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Masaru Katoh - One of the best experts on this subject based on the ideXlab platform.
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Prognostic value of wingless-type proteins in non-small cell lung cancer patients: a meta-analysis
Translational Lung Cancer Research, 2016Co-Authors: Jiajia Jin, Masaru Katoh, Ping Zhan, Hong Qian, Xiaoxia Wang, Kevin Phan, Jin-haeng Chung, Yong SongAbstract:Background: Wingless-type protein (Wnt) signaling pathway plays a crucial role in the development of human malignancies, such as epithelial-to-mesenchymal transition (EMT) and the maintenance of cancer stem cells (CSCs). Several studies have shown that the expression levels of Wnt proteins, ligands of Wnt signaling pathway, are related to clinical outcomes of non-small cell lung cancer (NSCLC) patients. This meta-analysis aimed to assess the prognostic value of Wnts proteins in patients with NSCLC. Methods: A multiple electronic literature search was conducted to identify all articles referring to the prognostic value of Wnt proteins in patients of NSCLC up to July 2016. Eligible studies were included in a meta-analysis in order to summarize the extracted data in terms of pooled hazard ratios (HRs) and their 95% confidence intervals (95% CIs). Results: Ten studies published between 2005 and 2015 were eligible for this meta-analysis. The total number of patients included was 1,805. The combined HR for all eligible studies evaluating the overall survival (OS) of NSCLC patients with positive Wnt expression was 1.60 (95% CI: 1.39–1.84). The subgroup analysis showed both Wnt1 and Wnt5a are associated with clinical outcome of NSCLC patients. Conclusions: Overexpression of Wnt proteins, as well as Wnt1 or Wnt5a alone, was markedly associated with adverse OS in lung cancer patients, suggesting that Wnts may act as a prognostic marker among NSCLCs.
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Networking of WNT, FGF, Notch, BMP, and Hedgehog Signaling Pathways during Carcinogenesis
Stem Cell Reviews, 2007Co-Authors: Masaru KatohAbstract:The biological functions of some orthologs within the human genome and model-animal genomes are evolutionarily conserved, but those of others are divergent due to protein evolution and promoter evolution. Because WNT signaling molecules play key roles during embryogenesis, tissue regeneration and carcinogenesis, the author’s group has carried out a human WNT-ome project for the comprehensive characterization of human genes encoding WNT signaling molecules. From 1996 to 2002, we cloned and characterized WNT2B/WNT13, WNT3, WNT3A, WNT5B, WNT6, WNT7B, WNT8A, WNT8B, WNT9A/WNT14, WNT9B/WNT14B, WNT10A, WNT10B, WNT11, FZD1, FZD2, FZD3, FZD4, FZD5, FZD6, FZD7, FZD8, FZD10, FRAT1, FRAT2, NKD1, NKD2, VANGL1, RHOU/ARHU, RHOV/ARHV, GIPC2, GIPC3, FBXW11/βTRCP2, SOX17, TCF7L1/TCF3 , and established a cDNA-PCR system for snap-shot and dynamic analyses on the WNT-transcriptome. In 2003, we identified and characterized PRICKLE1, PRICKLE2, DACT1/DAPPER1, DACT2/DAPPER2, DAAM2 , and BCL9L . After completion of the human WNT-ome project, we have been working on the stem cell signaling network. WNT signals are transduced to β-catenin, NLK, NFAT, PKC, JNK and RhoA signaling cascades. FGF20, JAG1 and DKK1 are target genes of the WNT-β-catenin signaling cascade. Cross-talk of WNT and FGF signaling pathways potentiates β-catenin and NFAT signaling cascades. BMP signals induce IHH upregulation in co-operation with RUNX. Hedgehog signals induce upregulation of SFRP1, JAG2 and FOXL1 , and then FOXL1 induces BMP4 upregulation. The balance between WNT-FGF-Notch and BMP-Hedgehog signaling networks is important for the maintenance of homoestasis among stem and progenitor cells. Disruption of the stem cell signaling network results in pathological conditions, such as congenital diseases and cancer.
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Comparative genomics on WNT3-Wnt9b gene cluster.
International journal of molecular medicine, 2005Co-Authors: Masaru KatohAbstract:WNT signals, transduced through Frizzled (FZD) receptors with extracellular WNT-binding domain and cytoplasmic Dishevelled-binding domain, are implicated in carcinogenesis and embryogenesis. WNT3-WNT9B (WNT14B) locus (17q21.31) and WNT3A-WNT9A (WNT14) locus (1q42.13) are paralogous regions within the human genome. Here, the rat WNT3 and Wnt9b genes were identified and characterized by using bioinformatics. WNT3 and Wnt9b genes at rat chromosome 10q32.1 were clustered in head-to-head manner with an interval of about 24 kb within AC105632.3 genome sequence. The rat WNT3 gene, consisting of five exons, encoded a 355-aa protein with N-terminal signal peptide, 24 conserved Cys residues and two Asn-linked glycosylation sites. The rat Wnt9b gene, consisting of four exons, encoded a 359-aa protein with N-terminal signal peptide, 24 conserved Cys residues and one Asn-linked glycosylation site. The rat WNT3 core promoter showed 80.5% nucleotide identity with human WNT3 core promoter, while rat Wnt9b core promoter showed 45.6% nucleotide identity with human WNT9B core promoter. MYB (c-Myb), ELK1, POU2F1 (OCT1), HNF4A (HNF-4), COMP1, NFYA (NF-Y) and NKX2-5 binding sites were conserved between rat WNT3 and human WNT3 core promoters. The WNT3-Wnt9b intergenic conserved region (IGCR), corresponding to nucleotide position 124747-125252 of AC105632.3 genome sequence, showed 85.6% nucleotide identity with human WNT3-WNT9B IGCR. GC content of rat WNT3-Wnt9b IGCR was 59.5%. WNT3-Wnt9b IGCR was predicted as regulatory element rather than gene because cDNA or EST derived from WNT3-Wnt9b IGCR was not identified. This is the first report on the rat WNT3 and Wnt9b genes as well as on comparative genomics on the WNT3-Wnt9b gene cluster.
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Identification and characterization of rat Wnt1 and Wnt10b genes in silico
International Journal of Oncology, 2005Co-Authors: Yuriko Katoh, Masaru KatohAbstract:WNT family genes encode WNT family glycoproteins, while Frizzled (FZD) family genes encode seven-transmembrane-type receptors with extracellular WNT-binding domain and cytoplasmic Dishevelled-binding domain. WNT signaling pathway is implicated in carcinogenesis and embryogenesis. WNT1-WNT10B, WNT6-WNT10A, WNT3-WNT9B (WNT14B), WNT3A-WNT9A (WNT14) gene clusters exist within the human genome. Here, we identified and characterized rat Wnt1 and Wnt10b genes by using bioinformatics. Rat Wnt1 gene, consisting of four exons, encoded a 370-aa protein with signal peptide, 22 conserved Cys residues and four Asn-linked glycosylation sites. Rat Wnt10b gene, consisting of five exons, encoded a 389-aa protein with signal peptide, 24 conserved Cys residues and two Asn-linked glycosylation sites. Wnt1 and Wnt10b genes at rat chromosome 7q36 were clustered in head-to-head manner with an interval of about 10 kb within AC096835.4 or AC118760.4 genome sequences. Promoter region, exon 1 and 5'-part of intron 1 were conserved between rat and human Wnt1 orthologs. Intergenic conserved region (IGCR) was identified within the Wnt1-Wnt10b gene cluster. GC content of rat Wnt1-Wnt10b IGCR (nucleotide position 14962-15875 of AC096835.4 genome sequence) was 59.4%. Rat Wnt1-Wnt10b IGCR showed 92.5 and 74.4% nucleotide identity with mouse Wnt1-Wnt10b IGCR and human WNT1-WNT10B IGCR, respectively. Wnt1-Wnt10b IGCR was predicted as regulatory element rather than gene because cDNA or EST derived from Wnt1-Wnt10b IGCR was not identified. This is the first report on rat Wnt1 and Wnt10b genes as well as on Wnt1-Wnt10b IGCR.
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Expression and regulation of WNT1 in human cancer: Up-regulation of WNT1 by β-estradiol in MCF-7 cells
International Journal of Oncology, 2003Co-Authors: Masaru KatohAbstract:WNT family of secreted-type glycoproteins play key roles in carcinogenesis and embryogenesis. We have cloned and characterized human WNT2B/WNT13, WNT3, WNT3A, WNT5B, WNT6, WNT7B, WNT8A, WNT8B, WNT10A, WNT10B, WNT11, WNT14 and WNT14B/WNT15 using bioinformatics and cDNA-PCR, and also reported frequent up-regulation of WNT2 in primary gastric cancer. Here, expression and regulation of WNT1 in human cancer were investigated using cDNA-PCR. WNT1 mRNA was relatively highly expressed in OKAJIMA cells (gastric cancer) and BxPC-3 cells (pancreatic cancer). Expression of WNT1 mRNA was up-regulated in 5 out of 10 cases of primary gastric cancer. Effects of beta-estradiol on expression of human WNT1 in MCF-7 cells (breast cancer) was next investigated, because mouse Wnt-1 induces mammary carcinogenesis even in estrogen receptor alpha (ERalpha) knockout mice. Expression of WNT1 mRNA was significantly up-regulated by beta-estradiol in MCF-7 cells. WNT1 was found to be one of estrogen target genes in human MCF-7 cells, which in part explains Wnt1-induced mammary carcinogenesis in ERalpha knockout mice.
Hans Clevers - One of the best experts on this subject based on the ideXlab platform.
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surrogate wnt agonists that phenocopy canonical wnt and β catenin signalling
Nature, 2017Co-Authors: Claudia Y Janda, Luke T Dang, Junlei Chang, Zhendong A Zhong, Owen Marecic, Dirk Siepe, Xingnan Li, James D Moody, Bart O Williams, Hans CleversAbstract:The authors describe water-soluble surrogate Wnt agonists, with specificity towards some frizzled (FZD) receptors, which can maintain human intestinal organoid cultures and have effects on the mouse liver in vivo. Wnt ligands interact with FZDand Lrp5/6-type receptors to influence diverse developmental, homeostatic and pathologic processes through β-catenin-dependent signalling. The promiscuity of Wnt ligands towards several receptors and the fact that Wnts can be hydrophobic make it difficult to produce therapeutic recombinant Wnts. Chris Garcia and colleagues have developed surrogate water-soluble Wnt agonists that have specificity towards certain FZDs.The new agonists act similarly to WNT3 in differentiation assays towards the osteogenic lineage in vitro, can maintain intestinal organoid cultures, and have in vivo effects on the mouse liver. Elsewhere in this issue, Calvin Kuo and colleagues use these novel water-soluble Wnt agonists in the mouse intestinal stem-cell niche to dissect the respective roles of R-spondin and Wnt ligands, both of which activate similar signalling receptors and pathways. They find that Lgr5+ intestinal stem cells normally differentiate unless both R-spondin and Wnt ligands are present. However, on their own, each ligand acts non-redundantly and in cooperation with Wnt agonists, activating R-spondin receptors to maintain stem-cell competency and these receptors are in turn activated in the presence of R-spondin to drive stem-cell expansion. These water-soluble Wnt agonists could be used in a range of assays to understand this signalling pathway and modulate it in therapeutical applications. Wnt proteins modulate cell proliferation and differentiation and the self-renewal of stem cells by inducing β-catenin-dependent signalling through the Wnt receptor frizzled (FZD) and the co-receptors LRP5 and LRP6 to regulate cell fate decisions and the growth and repair of several tissues1. The 19 mammalian Wnt proteins are cross-reactive with the 10 FZD receptors, and this has complicated the attribution of distinct biological functions to specific FZD and Wnt subtype interactions. Furthermore, Wnt proteins are modified post-translationally by palmitoylation, which is essential for their secretion, function and interaction with FZD receptors2,3,4. As a result of their acylation, Wnt proteins are very hydrophobic and require detergents for purification, which presents major obstacles to the preparation and application of recombinant Wnt proteins. This hydrophobicity has hindered the determination of the molecular mechanisms of Wnt signalling activation and the functional importance of FZD subtypes, and the use of Wnt proteins as therapeutic agents. Here we develop surrogate Wnt agonists, water-soluble FZD–LRP5/LRP6 heterodimerizers, with FZD5/FZD8-specific and broadly FZD-reactive binding domains. Similar to WNT3A, these Wnt agonists elicit a characteristic β-catenin signalling response in a FZD-selective fashion, enhance the osteogenic lineage commitment of primary mouse and human mesenchymal stem cells, and support the growth of a broad range of primary human organoid cultures. In addition, the surrogates can be systemically expressed and exhibit Wnt activity in vivo in the mouse liver, regulating metabolic liver zonation and promoting hepatocyte proliferation, resulting in hepatomegaly. These surrogates demonstrate that canonical Wnt signalling can be activated by bi-specific ligands that induce receptor heterodimerization. Furthermore, these easily produced, non-lipidated Wnt surrogate agonists facilitate functional studies of Wnt signalling and the exploration of Wnt agonists for translational applications in regenerative medicine.
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Redundant Sources of Wnt Regulate Intestinal Stem Cells and Promote Formation of Paneth Cells
Gastroenterology, 2012Co-Authors: Henner F. Farin, Johan H. Van Es, Hans CleversAbstract:Background & Aims Wnt signaling regulates multiple aspects of intestinal physiology, including stem cell maintenance. Paneth cells support stem cells by secreting Wnt, but little is known about the exact sources and primary functions of individual Wnt family members. Methods We analyzed intestinal tissues and cultured epithelial cells from adult mice with conditional deletion of WNT3 ( Vil-CreERT2 ; WNT3fl/fl mice). We also analyzed intestinal tissues and cells from Atoh1 mutant mice, which lack secretory cells. Results Unexpectedly, WNT3 was dispensable for maintenance of intestinal stem cells in mice, indicating a redundancy of Wnt signals. By contrast, cultured crypt organoids required Paneth cell–derived WNT3. Addition of exogenous Wnt, or coculture with mesenchymal cells, restored growth of Vil-CreERT2;WNT3fl/fl crypt organoids. Intestinal organoids from Atoh1 mutant mice did not grow or form Paneth cells; addition of WNT3 allowed growth in the absence of Paneth cells. Wnt signaling had a synergistic effect with the Lgr4/5 ligand R-spondin to induce formation of Paneth cells. Mosaic expression of WNT3 in organoids using a retroviral vector promoted differentiation of Paneth cells in a cell-autonomous manner. Conclusions Wnt is part of a signaling loop that affects homeostasis of intestinal stem and Paneth cells in mice. WNT3 signaling is required for growth and development of organoid cultures, whereas nonepithelial Wnt signals could provide a secondary physiological source of Wnt.
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wnt signaling is required for thymocyte development and activates tcf 1 mediated transcription
European Journal of Immunology, 2001Co-Authors: Frank J.t. Staal, Jan Meeldijk, Barbara C M Van De Weerdt, Garry P Nolan, Petra Moerer, Seppo Vainio, Hans CleversAbstract:T cell factor / lymphocyte enhancer factor (Tcf / Lef) transcription factors complex with the transcriptional co-activator β-catenin to transduce Wnt signals in a variety of developmental systems. The prototypic family member Tcf-1 is highly expressed in T lineage cells. Tcf1– / – mice are defective in cell cycling of early thymocyte stages. Here, we show that the interaction of β-catenin with Tcf-1 is required for full thymocyte development. This interaction may be established by signals mediated by Wnt1 and Wnt4, leading to increased Tcf-dependent transcriptional activity in thymocytes, as demonstrated in Tcf-LacZ reporter mice. Transduction of fetal thymocytes with Wnt1 and Wnt4 results in increased survival in an in vitro cell culture system. Retroviral expression of soluble Wnt receptor mutants that block Wnt signaling inhibits thymocyte development. These results imply an important role for the Wnt cascade in thymocyte development.
Lisa M. Galli - One of the best experts on this subject based on the ideXlab platform.
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Direct visualization of the Wntless-induced redistribution of WNT1 in developing chick embryos.
Developmental Biology, 2018Co-Authors: Lisa M. Galli, Frederick Santana, Chantilly Apollon, Linda A. Szabo, Keri Ngo, Laura W. BurrusAbstract:Paracrine Wnt signals are critical regulators of cell proliferation, specification, and differentiation during embryogenesis. Consistent with the discovery that Wnt ligands are post-translationally modified with palmitoleate (a 16 carbon mono-unsaturated fatty acid), our studies show that the vast majority of bioavailable chick WNT1 (cWNT1) produced in stably transfected L cells is cell-associated. Thus, it seems unlikely that the WNT1 signal is propagated by diffusion alone. Unfortunately, the production and transport of vertebrate Wnt proteins has been exceedingly difficult to study as few antibodies are able to detect endogenous Wnt proteins and fixation is known to disrupt the architecture of cells and tissues. Furthermore, vertebrate Wnts have been extraordinarily refractory to tagging. To help overcome these obstacles, we have generated a number of tools that permit the detection of WNT1 in palmitoylation assays and the visualization of chick and zebrafish WNT1 in live cells and tissues. Consistent with previous studies in fixed cells, live imaging of cells and tissues with overexpressed cWNT1-moxGFP shows predominant localization of the protein to a reticulated network that is likely to be the endoplasmic reticulum. As PORCN and WLS are important upstream regulators of Wnt gradient formation, we also undertook the generation of mCherry-tagged variants of both proteins. While co-expression of PORCN-mCherry had no discernible effect on the localization of WNT1-moxGFP, co-expression of WLS-mCherry caused a marked redistribution of WNT1-moxGFP to the cell surface and cellular projections in cultured cells as well as in neural crest and surface ectoderm cells in developing chick embryos. Our studies further establish that the levels of WLS, and not PORCN, are rate limiting with respect to WNT1 trafficking.
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Concentration-dependent effects of WNTLESS on WNT1/3A signaling.
Developmental Dynamics, 2014Co-Authors: Lisa M. Galli, Linda A. Szabo, Yin Min Htaik, Ouma Onguka, Laura W. BurrusAbstract:Background: WNTLESS (WLS) is a multi-transmembrane protein that transports Wnt ligands from the Golgi to the cell surface. Although WLS loss-of-function experiments in the developing central nervous system reveal phenotypes consistent with defects in WNT1 and WNT3A signaling, data from complementary gain-of-function experiments have not yet been reported. Here, we report the phenotypic consequences of WLS overexpression in cultured cells and in the developing chick spinal cord. Results: Overexpression of small amounts of WLS along with either WNT1 or WNT3A promotes the Wnt/β-catenin pathway in HEK293T cells, while overexpression of higher levels of WLS inhibits the Wnt/β-catenin pathway in these cells. Similarly, overexpressed WLS inhibits the Wnt/β-catenin pathway in the developing spinal cord, as assessed by cell proliferation and specification. These effects appear to be Wnt-specific as overexpression of WLS inhibits the expression of FZD10, a target of β-catenin-dependent transcription. Conclusions: Our results show that overexpression of WLS inhibits Wnt/β-catenin signaling in the spinal cord. As the activation of the Wnt/β-catenin pathway in the spinal cord requires WNT1 or WNT3A, our results are consistent with a model in which the relative concentration of WLS to Wnt regulates WNT1/3A signaling in the developing spinal cord. Developmental Dynamics 243:1095–1105, 2014. © 2014 Wiley Periodicals, Inc.
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Frizzled10 mediates WNT1 and WNT3A signaling in the dorsal spinal cord of the developing chick embryo.
Developmental Dynamics, 2014Co-Authors: Lisa M. Galli, Linda A. Szabo, Ouma Onguka, Roeben N. Munji, Susan C. Chapman, Ann Easton, Joseph S. Ramahi, Rowena Suriben, Camilla S TengAbstract:Background: WNT1 and WNT3A drive a dorsal to ventral gradient of b-catenin-dependent Wnt signaling in the developing spinal cord. However, the identity of the receptors mediating downstream functions remains poorly understood. Results: In this report, we show that the spatiotemporal expression patterns of FZD10 and WNT1/WNT3A are highly correlated. We further show that in the presence of LRP6, FZD10 promotes WNT1 and WNT3A signaling using an 8xSuperTopFlash reporter assay. Consistent with a functional role for FZD10, we demonstrate that FZD10 is required for proliferation in the spinal cord. Finally, by using an in situ proximity ligation assay, we observe an interaction between FZD10 and WNT1 and WNT3A proteins. Conclusions: Together, our results identify FZD10 as a receptor for WNT1 and WNT3A in the developing chick spinal cord. Developmental Dynamics 243:833–843, 2014. V C 2014 Wiley Periodicals, Inc.
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Porcupine-mediated lipid-modification regulates the activity and distribution of Wnt proteins in the chick neural tube.
Development, 2007Co-Authors: Lisa M. Galli, Tiffany L. Barnes, Stephanie S. Secrest, Tatsuhiko Kadowaki, Laura W. BurrusAbstract:A long-term goal of developmental biology is to understand how morphogens establish gradients that promote proper tissue patterning. A number of reports describe the formation of the Wg (Wnt1) gradient in Drosophila and have shown that Porcupine, a predicted membrane-bound O-acyl transferase, is required for the correct distribution of Wg protein. The discovery that Wnts are palmitoylated on a conserved cysteine residue suggests that porcupine activity and Wnt palmitoylation are important for the generation of Wnt gradients. To establish the role of porcupine in Wnt gradient formation in vertebrates, we tested the role of porcupine/Wnt palmitoylation in human embryonic kidney 293T cells and in the chick neural tube. Our results lead us to conclude that: (1) vertebrate Wnt1 and WNT3a possess at least one additional site for porcupine-mediated lipid-modification; (2) porcupine-mediated lipid-modification of Wnt proteins promotes their activity in 293T cells and in the chick neural tube; and (3) porcupine-mediated lipid-modification reduces the range of activity of Wnt1 and WNT3a in the chick neural tube. These findings highlight the importance of porcupine-mediated lipid modifications in the formation of vertebrate Wnt activity gradients.
Laura W. Burrus - One of the best experts on this subject based on the ideXlab platform.
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Direct visualization of the Wntless-induced redistribution of WNT1 in developing chick embryos.
Developmental Biology, 2018Co-Authors: Lisa M. Galli, Frederick Santana, Chantilly Apollon, Linda A. Szabo, Keri Ngo, Laura W. BurrusAbstract:Paracrine Wnt signals are critical regulators of cell proliferation, specification, and differentiation during embryogenesis. Consistent with the discovery that Wnt ligands are post-translationally modified with palmitoleate (a 16 carbon mono-unsaturated fatty acid), our studies show that the vast majority of bioavailable chick WNT1 (cWNT1) produced in stably transfected L cells is cell-associated. Thus, it seems unlikely that the WNT1 signal is propagated by diffusion alone. Unfortunately, the production and transport of vertebrate Wnt proteins has been exceedingly difficult to study as few antibodies are able to detect endogenous Wnt proteins and fixation is known to disrupt the architecture of cells and tissues. Furthermore, vertebrate Wnts have been extraordinarily refractory to tagging. To help overcome these obstacles, we have generated a number of tools that permit the detection of WNT1 in palmitoylation assays and the visualization of chick and zebrafish WNT1 in live cells and tissues. Consistent with previous studies in fixed cells, live imaging of cells and tissues with overexpressed cWNT1-moxGFP shows predominant localization of the protein to a reticulated network that is likely to be the endoplasmic reticulum. As PORCN and WLS are important upstream regulators of Wnt gradient formation, we also undertook the generation of mCherry-tagged variants of both proteins. While co-expression of PORCN-mCherry had no discernible effect on the localization of WNT1-moxGFP, co-expression of WLS-mCherry caused a marked redistribution of WNT1-moxGFP to the cell surface and cellular projections in cultured cells as well as in neural crest and surface ectoderm cells in developing chick embryos. Our studies further establish that the levels of WLS, and not PORCN, are rate limiting with respect to WNT1 trafficking.
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Concentration-dependent effects of WNTLESS on WNT1/3A signaling.
Developmental Dynamics, 2014Co-Authors: Lisa M. Galli, Linda A. Szabo, Yin Min Htaik, Ouma Onguka, Laura W. BurrusAbstract:Background: WNTLESS (WLS) is a multi-transmembrane protein that transports Wnt ligands from the Golgi to the cell surface. Although WLS loss-of-function experiments in the developing central nervous system reveal phenotypes consistent with defects in WNT1 and WNT3A signaling, data from complementary gain-of-function experiments have not yet been reported. Here, we report the phenotypic consequences of WLS overexpression in cultured cells and in the developing chick spinal cord. Results: Overexpression of small amounts of WLS along with either WNT1 or WNT3A promotes the Wnt/β-catenin pathway in HEK293T cells, while overexpression of higher levels of WLS inhibits the Wnt/β-catenin pathway in these cells. Similarly, overexpressed WLS inhibits the Wnt/β-catenin pathway in the developing spinal cord, as assessed by cell proliferation and specification. These effects appear to be Wnt-specific as overexpression of WLS inhibits the expression of FZD10, a target of β-catenin-dependent transcription. Conclusions: Our results show that overexpression of WLS inhibits Wnt/β-catenin signaling in the spinal cord. As the activation of the Wnt/β-catenin pathway in the spinal cord requires WNT1 or WNT3A, our results are consistent with a model in which the relative concentration of WLS to Wnt regulates WNT1/3A signaling in the developing spinal cord. Developmental Dynamics 243:1095–1105, 2014. © 2014 Wiley Periodicals, Inc.
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Porcupine-mediated lipid-modification regulates the activity and distribution of Wnt proteins in the chick neural tube.
Development, 2007Co-Authors: Lisa M. Galli, Tiffany L. Barnes, Stephanie S. Secrest, Tatsuhiko Kadowaki, Laura W. BurrusAbstract:A long-term goal of developmental biology is to understand how morphogens establish gradients that promote proper tissue patterning. A number of reports describe the formation of the Wg (Wnt1) gradient in Drosophila and have shown that Porcupine, a predicted membrane-bound O-acyl transferase, is required for the correct distribution of Wg protein. The discovery that Wnts are palmitoylated on a conserved cysteine residue suggests that porcupine activity and Wnt palmitoylation are important for the generation of Wnt gradients. To establish the role of porcupine in Wnt gradient formation in vertebrates, we tested the role of porcupine/Wnt palmitoylation in human embryonic kidney 293T cells and in the chick neural tube. Our results lead us to conclude that: (1) vertebrate Wnt1 and WNT3a possess at least one additional site for porcupine-mediated lipid-modification; (2) porcupine-mediated lipid-modification of Wnt proteins promotes their activity in 293T cells and in the chick neural tube; and (3) porcupine-mediated lipid-modification reduces the range of activity of Wnt1 and WNT3a in the chick neural tube. These findings highlight the importance of porcupine-mediated lipid modifications in the formation of vertebrate Wnt activity gradients.
Randall T. Moon - One of the best experts on this subject based on the ideXlab platform.
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WNT signalling pathways as therapeutic targets in cancer
Nature Reviews Cancer, 2012Co-Authors: Jamie N. Anastas, Randall T. MoonAbstract:Since the initial discovery of the oncogenic activity of WNT1 in mouse mammary glands, our appreciation for the complex roles for WNT signalling pathways in cancer has increased dramatically. WNTs and their downstream effectors regulate various processes that are important for cancer progression, including tumour initiation, tumour growth, cell senescence, cell death, differentiation and metastasis. Although WNT signalling pathways have been difficult to target, improved drug-discovery platforms and new technologies have facilitated the discovery of agents that can alter WNT signalling in preclinical models, thus setting the stage for clinical trials in humans.
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wnt β catenin regulation of the sp1 related transcription factor sp5l promotes tail development in zebrafish
Development, 2005Co-Authors: Christopher J Thorpe, Gilbert Weidinger, Randall T. MoonAbstract:Tail formation in vertebrates involves the specification of a population of multipotent precursors, the tailbud, which will give rise to all of the posterior structures of the embryo. Wnts are signaling proteins that are candidates for promoting tail outgrowth in zebrafish, although which Wnts are involved, what genes they regulate, and whether Wnts are required for initiation or maintenance steps in tail formation has not been resolved. We show here that both WNT3a and wnt8 are expressed in the zebrafish tailbud and that simultaneous inhibition of both WNT3a and wnt8 using morpholino oligonucleotides can completely block tail formation. In embryos injected with WNT3a and wnt8 morpholinos, expression of genes in undifferentiated presomitic mesoderm is initiated, but not maintained. To identify genes that might function downstream of Wnts in tail formation, a DNA microarray screen was conducted, revealing that sp5l , a member of the Sp1 family of zinc-finger transcription factors, is activated by Wnt signaling. Moreover, we show that sp5l expression in the developing tail is dependent on both WNT3a and wnt8 function. Supporting a role for sp5l in tail formation , we find that inhibition of sp5l strongly enhances the effects of WNT3a inhibition, and overexpression of sp5l RNA is able to completely restore normal tail development in WNT3a morphants. These data place sp5l downstream of WNT3a and wnt8 in a Wnt/β-catenin signaling pathway that controls tail development in zebrafish.
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wnt1 and wnt10b function redundantly at the zebrafish midbrain hindbrain boundary
Developmental Biology, 2003Co-Authors: Arne C. Lekven, Gerri R. Buckles, Nicholas Kostakis, Randall T. MoonAbstract:Abstract Wnt signals have been shown to be involved in multiple steps of vertebrate neural patterning, yet the relative contributions of individual Wnts to the process of brain regionalization is poorly understood. Wnt1 has been shown in the mouse to be required for the formation of the midbrain and the anterior hindbrain, but this function of wnt1 has not been explored in other model systems. Further, wnt1 is part of a Wnt cluster conserved in all vertebrates comprising wnt1 and wnt10b, yet the function of wnt10b during embryogenesis has not been explored. Here, we report that in zebrafish wnt10b is expressed in a pattern overlapping extensively with that of wnt1. We have generated a deficiency allele for these closely linked loci and performed morpholino antisense oligo knockdown to show that wnt1 and wnt10b provide partially redundant functions in the formation of the midbrain–hindbrain boundary (MHB). When both loci are deleted, the expression of pax2.1, en2, and her5 is lost in the ventral portion of the MHB beginning at the 8-somite stage. However, wnt1 and wnt10b are not required for the maintenance of fgf8, en3, wnt8b, or WNT3a expression. Embryos homozygous for the wnt1–wnt10b deficiency display a mild MHB phenotype, but are sensitized to reductions in either Pax2.1 or Fgf8; that is, in combination with mutant alleles of either of these loci, the morphological MHB is lost. Thus, wnt1 and wnt10b are required to maintain threshold levels of Pax2.1 and Fgf8 at the MHB.
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Wnt1 and wnt10b function redundantly at the zebrafish midbrain–hindbrain boundary
Developmental Biology, 2003Co-Authors: Arne C. Lekven, Gerri R. Buckles, Nicholas Kostakis, Randall T. MoonAbstract:Abstract Wnt signals have been shown to be involved in multiple steps of vertebrate neural patterning, yet the relative contributions of individual Wnts to the process of brain regionalization is poorly understood. Wnt1 has been shown in the mouse to be required for the formation of the midbrain and the anterior hindbrain, but this function of wnt1 has not been explored in other model systems. Further, wnt1 is part of a Wnt cluster conserved in all vertebrates comprising wnt1 and wnt10b, yet the function of wnt10b during embryogenesis has not been explored. Here, we report that in zebrafish wnt10b is expressed in a pattern overlapping extensively with that of wnt1. We have generated a deficiency allele for these closely linked loci and performed morpholino antisense oligo knockdown to show that wnt1 and wnt10b provide partially redundant functions in the formation of the midbrain–hindbrain boundary (MHB). When both loci are deleted, the expression of pax2.1, en2, and her5 is lost in the ventral portion of the MHB beginning at the 8-somite stage. However, wnt1 and wnt10b are not required for the maintenance of fgf8, en3, wnt8b, or WNT3a expression. Embryos homozygous for the wnt1–wnt10b deficiency display a mild MHB phenotype, but are sensitized to reductions in either Pax2.1 or Fgf8; that is, in combination with mutant alleles of either of these loci, the morphological MHB is lost. Thus, wnt1 and wnt10b are required to maintain threshold levels of Pax2.1 and Fgf8 at the MHB.
