Research Paper Volume 12, Issue 16 pp 16270—16293

CTCF promotes colorectal cancer cell proliferation and chemotherapy resistance to 5-FU via the P53-Hedgehog axis

Figure 6. CTCF enhances Hedgehog signaling pathway activation via targeting P53. (A) Venn diagram enrichment analysis of the 5-FU putative target genes. (B) Protein-protein interaction analysis via STRING (https://string-db.org/). (C) GSEA plots indicated that “P53_DN.V1_UP” gene set signature enriches in the CTCF high expression group and “P53_DN.V1_DN” gene set enriches in the CTCF low expression group (GSE17538, n = 177). (D) Schematic view of the P53 gene transcription start site (TSS) with a CTCF-binding site (CBS). (E) qRT-PCR analysis of P53 expression level in constructed cell lines. (F) ChIP-PCR results for CTCF on the CBS in HCT116 cells. (G) P53 luciferase reporter activity was analyzed in SW480 cells. (H) Western blot analysis of Key molecules of Hedgehog signaling pathway and P53 in different transfected groups with or without the stimulation of P53-specific siRNA. (I, J) Nuclear extract assays and western blot analyses of GLI1 in indicated cells. The above data are presented as mean ± SEM. * P<0.05, **P<0.01, and ***P<0.001.