Fig. 5.

DACH1 promotes adenomas organoid formation via modulating BMP signalling. a DACH1 overexpression induced upregulation of cancer stem cell marker genes. b and c. Gene Ontology (GO) analysis showed that DACH1 overexpression induced the upregulation of stem cell signature genes and the downregulation of cell cycle arrest signature genes. d and e. DACH1 induced the downregulation of ATOH8, TGFβ3, MSX1, NBL1, BMP7, and FKBP4 and the upregulation of FKBP8, ID1, and MAPK3 (experiments were performed in triplicate). f. IF images showing the colocalization of SMAD4 and DACH1 in the nuclei; scale bars=20 μm g-h. DACH1 coprecipitated endogenous SMAD4. Reverse immunoprecipitation was confirmed with an anti-SMAD4 antibody. i. DACH1 overexpression increased the protein level of SMAD4 and decreased the level of phosphorylated SMAD4 (Thr276) [Thr277]. j and k. DACH1 knockdown led to an increase of the mRNA levels of NBL1 and BMP7 compared with the shNC group, and siRNA mediated SMAD4 knockdown in HCT116-shDACH1 cells eliminated the increase. l. DACH1 overexpression was sufficient to compensate for the withdrawal of Noggin and supported the formation of adenoma organoids. m. Addition of Noggin into the culture medium for 24 and 36 h decreased the mRNA levels of NBL1 and BMP7, which were increased by DACH1 knockdown in HCT116 cells. n and o. Overexpression of DACH1 upregulates LGR5, Notch1 and the protein level of NICD, while did not induce significant upregulation of HES1. Scale bars=20 μm. For 5d, 5e, 5k, 5 m and 5n, **P < 0.01, *P < 0.05, Student's t-test. Error bars: mean±SD.