ± SEM of 3 biological replicates. D In vivo experimental design: 5 × 104 PDX luciferase-expressing cells injected NSG (3 pooled experiments) or NSGS (1 experiment) mice were treated for four weeks, five times a week, with Venetoclax (100 mg/kg), Trametinib (1 mg/kg) or the combination of both molecules. Arrowheads indicate timing of the imaging of the luciferase-expressing PDX leukemic cells. Leukemia development was monitored by bioluminescence tracking and mice were euthanized upon disease symptoms detection. E–F Follow up of luciferase intensity in photon per second (p/s) during and after treatment of NSG (E) and NSGS (F) mice. Mean ± SEM of the indicated number of mice per group is shown. G Kaplan–Meier survival plot of NSG mice after treatment. Median survival was 81 days for the sham treated (CTL) group, 129 days for Venetoclax alone, 95 days for the Trametinib alone and 164 days for the combination group. H Kaplan–Meier survival plot of NSGS mice after treatment. Median survival was 52.5 days for the CTL group, 56 days for the Trametinib alone group and 75 days for the combination group. Statistical significance is indicated as p values (B-C-E–F: Kruskal–Wallis test, G-H: Log-rank test). *: p < 0.05, **: p < 0.01, ***: p < 0.001, ****: p < 0.0001