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Flanagan DJ, Phesse TJ, Barker N, Schwab RHM, Amin N, Malaterre J, Stange DE, Nowell CJ, Currie SA, Saw JTS, Beuchert E, Ramsay RG, Sansom OJ, Ernst M, Clevers H, Vincan E. Frizzled7 functions as a Wnt receptor in intestinal epithelial Lgr5(+) stem cells. Stem Cell Reports 2015; 4:759-67. [PMID: 25892522 PMCID: PMC4437483 DOI: 10.1016/j.stemcr.2015.03.003] [Citation(s) in RCA: 116] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2014] [Revised: 03/18/2015] [Accepted: 03/20/2015] [Indexed: 12/14/2022] Open
Abstract
The mammalian adult small intestinal epithelium is a rapidly self-renewing tissue that is maintained by a pool of cycling stem cells intermingled with Paneth cells at the base of crypts. These crypt base stem cells exclusively express Lgr5 and require Wnt3 or, in its absence, Wnt2b. However, the Frizzled (Fzd) receptor that transmits these Wnt signals is unknown. We determined the expression profile of Fzd receptors in Lgr5(+) stem cells, their immediate daughter cells, and Paneth cells. Here we show Fzd7 is enriched in Lgr5(+) stem cells and binds Wnt3 and Wnt2b. Conditional deletion of the Fzd7 gene in adult intestinal epithelium leads to stem cell loss in vivo and organoid death in vitro. Crypts of conventional Fzd7 knockout mice show decreased basal Wnt signaling and impaired capacity to regenerate the epithelium following deleterious insult. These observations indicate that Fzd7 is required for robust Wnt-dependent processes in Lgr5(+) intestinal stem cells.
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brief-report |
10 |
116 |
2
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Rockman SP, Currie SA, Ciavarella M, Vincan E, Dow C, Thomas RJ, Phillips WA. Id2 is a target of the beta-catenin/T cell factor pathway in colon carcinoma. J Biol Chem 2001; 276:45113-9. [PMID: 11572874 DOI: 10.1074/jbc.m107742200] [Citation(s) in RCA: 115] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Activation of beta-catenin/T cell factor (TCF) transcription as a result of mutations in the adenomatous polyposis coli (APC) and/or beta-catenin genes occurs in the majority of colon tumors. An increasing number of genes, including c-myc and cyclin D1, have been implicated as targets of this pathway. We now report that the dominant negative helix-loop-helix regulator Id2 is also a target of the beta-catenin/TCF transcription pathway in colon adenocarcinoma. Investigation of the mechanism for the overexpression of Id2 in colon carcinoma cells demonstrated that the Id2 promoter is activated, and the Id2 protein is up-regulated by beta-catenin. Conversely, reducing free beta-catenin blocked this induction of promoter activity. We have also used an electrophoretic mobility shift assay and supershift to identify a motif in the Id2 promoter that binds to TCF4 protein. Site-directed mutagenesis of this motif abolished promoter reporter activity. Both transfection of Id2 into SW480 cells and induction of Id2 in HT29 colon cells was found to increase anchorage-independent survival of these cells. Growing evidence associates disruption to Id2 expression with tumorigenesis, and our findings suggest that this dysregulation of Id2 expression is due to the activation of the beta-catenin/TCF pathway.
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24 |
115 |
3
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Flanagan DJ, Barker N, Costanzo NSD, Mason EA, Gurney A, Meniel VS, Koushyar S, Austin CR, Ernst M, Pearson HB, Boussioutas A, Clevers H, Phesse TJ, Vincan E. Frizzled-7 Is Required for Wnt Signaling in Gastric Tumors with and Without Apc Mutations. Cancer Res 2019; 79:970-981. [PMID: 30622113 DOI: 10.1158/0008-5472.can-18-2095] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 11/13/2018] [Accepted: 01/04/2019] [Indexed: 11/16/2022]
Abstract
A subset of patients with gastric cancer have mutations in genes that participate in or regulate Wnt signaling at the level of ligand (Wnt) receptor (Fzd) binding. Moreover, increased Fzd expression is associated with poor clinical outcome. Despite these findings, there are no in vivo studies investigating the potential of targeting Wnt receptors for treating gastric cancer, and the specific Wnt receptor transmitting oncogenic Wnt signaling in gastric cancer is unknown. Here, we use inhibitors of Wnt/Fzd (OMP-18R5/vantictumab) and conditional gene deletion to test the therapeutic potential of targeting Wnt signaling in preclinical models of intestinal-type gastric cancer and ex vivo organoid cultures. Pharmacologic targeting of Fzd inhibited the growth of gastric adenomas in vivo. We identified Fzd7 to be the predominant Wnt receptor responsible for transmitting Wnt signaling in human gastric cancer cells and mouse models of gastric cancer, whereby Fzd7-deficient cells were retained in gastric adenomas but were unable to respond to Wnt signals and consequently failed to proliferate. Genetic deletion of Fzd7 or treatment with vantictumab was sufficient to inhibit the growth of gastric adenomas with or without mutations to Apc. Vantictumab is currently in phase Ib clinical trials for advanced pancreatic, lung, and breast cancer. Our data extend the scope of patients that may benefit from this therapeutic approach as we demonstrate that this drug will be effective in treating patients with gastric cancer regardless of APC mutation status. SIGNIFICANCE: The Wnt receptor Fzd7 plays an essential role in gastric tumorigenesis irrespective of Apc mutation status, therefore targeting Wnt/Fzd7 may be of therapeutic benefit to patients with gastric cancer.
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Research Support, Non-U.S. Gov't |
6 |
77 |
4
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Amin N, Vincan E. The Wnt signaling pathways and cell adhesion. Front Biosci (Landmark Ed) 2012; 17:784-804. [PMID: 22201774 DOI: 10.2741/3957] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In multicellular organisms, the processes of tissue and organ formation are governed by morphogenetic signaling pathways. The Wnt pathways regulate morphogenesis by controlling cell adhesion and migration; processes that when corrupted, lead to tumorgenesis. It is well known that the Wnt signaling pathways affect adhesion and migration via downstream effectors. Canonical Wnt signaling regulates cell adhesion by regulating the stability of beta-Catenin, a component of the adherens junction. Whereas, non-canonical signaling modulates cytoskeletal dynamics by regulating the activity of downstream effectors that function to organize the cytoskeleton. Recent studies have uncovered a multitude of points of crosstalk between the Wnt pathways and the mechanisms that control cellular architecture, from the level of receptors to the level of transcription. At the same time, cellular mechanisms that are responsible for the regulation of adhesion and migration also function to modulate the activity of several Wnt pathway components. Uncovering these points of crosstalk may lead to better understanding and treatment of the processes that can lead to tumorgenesis.
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Review |
13 |
66 |
5
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Torresi J, Tran BM, Christiansen D, Earnest-Silveira L, Schwab RHM, Vincan E. HBV-related hepatocarcinogenesis: the role of signalling pathways and innovative ex vivo research models. BMC Cancer 2019; 19:707. [PMID: 31319796 PMCID: PMC6637598 DOI: 10.1186/s12885-019-5916-6] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Accepted: 07/09/2019] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Hepatitis B virus (HBV) is the leading cause of liver cancer, but the mechanisms by which HBV causes liver cancer are poorly understood and chemotherapeutic strategies to cure liver cancer are not available. A better understanding of how HBV requisitions cellular components in the liver will identify novel therapeutic targets for HBV associated hepatocellular carcinoma (HCC). MAIN BODY The development of HCC involves deregulation in several cellular signalling pathways including Wnt/FZD/β-catenin, PI3K/Akt/mTOR, IRS1/IGF, and Ras/Raf/MAPK. HBV is known to dysregulate several hepatocyte pathways and cell cycle regulation resulting in HCC development. A number of these HBV induced changes are also mediated through the Wnt/FZD/β-catenin pathway. The lack of a suitable human liver model for the study of HBV has hampered research into understanding pathogenesis of HBV. Primary human hepatocytes provide one option; however, these cells are prone to losing their hepatic functionality and their ability to support HBV replication. Another approach involves induced-pluripotent stem (iPS) cell-derived hepatocytes. However, iPS technology relies on retroviruses or lentiviruses for effective gene delivery and pose the risk of activating a range of oncogenes. Liver organoids developed from patient-derived liver tissues provide a significant advance in HCC research. Liver organoids retain the characteristics of their original tissue, undergo unlimited expansion, can be differentiated into mature hepatocytes and are susceptible to natural infection with HBV. CONCLUSION By utilizing new ex vivo techniques like liver organoids it will become possible to develop improved and personalized therapeutic approaches that will improve HCC outcomes and potentially lead to a cure for HBV.
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Review |
6 |
66 |
6
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Phesse TJ, Buchert M, Stuart E, Flanagan DJ, Faux M, Afshar-Sterle S, Walker F, Zhang HH, Nowell CJ, Jorissen R, Tan CW, Hirokawa Y, Eissmann MF, Poh AR, Malaterre J, Pearson HB, Kirsch DG, Provero P, Poli V, Ramsay RG, Sieber O, Burgess AW, Huszar D, Vincan E, Ernst M. Partial inhibition of gp130-Jak-Stat3 signaling prevents Wnt-β-catenin-mediated intestinal tumor growth and regeneration. Sci Signal 2014; 7:ra92. [PMID: 25270258 DOI: 10.1126/scisignal.2005411] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Most colon cancers arise from somatic mutations in the tumor suppressor gene APC (adenomatous polyposis coli), and these mutations cause constitutive activation of the Wnt-to-β-catenin pathway in the intestinal epithelium. Because Wnt-β-catenin signaling is required for homeostasis and regeneration of the adult intestinal epithelium, therapeutic targeting of this pathway is challenging. We found that genetic activation of the cytokine-stimulated pathway mediated by the receptor gp130, the associated Jak (Janus kinase) kinases, and the transcription factor Stat3 (signal transducer and activator of transcription 3) was required for intestinal regeneration in response to irradiation-induced damage in wild-type mice and for tumorigenesis in Apc-mutant mice. Systemic pharmacological or partial genetic inhibition of gp130-Jak-Stat3 signaling suppressed intestinal regeneration, the growth of tumors in Apc-mutant mice, and the growth of colon cancer xenografts. The growth of Apc-mutant tumors depended on gp130-Jak-Stat3 signaling for induction of the polycomb repressor Bmi-1, and the associated repression of genes encoding the cell cycle inhibitors p16 and p21. However, suppression of gp130-Jak-Stat3 signaling did not affect Wnt-β-catenin signaling or homeostasis in the intestine. Thus, these data not only suggest a molecular mechanism for how the gp130-Jak-Stat3 pathway can promote cancer but also provide a rationale for therapeutic inhibition of Jak in colon cancer.
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Research Support, Non-U.S. Gov't |
11 |
65 |
7
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Sakthianandeswaren A, Christie M, D'Andreti C, Tsui C, Jorissen RN, Li S, Fleming NI, Gibbs P, Lipton L, Malaterre J, Ramsay RG, Phesse TJ, Ernst M, Jeffery RE, Poulsom R, Leedham SJ, Segditsas S, Tomlinson IPM, Bernhard OK, Simpson RJ, Walker F, Faux MC, Church N, Catimel B, Flanagan DJ, Vincan E, Sieber OM. PHLDA1 expression marks the putative epithelial stem cells and contributes to intestinal tumorigenesis. Cancer Res 2011; 71:3709-19. [PMID: 21558389 DOI: 10.1158/0008-5472.can-10-2342] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Studies employing mouse models have identified crypt base and position +4 cells as strong candidates for intestinal epithelial stem cells. Equivalent cell populations are thought to exist in the human intestine; however robust and specific protein markers are lacking. Here, we show that in the human small and large intestine, PHLDA1 is expressed in discrete crypt base and some position +4 cells. In small adenomas, PHLDA1 was expressed in a subset of undifferentiated and predominantly Ki-67-negative neoplastic cells, suggesting that a basic hierarchy of differentiation is retained in early tumorigenesis. In large adenomas, carcinomas, and metastases PHLDA1 expression became widespread, with increased expression and nuclear localization at invasive margins. siRNA-mediated suppression of PHLDA1 in colon cancer cells inhibited migration and anchorage-independent growth in vitro and tumor growth in vivo. The integrins ITGA2 and ITGA6 were downregulated in response to PHLDA1 suppression, and accordingly cell adhesion to laminin and collagen was significantly reduced. We conclude that PHLDA1 is a putative epithelial stem cell marker in the human small and large intestine and contributes to migration and proliferation in colon cancer cells.
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62 |
8
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Vincan E, Darcy PK, Farrelly CA, Faux MC, Brabletz T, Ramsay RG. Frizzled-7 dictates three-dimensional organization of colorectal cancer cell carcinoids. Oncogene 2006; 26:2340-52. [PMID: 17016432 DOI: 10.1038/sj.onc.1210026] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Progression of colorectal cancer (CRC) involves spatial and temporal occurrences of epithelial-mesenchymal transition (EMT), whereby tumour cells acquire a more invasive and metastatic phenotype. Subsequently, the disseminated mesenchymal tumour cells must undergo a reverse transition (mesenchymal-epithelial transition, MET) at the site of metastases, as most metastases recapitulate the pathology of their corresponding primary tumours. Importantly, initiation of tumour growth at the secondary site is the rate-limiting step in metastasis. However, investigation of this dynamic reversible EMT and MET that underpins CRC morphogenesis has been hindered by a lack of suitable in vitro models. To this end, we have established a unique in vitro model of CRC morphogenesis, which we term LIM1863-Mph (morphogenetic). LIM1863-Mph cells spontaneously undergo cyclic transitions between two-dimensional monolayer (migratory, mesenchymal) and three-dimensional sphere (carcinoid, epithelial) states. Using RNAi, we demonstrate that FZD7 is necessary for MET of the monolayer cells as loss of FZD7 results in the persistence of a mesenchymal state (increased SNAI2/decreased E-cadherin). Moreover, FZD7 is also required for migration of the LIM1863-Mph monolayer cells. During development, FZD7 orchestrates either migratory or epithelialization events depending on the context. Our findings strongly implicate similar functional diversity for FZD7 during CRC morphogenesis.
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Research Support, Non-U.S. Gov't |
19 |
58 |
9
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Flanagan DJ, Austin CR, Vincan E, Phesse TJ. Wnt Signalling in Gastrointestinal Epithelial Stem Cells. Genes (Basel) 2018; 9:genes9040178. [PMID: 29570681 PMCID: PMC5924520 DOI: 10.3390/genes9040178] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 03/16/2018] [Accepted: 03/19/2018] [Indexed: 02/06/2023] Open
Abstract
Wnt signalling regulates several cellular functions including proliferation, differentiation, apoptosis and migration, and is critical for embryonic development. Stem cells are defined by their ability for self-renewal and the ability to be able to give rise to differentiated progeny. Consequently, they are essential for the homeostasis of many organs including the gastrointestinal tract. This review will describe the huge advances in our understanding of how stem cell functions in the gastrointestinal tract are regulated by Wnt signalling, including how deregulated Wnt signalling can hijack these functions to transform cells and lead to cancer.
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Review |
7 |
54 |
10
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Flanagan DJ, Vincan E, Phesse TJ. Wnt Signaling in Cancer: Not a Binary ON:OFF Switch. Cancer Res 2019; 79:5901-5906. [PMID: 31431458 PMCID: PMC7616966 DOI: 10.1158/0008-5472.can-19-1362] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 07/16/2019] [Accepted: 08/07/2019] [Indexed: 11/16/2022]
Abstract
In the March 1 issue of Cancer Research, we identified the Wnt receptor Fzd7 as an attractive therapeutic target for the treatment of gastric cancer. In summary, we showed that pharmacological inhibition of Wnt receptors, or genetic deletion of Fzd7, blocks the initiation and growth of gastric tumors. Inhibiting Fzd receptors, specifically Fzd7, inhibits the growth of gastric cancer cells even in the presence of adenomatous polyposis coli (Apc) mutation. Apc is located in the cytoplasm downstream of Fzd7 in the Wnt signaling cascade and APC mutations activate Wnt/β-catenin signaling, therefore, this result seems counterintuitive. Here, we analyze this result in greater detail in the context of current knowledge of Wnt signaling and discuss the wider implications of this aspect of Wnt signaling in other cancers.
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Review |
6 |
54 |
11
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Koushyar S, Powell AG, Vincan E, Phesse TJ. Targeting Wnt Signaling for the Treatment of Gastric Cancer. Int J Mol Sci 2020; 21:E3927. [PMID: 32486243 PMCID: PMC7311964 DOI: 10.3390/ijms21113927] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 05/27/2020] [Accepted: 05/28/2020] [Indexed: 02/06/2023] Open
Abstract
The Wnt signaling pathway is evolutionarily conserved, regulating both embryonic development and maintaining adult tissue homeostasis. Wnt signaling controls several fundamental cell functions, including proliferation, differentiation, migration, and stemness. It therefore plays an important role in the epithelial homeostasis and regeneration of the gastrointestinal tract. Often, both hypo- or hyper-activation of the pathway due to genetic, epigenetic, or receptor/ligand alterations are seen in many solid cancers, such as breast, colorectal, gastric, and prostate. Gastric cancer (GC) is the fourth commonest cause of cancer worldwide and is the second leading cause of cancer-related death annually. Although the number of new diagnoses has declined over recent decades, prognosis remains poor, with only 15% surviving to five years. Geographical differences in clinicopathological features are also apparent, with epidemiological and genetic studies revealing GC to be a highly heterogeneous disease with phenotypic diversity as a result of etiological factors. The molecular heterogeneity associated with GC dictates that a single 'one size fits all' approach to management is unlikely to be successful. Wnt pathway dysregulation has been observed in approximately 50% of GC tumors and may offer a novel therapeutic target for patients who would otherwise have a poor outcome. This mini review will highlight some recent discoveries involving Wnt signaling in GC.
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Review |
5 |
52 |
12
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Cheasley D, Pereira L, Lightowler S, Vincan E, Malaterre J, Ramsay RG. Myb Controls Intestinal Stem Cell Genes and Self-Renewal. Stem Cells 2011; 29:2042-50. [DOI: 10.1002/stem.761] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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14 |
47 |
13
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Vincan E, Darcy PK, Smyth MJ, Thompson EW, Thomas RJS, Phillips WA, Ramsay RG. Frizzled-7 receptor ectodomain expression in a colon cancer cell line induces morphological change and attenuates tumor growth. Differentiation 2005; 73:142-53. [PMID: 15901282 DOI: 10.1111/j.1432-0436.2005.00015.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Frizzled (FZD) receptors have a conserved N-terminal extracellular cysteine-rich domain that interacts with Wnts and co-expression of the receptor ectodomain can antagonize FZD-mediated signalling. Using the ectodomain as an antagonist we have modulated endogenous FZD7 signalling in the moderately differentiated colon adenocarcinoma cell line, SK-CO-1. Unlike the parental cell line, which grows as tightly associated adherent cell clusters, the FZD7 ectodomain expressing cells display a spread out morphology and grow as a monolayer in tissue culture. This transition in morphology was associated with decreased levels of plasma membrane-associated E-cadherin and beta-catenin, localized increased levels of vimentin and redistribution of alpha6 integrin to cellular processes in the FZD7 ectodomain expressing cells. The morphological and phenotype changes induced by FZD7 ectodomain expression in SK-CO-1 cells is thus consistent with the cells undergoing an epithelial-to-mesenchymal-like transition. Furthermore, initiation of tumor formation in a xenograft tumor growth assay was attenuated in the FZD7 ectodomain expressing cells. Our results indicate a pivotal role for endogenous FZD7 in morphology transitions that are associated with colon tumor initiation and progression.
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Research Support, Non-U.S. Gov't |
20 |
47 |
14
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Preston SP, Stutz MD, Allison CC, Nachbur U, Gouil Q, Tran BM, Duvivier V, Arandjelovic P, Cooney JP, Mackiewicz L, Meng Y, Schaefer J, Bader SM, Peng H, Valaydon Z, Rajasekaran P, Jennison C, Lopaticki S, Farrell A, Ryan M, Howell J, Croagh C, Karunakaran D, Schuster-Klein C, Murphy JM, Fifis T, Christophi C, Vincan E, Blewitt ME, Thompson A, Boddey JA, Doerflinger M, Pellegrini M. Epigenetic Silencing of RIPK3 in Hepatocytes Prevents MLKL-mediated Necroptosis From Contributing to Liver Pathologies. Gastroenterology 2022; 163:1643-1657.e14. [PMID: 36037995 DOI: 10.1053/j.gastro.2022.08.040] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 08/15/2022] [Accepted: 08/16/2022] [Indexed: 01/21/2023]
Abstract
BACKGROUND & AIMS Necroptosis is a highly inflammatory mode of cell death that has been implicated in causing hepatic injury including steatohepatitis/ nonalcoholic steatohepatitis (NASH); however, the evidence supporting these claims has been controversial. A comprehensive, fundamental understanding of cell death pathways involved in liver disease critically underpins rational strategies for therapeutic intervention. We sought to define the role and relevance of necroptosis in liver pathology. METHODS Several animal models of human liver pathology, including diet-induced steatohepatitis in male mice and diverse infections in both male and female mice, were used to dissect the relevance of necroptosis in liver pathobiology. We applied necroptotic stimuli to primary mouse and human hepatocytes to measure their susceptibility to necroptosis. Paired liver biospecimens from patients with NASH, before and after intervention, were analyzed. DNA methylation sequencing was also performed to investigate the epigenetic regulation of RIPK3 expression in primary human and mouse hepatocytes. RESULTS Identical infection kinetics and pathologic outcomes were observed in mice deficient in an essential necroptotic effector protein, MLKL, compared with control animals. Mice lacking MLKL were indistinguishable from wild-type mice when fed a high-fat diet to induce NASH. Under all conditions tested, we were unable to induce necroptosis in hepatocytes. We confirmed that a critical activator of necroptosis, RIPK3, was epigenetically silenced in mouse and human primary hepatocytes and rendered them unable to undergo necroptosis. CONCLUSIONS We have provided compelling evidence that necroptosis is disabled in hepatocytes during homeostasis and in the pathologic conditions tested in this study.
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42 |
15
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Vincan E. Frizzled/WNT signalling: the insidious promoter of tumour growth and progression. FRONT BIOSCI-LANDMRK 2004; 9:1023-34. [PMID: 14977525 DOI: 10.2741/1311] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The recognition that the processes involved in tumour formation are strikingly similar to developmental morphogenetic processes, such as gastrulation, has refashioned our approach to cancer research. Wnt and its receptor Frizzled govern the morphogenetic processes of gastrulation. Directed cell movements during gastrulation require the cells to undergo transient epithelial to mesenchymal transitions, enabling the cells to dissociate and migrate. To do this, Frizzleds activate different intracellular signalling cascades that affect cellular processes such as differentiation, proliferation, cell motility and cell polarity. Cell dissociation and migration are also essential for tumour cell invasion and metastases and the frequent deregulation of Wnt and Frizzled in human cancers implicates them in this process. Indeed recent evidence links both canonical (Wnt/beta-catenin) and non-canonical (Wnt/Ca2+) pathways to tumour invasion and metastases, emphasizing the importance of Frizzled in tumour growth and progression.
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Review |
21 |
41 |
16
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Dimitriadis A, Vincan E, Mohammed IM, Roczo N, Phillips WA, Baindur-Hudson S. Expression of Wnt genes in human colon cancers. Cancer Lett 2001; 166:185-91. [PMID: 11311491 DOI: 10.1016/s0304-3835(01)00428-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A polymerase chain reaction-based approach was used to study the expression of Wnt genes in human colon carcinoma tissue and normal colon mucosa. In a number of cases Wnts 2, 4, 5a, 6 and/or 7a were found to be more highly expressed in colon carcinoma tissue compared to surrounding normal-appearing mucosa from the same patients. Wnts 4, 5a, 6 and 7a, but not 2, were also found to be expressed in colon cancer cell lines. The increased levels of expression of these Wnt genes in tumor tissue may indicate their possible involvement in human colon tumorigenesis.
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32 |
17
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Flanagan DJ, Vincan E, Phesse TJ. Winding back Wnt signalling: potential therapeutic targets for treating gastric cancers. Br J Pharmacol 2017; 174:4666-4683. [PMID: 28568899 DOI: 10.1111/bph.13890] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 05/17/2017] [Accepted: 05/22/2017] [Indexed: 12/21/2022] Open
Abstract
Gastric cancer persists as a frequent and deadly disease that claims over 700 000 lives annually. Gastric cancer is a multifactorial disease that is genetically, cytologically and architecturally more heterogeneous than other gastrointestinal cancers, making it therapeutically challenging. As such, and largely attributed to late-stage diagnosis, gastric cancer patients show only partial response to standard chemo and targeted molecular therapies, highlighting an urgent need to develop new targeted therapies for this disease. Wnt signalling has a well-documented history in the genesis of many cancers and is, therefore, an attractive therapeutic target. As such, drug discovery has focused on developing inhibitors that target multiple nodes of the Wnt signalling cascade, some of which have progressed to clinical trials. The collective efforts of patient genomic profiling has uncovered genetic lesions to multiple components of the Wnt pathway in gastric cancer patients, which strongly suggest that Wnt-targeted therapies could offer therapeutic benefits for gastric cancer patients. These data have been supported by studies in mouse models of gastric cancer, which identify Wnt signalling as a driver of gastric tumourigenesis. Here, we review the current literature regarding Wnt signalling in gastric cancer and highlight the suitability of each class of Wnt inhibitor as a potential treatment for gastric cancer patients, in relation to the type of Wnt deregulation observed. LINKED ARTICLES This article is part of a themed section on WNT Signalling: Mechanisms and Therapeutic Opportunities. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.24/issuetoc.
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Review |
8 |
32 |
18
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Sully V, Pownall S, Vincan E, Bassal S, Borowski AH, Hart PH, Rockman SP, Phillips WA. Functional abnormalities in protein tyrosine phosphatase epsilon-deficient macrophages. Biochem Biophys Res Commun 2001; 286:184-8. [PMID: 11485326 DOI: 10.1006/bbrc.2001.5360] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Protein tyrosine phosphatase epsilon (PTP epsilon)-deficient mice were generated by targeted deletion of exons 3, 4, and 5 of the Ptpre gene. Mice homozygous for this deletion (Ptpre(Delta3-5)) were fertile, bred and developed normally and exhibited no overt phenotype. However, closer examination of the function of macrophages from these mice revealed a defect in the regulation of the respiratory burst. While bacterial lipopolysaccharide (LPS) or tumour necrosis factor alpha (TNFalpha) were able to prime bone marrow-derived macrophages (BMM) from wild type (Ptpre(+)) macrophages for an enhanced respiratory burst, they were unable to do so in macrophages from PTP epsilon-deficient mice. PTP epsilon-deficient BMM also had abnormalities in cytokine production with a reduced ability to produce TNFalpha and enhanced IL-10 production in response to challenge with LPS. These findings suggest an important role for PTP epsilon in the control of macrophage function.
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19
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Ramsay RG, Micallef SJ, Williams B, Lightowler S, Vincan E, Heath JK, Mantamadiotis T, Bertoncello I. Colony-stimulating factor-1 promotes clonogenic growth of normal murine colonic crypt epithelial cells in vitro. J Interferon Cytokine Res 2005; 24:416-27. [PMID: 15296653 DOI: 10.1089/1079990041535638] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The intestinal epithelium is a continuously renewing tissue. In the colon, stem cells are maintained at the base of highly organized crypts, where they undergo asymmetric division and give rise to daughter cells that proliferate and migrate up the crypt as they differentiate, then become senescent and are finally shed into the intestinal lumen. The growth factor requirements of fetal and prenatal colon cells for colony formation and that influence the establishment of cell lines from Immorto-mouse (Charles River, Wilmington, MA) transgenic embryos were explored. Single cell suspensions were isolated and cultured in a large range of growth factor combinations and conditions to determine their growth properties in soft agar. We report an important advance in the culture of mouse colonocytes by using macrophage colony-stimulating factor (CSF-1) and granulocyte-macrophage colony-stimulating factor (GM-CSF). A substantial proportion of colonies grown under low oxygen tension in the presence of CSF-1 and GM-CSF express intestinal epithelial A33 antigen, have the expected gene expression profile, including c-fms and transcription factor c-myb, and show an appropriate epithelial cell morphology and undetectable CD45. Confocal microscopy on isolated crypts displays basolateral expression of c-Fms and E-cadherin on most epithelial cells. Fetal colon cultures from the Immorto-mouse with CSF-1 produced rapid outgrowth and readily established cell lines, in contrast to cultures without CSF-1. These observations have implications for the understanding of colon epithelial development and recovery following cytotoxic damage as well as providing a basis for the observation that some colon (and other epithelial) tumor cells respond to CSF-1 and GM-CSF.
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Vincan E, Brabletz T, Faux MC, Ramsay RG. A human three-dimensional cell line model allows the study of dynamic and reversible epithelial-mesenchymal and mesenchymal-epithelial transition that underpins colorectal carcinogenesis. Cells Tissues Organs 2007; 185:20-8. [PMID: 17587804 DOI: 10.1159/000101299] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Developmental morphogenesis relies on cell transitions between epithelial and mesenchymal states. Colorectal cancer (CRC) progression can also be described as 'morphogenesis' as it involves epithelial-mesenchymal transition (EMT), whereby tumour cells become more invasive and metastatic. Subsequently, the disseminated tumour cells must undergo a reverse transition (MET), as the pathology of most primary tumours is re-capitulated by their established metastases. Disseminated tumour cells can remain 'dormant' for many years. Consequently, tumour initiation at the secondary site is the rate-limiting step in metastasis. Metastasis is governed by cell intrinsic and extrinsic (microenvironment) factors, thus much of what we know about metastasis is drawn from in vivo model systems. However, the molecular mechanisms controlling release from 'dormancy' are still largely unknown due to the complexity this presents for the in vivo situation. An in vitro morphogenesis culture system would present a great advantage. To this end, we have established a unique model of CRC morphogenesis, using a variant of the human cell line LIM1863 (LIM1863-Mph). In this model system LIM1863-Mph cells show plasticity between epithelial and mesenchymal states. The transitions are reversible and bear the phenotypic hallmarks of CRC morphogenesis. Importantly, we have demonstrated a pivotal role for FZD7 in these phenotype transitions, implicating Wnt signalling in orchestrating CRC morphogenesis.
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Thiem S, Eissmann MF, Elzer J, Jonas A, Putoczki TL, Poh A, Nguyen P, Preaudet A, Flanagan D, Vincan E, Waring P, Buchert M, Jarnicki A, Ernst M. Stomach-Specific Activation of Oncogenic KRAS and STAT3-Dependent Inflammation Cooperatively Promote Gastric Tumorigenesis in a Preclinical Model. Cancer Res 2016; 76:2277-87. [DOI: 10.1158/0008-5472.can-15-3089] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 01/11/2016] [Indexed: 11/16/2022]
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Byun DS, Ahmed N, Nasser S, Shin J, Al-Obaidi S, Goel S, Corner GA, Wilson AJ, Flanagan DJ, Williams DS, Augenlicht LH, Vincan E, Mariadason JM. Intestinal epithelial-specific PTEN inactivation results in tumor formation. Am J Physiol Gastrointest Liver Physiol 2011; 301:G856-64. [PMID: 21836055 PMCID: PMC3220321 DOI: 10.1152/ajpgi.00178.2011] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is a negative regulator of phosphatidylinositol 3-kinase (PI3K) signaling that is frequently inactivated in colorectal cancer through mutation, loss of heterozygosity, or epigenetic mechanisms. The aim of this study was to determine the effect of intestinal-specific PTEN inactivation on intestinal epithelial homeostasis and tumorigenesis. PTEN was deleted specifically in the intestinal epithelium, by crossing PTEN(Lox/Lox) mice with villin(Cre) mice. PTEN was robustly expressed in the intestinal epithelium and maximally in the differentiated cell compartment. Targeted inactivation of PTEN in the intestinal epithelium of PTEN(Lox/Lox)/villin(Cre) mice was confirmed by genotyping, immunohistochemistry, and qPCR. While intestinal-specific PTEN deletion did not have a major effect on cell fate determination or proliferation in the small intestine, it did increase phosphorylated (p) protein kinase B (AKT) expression in the intestinal epithelium, and 19% of animals developed small intestinal adenomas and adenocarcinomas at 12 mo of age. These tumors demonstrated pAKT and nuclear β-catenin staining, indicating simultaneous activation of the PI3K/AKT and Wnt signaling pathways. These findings demonstrate that, while PTEN inactivation alone has a minimal effect on intestinal homeostasis, it can facilitate tumor promotion upon deregulation of β-catenin/TCF signaling, further establishing PTEN as a bona fide tumor suppressor gene in intestinal cancer.
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Schwab RHM, Amin N, Flanagan DJ, Johanson TM, Phesse TJ, Vincan E. Wnt is necessary for mesenchymal to epithelial transition in colorectal cancer cells. Dev Dyn 2017; 247:521-530. [PMID: 28560804 DOI: 10.1002/dvdy.24527] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 05/13/2017] [Accepted: 05/17/2017] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Metastasis underlies most colorectal cancer mortality. Cancer cells spread through the body as single cells or small clusters of cells that have an invasive, mesenchymal, nonproliferative phenotype. At the secondary site, they revert to a proliferative "tumor constructing" epithelial phenotype to rebuild a tumor. We previously developed a unique in vitro three-dimensional model, called LIM1863-Mph, which faithfully recapitulates these reversible transitions that underpin colorectal cancer metastasis. Wnt signaling plays a key role in these transitions and is initiated by the coupling of extracellular Wnt to Frizzled (FZD). Using the LIM1863-Mph model system we demonstrated that the Wnt receptor FZD7 is necessary for mesenchymal to epithelial transition (MET). Here we investigate the role of Wnt in MET. RESULTS Wnt secretion is dependent on palmitoylation by Porcupine (PORC). A PORC inhibitor (IWP2) that prevents Wnt secretion, blocked the epithelial transition of mesenchymal LIM1863-Mph cells. Wnt gene array analysis identified several Wnts that are upregulated in epithelial compared with mesenchymal LIM1863-Mph cells, suggesting these ligands in MET. Wnt2B was the most abundant differentially expressed Wnt gene. Indeed, recombinant Wnt2B could overcome the IWP2-mediated block in epithelial transition of mesenchymal LIM1863-Mph cells. CONCLUSIONS Wnt2B co-operates with Frizzled7 to mediate MET in colorectal cancer. Developmental Dynamics 247:521-530, 2018. © 2017 Wiley Periodicals, Inc.
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Research Support, Non-U.S. Gov't |
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Vincan E, Flanagan DJ, Pouliot N, Brabletz T, Spaderna S. Variable FZD7 expression in colorectal cancers indicates regulation by the tumour microenvironment. Dev Dyn 2010; 239:311-7. [PMID: 19655379 DOI: 10.1002/dvdy.22045] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Recent evidence shows that a sub-population of Wnt/beta-catenin target genes is specifically induced in different tissue contexts. FZD7 is a putative Wnt/beta-catenin target gene and although it is highly expressed in well-differentiated colorectal cancer tumour cells, its expression is decreased in de-differentiated tumour cells at the invasive front despite elevated Wnt/beta-catenin signalling in this area. This variable expression of FZD7 implicates additional regulation by the microenvironment; however, this has not been investigated. To begin to elucidate the role of extracellular matrix in regulating FZD7 expression, we generated a FZD7 promoter reporter and analysed FZD7 promoter activity in colorectal cancer cells grown on different matrices. We demonstrate that the FZD7 promoter is regulated by beta-catenin in colorectal cancer cells and observed decreased promoter activity in cells grown on fibronectin but not collagen I or collagen IV. Thus, expression of FZD7 in colorectal cancer may be regulated by fibronectin in the microenvironment.
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Daniel PM, Filiz G, Brown DV, Christie M, Waring PM, Zhang Y, Haynes JM, Pouton C, Flanagan D, Vincan E, Johns TG, Montgomery K, Phillips WA, Mantamadiotis T. PI3K activation in neural stem cells drives tumorigenesis which can be ameliorated by targeting the cAMP response element binding protein. Neuro Oncol 2019; 20:1344-1355. [PMID: 29718345 DOI: 10.1093/neuonc/noy068] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Background Hyperactivation of phosphoinositide 3-kinase (PI3K) signaling is common in cancers, but the precise role of the pathway in glioma biology remains to be determined. Some understanding of PI3K signaling mechanisms in brain cancer comes from studies on neural stem/progenitor cells (NSPCs), where signals transmitted via the PI3K pathway cooperate with other intracellular pathways and downstream transcription factors to regulate critical cell functions. Methods To investigate the role of the PI3K pathway in glioma initiation and development, we generated a mouse model targeting the inducible expression of a PIK3CAH1047A oncogenic mutant and deletion of the PI3K negative regulator, phosphatase and tensin homolog (PTEN), to NSPCs. Results Expression of a Pik3caH1047A was sufficient to generate tumors with oligodendroglial features, but simultaneous loss of PTEN was required for the development of invasive, high-grade glioma. Pik3caH1047A-PTEN mutant NSPCs exhibited enhanced neurosphere formation which correlated with increased Wnt signaling, while loss of cAMP response element binding protein (CREB) in Pik3caH1047A-Pten mutant tumors led to longer symptom-free survival in mice. Conclusion Taken together, our findings present a novel mouse model for glioma demonstrating that the PI3K pathway is important for initiation of tumorigenesis and that disruption of downstream CREB signaling attenuates tumor expansion.
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