Organoid modelling identifies that DACH1 functions as a tumour promoter in colorectal cancer by modulating BMP signalling

Abstract

Background: Dachshund homologue 1 (DACH1) is highly expressed in LGR5+ intestinal stem cells and colorectal tumours. However, the roles of DACH1 in intestinal cell stemness and colorectal tumorigenesis remain largely undefined. Methods: We used immunohistochemistry, western blotting and quantitative real-time PCR to analyse DACH1 expression in colorectal cancer (CRC) samples. CRISPR/Cas9 gene editing and lentiviral vector-mediated overexpression and shRNA-mediated knockdown of DACH1 were utilized to modulate DACH1 expression in cell lines and organoids. An intestinal organoid-based functional model was analysed, and cancer cell colony formation, sphere formation assays and murine xenotransplants were performed to reveal the role of DACH1 in CRC cell proliferation, stemness and tumorigenesis. Immunofluorescence, co-immunoprecipitation, RNA interference and microarray data analyses were conducted to demonstrate the association between DACH1 and the bone morphogenetic protein (BMP) signalling pathway. Findings: DACH1 is specifically expressed in discrete crypt base cells, and increased DACH1 expression was found in all stages of CRC. Moreover, the high expression of DACH1 independently predicted poor prognosis. In colon cancer cells, shRNA-mediated suppression of DACH1 inhibited cell growth in vitro and in vivo. By studying the intestinal organoid-based functional model, we found that depletion of DACH1 reduced the organoid formation efficiency and tumour organoid size. DACH1 overexpression stimulated both colonsphere formation and tumour organoid formation in the context of dysregulated BMP signalling. Mechanistic characterizations indicated that overexpression of DACH1 affects a subset of stem cell signature genes implicated in stem cell proliferation and maintenance through the suppression of BMP signalling via SMAD4. Interpretation: Together, our study highlights DACH1 as an integral regulator of BMP signalling during intestinal tumorigenesis, and DACH1 could be a potential prognostic marker and therapeutic target for colorectal cancer patients.

A Dynamic Transcription Factor Signature Along the Colorectal Adenoma-Carcinoma Sequence in Patients With Co-Occurrent Adenoma and Carcinoma

“…As is known, DACH1 expression was aberrantly augmented in LGR5 + intestinal stem cells. It was revealed to predetermine the stem cell proliferation and maintenance in CRC through suppressing BMP signaling (26). Consistently, in our case, DACH1 protein expression was upregulated in the COAD and READ and was highly enriched in stem cell-related GO terms, indicating DACH1 might maintain the stemness of crypt base cells and promote normal epithelium-adenoma-carcinoma progression.…”

Ginsenoside Rg3 Prevents Oncogenic Long Noncoding RNA ATXN8OS from Inhibiting Tumor-Suppressive microRNA-424-5p in Breast Cancer Cells

“…Specifically, our study focused on EYA1, CHRM3, and DACH1 because they had a target sequence for miR-424-5p ( Figure 4 C) and showed hypermethylation in the array data, suggesting that they were downregulated by Rg3. Additionally, these three genes had previously been reported to possess oncogenic properties in several cancer types [ 26 , 27 ], except DACH1, which functioned as either a tumor promoter [ 28 ] or suppressor [ 29 ] depending on the cancer type. Consistent with the hypermethylation status, EYA1, CHRM3, and DACH1 were downregulated by 39–95% by Rg3, as determined by our qRT-PCR assays ( Figure 4 D).…”

Dach1-Variant 4 Plays an Oncogenic Role and Promotes Radioresistance in Prostate Cancer

“…2). Collectively, these analysis in colorectal tissues suggested that Hu and colleagues have brought to light oncogenic activities that were attributable to both DACH1-v1 and DACH1-v4 long variants [25]. In light of these data, the PC3 cell line preferentially expresses DACH1-v4 and PRAD patients DACH1-v1, however both isoforms have oncogenic potential.…”

“…Hu et al reported that DACH1 was expressed in intestine crypt basal cells and that DACH1 was necessary for the formation of tumor organoids, which were considered by the authors to serve as a functional assay of tumorigenesis. Moreover, high expression of DACH1 in colorectal cancer at all stages of tumor progression correlated with poor prognosis [25].…”