Loss of Caspase-3 impairs leukemia maintenance and self-renewal of LSCs. (A) Survival of secondary transplantation model. Leukemia cells (1 × 105) from the AE9a-WT and AE9a-Caspase-3−/− group were injected into sublethally irradiated recipient mice. (B) WBC counts in the AE9a-WT and AE9a-Caspase3−/− groups in the secondary transplantation model 5 weeks after transplantation. (C) Loss of Caspase-3 significantly decreases the frequency of leukemia-initiating cells in the limiting dilution assay. The log-fraction plot (left panel) showing the results of the limiting dilution assay by using different dilutions of leukemia cells from AE9a-WT and AE9a-Caspase-3−/− groups in vivo (right panel). (D) Deletion of Caspase-3 decreases the self-renewal capacity of AE9a-expressing fetal liver cells in serial replating assays. Shown is the numbers of colonies generated from 1000 AE9a-expressing cells in each plating. (E) Deletion of Caspase-3 decreases the self-renewal capacity of AE9a-transduced fetal liver cells in LTC-IC assays. Shown is the number of colonies generated from 1000 AE9a-expressing cells. CFU, colony-forming unit.
