Fig. 2

FOXO3a suppresses BCSC properties and tumorigenicity. a The top 10% of CD44^high or CD44^low subpopulations of MDA-MB-231 cells were isolated by flow cytometry sorting. b qRT-PCR analysis of FOXO3a expression in CD44^high or CD44^low subpopulations of MDA-MB-231 cells. c MDA-MB-231 and BT549 cells were transfected with FOXO3a-lentiviral vectors or pCMV-FOXO3a expression vector, and FOXO3a expression was measured by western blot. d MDA-MB-231 and BT549 cells were transfected with FOXO3a lentiviral vectors, and the percentages of CD44^high/CD44^low cells were measured by flow cytometry. e MDA-MB-231 and BT549 cells were transfected with pCMV-FOXO3a expression vector, and the percentages of ALDH⁺ cells were measured by ALDEFLUOR assay. f Self-renewal of CSCs in control and FOXO3a-overexpressing cells as measured by a mammosphere formation assay. Scale bar, 50 μm. g Soft agar cloning in control and FOXO3a-overexpressing cells. Scale bar, 100 μm. g–i MCF-7 and T47D cells were transfected with FOXO3a siRNA, h FOXO3a expression was measured by qRT-PCR analysis; i the percentage of CD44^high/CD44^low cells were measured by flow cytometry; j the percentage of ALDH⁺ cells was measured by ALDEFLUOR assay. A two-tailed Student’s t test was used for statistical analysis (*P < 0.05, **P < 0.01, ***P < 0.001)