Fig. 5: FXR functions as a repressor of Wnt/β-catenin signaling by interacting with β-catenin in colon cancer cells.
From: Farnesoid X receptor antagonizes Wnt/β-catenin signaling in colorectal tumorigenesis
a Co-immunoprecipitation showed the physical interaction between FXR and TCF4 in HEK293 cells co-expressing HA-tagged TCF4 and Myc-tagged FXR. The cell lysates were subjected to IP with an anti-HA or Myc antibody. b Co-immunoprecipitation showed the physical interaction between FXR and β-catenin in HEK293 cells co-expressing Flag-β-catenin and Myc-tagged FXR. The cell lysates were subjected to IP with an anti-Flag or Myc antibody. c Co-immunoprecipitation showed the physical interaction between endogenous FXR and β-catenin was also observed in HT-29 and Caco-2 cells. The cell lysates were subjected to IP with an anti-FXR. d Ectopic expression of FXR impaired the interaction of β-catenin and TCF4. Plasmids of HA-tagged-TCF4, Flag-tagged-β-catenin, and FXR-shRNA lentivirus were co-transfected into HEK293 cells. The cell lysates were subjected to IP with an anti-Flag antibody. e Knockdown of FXR enhanced the interaction of β-catenin and TCF4. HT-29 cells were infected with FXR-shRNA lentivirus or control lentivirus. The nuclear fractions were incubated with an anti-TCF4 antibody for the IP experiment. IgG was used as a negative control. f Ectopic expression of FXR enhanced the interaction of β-catenin and TCF4. SW480 cells were infected with FXR lentivirus or control lentivirus. The nuclear fractions were incubated with an anti-TCF4 antibody for the IP experiment.
