Figure 3.

Binding of STAT3 represses GATA6 expression in AGS gastric cancer cells: Using lentiviral small hairpin RNA (shRNA), chromatin immunoprecipitation (ChIP)-PCR experiments were performed to examine the relative binding of STAT3 to the GATA6 promoter in AGS cells and cells with depleted STAT3. (A) The genomic structure of the GATA6 promoter and the location of the ChIP-PCR primer (red arrow heads) targeting the putative STAT3 binding site at the upstream promoter region. STAT3 binding was significantly enriched in the (B) GATA6 promoter but not (C) β-actin (ACTB) promoter (negative control) in AGS cells; (D) Depletion of STAT3 significantly restored GATA6 expression in AGS cells. *** p < 0.005, * p < 0.05. n.s.: not significant.