Fig. 5: FOXC1 is critical for IGF-1-induced ESCC stemness.

A, B KYSE-150 and ECA-109 cells were administrated with 10 ng/mL、50 ng/mL IGF-1 for 0, 4, 8, 12 h, and then the mRNA and protein levels of FOXC1 were examined by western blot analysis (A) and qPCR analysis (B). C, D KYSE-150 and ECA-109 cells were transfected with LV-shcontrol or LV-shFOXC1 lentiviral vectors and then treated with or without IGF-1 (50 ng/mL, 12 h). Next, the FOXC1 expression was analyzed by western blot analysis (C) and qPCR analysis (D). E CCK8 assay demonstrated that IGF-1 treatment increased the proliferation ability of KYSE-150 and ECA-109 cells, while FOXC1 knockdown reduced these capabilities. F, G Western blot analysis (F) and qPCR analysis (G) indicated that IGF-1 treatment increased the expression of cancer stem cell markers CD44 and CD133 while FOXC1 knockdown reduced the expression of CD44 and CD133. H, I IGF-1 treatment increased the tolerance to cisplatin while FOXC1 knockdown reduced the effect. The cell viability was detected by CCK8 assay (H) and apoptosis assay (I). J Sphere-formation assay indicated that IGF-1 treatment increased the sphere-formation ability of KYSE-150 and ECA-109 cells, while FOXC1 knockdown reduced these capabilities. The scale bars represent 200μm. *P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001.The p values were obtained by two-way ANOVA (E, H) or one-way ANOVA (others). Data are presented as mean (n = 3) ± S.D. All experiments were performed at least three times.