Cytoplasmic FOXO1 is not required for survival and proliferation of T24 mt mouse cells. (A) Immunofluorescence analysis of mouse BL cells using FOXO1 antibody (red). Parental cells (mouse BL#19) characterized by a heterozygous T24 mutation (wt⁺/mt⁺) and isogenic cell line clones in which the wt (wt⁻/mt⁺) or the mt Foxo1 allele (wt⁺/mt⁻) was ablated are shown. Foxo1 KO cells (wt⁻/mt⁻) complete the analysis. Cell nuclei were counterstained with DAPI (blue; scale bar, 5 μm). (B) Growth curves of parental cell line clones (wt⁺/mt⁺) and isogenic cell line clones that express mt (wt⁻/mt⁺) or wt FOXO1 (wt⁺/mt⁻). Foxo1 KO cells (wt⁻/mt⁻) complete the analysis. The graph summarizes data of 3 experiments. Bars indicate the standard deviation. **P < .01; ***P < .001 (Wilcoxon–Mann-Whitney test). (C) Quantification of dead cells and proliferating cells in cell line clones as analyzed in panel B. FACS analysis of BrdU and 7-AAD staining was used to determine the cellular phenotype. Bars indicate the standard deviation. *P < .05; ***P < .001; ****P < .0001 (Wilcoxon–Mann-Whitney test).