Fig. 4: FOXO1 controls the TRIB3-SOX2 Axle in BCCs.

a Sample immunoblots and quantitative analyses of the expression of SOX2 after silencing the SOX2 transcriptional factor FOXO1 in MCF7 cells. b, c SOX2 transcriptional activity in HMLE cells (b) transfected with a control vector or a TRIB3-expressing vector and either CTRL-shRNA or FOXO1-shRNA (as indicated at the bottom), or in MCF7 cells (c) transfected with CTRL-shRNA or TRIB3-shRNA, and either a control vector or a FOXO1-expressing vector. d FOXO1 ChIP-SOX2 promoter activity in HMLE cells transfected with a control vector or a TRIB3-expressing vector (as indicated at the bottom) or MCF7 cells transfected with either CTRL-shRNA or TRIB3-shRNA. e, f Immunoblots and statistical analysis of protein lysates of HMLE cells (e) transfected with a control vector or a TRIB3-expressing vector and either CTRL-shRNA or FOXO1-shRNA (as indicated on the top), or of MCF7 cells (f) transfected with CTRL-shRNA or TRIB3-shRNA and either a control vector or a FOXO1-expressing vector. g Formalin-fixed, paraffin-embedded tissue microarray sections of normal or breast cancer tissues were stained with an anti-FOXO1 antibody. Tissue-bound FOXO1 is shown in brown (top). A 3 × 2 contingency table shows the correlation between TRIB3 and FOXO1 based on their relative expression, graded by the percentage and intensity of the brown color staining in the immunohistological images (bottom). h, i Tumor spheroid formation of HMLE cells (h) transfected with a control vector or a TRIB3-expressing vector and either CTRL-shRNA or FOXO1-shRNA (as indicated at the bottom), or of MCF7 cells (i) transfected with CTRL-shRNA or TRIB3-shRNA and either a control vector or a FOXO1-expressing vector. All data are shown as the number of mammospheres per 1000 cells. Data are shown as the mean ± SEM; P > 0.05 was considered not significant (NS); *P < 0.05, **P < 0.01, and ***P < 0.001 compared with the vector or CTRL-shRNA group. Source data are provided as a Source Data file.