Fig. 4

p-TGIF2 downregulates the expression of E-cadherin by binding to its promoter. (A) Representative IHC images of TGIF2 and E-cadherin expression in the NSCLC tissue array. (B) E-cadherin expression was assessed in 50 upregulated and 10 downregulated cases of TGIF2 expression. (C) Spearman’s correlation of the expression of E-cadherin and TGIF2 in human NSCLC tissues. (D) Luciferase assay of CDH1 promoter activity. H1299 cells were transfected with pGL3-CDH1-promoter and empty vector, TGIF2^WT, or TGIF2^AA and subjected to dual-luciferase analysis. (E) The promoter region of the CDH1 gene scanned by nine amplicons. (F) TGIF2 ChIP-qPCR of the CDH1 promoter at the indicated regions in H1299 cells. Mouse IgG served as a negative control. (G) ChIP assay with IgG and anti-TGIF2 antibody in H1299 cells followed by PCR. **, p < 0.01; ***, p < 0.001; ns, not significant. PC, positive control. All data are representative of three repeated experiments