Abstract 1228
Background
Crypt base cells are candidates for intestinal epithelial stem cells (ISC). But limited progress has been made concerning the modulation of stem cells. DACH1 is upregulated in LGR5+ ISC cells with stemness maintenance. Hence, we postulated that DACH1 may serve as a putative modulator of intestine stem cells leading to carcinogenesis.
Methods
We established colon normal, adenomas and cancers organoids, which supported stem cell proliferation and undifferentiation in vitro. A stable and efficient culture system for colon epithelial crypts and tumor organoids was use to facilitate investigation of the dynamics and factors affecting colon stem cell niche and carcinogenesis.
Results
We showed that in the mouse and human intestine, DACH1 was expressed in discrete crypt base. In colorectal cancer, DACH1 expression became widespread, with increased expression and nuclear localization at all stages. ShRNA-mediated inhibition of DACH1 in colon cancer cells inhibited colony formation in vitro and tumor growth in vivo through affecting cancer stem cell signatures. What is more, DACH1 stimulated both colonosphere formation and tumor organoid formation in vitro. Mechanistic characterization indicated that DACH1 recruited and interacts with SMAD4 to suppress BMP signaling pathway. Eventually, DACH1 induced stemness of organoids through BMP-mediated transcriptional increasing of a large number of stem cell signature genes, including Notch1, Msi-2 and Sox9. Here we provided evidence for an essential role of DACH1 in inducing stem cell self-renewal through direct upregulating stem cell signature genes. In detail, DACH1 was shown by microarray analyses to repress BMP induction of Smad signaling, then DACH1 binding to Smad4 was required for repression of Smad signaling
Conclusions
In conclusion, our findings illustrate an essential role of DACH1 signaling in inducing stem cell expansion during intestinal homeostasis and tumor development. This study also provided a mechanistic insight into the function of DACH1 in maintaining stem cell self-renewal via Smad4.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
San-Jun Cai.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
4250 - Phase II study of avelumab in combination with cetuximab as a rechallenge strategy in pre-treated RAS wild type metastatic colorectal cancer patients: CAVE (cetuximab-avelumab) Colon.
Presenter: Erika Martinelli
Session: Poster Display session 2
Resources:
Abstract
5234 - The ORCHESTRA trial; A phase III trial of adding tumor debulking to systemic therapy versus systemic therapy alone in multi-organ metastatic colorectal cancer (mCRC).
Presenter: Lotte Bakkerus
Session: Poster Display session 2
Resources:
Abstract
5294 - EMERGE: Epigenetic Modulation of the Immune Response in Gastrointestinal cancers
Presenter: Elizabeth Cartwright
Session: Poster Display session 2
Resources:
Abstract
913 - Phase III, international, multicenter, randomized, open-label trial of adjuvant nab-paclitaxel plus gemcitabine (nab-P/G) vs gemcitabine (G) alone for surgically resected pancreatic adenocarcinoma (APACT): subgroup analyses
Presenter: Margaret Tempero
Session: Poster Display session 2
Resources:
Abstract
1668 - FOLFIRINOX in locally advanced (LA) and borderline resectable (BR) pancreatic adenocarcinoma : update of the AGEO cohort.
Presenter: Edouard Auclin
Session: Poster Display session 2
Resources:
Abstract
2559 - Impact of adjuvant treatment with nab-paclitaxel and gemcitabine (nab-P+GEM) vs gemcitabine alone (GEM) on health-related quality of life (QoL) in patients (pts) with surgically resected pancreatic adenocarcinoma (PA) in the Adjuvant Pancreatic Adenocarcinoma Clinical Trial (APACT)
Presenter: Hanno Riess
Session: Poster Display session 2
Resources:
Abstract
4897 - Early detection of pancreatic ductal adenocarcinoma using methylation signatures in circulating tumor DNA
Presenter: Xiao-ding Liu
Session: Poster Display session 2
Resources:
Abstract
1755 - Evaluation of minimal important difference (MID) for the European Organisation for Research and Treatment of Cancer (EORTC) Pancreatic Cancer Module (PAN26) in patients with surgically resected pancreatic adenocarcinoma
Presenter: Michele Reni
Session: Poster Display session 2
Resources:
Abstract
2876 - Multispectral analysis of lymphocyte complexity in periampullary adenocarcinoma
Presenter: Sebastian Lundgren
Session: Poster Display session 2
Resources:
Abstract
1902 - Phase II trial of preoperative modified FOLFIRINOX (mFOLFIRINOX) followed by postoperative gemcitabine (GEM) in patients (pts) with borderline resectable (BR) and locally advanced (LA) pancreatic ductal adenocarcinoma (PDAC)
Presenter: Jae Ho Jeong
Session: Poster Display session 2
Resources:
Abstract