FOXP1 contributes to human CD34⁺HSPC and leukemic cell growth. (A-E) Human cord blood CD34⁺ cells were transduced or not (nt) with lentiviral vectors encoding shRNAs targeting FOXP1 (shFOXP1#a, #b, #c; sequences detailed in supplemental Table 8) or luciferase as control (shCtrl). (A) Immunoblot analysis of the indicated proteins at day 3 posttransduction. Actin was used as loading control. (B) Cell expansion analysis along time posttransduction (n = 4). (C) Cell cycle analysis upon propidium iodide labeling at day 3 posttransduction (n = 3). (D) Annexin V labeling assessed at day 4 posttransduction (n = 4). (E) CFC assays at day 7 posttransduction (n = 3). (F-I) MOLM-14 leukemia cells were transduced or not (nt) with the indicated shRNA-encoding vectors. (F) Immunoblot analysis of the indicated proteins at day 3 posttransduction. Actin was used as loading control. (G) Cell expansion analysis along time posttransduction (n = 3). (H) Cell cycle analysis upon propidium iodide labeling at day 2 posttransduction (n = 3). (I) Annexin V labeling at day 3 posttransduction (n = 3). (J) Immunoblot analysis of the indicated proteins at day 3 (CD34⁺) and day 2 (MOLM-14) posttransduction. Actin was used as loading control. Data are expressed as mean ± SEM. *P < .05; **P < .01; ***P < .001 (Student t test).