Transcriptome analysis of Brg1 deficient small intestinal epithelium in the context of normal and aberrant Wnt signalling
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE46129 | GEO | 2013/08/07
SECONDARY ACCESSION(S): PRJNA197327
REPOSITORIES: GEO
Similar Datasets
Project description:Brg1 has been reported to act as a trans-activator for the Wnt pathway by interacting with beta-catenin. Given this interaction and the crucial role Wnt signalling plays in the intestinal homeostasis, we aimed to investigate the effect of Brg1 loss on gene expression in normal and Wnt activated small intestinal epithelium. We used VillinCreERT2 Cre recombinase and loxP targeted allels of Brg1 and Apc to generate 4 cohorts of conditional knock-out mice: Cre-negative controls (n=4), Brg1 deficient (n=4), Apc deficient (n=3) and double Brg1-Apc deficient (n=4). All mice were induced by 4x80mg/kg daily injections of Tamoxifen. Epithelium enriched (gut scrapes) samples of small intestine (jejunum) were collected at day 4 post induction. Loss of Brg1 expression in the small intestinal epithelium at this time point was confirmed by immunohistochemistry.
2013-08-07 | E-GEOD-46129 | biostudies-arrayexpress
Project description:The contribution of deubiquitylating enzymes to b-Catenin stabilisation in intestinal stem cells and colorectal cancer (CRC) is poorly understood. Here, we report the deubiquitylase USP10 as APC-truncation- specific regulator enhancer of b-Catenin stability, potentiating WNT signalling pathway in CRC and cancer stem cells. Mechanistically, interaction studies in various CRC cell lines and in vitro binding studies, together with computational modelling, revealed that USP10 binding to b-Catenin is mediated via its USP10 unstructured N-terminus and requires truncated in the absence of full-length APC. Notably, loss of USP10 in CRISPR engineered intestinal organoids reduces tumorigenic properties of CRC cells and organoids, and blocks the super competitor-properties of APC-mutated intestinal cells, elicits induces the expression of differentiation genes, and opposes the APC-truncated phenotype in an intestinal hyperplasia model of D.melanogaster. Taken together, our findings reveal USP10s role in intestinal tumourigenesis by stabilising b-Catenin, leading to aberrant WNT signalling, enhancing cancer cell stemness and implicate the DUB USP10 as a cancer specific therapeutic vulnerability in Apc truncated CRC.
2024-01-01 | GSE226364 | GEO
Project description:Tumourigenesis within the intestine is potently driven by deregulation of the Wnt pathway, a process epigenetically regulated by the chromatin remodelling factor Brg1. We aimed to investigate this interdependency in an in vivo setting and assess the viability of Brg1 as a potential therapeutic target. Using a range of transgenic approaches, we deleted Brg1 in the context of Wnt-activated murine small intestinal epithelium. Pan-epithelial loss of Brg1 using VillinCreERT2 and AhCreERT transgenes attenuated expression of Wnt target genes, including a subset of stem cell-specific genes and suppressed Wnt-driven tumourigenesis improving animal survival. A similar increase in survival was observed when Wnt activation and Brg1 loss were restricted to the Lgr5 expressing intestinal stem cell population. We propose a mechanism whereby Brg1 function is required for aberrant Wnt signalling and ultimately for the maintenance of the tumour initiating cell compartment, such that loss of Brg1 in an Apc-deficient context suppresses adenoma formation. Our results highlight potential therapeutic value of targeting Brg1 and serve as a proof of concept that targeting the cells of origin of cancer may be of therapeutic relevance.
| S-EPMC4091792 | biostudies-literature
Project description:Background: Wnt signaling maintains the undifferentiated state of intestinal crypt progenitor cells by inducing the formation of nuclear TCF4/beta-catenin complexes. In colorectal cancer, activating mutations in Wnt pathway components cause inappropriate activation of TCF4/beta-catenin -driven transcription. Despite the passage of a decade after the discovery of TCF4 and beta-catenin as the molecular effectors of the Wnt signal, few transcriptional activators essential and unique to the regulation of this transcription program have been found. Methodology/Principal Findings: Using proteomics, we identified the leukemia-associated Mllt10/Af10 and the methyltransferase Dot1l, as Tcf4/beta-catenin interactors in mouse small intestinal crypts. Mllt10/Af10-Dot1l, essential for transcription elongation, are recruited to Wnt target genes in a beta-catenin -dependent manner, resulting in H3K79 methylation over their coding regions in vivo in proliferative crypts of mouse small intestine, in colorectal cancer and Wnt-inducible HEK293T cells. Depletion of MLLT10/AF10 in colorectal cancer and Wnt-inducible HEK293T cells followed by expression array analysis identifies MLLT10/AF10 and DOT1L as essential activators dedicated to Wnt target gene regulation. In contrast, previously published b-catenin coactivators p300 and beta-catenin displayed a more pleiotropic target gene expression profile controlling Wnt and other pathways. tcf4, mllt10/af10 and dot1l are co-expressed in Wnt-driven tissues in zebrafish and essential for Wnt-reporter activity. Intestinal differentiation defects in apc-mutant zebrafish can be rescued by depletion of Mllt10 and Dot1l, establishing these genes as activators downstream of Apc in Wnt target gene activation in vivo. Morpholino-depletion of mllt10/af10-dot1l in zebrafish results in defects in intestinal homeostasis and a significant reduction in the in vivo expression of direct Wnt target genes and in the number of proliferative intestinal epithelial cells. Conclusions/Significance: We conclude that Mllt10/Af10-Dot1l are essential, dedicated activators of Wnt-dependent transcription, critical for maintenance of intestinal proliferation and homeostasis. The methyltransferase Dot1l may present an attractive candidate for drug targeting in colorectal cancer. 6 samples for Ls174T cells: si-b-catenin against si-control and dyeswap of it, si-control, si-MLLT10, si-BRG1 and si-P300 are hybridized against common reference RNA; 6 samples of HEK293T cells: Wnt3A or control medium (CM) induction for 9 hours, si-MLLT10, si-DOT1L, si-BRG1 and si-P300 upon 9 hour Wnt3A induction are all hybridized against common reference RNA
2010-04-20 | E-GEOD-21367 | biostudies-arrayexpress
Project description:Wnt/β-catenin signaling is essential for intestinal stem cell homeostasis and aberrant activation of this signaling leads to tumorigenesis. Here we report a function of YTHDF1, an mRNA m6A reader, in mediating β-catenin hyperactivation. Wnt signaling promotes YTHDF1 expression at the translational level. YTHDF1 is dispensable for normal intestinal development in mice while essential for intestinal regeneration. Ythdf1 knockout reduces the stemness of intestinal stem cells, which blocks Wnt-driven tumorigenesis. Genome-wide analysis identifies a subset of Wnt signaling components regulated by YTHDF1 in an m6A-dependent manner. Moreover, we demonstrate that YTHDF1 promotes the translation of TCF7L2/TCF4 to augment β-catenin activation. Targeting YTHDF1 in the established tumors leads to tumor shrinkage and prolonged survival. Together, our studies uncover YTHDF1 as an integral regulator of Wnt signaling at the translational level during intestinal tumorigenesis, which might serve as a promising target for colorectal cancer therapy.
2019-08-31 | GSE136664 | GEO
Project description:The forkhead box transcription factor FOXQ1 is aberrantly induced in various cancers, and contributes to tumour growth and metastasis. It has been suggested that the oncogenic potential of FOXQ1 may be explained by its activation of the Wnt/β-catenin signalling pathway.However, the mode of action of FOXQ1 in the Wnt pathway remains to be resolved. Here we report that FOXQ1 is bimodal transcriptional activator of Wnt target gene expression in normal and cancer cells. Using co-immunoprecipitation, proximity proteomics, and reporter assays, we show that FOXQ1 engages the Wnt transcriptional complex to promote gene expressionvia TCF/LEF transcription factors.
2022-10-05 | PXD030464 | Pride
Project description:The aim of this experiment was to determine the contribution that components of the Wnt enhancesome (Bcl9/9l) make to Wnt driven intestinal transcriptional programmes in the context of normal intestinal homeostasis, or intestinal transformation driven by Apc depletion or B-catenin mutation.
2019-01-15 | E-MTAB-7546 | biostudies-arrayexpress
Project description:This study aimed to further understand context-specific direct Wnt target gene expression through the use of beta-catenin and FoxH1 ChIP Sequencing data at various developmental stages representing both maternal and zygotic Wnt signalling. Results were further supported through the use of RNA sequencing data from beta-catenin, FoxH1 and nodal gene knock down assays.
2020-06-21 | E-MTAB-8555 | biostudies-arrayexpress
Project description:The Wnt-signalling pathway is one of the core de-regulated pathways in chronic lymphocytic leukemia (CLL), activated in a subset of patients by somatic coding mutations. Here we describe an alternative mechanism of Wnt-activation in malignant B cells, mediated by Notch2 activity in mesenchymal stromal cells (MSC) in the tumor microenvironment. We identified that tumor cells specifically induce and activate Notch2 in MSCs. Notch2 orchestrates the expression of target genes essential for the activation of canonical Wnt-signaling in CLL cells. Mechanistically, stromal Notch2 mediates the stabilization of â-catenin by inhibiting the activation of Gsk3-â in malignant B cells. Pharmacological inhibition of the Wnt-pathway mitigates microenvironment-mediated survival of malignant B cells in vitro. Similarly, inhibition of Notch-signaling impaired survival of CLL cells and disease engraftment in a PDX mouse model. Notch2 activation in the tumour microenvironment is a pre-requisite for the GSK3-â dependent activation of the canonical Wnt-signaling in tumor cells.
2018-09-19 | PXD010401 | Pride
Project description:Hypothesis and proof of concept:
Our hypothesis is that increase in cellular iron import proteins (TfR1, DMT1) occur early in the adenoma-carcinoma sequence through mutations in APC and lead to cellular iron loading. As demonstrated in our previous work the effects of this iron loading is to mediate increased Wnt signalling resulting in c-myc induction. This in turn serves to increase the expression of iron import proteins (TfR1, DMT1) and decrease the expression of iron export (ferroportin [FPN]) and storage (ferritin) proteins. Such a hypothesis explains how Wnt signalling controls iron metabolism and ensures that there is adequate cellular iron for ATP generation and cellular proliferation.
Experimental design:
To test such a hypothesis we aim to prospectively collect the following colorectal tissue from patients attending for colonoscopy:
1. Normal colonic mucosa in patients with no colorectal pathology (n = 30)
2. Polyps and matched normal colon (n = 30)
3. Colorectal cancers and matched normal colon (n = 30)
We also intend to collect serum and urine from the following patient groups:
4. Normal colonoscopy (n = 30)
5. Colorectal adenomas (n = 30)
6. Colorectal cancers (n = 30)
Primary outcome(s): Measured at baseline, using the expression of proteins in the tissue and serum to detect the cellular and systemic iron transport proteins. The techniques used will include mass spectrometry, western blotting, real time PCR and immunohistochemistry.
| 2416626 | ecrin-mdr-crc