Rac1b modulates intestinal tumourigenesis via modulation of Wnt and Egfr signalling pathways
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA705373 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description: Not available
| S-EPMC8058071 | biostudies-literature
Project description:mRNAseq of Apc mutant and Apc Rac1b double mutant mouse intestinal tumours.
2021-03-11 | GSE167876 | GEO
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
Project description:Abstract: RAS-like (RAL) GTPases function in Wnt signalling-dependent intestinal stem cell proliferation and regeneration. Whether RAL proteins work as canonical RAS effectors in the intestine, and the mechanisms of how they contribute to tumorigenesis remain unclear. Here, we show that RAL GTPases are necessary and sufficient to activate EGFR/MAPK signalling in the intestine. We identify non-canonical roles of RAL GTPases not as RAS effectors, but rather by acting upstream of RAS activation via induction of EGFR internalisation . Knocking down Drosophila RalA from intestinal stem and progenitor cells leads to increased levels of plasma membrane-associated EGFR and decreased MAPK pathway activation. Importantly, in addition to impacting stem cell proliferation and damage-induced intestinal regeneration, this function of RAL GTPases drives EGFR-dependent tumorigenic growth in the intestine and in human mammary epithelium. Altogether, our results reveal previously unrecognised cellular and molecular contexts where RAL GTPases become essential mediators of EGFR-driven tissue homeostasis and malignant transformation. Results: RalA is required within ISCs to induce midgut adult midgut regeneration following damage by oral infection with Erwinia carotovora carotovora 15 (Ecc15) (Johansson et al., 2019). To achieve a global view of intestinal pathways affected by RalA, we performed a transcriptomic analysis by RNAseq of whole midguts from vehicle treated (Mock) or damaged (Ecc15 fed) control animals or following RalA knockdown in intestinal stem and progenitor cells using the escargot-gal4 driver (ISC/EB>) (Micchelli and Perrimon, 2006). Consistent with its effect on ISC proliferation (Johansson et al., 2019), RalA knockdown significantly impaired damage-induced upregulation of cell cycle genes in the midgut. Additionally, levels of multiple transcriptional targets of the EGFR/MAPK pathway (Golembo et al., 1996; Hsu et al., 2001; Jin et al., 2015; Meng and Biteau, 2015), such as argos (aos), rhomboid (rho), Sox21a and string (stg) were increased following Ecc15 infection in control midguts. The upregulation of these target genes was significantly impaired upon RalA knockdown.
2021-02-01 | GSE162421 | GEO
Project description:RAL GTPases mediate EGFR/MAPK signalling-driven intestinal stem cell proliferation and tumourigenesis upstream of RAS activation.
| PRJNA681831 | ENA
Project description:WNT signalling activity on epiblast cells
| PRJNA401007 | ENA
Project description:The Wnt/ß-catenin pathway is orchestrating the development of the blood-brain barrier (BBB), but its downstream mediators have remained elusive. To identify potential effectors, we generated an endothelial cell specific Axin1 over-expressing mouse model, AOEiEC. We found that in AOEiE mice Wnt/ß-catenin signalling was down regulated leading to premature regression and remodelling without directly compromising BBB integrity. Interestingly, by comparing transcriptomes of endothelial cells from control and AOEiEC mice, we identified Adamtsl2 as a novel Wnt/ß-catenin-induced, secreted factor, important for stabilizing the cerebral vasculature during development. Importantly, loss-of-function and gain-of-function experiments revealed that Adamtsl2 alone was sufficient to rescue CNS vascular defects seen upon Wnt-signalling inhibition. Furthermore, using various cell and animal models we demonstrate that Adamtsl2 exerts its function by fine-tuning the TGFβ signalling pathway in CNS vessels. In conclusion, this study implicates Adamtsl2 as a mediator of Wnt/ß-catenin signalling during BBB development by linking it to TGFβ signalling.
2019-01-31 | GSE77874 | GEO
Project description:Padala2017- ERK, PI3K/Akt and Wnt signalling
network (EGFR overexpression)
Crosstalk model of the ERK, Wnt and Akt
signalling pathways with EGFR overexpression.
This model is described in the article:
Cancerous perturbations
within the ERK, PI3K/Akt, and Wnt/?-catenin signaling network
constitutively activate inter-pathway positive feedback
loops.
Padala RR, Karnawat R, Viswanathan
SB, Thakkar AV, Das AB.
Mol Biosyst 2017 May; 13(5):
830-840
Abstract:
Perturbations in molecular signaling pathways are a result
of genetic or epigenetic alterations, which may lead to
malignant transformation of cells. Despite cellular robustness,
specific genetic or epigenetic changes of any gene can trigger
a cascade of failures, which result in the malfunctioning of
cell signaling pathways and lead to cancer phenotypes. The
extent of cellular robustness has a link with the architecture
of the network such as feedback and feedforward loops.
Perturbation in components within feedback loops causes a
transition from a regulated to a persistently activated state
and results in uncontrolled cell growth. This work represents
the mathematical and quantitative modeling of ERK, PI3K/Akt,
and Wnt/?-catenin signaling crosstalk to show the dynamics of
signaling responses during genetic and epigenetic changes in
cancer. ERK, PI3K/Akt, and Wnt/?-catenin signaling crosstalk
networks include both intra and inter-pathway feedback loops
which function in a controlled fashion in a healthy cell. Our
results show that cancerous perturbations of components such as
EGFR, Ras, B-Raf, PTEN, and components of the destruction
complex cause extreme fragility in the network and
constitutively activate inter-pathway positive feedback loops.
We observed that the aberrant signaling response due to the
failure of specific network components is transmitted
throughout the network via crosstalk, generating an additive
effect on cancer growth and proliferation.
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BIOMD0000000656.
To cite BioModels Database, please use:
Chelliah V et al. BioModels: ten-year
anniversary. Nucl. Acids Res. 2015, 43(Database
issue):D542-8.
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2019-08-09 | BIOMD0000000656 | BioModels
Project description:The function of the FAM83F protein, like the functions of many members of the FAM83 family, is poorly understood. Here we show that injection of Fam83f mRNA into Xenopus embryos causes axis duplication, a phenotype indicative of enhanced Wnt signalling. Consistent with this, overexpression of FAM83F activates Wnt signalling, whilst ablation of FAM83F from human colorectal cancer (CRC) cells attenuates it. We demonstrate that FAM83F is farnesylated and interacts and co-localises with CK1α at the plasma membrane. This interaction with CK1α is essential for FAM83F to activate Wnt signalling, and FAM83F mutants that do not interact with CK1α fail to induce axis duplication in Xenopus embryos and to activate Wnt signalling in cells. FAM83F acts upstream of GSK-3β, because the attenuation of Wnt signalling caused by loss of FAM83F can be rescued by GSK-3 inhibition. Introduction of a farnesyl-deficient mutant of FAM83F in cells through CRISPR/Cas9 genome editing redirects the FAM83F-CK1α complex away from the plasma membrane and significantly attenuates Wnt signalling, indicating that FAM83F exerts its effects on Wnt signalling at the plasma membrane.
2020-12-23 | PXD023121 | Pride
Project description:Ciliary associated extracellular vesicles modulate WNT signalling
| PRJNA641812 | ENA