FIGURE 4.

FoxO4 inhibits CDX2 expression by directly targeting the CDX2 promoter region. (A) Serially truncated CDX2 promoter constructs were cloned into pGL3‐luciferase reporter plasmids and transfected into GES‐1 cells. Four hours after transfection, the cells were treated with CDCA (200 μM) for 24 hr, and the relative luciferase activities were determined 72 hr later. (B) A ChIP assay demonstrated the direct binding of FoxO4 to the CDX2 promoter in GES‐1 cells. M: Marker. (C,D) qRT‐PCR of the ChIP products validated the binding capacity of FoxO4 to the CDX2 promoter. Means ± SEM of a representative experiment (n = 3) performed in triplicate is shown. *p < .05; **p < .01; ***p < .001; ns, not significant