101
|
Nag JK, Kancharla A, Maoz M, Turm H, Agranovich D, Gupta CL, Uziely B, Bar-Shavit R. Low-density lipoprotein receptor-related protein 6 is a novel coreceptor of protease-activated receptor-2 in the dynamics of cancer-associated β-catenin stabilization. Oncotarget 2018; 8:38650-38667. [PMID: 28418856 PMCID: PMC5503561 DOI: 10.18632/oncotarget.16246] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 02/17/2017] [Indexed: 01/28/2023] Open
Abstract
Protease-activated receptor-2 (PAR2) plays a central role in cancer; however, the molecular machinery of PAR2-instigated tumors remains to be elucidated. We show that PAR2 is a potent inducer of β-catenin stabilization, a core process in cancer biology, leading to its transcriptional activity. Novel association of low-density lipoprotein-related protein 6 (LRP6), a known coreceptor of Frizzleds (Fz), with PAR2 takes place following PAR2 activation. The association between PAR2 and LRP6 was demonstrated employing co-immunoprecipitation, bioluminescence resonance energy transfer (BRET), and confocal microscopy analysis. The association was further supported by ZDOCK protein-protein server. PAR2-LRP6 interaction promotes rapid phosphorylation of LRP6, which results in the recruitment of Axin. Confocal microscopy of PAR2-driven mammary gland tumors in vivo, as well as in vitro confirms the association between PAR2 and LRP6. Indeed, shRNA silencing of LRP6 potently inhibits PAR2-induced β-catenin stabilization, demonstrating its critical role in the induced path. We have previously shown a novel link between protease-activated receptor-1 (PAR1) and β-catenin stabilization, both in a transgenic (tg) mouse model with overexpression of human PAR1 (hPar1) in the mammary glands, and in cancer epithelial cell lines. Unlike in PAR1-Gα13 axis, both Gα12 and Gα13 are equally involved in PAR2-induced β-catenin stabilization. Disheveled (DVL) is translocated to the cell nucleus through the DVL-PDZ domain. Collectively, our data demonstrate a novel PAR2-LRP6-Axin interaction as a key axis of PAR2-induced β-catenin stabilization in cancer. This newly described axis enhances our understanding of cancer biology, and opens new avenues for future development of anti-cancer therapies.
Collapse
Affiliation(s)
- Jeetendra Kumar Nag
- Sharett Institute of Oncology, Hadassah-Hebrew University Medical Center, Jerusalem 91120, Israel
| | - Arun Kancharla
- Sharett Institute of Oncology, Hadassah-Hebrew University Medical Center, Jerusalem 91120, Israel
| | - Myriam Maoz
- Sharett Institute of Oncology, Hadassah-Hebrew University Medical Center, Jerusalem 91120, Israel
| | - Hagit Turm
- Sharett Institute of Oncology, Hadassah-Hebrew University Medical Center, Jerusalem 91120, Israel
| | - Daniel Agranovich
- Sharett Institute of Oncology, Hadassah-Hebrew University Medical Center, Jerusalem 91120, Israel
| | - Chhedi Lal Gupta
- Department of Biosciences, Integral University, Lucknow, Uttar Pradesh 226026, India
| | - Beatrice Uziely
- Sharett Institute of Oncology, Hadassah-Hebrew University Medical Center, Jerusalem 91120, Israel
| | - Rachel Bar-Shavit
- Sharett Institute of Oncology, Hadassah-Hebrew University Medical Center, Jerusalem 91120, Israel
| |
Collapse
|
102
|
Li Z, Wang Y, Li Y, Yin W, Mo L, Qian X, Zhang Y, Wang G, Bu F, Zhang Z, Ren X, Zhu B, Niu C, Xiao W, Zhang W. Ube2s stabilizes β-Catenin through K11-linked polyubiquitination to promote mesendoderm specification and colorectal cancer development. Cell Death Dis 2018; 9:456. [PMID: 29674637 PMCID: PMC5908793 DOI: 10.1038/s41419-018-0451-y] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 02/20/2018] [Accepted: 03/01/2018] [Indexed: 01/01/2023]
Abstract
The canonical Wnt/β-Catenin signaling pathway is widely involved in regulating diverse biological processes. Dysregulation of the pathway results in severe consequences, such as developmental defects and malignant cancers. Here, we identified Ube2s as a novel activator of the Wnt/β-Catenin signaling pathway. It modified β-Catenin at K19 via K11-linked polyubiquitin chain. This modification resulted in an antagonistic effect against the destruction complex/β-TrCP cascade-orchestrated β-Catenin degradation. As a result, the stability of β-Catenin was enhanced, thus promoting its cellular accumulation. Importantly, Ube2s-promoted β-Catenin accumulation partially released the dependence on exogenous molecules for the process of embryonic stem (ES) cell differentiation into mesoendoderm lineages. Moreover, we demonstrated that UBE2S plays a critical role in determining the malignancy properties of human colorectal cancer (CRC) cells in vitro and in vivo. The findings in this study extend our mechanistic understanding of the mesoendodermal cell fate commitment, and provide UBE2S as a putative target for human CRC therapy.
Collapse
Affiliation(s)
- Zhaoyan Li
- College of Life Sciences, Capital Normal University, Beijing, China
| | - Yan Wang
- College of Life Sciences, Capital Normal University, Beijing, China
| | - Yadan Li
- College of Life Sciences, Capital Normal University, Beijing, China
| | - Wanqi Yin
- College of Life Sciences, Capital Normal University, Beijing, China
| | - Libin Mo
- College of Life Sciences, Capital Normal University, Beijing, China
| | - Xianghao Qian
- College of Life Sciences, Capital Normal University, Beijing, China
| | - Yiran Zhang
- College of Life Sciences, Capital Normal University, Beijing, China
| | - Guifen Wang
- College of Life Sciences, Capital Normal University, Beijing, China
| | - Fan Bu
- College of Life Sciences, Capital Normal University, Beijing, China
| | - Zhiling Zhang
- College of Life Sciences, Capital Normal University, Beijing, China
| | - Xiaofang Ren
- College of Life Sciences, Capital Normal University, Beijing, China
| | - Baochang Zhu
- College of Life Sciences, Capital Normal University, Beijing, China
| | - Chang Niu
- College of Life Sciences, Capital Normal University, Beijing, China
| | - Wei Xiao
- College of Life Sciences, Capital Normal University, Beijing, China.
| | - Weiwei Zhang
- College of Life Sciences, Capital Normal University, Beijing, China.
| |
Collapse
|
103
|
Schaefer KN, Bonello TT, Zhang S, Williams CE, Roberts DM, McKay DJ, Peifer M. Supramolecular assembly of the beta-catenin destruction complex and the effect of Wnt signaling on its localization, molecular size, and activity in vivo. PLoS Genet 2018; 14:e1007339. [PMID: 29641560 PMCID: PMC5912785 DOI: 10.1371/journal.pgen.1007339] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 04/23/2018] [Accepted: 03/28/2018] [Indexed: 11/18/2022] Open
Abstract
Wnt signaling provides a paradigm for cell-cell signals that regulate embryonic development and stem cell homeostasis and are inappropriately activated in cancers. The tumor suppressors APC and Axin form the core of the multiprotein destruction complex, which targets the Wnt-effector beta-catenin for phosphorylation, ubiquitination and destruction. Based on earlier work, we hypothesize that the destruction complex is a supramolecular entity that self-assembles by Axin and APC polymerization, and that regulating assembly and stability of the destruction complex underlie its function. We tested this hypothesis in Drosophila embryos, a premier model of Wnt signaling. Combining biochemistry, genetic tools to manipulate Axin and APC2 levels, advanced imaging and molecule counting, we defined destruction complex assembly, stoichiometry, and localization in vivo, and its downregulation in response to Wnt signaling. Our findings challenge and revise current models of destruction complex function. Endogenous Axin and APC2 proteins and their antagonist Dishevelled accumulate at roughly similar levels, suggesting competition for binding may be critical. By expressing Axin:GFP at near endogenous levels we found that in the absence of Wnt signals, Axin and APC2 co-assemble into large cytoplasmic complexes containing tens to hundreds of Axin proteins. Wnt signals trigger recruitment of these to the membrane, while cytoplasmic Axin levels increase, suggesting altered assembly/disassembly. Glycogen synthase kinase3 regulates destruction complex recruitment to the membrane and release of Armadillo/beta-catenin from the destruction complex. Manipulating Axin or APC2 levels had no effect on destruction complex activity when Wnt signals were absent, but, surprisingly, had opposite effects on the destruction complex when Wnt signals were present. Elevating Axin made the complex more resistant to inactivation, while elevating APC2 levels enhanced inactivation. Our data suggest both absolute levels and the ratio of these two core components affect destruction complex function, supporting models in which competition among Axin partners determines destruction complex activity.
Collapse
Affiliation(s)
- Kristina N. Schaefer
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Teresa T. Bonello
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Shiping Zhang
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Clara E. Williams
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - David M. Roberts
- Department of Biology, Franklin and Marshall College, Lancaster, PA, United States of America
| | - Daniel J. McKay
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Mark Peifer
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
- * E-mail:
| |
Collapse
|
104
|
Gammons M, Bienz M. Multiprotein complexes governing Wnt signal transduction. Curr Opin Cell Biol 2018; 51:42-49. [PMID: 29153704 DOI: 10.1016/j.ceb.2017.10.008] [Citation(s) in RCA: 136] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 10/10/2017] [Indexed: 12/30/2022]
Abstract
Three multiprotein complexes have key roles in transducing Wnt signals from the plasma membrane to the cell nucleus - the β-catenin destruction complex, or Axin degradasome, which targets the Wnt effector β-catenin for proteasomal degradation in the absence of Wnt; the Wnt signalosome, assembled by polymerization of Dishevelled upon Wnt engaging its receptors, to inactivate the Axin degradasome, which allows β-catenin to accumulate; and the Wnt enhanceosome which enables β-catenin to gain access to target genes, to relieve their transcriptional repression by Groucho/TLE. This review focuses on recent advances that have highlighted mechanistic principles governing the assembly and function of these complexes.
Collapse
Affiliation(s)
- Melissa Gammons
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Mariann Bienz
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK.
| |
Collapse
|
105
|
Chiu CY, Sun SC, Chiang CK, Wang CC, Chan DC, Chen HJ, Liu SH, Yang RS. Plasticizer di(2-ethylhexyl)phthalate interferes with osteoblastogenesis and adipogenesis in a mouse model. J Orthop Res 2018; 36:1124-1134. [PMID: 28921615 DOI: 10.1002/jor.23740] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/26/2016] [Accepted: 09/13/2017] [Indexed: 02/04/2023]
Abstract
Plasticizer di(2-ethylhexyl)phthalate (DEHP) can leach from medical devices such as blood storage bags and the tubing. Recently, epidemiological studies showed that phthalate metabolites levels in the urine are associated with low bone mineral density (BMD) in older women. The detailed effect and mechanism of DEHP on osteoblastogenesis and adipogenesis, and bone loss remain to be clarified. Here, we investigated the effect and mechanism of DEHP and its active metabolite mono(2-ethylhexyl)phthalate (MEHP) on osteoblastogenesis and adipogenesis. The in vitro study showed that osteoblast differentiation of bone marrow stromal cells (BMSCs) was significantly and dose-dependently decreased by DEHP and MEHP (10-100 µM) without cytotoxicity to BMSCs. The mRNA expressions of alkaline phosphatase, Runx2, osteocalcin (OCN), Wnt1, and β-catenin were significantly decreased in DEHP- and MEHP-treated BMSCs during differentiation. MEHP, but not DEHP, significantly increased the adipocyte differentiation of BMSCs and PPARγ mRNA expression. Both DEHP and MEHP significantly increased the ratios of phosphorylated β-catenin/β-catenin and inhibited osteoblastogenesis, which could be reversed by Wnt activator lithium chloride and PPARγ inhibitor T0070907. Moreover, exposure of mice to DEHP (1, 10, and 100 mg/kg) for 8 weeks altered BMD and microstructure. In BMSCs isolated from DEHP-treated mice, osteoblastogenesis and Runx2, Wnt1, and β-catenin expression were decreased, but adipogenesis and PPARγ expression were increased. These findings suggest that DEHP and its metabolite MEHP exposure may inhibit osteoblastogenesis and promote adipogenesis of BMSCs through the Wnt/β-catenin-regulated and thus triggering bone loss. PPARγ signaling may play an important role in MEHP- and DEHP-induced suppression of osteogenesis. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1124-1134, 2018.
Collapse
Affiliation(s)
- Chen-Yuan Chiu
- Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan.,Department of Cell and Tissue Engineering, Changhua Christian Hospital, Changhua, Taiwan
| | - Shih-Chun Sun
- Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Chih-Kang Chiang
- Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan.,Departments of Integrated Diagnostics and Therapeutics and Internal Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Ching-Chia Wang
- Department of Pediatrics, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Ding-Cheng Chan
- Department of Geriatrics and Gerontology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Huang-Jen Chen
- Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Shing-Hwa Liu
- Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan.,Department of Pediatrics, College of Medicine, National Taiwan University, Taipei, Taiwan.,Department of Medical Research, China Medical University Hospital, China Medical University, Taichung, Taiwan
| | - Rong-Sen Yang
- Department of Orthopaedics, College of Medicine, National Taiwan University, Taipei, Taiwan
| |
Collapse
|
106
|
Brunt L, Scholpp S. The function of endocytosis in Wnt signaling. Cell Mol Life Sci 2018; 75:785-795. [PMID: 28913633 PMCID: PMC5809524 DOI: 10.1007/s00018-017-2654-2] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Revised: 08/17/2017] [Accepted: 09/06/2017] [Indexed: 10/31/2022]
Abstract
Wnt growth factors regulate one of the most important signaling networks during development, tissue homeostasis and disease. Despite the biological importance of Wnt signaling, the mechanism of endocytosis during this process is ill described. Wnt molecules can act as paracrine signals, which are secreted from the producing cells and transported through neighboring tissue to activate signaling in target cells. Endocytosis of the ligand is important at several stages of action: One central function of endocytic trafficking in the Wnt pathway occurs in the source cell. Furthermore, the β-catenin-dependent Wnt ligands require endocytosis for signal activation and to regulate gene transcription in the responding cells. Alternatively, Wnt/β-catenin-independent signaling regulates endocytosis of cell adherence plaques to control cell migration. In this comparative review, we elucidate these three fundamental interconnected functions, which together regulate cellular fate and cellular behavior. Based on established hypotheses and recent findings, we develop a revised picture for the complex function of endocytosis in the Wnt signaling network.
Collapse
Affiliation(s)
- Lucy Brunt
- Living Systems Institute, School of Biosciences, College of Life and Environmental Science, University of Exeter, Exeter, EX4 4QD, UK
| | - Steffen Scholpp
- Living Systems Institute, School of Biosciences, College of Life and Environmental Science, University of Exeter, Exeter, EX4 4QD, UK.
- Institute of Toxicology and Genetics (ITG), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany.
| |
Collapse
|
107
|
Tacchelly-Benites O, Wang Z, Yang E, Benchabane H, Tian A, Randall MP, Ahmed Y. Axin phosphorylation in both Wnt-off and Wnt-on states requires the tumor suppressor APC. PLoS Genet 2018; 14:e1007178. [PMID: 29408853 PMCID: PMC5800574 DOI: 10.1371/journal.pgen.1007178] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 12/30/2017] [Indexed: 12/24/2022] Open
Abstract
The aberrant activation of Wnt signal transduction initiates the development of 90% of colorectal cancers, the majority of which arise from inactivation of the tumor suppressor Adenomatous polyposis coli (APC). In the classical model for Wnt signaling, the primary role of APC is to act, together with the concentration-limiting scaffold protein Axin, in a “destruction complex” that directs the phosphorylation and consequent proteasomal degradation of the transcriptional activator β-catenin, thereby preventing signaling in the Wnt-off state. Following Wnt stimulation, Axin is recruited to a multiprotein “signalosome” required for pathway activation. Whereas it is well-documented that APC is essential in the destruction complex, APC’s role in this complex remains elusive. Here, we demonstrate in Drosophila that Axin exists in two distinct phosphorylation states in Wnt-off and Wnt-on conditions, respectively, that underlie its roles in the destruction complex and signalosome. These two Axin phosphorylation states are catalyzed by glycogen synthase kinase 3 (GSK3), and unexpectedly, completely dependent on APC in both unstimulated and Wnt-stimulated conditions. In a major revision of the classical model, we show that APC is essential not only in the destruction complex, but also for the rapid transition in Axin that occurs after Wnt stimulation and Axin’s subsequent association with the Wnt co-receptor LRP6/Arrow, one of the earliest steps in pathway activation. We propose that this novel requirement for APC in Axin regulation through phosphorylation both prevents signaling in the Wnt-off state and promotes signaling immediately following Wnt stimulation. The Wnt signal transduction pathway directs fundamental cellular processes during development and in homeostasis. Wnt signaling is deregulated in 90% of colorectal cancers, most of which are triggered by inactivation of the tumor suppressor Adenomatous polyposis coli (APC). In the classical model, APC’s sole role in Wnt signaling is to target the transcriptional coactivator β-catenin for phosphorylation and subsequent degradation, and thereby to inhibit signaling in the unstimulated state. However, the mechanisms by which APC functions remain unknown. Herein, we provide evidence in Drosophila that supports a major role for APC in the direct regulation of the scaffold protein Axin in both Wnt-on and Wnt-off conditions. Our results indicate that APC promotes Axin phosphorylation, which is required not only to inhibit signaling in the unstimulated state, but also to activate signaling following Wnt stimulation. These unanticipated findings support a more active and multifaceted role for APC in Wnt signaling than previously known, and force revision of the current model for APC function.
Collapse
Affiliation(s)
- Ofelia Tacchelly-Benites
- Department of Molecular and Systems Biology and the Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, Hanover, NH, United States of America
| | - Zhenghan Wang
- Department of Molecular and Systems Biology and the Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, Hanover, NH, United States of America
| | - Eungi Yang
- Department of Molecular and Systems Biology and the Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, Hanover, NH, United States of America
| | - Hassina Benchabane
- Department of Molecular and Systems Biology and the Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, Hanover, NH, United States of America
| | - Ai Tian
- Department of Molecular and Systems Biology and the Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, Hanover, NH, United States of America
| | - Michael P. Randall
- Department of Molecular and Systems Biology and the Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, Hanover, NH, United States of America
| | - Yashi Ahmed
- Department of Molecular and Systems Biology and the Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, Hanover, NH, United States of America
- * E-mail:
| |
Collapse
|
108
|
Higashimori A, Dong Y, Zhang Y, Kang W, Nakatsu G, Ng SSM, Arakawa T, Sung JJY, Chan FKL, Yu J. Forkhead Box F2 Suppresses Gastric Cancer through a Novel FOXF2-IRF2BPL-β-Catenin Signaling Axis. Cancer Res 2018; 78:1643-1656. [PMID: 29374064 DOI: 10.1158/0008-5472.can-17-2403] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 12/26/2017] [Accepted: 01/22/2018] [Indexed: 12/23/2022]
Abstract
DNA methylation has been identified as a hallmark of gastric cancer (GC). Identifying genes that are repressed by DNA promoter methylation is essential in providing insights into the molecular pathogenesis of gastric cancer. Using genome-wide methylation studies, we identified that transcription factor forkhead box F2 (FOXF2) was preferentially methylated in gastric cancer. We then investigated the functional significance and clinical implication of FOXF2 in gastric cancer. FOXF2 was silenced in gastric cancer cell lines and cancer tissues by promoter methylation, which was negatively associated with mRNA expression. Ectopic expression of FOXF2 inhibited proliferation, colony formation, G1-S cell-cycle transition, induced apoptosis of gastric cancer cell lines, and suppressed growth of xenograft tumors in nude mice; knockdown of FOXF2 elicited opposing effects. FOXF2 inhibited Wnt signaling by inducing β-catenin protein ubiquitination and degradation independently of GSK-3β. FOXF2 directly bound the promoter of E3 ligase interferon regulatory factor 2-binding protein-like (IRF2BPL) and induced its transcriptional expression. IRF2BPL in turn interacted with β-catenin, increasing its ubiquitination and degradation. Multivariate Cox regression analysis identified FOXF2 hypermethylation as an independent prognostic factor of poor survival in early-stage gastric cancer patients. In conclusion, FOXF2 is a critical tumor suppressor in gastric carcinogenesis whose methylation status serves as an independent prognostic factor for gastric cancer patients.Significance: FOXF2-mediated upregulation of the E3 ligase IRF2BPL drives ubiquitylation and degradation of β-catenin in gastric cancer, blunting Wnt signaling and suppressing carcinogenesis. Cancer Res; 78(7); 1643-56. ©2018 AACR.
Collapse
Affiliation(s)
- Akira Higashimori
- Institute of Digestive Disease and Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease and Li Ka Shing Institute of Health Sciences, Shenzhen Research Institute, The Chinese University of Hong Kong, Shatin, Hong Kong.,Department of Gastroenterology, Osaka City University Graduate School of Medicine, Abeno-ku, Osaka, Japan
| | - Yujuan Dong
- Institute of Digestive Disease and Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease and Li Ka Shing Institute of Health Sciences, Shenzhen Research Institute, The Chinese University of Hong Kong, Shatin, Hong Kong.,Department of Surgery, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Yanquan Zhang
- Institute of Digestive Disease and Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease and Li Ka Shing Institute of Health Sciences, Shenzhen Research Institute, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Wei Kang
- Department of Anatomical and Cellular Pathology, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Geicho Nakatsu
- Institute of Digestive Disease and Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease and Li Ka Shing Institute of Health Sciences, Shenzhen Research Institute, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Simon S M Ng
- Department of Surgery, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Tetsuo Arakawa
- Department of Gastroenterology, Osaka City University Graduate School of Medicine, Abeno-ku, Osaka, Japan
| | - Joseph J Y Sung
- Institute of Digestive Disease and Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease and Li Ka Shing Institute of Health Sciences, Shenzhen Research Institute, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Francis K L Chan
- Institute of Digestive Disease and Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease and Li Ka Shing Institute of Health Sciences, Shenzhen Research Institute, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Jun Yu
- Institute of Digestive Disease and Department of Medicine and Therapeutics, State Key Laboratory of Digestive Disease and Li Ka Shing Institute of Health Sciences, Shenzhen Research Institute, The Chinese University of Hong Kong, Shatin, Hong Kong.
| |
Collapse
|
109
|
Li M, Han Y, Zhou H, Li X, Lin C, Zhang E, Chi X, Hu J, Xu H. Transmembrane protein 170B is a novel breast tumorigenesis suppressor gene that inhibits the Wnt/β-catenin pathway. Cell Death Dis 2018; 9:91. [PMID: 29367600 PMCID: PMC5833782 DOI: 10.1038/s41419-017-0128-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 11/03/2017] [Accepted: 11/06/2017] [Indexed: 02/06/2023]
Abstract
The identification of specific drug targets guides the development of precise cancer treatments. Compared with oncogenes, tumor suppressor genes have been poorly studied in the treatment of breast cancer. We integrate the microRNA expression array from GEO (Gene Expression Omnibus) and TCGA (The Cancer Genome Atlas) databases in clinical breast cancer tissues, and find that miR-27a is significantly upregulated and correlated with poor survival outcome and tumor progression. Transmembrane protein 170B (TMEM170B), a new functional target of miR-27a, is identified via target prediction and experimental validation, suppressing breast cancer proliferation, metastasis, and tumorigenesis. Furthermore, TMEM170B overexpression promotes cytoplasmic β-catenin phosphorylation, resulting in the inhibition of β-catenin stabilization, reduction of nuclear β-catenin levels and downstream targets expression. Clinically, TMEM170B or β-catenin expression is significantly correlated with overall survival ratio in breast cancer patients. Thus, these results highlight TMEM170B as a novel tumor suppressor target in association with the β-catenin pathway, which may provide a new therapeutic approach for human breast cancer therapy.
Collapse
Affiliation(s)
- Mengwei Li
- The Engineering Research Center of Peptide Drug Discovery and Development, China Pharmaceutical University, Nanjing, 210009, China.,State Key Laboratory of Natural Medicines, Ministry of Education, China Pharmaceutical University, Nanjing, 210009, China
| | - Yanzhen Han
- The Engineering Research Center of Peptide Drug Discovery and Development, China Pharmaceutical University, Nanjing, 210009, China.,State Key Laboratory of Natural Medicines, Ministry of Education, China Pharmaceutical University, Nanjing, 210009, China
| | - Haoze Zhou
- The Engineering Research Center of Peptide Drug Discovery and Development, China Pharmaceutical University, Nanjing, 210009, China.,State Key Laboratory of Natural Medicines, Ministry of Education, China Pharmaceutical University, Nanjing, 210009, China
| | - Xin Li
- The Engineering Research Center of Peptide Drug Discovery and Development, China Pharmaceutical University, Nanjing, 210009, China.,State Key Laboratory of Natural Medicines, Ministry of Education, China Pharmaceutical University, Nanjing, 210009, China
| | - Chenyu Lin
- The Engineering Research Center of Peptide Drug Discovery and Development, China Pharmaceutical University, Nanjing, 210009, China.,State Key Laboratory of Natural Medicines, Ministry of Education, China Pharmaceutical University, Nanjing, 210009, China
| | - Erhao Zhang
- The Engineering Research Center of Peptide Drug Discovery and Development, China Pharmaceutical University, Nanjing, 210009, China.,State Key Laboratory of Natural Medicines, Ministry of Education, China Pharmaceutical University, Nanjing, 210009, China
| | - Xiaowei Chi
- The Engineering Research Center of Peptide Drug Discovery and Development, China Pharmaceutical University, Nanjing, 210009, China.,State Key Laboratory of Natural Medicines, Ministry of Education, China Pharmaceutical University, Nanjing, 210009, China
| | - Jialiang Hu
- The Engineering Research Center of Peptide Drug Discovery and Development, China Pharmaceutical University, Nanjing, 210009, China. .,State Key Laboratory of Natural Medicines, Ministry of Education, China Pharmaceutical University, Nanjing, 210009, China.
| | - Hanmei Xu
- The Engineering Research Center of Peptide Drug Discovery and Development, China Pharmaceutical University, Nanjing, 210009, China. .,State Key Laboratory of Natural Medicines, Ministry of Education, China Pharmaceutical University, Nanjing, 210009, China.
| |
Collapse
|
110
|
Krishnamurthy N, Kurzrock R. Targeting the Wnt/beta-catenin pathway in cancer: Update on effectors and inhibitors. Cancer Treat Rev 2018; 62:50-60. [PMID: 29169144 PMCID: PMC5745276 DOI: 10.1016/j.ctrv.2017.11.002] [Citation(s) in RCA: 755] [Impact Index Per Article: 107.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 11/01/2017] [Accepted: 11/03/2017] [Indexed: 12/17/2022]
Abstract
The Wnt/beta-catenin pathway is a family of proteins that is implicated in many vital cellular functions such as stem cell regeneration and organogenesis. Several intra-cellular signal transduction pathways are induced by Wnt, notably the Wnt/beta-catenin dependent pathway or canonical pathway and the non-canonical or beta-catenin-independent pathway; the latter includes the Wnt/Ca2+ and Planar Cell Polarity pathway (PCP). Wnt activation occurs at the intestinal crypt floor, and is critical to optimal maintenance of stem cells. Colorectal cancers show evidence of Wnt signaling pathway activation and this is associated with loss of function of the tumor regulator APC. Wnt activation has been observed in breast, lung, and hematopoietic malignancies and contributes to tumor recurrence. The Wnt pathway cross talks with the Notch and Sonic Hedgehog pathways, which has implications for therapeutic interventions in cancers. There are significant challenges in targeting the Wnt pathway, including finding agents that are efficacious without damaging the system of normal somatic stem cell function in cellular repair and tissue homeostasis. Here, we comprehensively review the Wnt pathway and its interactions with the Notch and Sonic Hedgehog pathways. We present the state of the field in effectors and inhibitors of Wnt signaling, including updates on clinical trials in various cancers with inhibitors of Wnt, Notch, and Sonic Hedgehog.
Collapse
Affiliation(s)
- Nithya Krishnamurthy
- Center for Personalized Cancer Therapy, UCSD Moores Cancer Center, University of California San Diego, La Jolla, CA, USA.
| | - Razelle Kurzrock
- Center for Personalized Cancer Therapy, UCSD Moores Cancer Center, University of California San Diego, La Jolla, CA, USA; Division of Hematology-Oncology, University of California San Diego, La Jolla, CA, USA
| |
Collapse
|
111
|
Zwamborn RA, Snijders C, An N, Thomson A, Rutten BP, de Nijs L. Wnt Signaling in the Hippocampus in Relation to Neurogenesis, Neuroplasticity, Stress and Epigenetics. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2018; 158:129-157. [DOI: 10.1016/bs.pmbts.2018.04.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
|
112
|
Solberg NT, Waaler J, Lund K, Mygland L, Olsen PA, Krauss S. TANKYRASE Inhibition Enhances the Antiproliferative Effect of PI3K and EGFR Inhibition, Mutually Affecting β-CATENIN and AKT Signaling in Colorectal Cancer. Mol Cancer Res 2017; 16:543-553. [DOI: 10.1158/1541-7786.mcr-17-0362] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 09/30/2017] [Accepted: 11/10/2017] [Indexed: 11/16/2022]
|
113
|
Mariotti L, Pollock K, Guettler S. Regulation of Wnt/β-catenin signalling by tankyrase-dependent poly(ADP-ribosyl)ation and scaffolding. Br J Pharmacol 2017; 174:4611-4636. [PMID: 28910490 PMCID: PMC5727255 DOI: 10.1111/bph.14038] [Citation(s) in RCA: 102] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 07/28/2017] [Accepted: 08/07/2017] [Indexed: 12/24/2022] Open
Abstract
The Wnt/β-catenin signalling pathway is pivotal for stem cell function and the control of cellular differentiation, both during embryonic development and tissue homeostasis in adults. Its activity is carefully controlled through the concerted interactions of concentration-limited pathway components and a wide range of post-translational modifications, including phosphorylation, ubiquitylation, sumoylation, poly(ADP-ribosyl)ation (PARylation) and acetylation. Regulation of Wnt/β-catenin signalling by PARylation was discovered relatively recently. The PARP tankyrase PARylates AXIN1/2, an essential central scaffolding protein in the β-catenin destruction complex, and targets it for degradation, thereby fine-tuning the responsiveness of cells to the Wnt signal. The past few years have not only seen much progress in our understanding of the molecular mechanisms by which PARylation controls the pathway but also witnessed the successful development of tankyrase inhibitors as tool compounds and promising agents for the therapy of Wnt-dependent dysfunctions, including colorectal cancer. Recent work has hinted at more complex roles of tankyrase in Wnt/β-catenin signalling as well as challenges and opportunities in the development of tankyrase inhibitors. Here we review some of the latest advances in our understanding of tankyrase function in the pathway and efforts to modulate tankyrase activity to re-tune Wnt/β-catenin signalling in colorectal cancer cells. 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.
Collapse
Affiliation(s)
- Laura Mariotti
- Division of Structural BiologyThe Institute of Cancer ResearchLondonUK
- Division of Cancer BiologyThe Institute of Cancer ResearchLondonUK
| | - Katie Pollock
- Division of Structural BiologyThe Institute of Cancer ResearchLondonUK
- Division of Cancer BiologyThe Institute of Cancer ResearchLondonUK
- Division of Cancer TherapeuticsThe Institute of Cancer ResearchLondonUK
| | - Sebastian Guettler
- Division of Structural BiologyThe Institute of Cancer ResearchLondonUK
- Division of Cancer BiologyThe Institute of Cancer ResearchLondonUK
| |
Collapse
|
114
|
Lu Y, Xie S, Zhang W, Zhang C, Gao C, Sun Q, Cai Y, Xu Z, Xiao M, Xu Y, Huang X, Wu X, Liu W, Wang F, Kang Y, Zhou T. Twa1/Gid8 is a β-catenin nuclear retention factor in Wnt signaling and colorectal tumorigenesis. Cell Res 2017; 27:1422-1440. [PMID: 28829046 PMCID: PMC5717399 DOI: 10.1038/cr.2017.107] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 12/25/2016] [Accepted: 07/04/2017] [Indexed: 12/26/2022] Open
Abstract
Hyperactivation of Wnt/β-catenin signaling is one of the major causes of human colorectal cancer (CRC). A hallmark of Wnt signaling is the nuclear accumulation of β-catenin. Although β-catenin nuclear import and export have been widely investigated, the underlying mechanism of β-catenin's nuclear retention remains largely unknown. Here, we report that Twa1/Gid8 is a key nuclear retention factor for β-catenin during Wnt signaling and colorectal carcinogenesis. In the absence of Wnt, Twa1 exists together with β-catenin in the Axin complex and undergoes ubiquitination and degradation. Upon Wnt signaling, Twa1 translocates into the nucleus, where it binds and retains β-catenin. Depletion of Twa1 attenuates Wnt-stimulated gene expression, dorsal development of zebrafish embryos and xenograft tumor growth of CRC cells. Moreover, nuclear Twa1 is significantly upregulated in human CRC tissues, correlating with the nuclear accumulation of β-catenin and poor prognosis. Thus, our results identify Twa1 as a previously undescribed regulator of the Wnt pathway for promoting colorectal tumorigenesis by facilitating β-catenin nuclear retention.
Collapse
Affiliation(s)
- Yi Lu
- Department of Cell Biology and Program in Molecular Cell Biology, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, Zhejiang 310003, China
| | - Shanshan Xie
- Department of Cell Biology and Program in Molecular Cell Biology, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Wen Zhang
- Department of Cell Biology and Program in Molecular Cell Biology, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Cheng Zhang
- Department of Cell Biology and Program in Molecular Cell Biology, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Cheng Gao
- Department of Cell Biology and Program in Molecular Cell Biology, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Qiang Sun
- Department of Cell Biology and Program in Molecular Cell Biology, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Yuqi Cai
- Department of Cell Biology and Program in Molecular Cell Biology, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
- Current address: Division of Pulmonary Biology, Cincinnati Children's Hospital, Cincinnati, OH 45229, USA
| | - Zhangqi Xu
- Department of Cell Biology and Program in Molecular Cell Biology, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Min Xiao
- Department of Cell Biology and Program in Molecular Cell Biology, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Yanjun Xu
- Zhejiang Cancer Hospital, Hangzhou, Zhejiang 310022, China
| | - Xiao Huang
- Institute of Cellular and Developmental Biology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Ximei Wu
- Department of Cell Biology and Program in Molecular Cell Biology, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Wei Liu
- Department of Cell Biology and Program in Molecular Cell Biology, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, Zhejiang 310003, China
| | - Fudi Wang
- Department of Cell Biology and Program in Molecular Cell Biology, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, Zhejiang 310003, China
| | - Yibin Kang
- Department of Molecular Biology, Princeton University, Princeton, NJ 08540, USA
| | - Tianhua Zhou
- Department of Cell Biology and Program in Molecular Cell Biology, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, Zhejiang 310003, China
| |
Collapse
|
115
|
XAV939 Inhibits Intima Formation by Decreasing Vascular Smooth Muscle Cell Proliferation and Migration Through Blocking Wnt Signaling. J Cardiovasc Pharmacol 2017; 68:414-424. [PMID: 27525574 DOI: 10.1097/fjc.0000000000000427] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Excessive proliferation, migration, and oxidative stress of vascular smooth muscle cells (VSMCs) are key mechanisms involved in intima formation, which is the basic pathological process of in stent restenosis. This study aims at exploring the role of XAV939 in proliferation, migration, and reactive oxygen species (ROS) generation of VSMCs, and hence evaluating its effects on intima formation. METHODS Carotid artery ligation models for C57BL/6 mice were established and gave them different intervention: saline, XAV939, Axin2 overexpression adenovirus, and negative control adenovirus. The intima formation was assayed by intima area and intima/media ratio. To investigate the underlying mechanisms, primary rat VSMCs were cultured and treated with XAV939 and platelet-derived growth factor-BB. EdU, direct cell counting, cell wound-healing assay, and flow cytometry were used to measure proliferation, migration, cell cycle, apoptosis, and ROS generation of VSMCs, respectively. By Western blot, we examined proliferating cell nuclear antigen, Cyclin D1, Cyclin E, p21, β-actin, JNK, phosphorylated JNK, Axin2 and β-catenin expression. Immunofluorescence staining and confocal microscopy were conducted to detect translocation of β-catenin. RESULTS XAV939 inhibited intima formation, which was exhibited by the loss of intima area and I/M ratio and attenuated proliferation, migration, and ROS generation, as well as promoted cell cycle arrest of VSMCs. Specifically, XAV939 inhibited Wnt pathway. CONCLUSIONS XAV939 attenuates intima formation because of its inhibition of proliferation, migration, and apoptosis of VSMCs through suppression of Wnt signaling pathway.
Collapse
|
116
|
Hussain M, Xu C, Lu M, Wu X, Tang L, Wu X. Wnt/β-catenin signaling links embryonic lung development and asthmatic airway remodeling. Biochim Biophys Acta Mol Basis Dis 2017; 1863:3226-3242. [PMID: 28866134 DOI: 10.1016/j.bbadis.2017.08.031] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Revised: 08/10/2017] [Accepted: 08/29/2017] [Indexed: 12/23/2022]
Abstract
Embryonic lung development requires reciprocal endodermal-mesodermal interactions; mediated by various signaling proteins. Wnt/β-catenin is a signaling protein that exhibits the pivotal role in lung development, injury and repair while aberrant expression of Wnt/β-catenin signaling leads to asthmatic airway remodeling: characterized by hyperplasia and hypertrophy of airway smooth muscle cells, alveolar and vascular damage goblet cells metaplasia, and deposition of extracellular matrix; resulting in decreased lung compliance and increased airway resistance. The substantial evidence suggests that Wnt/β-catenin signaling links embryonic lung development and asthmatic airway remodeling. Here, we summarized the recent advances related to the mechanistic role of Wnt/β-catenin signaling in lung development, consequences of aberrant expression or deletion of Wnt/β-catenin signaling in expansion and progression of asthmatic airway remodeling, and linking early-impaired pulmonary development and airway remodeling later in life. Finally, we emphasized all possible recent potential therapeutic significance and future prospectives, that are adaptable for therapeutic intervention to treat asthmatic airway remodeling.
Collapse
Affiliation(s)
- Musaddique Hussain
- Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou City 310058, China; The Key Respiratory Drug Research Laboratory of China Food and Drug Administration, School of Medicine, Zhejiang University, Hangzhou City 310058, China.
| | - Chengyun Xu
- Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou City 310058, China; The Key Respiratory Drug Research Laboratory of China Food and Drug Administration, School of Medicine, Zhejiang University, Hangzhou City 310058, China
| | - Meiping Lu
- Department of Respiratory Medicine, the Affiliated Children Hospital, School of Medicine, Zhejiang University, Hangzhou City 310006, China
| | - Xiling Wu
- Department of Respiratory Medicine, the Affiliated Children Hospital, School of Medicine, Zhejiang University, Hangzhou City 310006, China.
| | - Lanfang Tang
- Department of Respiratory Medicine, the Affiliated Children Hospital, School of Medicine, Zhejiang University, Hangzhou City 310006, China
| | - Ximei Wu
- Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou City 310058, China; The Key Respiratory Drug Research Laboratory of China Food and Drug Administration, School of Medicine, Zhejiang University, Hangzhou City 310058, China.
| |
Collapse
|
117
|
Mah KM, Weiner JA. Regulation of Wnt signaling by protocadherins. Semin Cell Dev Biol 2017; 69:158-171. [PMID: 28774578 PMCID: PMC5586504 DOI: 10.1016/j.semcdb.2017.07.043] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 07/21/2017] [Accepted: 07/28/2017] [Indexed: 12/23/2022]
Abstract
The ∼70 protocadherins comprise the largest group within the cadherin superfamily. Their diversity, the complexity of the mechanisms through which their genes are regulated, and their many critical functions in nervous system development have engendered a growing interest in elucidating the intracellular signaling pathways through which they act. Recently, multiple protocadherins across several subfamilies have been implicated as modulators of Wnt signaling pathways, and through this as potential tumor suppressors. Here, we review the extant data on the regulation by protocadherins of Wnt signaling pathways and components, and highlight some key unanswered questions that could shape future research.
Collapse
Affiliation(s)
- Kar Men Mah
- Department of Biology, The University of Iowa, Iowa City, IA, USA.
| | - Joshua A Weiner
- Department of Biology, The University of Iowa, Iowa City, IA, USA; Department of Psychiatry, The University of Iowa, Iowa City, IA, USA; Iowa Neuroscience Institute, The University of Iowa, Iowa City, IA, USA.
| |
Collapse
|
118
|
Tortelote GG, Reis RR, de Almeida Mendes F, Abreu JG. Complexity of the Wnt/β‑catenin pathway: Searching for an activation model. Cell Signal 2017; 40:30-43. [PMID: 28844868 DOI: 10.1016/j.cellsig.2017.08.008] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 08/08/2017] [Accepted: 08/23/2017] [Indexed: 12/13/2022]
Abstract
Wnt signaling refers to a conserved signaling pathway, widely studied due to its roles in cellular communication, cell fate decisions, development and cancer. However, the exact mechanism underlying inhibition of the GSK phosphorylation towards β-catenin and activation of the pathway after biding of Wnt ligand to its cognate receptors at the plasma membrane remains unclear. Wnt target genes are widely spread over several animal phyla. They participate in a plethora of functions during the development of an organism, from axial specification, gastrulation and organogenesis all the way to regeneration and repair in adults. Temporal and spatial oncogenetic re-activation of Wnt signaling almost certainly leads to cancer. Wnt signaling components have been extensively studied as possible targets in anti-cancer therapies. In this review we will discuss one of the most intriguing questions in this field, that is how β-catenin, a major component in this pathway, escapes the destruction complex, gets stabilized in the cytosol and it is translocated to the nucleus where it acts as a co-transcription factor. Four major models have evolved during the past 20years. We dissected each of them along with current views and future perspectives on this pathway. This review will focus on the molecular mechanisms by which Wnt proteins modulate β-catenin cytoplasmic levels and the relevance of this pathway for the development and cancer.
Collapse
Affiliation(s)
- Giovane G Tortelote
- Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
| | - Renata R Reis
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Fabio de Almeida Mendes
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Jose Garcia Abreu
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
| |
Collapse
|
119
|
van Kappel EC, Maurice MM. Molecular regulation and pharmacological targeting of the β-catenin destruction complex. Br J Pharmacol 2017. [PMID: 28634996 PMCID: PMC5727331 DOI: 10.1111/bph.13922] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The β‐catenin destruction complex is a dynamic cytosolic multiprotein assembly that provides a key node in Wnt signalling regulation. The core components of the destruction complex comprise the scaffold proteins axin and adenomatous polyposis coli and the Ser/Thr kinases casein kinase 1 and glycogen synthase kinase 3. In unstimulated cells, the destruction complex efficiently drives degradation of the transcriptional coactivator β‐catenin, thereby preventing the activation of the Wnt/β‐catenin pathway. Mutational inactivation of the destruction complex is a major pathway in the pathogenesis of cancer. Here, we review recent insights in the regulation of the β‐catenin destruction complex, including newly identified interaction interfaces, regulatory elements and post‐translationally controlled mechanisms. In addition, we discuss how mutations in core destruction complex components deregulate Wnt signalling via distinct mechanisms and how these findings open up potential therapeutic approaches to restore destruction complex activity in cancer cells. 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
Collapse
Affiliation(s)
- Eline C van Kappel
- Department of Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Madelon M Maurice
- Department of Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| |
Collapse
|
120
|
Membrane Targeting of Disheveled Can Bypass the Need for Arrow/LRP5. Sci Rep 2017; 7:6934. [PMID: 28761148 PMCID: PMC5537288 DOI: 10.1038/s41598-017-04414-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 05/15/2017] [Indexed: 12/03/2022] Open
Abstract
The highly conserved Wnt signaling pathway regulates cell proliferation and differentiation in vertebrates and invertebrates. Upon binding of a Wnt ligand to a receptor of the Fz family, Disheveled (Dsh/Dvl) transduces the signal during canonical and non-canonical Wnt signaling. The specific details of how this process occurs have proven difficult to study, especially as Dsh appears to function as a switch between different branches of Wnt signaling. Here we focus on the membrane-proximal events that occur once Dsh is recruited to the membrane. We show that membrane-tethering of the Dsh protein is sufficient to induce canonical Wnt signaling activation even in the absence of the Wnt co-receptor Arrow/LRP5/6. We map the protein domains required for pathway activation in membrane tethered constructs finding that both the DEP and PDZ domains are dispensable for canonical signaling only in membrane-tethered Dsh, but not in untethered/normal Dsh. These data lead to a signal activation model, where Arrow is required to localize Dsh to the membrane during canonical Wnt signaling placing Dsh downstream of Arrow.
Collapse
|
121
|
Yi JJ, Paranjape SR, Walker MP, Choudhury R, Wolter JM, Fragola G, Emanuele MJ, Major MB, Zylka MJ. The autism-linked UBE3A T485A mutant E3 ubiquitin ligase activates the Wnt/β-catenin pathway by inhibiting the proteasome. J Biol Chem 2017; 292:12503-12515. [PMID: 28559284 PMCID: PMC5535025 DOI: 10.1074/jbc.m117.788448] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 05/23/2017] [Indexed: 02/02/2023] Open
Abstract
UBE3A is a HECT domain E3 ubiquitin ligase whose dysfunction is linked to autism, Angelman syndrome, and cancer. Recently, we characterized a de novo autism-linked UBE3A mutant (UBE3AT485A) that disrupts phosphorylation control of UBE3A activity. Through quantitative proteomics and reporter assays, we found that the UBE3AT485A protein ubiquitinates multiple proteasome subunits, reduces proteasome subunit abundance and activity, stabilizes nuclear β-catenin, and stimulates canonical Wnt signaling more effectively than wild-type UBE3A. We also found that UBE3AT485A activates Wnt signaling to a greater extent in cells with low levels of ongoing Wnt signaling, suggesting that cells with low basal Wnt activity are particularly vulnerable to UBE3AT485A mutation. Ligase-dead UBE3A did not stimulate Wnt pathway activation. Overexpression of several proteasome subunits reversed the effect of UBE3AT485A on Wnt signaling. We also observed that subunits that interact with UBE3A and affect Wnt signaling are located along one side of the 19S regulatory particle, indicating a previously unrecognized spatial organization to the proteasome. Altogether, our findings indicate that UBE3A regulates Wnt signaling in a cell context-dependent manner and that an autism-linked mutation exacerbates these signaling effects. Our study has broad implications for human disorders associated with UBE3A gain or loss of function and suggests that dysfunctional UBE3A might affect additional proteins and pathways that are sensitive to proteasome activity.
Collapse
Affiliation(s)
- Jason J Yi
- Department of Neuroscience, Washington University School of Medicine, Saint Louis, Missouri 63110
| | - Smita R Paranjape
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, North Carolina 27599; UNC Neuroscience Center, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Matthew P Walker
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, North Carolina 27599; Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Rajarshi Choudhury
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599; Department of Pharmacology, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Justin M Wolter
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, North Carolina 27599; UNC Neuroscience Center, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Giulia Fragola
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, North Carolina 27599; UNC Neuroscience Center, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Michael J Emanuele
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599; Department of Pharmacology, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Michael B Major
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, North Carolina 27599; Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Mark J Zylka
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, North Carolina 27599; UNC Neuroscience Center, University of North Carolina, Chapel Hill, North Carolina 27599; Carolina Institute for Developmental Disabilities, University of North Carolina, Chapel Hill, North Carolina 27599.
| |
Collapse
|
122
|
Wnt/β-Catenin Signaling, Disease, and Emerging Therapeutic Modalities. Cell 2017; 169:985-999. [PMID: 28575679 DOI: 10.1016/j.cell.2017.05.016] [Citation(s) in RCA: 3052] [Impact Index Per Article: 381.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 05/07/2017] [Accepted: 05/09/2017] [Indexed: 12/13/2022]
Abstract
The WNT signal transduction cascade is a main regulator of development throughout the animal kingdom. Wnts are also key drivers of most types of tissue stem cells in adult mammals. Unsurprisingly, mutated Wnt pathway components are causative to multiple growth-related pathologies and to cancer. Here, we describe the core Wnt/β-catenin signaling pathway, how it controls stem cells, and contributes to disease. Finally, we discuss strategies for Wnt-based therapies.
Collapse
|
123
|
Kjolby RAS, Harland RM. Genome-wide identification of Wnt/β-catenin transcriptional targets during Xenopus gastrulation. Dev Biol 2017; 426:165-175. [PMID: 27091726 PMCID: PMC6288011 DOI: 10.1016/j.ydbio.2016.03.021] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 03/16/2016] [Accepted: 03/16/2016] [Indexed: 10/21/2022]
Abstract
The canonical Wnt/β-catenin signaling pathway plays multiple roles during Xenopus gastrulation, including posteriorization of the neural plate, patterning of the mesoderm, and induction of the neural crest. Wnt signaling stabilizes β-catenin, which then activates target genes. However, few targets of this signaling pathway that mediate early developmental processes are known. Here we sought to identify transcriptional targets of the Wnt/β-catenin signaling pathway using a genome-wide approach. We selected putative targets using the criteria of reduced expression upon zygotic Wnt knockdown, β-catenin binding within 50kb of the gene, and expression in tissues that receive Wnt signaling. Using these criteria, we found 21 novel direct transcriptional targets of Wnt/β-catenin signaling during gastrulation and in addition have identified putative regulatory elements for further characterization in future studies.
Collapse
Affiliation(s)
- Rachel A S Kjolby
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Richard M Harland
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA.
| |
Collapse
|
124
|
Alldredge A, Fuhrmann S. Loss of Axin2 Causes Ocular Defects During Mouse Eye Development. Invest Ophthalmol Vis Sci 2017; 57:5253-5262. [PMID: 27701636 PMCID: PMC5054732 DOI: 10.1167/iovs.15-18599] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose The scaffold protein Axin2 is an antagonist and universal target of the Wnt/β-catenin pathway. Disruption of Axin2 may lead to developmental eye defects; however, this has not been examined. The purpose of this study was to investigate the role of Axin2 during ocular and extraocular development in mouse. Methods Animals heterozygous and homozygous for a Axin2lacZ knock-in allele were analyzed at different developmental stages for reporter expression, morphology as well as for the presence of ocular and extraocular markers using histologic and immunohistochemical techniques. Results During early eye development, the Axin2lacZ reporter was expressed in the periocular mesenchyme, RPE, and optic stalk. In the developing retina, Axin2lacZ reporter expression was initiated in ganglion cells at late embryonic stages and robustly expressed in subpopulations of amacrine and horizontal cells postnatally. Activation of the Axin2lacZ reporter overlapped with labeling of POU4F1, PAX6, and Calbindin. Germline deletion of Axin2 led to variable ocular phenotypes ranging from normal to severely defective eyes exhibiting microphthalmia, coloboma, lens defects, and expanded ciliary margin. These defects were correlated with abnormal tissue patterning in individual affected tissues, such as the optic fissure margins in the ventral optic cup and in the expanded ciliary margin. Conclusions Our results reveal a critical role for Axin2 during ocular development, likely by restricting the activity of the Wnt/β-catenin pathway.
Collapse
Affiliation(s)
- Ashley Alldredge
- Department of Ophthalmology and Visual Sciences, Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Sabine Fuhrmann
- Department of Ophthalmology and Visual Sciences, Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| |
Collapse
|
125
|
Alok A, Lei Z, Jagannathan NS, Kaur S, Harmston N, Rozen SG, Tucker-Kellogg L, Virshup DM. Wnt proteins synergize to activate β-catenin signaling. J Cell Sci 2017; 130:1532-1544. [PMID: 28289266 DOI: 10.1242/jcs.198093] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 03/07/2017] [Indexed: 12/31/2022] Open
Abstract
Wnt ligands are involved in diverse signaling pathways that are active during development, maintenance of tissue homeostasis and in various disease states. While signaling regulated by individual Wnts has been extensively studied, Wnts are rarely expressed alone, and the consequences of Wnt gene co-expression are not well understood. Here, we studied the effect of co-expression of Wnts on the β-catenin signaling pathway. While some Wnts are deemed 'non-canonical' due to their limited ability to activate β-catenin when expressed alone, unexpectedly, we find that multiple Wnt combinations can synergistically activate β-catenin signaling in multiple cell types. WNT1- and WNT7B-mediated synergistic Wnt signaling requires FZD5, FZD8 and LRP6, as well as the WNT7B co-receptors GPR124 (also known as ADGRA2) and RECK. Unexpectedly, this synergistic signaling occurs downstream of β-catenin stabilization, and is correlated with increased lysine acetylation of β-catenin. Wnt synergy provides a general mechanism to confer increased combinatorial control over this important regulatory pathway.
Collapse
Affiliation(s)
- Anshula Alok
- Programme in Cancer and Stem Cell Biology, Duke-NUS Medical School, 169857 Singapore
| | - Zhengdeng Lei
- Programme in Cancer and Stem Cell Biology, Duke-NUS Medical School, 169857 Singapore.,Centre for Computational Biology, Duke-NUS Medical School, 169857 Singapore
| | - N Suhas Jagannathan
- Programme in Cancer and Stem Cell Biology, Duke-NUS Medical School, 169857 Singapore.,Centre for Computational Biology, Duke-NUS Medical School, 169857 Singapore
| | - Simran Kaur
- Programme in Cancer and Stem Cell Biology, Duke-NUS Medical School, 169857 Singapore
| | - Nathan Harmston
- Centre for Computational Biology, Duke-NUS Medical School, 169857 Singapore
| | - Steven G Rozen
- Programme in Cancer and Stem Cell Biology, Duke-NUS Medical School, 169857 Singapore.,Centre for Computational Biology, Duke-NUS Medical School, 169857 Singapore
| | - Lisa Tucker-Kellogg
- Programme in Cancer and Stem Cell Biology, Duke-NUS Medical School, 169857 Singapore.,Centre for Computational Biology, Duke-NUS Medical School, 169857 Singapore
| | - David M Virshup
- Programme in Cancer and Stem Cell Biology, Duke-NUS Medical School, 169857 Singapore .,Department of Pediatrics, Duke University School of Medicine, Durham, NC, USA
| |
Collapse
|
126
|
Duñach M, Del Valle-Pérez B, García de Herreros A. p120-catenin in canonical Wnt signaling. Crit Rev Biochem Mol Biol 2017; 52:327-339. [PMID: 28276699 DOI: 10.1080/10409238.2017.1295920] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Canonical Wnt signaling controls β-catenin protein stabilization, its translocation to the nucleus and the activation of β-catenin/Tcf-4-dependent transcription. In this review, we revise and discuss the recent results describing actions of p120-catenin in different phases of this pathway. More specifically, we comment its involvement in four different steps: (i) the very early activation of CK1ɛ, essential for Dvl-2 binding to the Wnt receptor complex; (ii) the internalization of GSK3 and Axin into multivesicular bodies, necessary for a complete stabilization of β-catenin; (iii) the activation of Rac1 small GTPase, required for β-catenin translocation to the nucleus; and (iv) the release of the inhibitory action caused by Kaiso transcriptional repressor. We integrate these new results with the previously known action of other elements in this pathway, giving a particular relevance to the responses of the Wnt pathway not required for β-catenin stabilization but for β-catenin transcriptional activity. Moreover, we discuss the possible future implications, suggesting that the two cellular compartments where β-catenin is localized, thus, the adherens junction complex and the Wnt signalosome, are more physically connected that previously thought.
Collapse
Affiliation(s)
- Mireia Duñach
- a Departament de Bioquímica i Biologia Molecular, CEB, Facultat de Medicina , Universitat Autònoma de Barcelona , Bellaterra , Spain
| | - Beatriz Del Valle-Pérez
- a Departament de Bioquímica i Biologia Molecular, CEB, Facultat de Medicina , Universitat Autònoma de Barcelona , Bellaterra , Spain
| | - Antonio García de Herreros
- b Programa de Recerca en Càncer , Institut Hospital del Mar d'Investigacions Mèdiques (IMIM) , Barcelona , Spain.,c Departament de Ciències Experimentals i de la Salut , Universitat Pompeu Fabra , Barcelona , Spain
| |
Collapse
|
127
|
Abstract
Glycogen synthase kinase-3 (GSK-3) is a ubiquitously expressed protein kinase that sits at the nexus of multiple signaling pathways. Its deep integration into cellular control circuits is consummate to its implication in diseases ranging from mood disorders to diabetes to neurodegenerative diseases and cancers. The selectivity and insulation of such a promiscuous kinase from unwanted crosstalk between pathways, while orchestrating a multifaceted response to cellular stimuli, offer key insights into more general mechanisms of cell regulation. Here, we review recent advances that have contributed to the understanding of GSK-3 and its role in driving appreciation of intracellular signal coordination.
Collapse
Affiliation(s)
- Kevin W Cormier
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, 600 University Avenue, Toronto, ON, M5G 1X5, Canada
| | - James R Woodgett
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, 600 University Avenue, Toronto, ON, M5G 1X5, Canada
| |
Collapse
|
128
|
Morrow KA, Das S, Meng E, Menezes ME, Bailey SK, Metge BJ, Buchsbaum DJ, Samant RS, Shevde LA. Loss of tumor suppressor Merlin results in aberrant activation of Wnt/β-catenin signaling in cancer. Oncotarget 2017; 7:17991-8005. [PMID: 26908451 PMCID: PMC4951266 DOI: 10.18632/oncotarget.7494] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 02/11/2016] [Indexed: 11/25/2022] Open
Abstract
The expression of the tumor suppressor Merlin is compromised in nervous system malignancies due to genomic aberrations. We demonstrated for the first time, that in breast cancer, Merlin protein expression is lost due to proteasome-mediated elimination. Immunohistochemical analysis of tumor tissues from patients with metastatic breast cancer revealed characteristically reduced Merlin expression. Importantly, we identified a functional role for Merlin in impeding breast tumor xenograft growth and reducing invasive characteristics. We sought to determine a possible mechanism by which Merlin accomplishes this reduction in malignant activity. We observed that breast and pancreatic cancer cells with loss of Merlin show an aberrant increase in the activity of β-catenin concomitant with nuclear localization of β-catenin. We discovered that Merlin physically interacts with β-catenin, alters the sub-cellular localization of β-catenin, and significantly reduces the protein levels of β-catenin by targeting it for degradation through the upregulation of Axin1. Consequently, restoration of Merlin inhibited β-catenin-mediated transcriptional activity in breast and pancreatic cancer cells. We also present evidence that loss of Merlin sensitizes tumor cells to inhibition by compounds that target β-catenin-mediated activity. Thus, this study provides compelling evidence that Merlin reduces the malignant activity of pancreatic and breast cancer, in part by suppressing the Wnt/β-catenin pathway. Given the potent role of Wnt/β-catenin signaling in breast and pancreatic cancer and the flurry of activity to test β-catenin inhibitors in the clinic, our findings are opportune and provide evidence for Merlin in restraining aberrant activation of Wnt/β-catenin signaling.
Collapse
Affiliation(s)
- K Adam Morrow
- Mitchell Cancer Institute, University of South Alabama, Mobile, AL, USA
| | - Shamik Das
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Erhong Meng
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
| | | | - Sarah K Bailey
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Brandon J Metge
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Donald J Buchsbaum
- Department of Radiation Oncology, University of Alabama at Birmingham, Birmingham, AL, USA.,Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Rajeev S Samant
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA.,Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Lalita A Shevde
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA.,Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL, USA
| |
Collapse
|
129
|
Houston DW. Vertebrate Axial Patterning: From Egg to Asymmetry. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 953:209-306. [PMID: 27975274 PMCID: PMC6550305 DOI: 10.1007/978-3-319-46095-6_6] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The emergence of the bilateral embryonic body axis from a symmetrical egg has been a long-standing question in developmental biology. Historical and modern experiments point to an initial symmetry-breaking event leading to localized Wnt and Nodal growth factor signaling and subsequent induction and formation of a self-regulating dorsal "organizer." This organizer forms at the site of notochord cell internalization and expresses primarily Bone Morphogenetic Protein (BMP) growth factor antagonists that establish a spatiotemporal gradient of BMP signaling across the embryo, directing initial cell differentiation and morphogenesis. Although the basics of this model have been known for some time, many of the molecular and cellular details have only recently been elucidated and the extent that these events remain conserved throughout vertebrate evolution remains unclear. This chapter summarizes historical perspectives as well as recent molecular and genetic advances regarding: (1) the mechanisms that regulate symmetry-breaking in the vertebrate egg and early embryo, (2) the pathways that are activated by these events, in particular the Wnt pathway, and the role of these pathways in the formation and function of the organizer, and (3) how these pathways also mediate anteroposterior patterning and axial morphogenesis. Emphasis is placed on comparative aspects of the egg-to-embryo transition across vertebrates and their evolution. The future prospects for work regarding self-organization and gene regulatory networks in the context of early axis formation are also discussed.
Collapse
Affiliation(s)
- Douglas W Houston
- Department of Biology, The University of Iowa, 257 BB, Iowa City, IA, 52242, USA.
| |
Collapse
|
130
|
Lebensohn AM, Dubey R, Neitzel LR, Tacchelly-Benites O, Yang E, Marceau CD, Davis EM, Patel BB, Bahrami-Nejad Z, Travaglini KJ, Ahmed Y, Lee E, Carette JE, Rohatgi R. Comparative genetic screens in human cells reveal new regulatory mechanisms in WNT signaling. eLife 2016; 5. [PMID: 27996937 PMCID: PMC5257257 DOI: 10.7554/elife.21459] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 12/07/2016] [Indexed: 12/15/2022] Open
Abstract
The comprehensive understanding of cellular signaling pathways remains a challenge due to multiple layers of regulation that may become evident only when the pathway is probed at different levels or critical nodes are eliminated. To discover regulatory mechanisms in canonical WNT signaling, we conducted a systematic forward genetic analysis through reporter-based screens in haploid human cells. Comparison of screens for negative, attenuating and positive regulators of WNT signaling, mediators of R-spondin-dependent signaling and suppressors of constitutive signaling induced by loss of the tumor suppressor adenomatous polyposis coli or casein kinase 1α uncovered new regulatory features at most levels of the pathway. These include a requirement for the transcription factor AP-4, a role for the DAX domain of AXIN2 in controlling β-catenin transcriptional activity, a contribution of glycophosphatidylinositol anchor biosynthesis and glypicans to R-spondin-potentiated WNT signaling, and two different mechanisms that regulate signaling when distinct components of the β-catenin destruction complex are lost. The conceptual and methodological framework we describe should enable the comprehensive understanding of other signaling systems. DOI:http://dx.doi.org/10.7554/eLife.21459.001 When an embryo is developing, its cells must communicate with one another to coordinate the processes that shape the body’s tissues and organs. Cells often communicate by releasing signaling molecules that engage with proteins called receptors on the surface of other cells. This triggers a series of events that sends the signal along a “pathway” of biochemical reactions inside the receiving cell and leads to the activation of genes. One such signaling pathway is triggered by the WNT proteins and is used extensively in all animals. The WNT pathway instructs cells to grow and divide, establishes the identity of specific cell types and maintains populations of stem cells that can regenerate tissues in adulthood as well. The WNT pathway must be carefully regulated because various types of cancer can develop if the pathway becomes too active. Some signaling pathways are well conserved between different animals. Many genetic studies into the WNT pathway have focused on animals that are easier to work with in the laboratory, like worms or flies. However, there may be differences in the way these pathways are regulated between these model animals and humans. Therefore, to understand how the WNT pathway operates in humans, it was important to study it in human cells too. Lebensohn et al. have now carried out a series of genetic screens in human cells that contain only one copy of each gene instead of the usual two. These cells – referred to as haploid cells – are ideal for genetic studies because only a single copy of a gene has to be disrupted in order to analyze the consequences of that gene’s loss. The screens searched for genes that regulate WNT signaling: those that keep the pathway “off” in the absence of WNT and those that turn the pathway “on” in response to WNT. By comparing the outcomes of these screens, Lebensohn et al. identified previously unknown regulators and uncovered new roles for known regulators of the WNT pathway. For instance, a regulator called TFAP4, which had not previously been linked to the pathway, was shown to activate WNT signaling. In another case, enzymes that make molecules called glycophosphatidylinositol anchors, and cell-surface proteins that are modified with those anchors, were found to amplify WNT signaling. Lebensohn et al. also identified genes that were needed to sustain the uncontrolled WNT signaling in cells that carried cancer-causing mutations in this pathway. Further studies could now explore if drugs can target these genes, or the molecules encoded by them, to treat cancers in which the WNT pathway is excessively activated. Other studies could also use the same methods to explore more signaling pathways and gain new insights into important biological processes in human cells. DOI:http://dx.doi.org/10.7554/eLife.21459.002
Collapse
Affiliation(s)
- Andres M Lebensohn
- Department of Biochemistry, Stanford University School of Medicine, Stanford, United States.,Department of Medicine, Stanford University School of Medicine, Stanford, United States
| | - Ramin Dubey
- Department of Biochemistry, Stanford University School of Medicine, Stanford, United States.,Department of Medicine, Stanford University School of Medicine, Stanford, United States
| | - Leif R Neitzel
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, United States
| | - Ofelia Tacchelly-Benites
- Department of Molecular and Systems Biology and the Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, Hanover, United States
| | - Eungi Yang
- Department of Molecular and Systems Biology and the Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, Hanover, United States
| | - Caleb D Marceau
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, United States
| | - Eric M Davis
- Department of Molecular Cellular, and Developmental Biology, University of Colorado, Boulder, Boulder, United States
| | - Bhaven B Patel
- Department of Biochemistry, Stanford University School of Medicine, Stanford, United States.,Department of Medicine, Stanford University School of Medicine, Stanford, United States
| | - Zahra Bahrami-Nejad
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, United States
| | - Kyle J Travaglini
- Department of Biochemistry, Stanford University School of Medicine, Stanford, United States
| | - Yashi Ahmed
- Department of Molecular and Systems Biology and the Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, Hanover, United States
| | - Ethan Lee
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, United States
| | - Jan E Carette
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, United States
| | - Rajat Rohatgi
- Department of Biochemistry, Stanford University School of Medicine, Stanford, United States.,Department of Medicine, Stanford University School of Medicine, Stanford, United States
| |
Collapse
|
131
|
Wang Z, Tacchelly-Benites O, Yang E, Ahmed Y. Dual Roles for Membrane Association of Drosophila Axin in Wnt Signaling. PLoS Genet 2016; 12:e1006494. [PMID: 27959917 PMCID: PMC5154497 DOI: 10.1371/journal.pgen.1006494] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 11/17/2016] [Indexed: 12/25/2022] Open
Abstract
Deregulation of the Wnt signal transduction pathway underlies numerous congenital disorders and cancers. Axin, a concentration-limiting scaffold protein, facilitates assembly of a “destruction complex” that prevents signaling in the unstimulated state and a plasma membrane-associated “signalosome” that activates signaling following Wnt stimulation. In the classical model, Axin is cytoplasmic under basal conditions, but relocates to the cell membrane after Wnt exposure; however, due to the very low levels of endogenous Axin, this model is based largely on examination of Axin at supraphysiological levels. Here, we analyze the subcellular distribution of endogenous Drosophila Axin in vivo and find that a pool of Axin localizes to cell membrane proximal puncta even in the absence of Wnt stimulation. Axin localization in these puncta is dependent on the destruction complex component Adenomatous polyposis coli (Apc). In the unstimulated state, the membrane association of Axin increases its Tankyrase-dependent ADP-ribosylation and consequent proteasomal degradation to control its basal levels. Furthermore, Wnt stimulation does not result in a bulk redistribution of Axin from cytoplasmic to membrane pools, but causes an initial increase of Axin in both of these pools, with concomitant changes in two post-translational modifications, followed by Axin proteolysis hours later. Finally, the ADP-ribosylated Axin that increases rapidly following Wnt stimulation is membrane associated. We conclude that even in the unstimulated state, a pool of Axin forms membrane-proximal puncta that are dependent on Apc, and that membrane association regulates both Axin levels and Axin’s role in the rapid activation of signaling that follows Wnt exposure. Axin is a scaffold protein with essential roles in Wnt signal transduction. In the classical model, the transition from the unstimulated to stimulated state is thought to be achieved by recruitment of Axin from cytosol to plasma membrane. We find that a pool of endogenous Drosophila Axin is localized in puncta juxtaposed with the cell membrane even under basal conditions and is targeted for degradation by the ADP-ribose polymerase Tankyrase. Wnt stimulation initially results in increased Axin levels in both the cytosolic and membrane pools, which may enhance the robust activation of signaling.
Collapse
Affiliation(s)
- Zhenghan Wang
- Department of Molecular and Systems Biology and the Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, Hanover, NH, United States of America
| | - Ofelia Tacchelly-Benites
- Department of Molecular and Systems Biology and the Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, Hanover, NH, United States of America
| | - Eungi Yang
- Department of Molecular and Systems Biology and the Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, Hanover, NH, United States of America
| | - Yashi Ahmed
- Department of Molecular and Systems Biology and the Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth College, Hanover, NH, United States of America
- * E-mail:
| |
Collapse
|
132
|
Tanabe S, Kawabata T, Aoyagi K, Yokozaki H, Sasaki H. Gene expression and pathway analysis of CTNNB1 in cancer and stem cells. World J Stem Cells 2016; 8:384-395. [PMID: 27928465 PMCID: PMC5120243 DOI: 10.4252/wjsc.v8.i11.384] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 07/22/2016] [Accepted: 09/21/2016] [Indexed: 02/06/2023] Open
Abstract
AIM To investigate β-catenin (CTNNB1) signaling in cancer and stem cells, the gene expression and pathway were analyzed using bioinformatics. METHODS The expression of the catenin β 1 (CTNNB1) gene, which codes for β-catenin, was analyzed in mesenchymal stem cells (MSCs) and gastric cancer (GC) cells. Beta-catenin signaling and the mutation of related proteins were also analyzed using the cBioPortal for Cancer Genomics and HOMology modeling of Complex Structure (HOMCOS) databases. RESULTS The expression of the CTNNB1 gene was up-regulated in GC cells compared to MSCs. The expression of EPH receptor A8 (EPHA8), synovial sarcoma translocation chromosome 18 (SS18), interactor of little elongation complex ELL subunit 1 (ICE1), patched 1 (PTCH1), mutS homolog 3 (MSH3) and caspase recruitment domain family member 11 (CARD11) were also shown to be altered in GC cells in the cBioPortal for Cancer Genomics analysis. 3D complex structures were reported for E-cadherin 1 (CDH1), lymphoid enhancer binding factor 1 (LEF1), transcription factor 7 like 2 (TCF7L2) and adenomatous polyposis coli protein (APC) with β-catenin. CONCLUSION The results indicate that the epithelial-mesenchymal transition (EMT)-related gene CTNNB1 plays an important role in the regulation of stem cell pluripotency and cancer signaling.
Collapse
Affiliation(s)
- Shihori Tanabe
- Shihori Tanabe, Division of Risk Assessment, National Institute of Health Sciences, Tokyo 158-8501, Japan
| | - Takeshi Kawabata
- Shihori Tanabe, Division of Risk Assessment, National Institute of Health Sciences, Tokyo 158-8501, Japan
| | - Kazuhiko Aoyagi
- Shihori Tanabe, Division of Risk Assessment, National Institute of Health Sciences, Tokyo 158-8501, Japan
| | - Hiroshi Yokozaki
- Shihori Tanabe, Division of Risk Assessment, National Institute of Health Sciences, Tokyo 158-8501, Japan
| | - Hiroki Sasaki
- Shihori Tanabe, Division of Risk Assessment, National Institute of Health Sciences, Tokyo 158-8501, Japan
| |
Collapse
|
133
|
Lian G, Dettenhofer M, Lu J, Downing M, Chenn A, Wong T, Sheen V. Filamin A- and formin 2-dependent endocytosis regulates proliferation via the canonical Wnt pathway. Development 2016; 143:4509-4520. [PMID: 27789627 DOI: 10.1242/dev.139295] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 10/18/2016] [Indexed: 01/07/2023]
Abstract
Actin-associated proteins regulate multiple cellular processes, including proliferation and differentiation, but the molecular mechanisms underlying these processes are unclear. Here, we report that the actin-binding protein filamin A (FlnA) physically interacts with the actin-nucleating protein formin 2 (Fmn2). Loss of FlnA and Fmn2 impairs proliferation, thereby generating multiple embryonic phenotypes, including microcephaly. FlnA interacts with the Wnt co-receptor Lrp6. Loss of FlnA and Fmn2 impairs Lrp6 endocytosis, downstream Gsk3β activity, and β-catenin accumulation in the nucleus. The proliferative defect in Flna and Fmn2 null neural progenitors is rescued by inhibiting Gsk3β activity. Our findings thus reveal a novel mechanism whereby actin-associated proteins regulate proliferation by mediating the endocytosis and transportation of components in the canonical Wnt pathway. Moreover, the Fmn2-dependent signaling in this pathway parallels that seen in the non-canonical Wnt-dependent regulation of planar cell polarity through the Formin homology protein Daam. These studies provide evidence for integration of actin-associated processes in directing neuroepithelial proliferation.
Collapse
Affiliation(s)
- Gewei Lian
- Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02115, USA
| | - Markus Dettenhofer
- Central European Institute of Technology, Žerotínovo nám. 9, Brno 601 77, Czech Republic
| | - Jie Lu
- Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02115, USA
| | - Michael Downing
- Department of Pathology, University of Illinois College of Medicine, Chicago, IL 60612, USA
| | - Anjen Chenn
- Department of Pathology, University of Illinois College of Medicine, Chicago, IL 60612, USA
| | - Timothy Wong
- Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02115, USA
| | - Volney Sheen
- Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02115, USA
| |
Collapse
|
134
|
Abstract
WNK (With-No-Lysine (K)) kinases are serine-threonine kinases characterized by an atypical placement of a catalytic lysine within the kinase domain. Mutations in human WNK1 or WNK4 cause an autosomal dominant syndrome of hypertension and hyperkalemia, reflecting the fact that WNK kinases are critical regulators of renal ion transport processes. Here, the role of WNKs in the regulation of ion transport processes in vertebrate and invertebrate renal function, cellular and organismal osmoregulation, and cell migration and cerebral edema will be reviewed, along with emerging literature demonstrating roles for WNKs in cardiovascular and neural development, Wnt signaling, and cancer. Conserved roles for these kinases across phyla are emphasized.
Collapse
Affiliation(s)
| | - Andreas Jenny
- Albert Einstein College of Medicine, New York, NY, United States.
| |
Collapse
|
135
|
Noelanders R, Vleminckx K. How Wnt Signaling Builds the Brain: Bridging Development and Disease. Neuroscientist 2016; 23:314-329. [DOI: 10.1177/1073858416667270] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Wnt/β-catenin signaling plays a crucial role throughout all stages of brain development and remains important in the adult brain. Accordingly, many neurological disorders have been linked to Wnt signaling. Defects in Wnt signaling during neural development can give rise to birth defects or lead to neurological dysfunction later in life. Developmental signaling events can also be hijacked in the adult and result in disease. Moreover, knowledge about the physiological role of Wnt signaling in the brain might lead to new therapeutic strategies for neurological diseases. Especially, the important role for Wnt signaling in neural differentiation of pluripotent stem cells has received much attention as this might provide a cure for neurodegenerative disorders. In this review, we summarize the versatile role of Wnt/β-catenin signaling during neural development and discuss some recent studies linking Wnt signaling to neurological disorders.
Collapse
Affiliation(s)
- Rivka Noelanders
- Unit of Developmental Biology, Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Kris Vleminckx
- Unit of Developmental Biology, Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| |
Collapse
|
136
|
Wnt Signaling in Cell Motility and Invasion: Drawing Parallels between Development and Cancer. Cancers (Basel) 2016; 8:cancers8090080. [PMID: 27589803 PMCID: PMC5040982 DOI: 10.3390/cancers8090080] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 08/09/2016] [Accepted: 08/22/2016] [Indexed: 12/12/2022] Open
Abstract
The importance of canonical and non-canonical Wnt signal transduction cascades in embryonic development and tissue homeostasis is well recognized. The aberrant activation of these pathways in the adult leads to abnormal cellular behaviors, and tumor progression is frequently a consequence. Here we discuss recent findings and analogies between Wnt signaling in developmental processes and tumor progression, with a particular focus on cell motility and matrix invasion and highlight the roles of the ARF (ADP-Ribosylation Factor) and Rho-family small GTP-binding proteins. Wnt-regulated signal transduction from cell surface receptors, signaling endosomes and/or extracellular vesicles has the potential to profoundly influence cell movement, matrix degradation and paracrine signaling in both development and disease.
Collapse
|
137
|
Mah KM, Houston DW, Weiner JA. The γ-Protocadherin-C3 isoform inhibits canonical Wnt signalling by binding to and stabilizing Axin1 at the membrane. Sci Rep 2016; 6:31665. [PMID: 27530555 PMCID: PMC4987702 DOI: 10.1038/srep31665] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 07/21/2016] [Indexed: 01/14/2023] Open
Abstract
The 22 γ-Protocadherin (γ-Pcdh) adhesion molecules encoded by the Pcdhg gene cluster play critical roles in nervous system development, including regulation of dendrite arborisation, neuronal survival, and synaptogenesis. Recently, they have been implicated in suppression of tumour cell growth by inhibition of canonical Wnt signalling, though the mechanisms through which this occurs remain unknown. Here, we show differential regulation of Wnt signalling by individual γ-Pcdhs: The C3 isoform uniquely inhibits the pathway, whilst 13 other isoforms upregulate signalling. Focusing on the C3 isoform, we show that its unique variable cytoplasmic domain (VCD) is the critical one for Wnt pathway inhibition. γ-Pcdh-C3, but not other isoforms, physically interacts with Axin1, a key component of the canonical Wnt pathway. The C3 VCD competes with Dishevelled for binding to the DIX domain of Axin1, which stabilizes Axin1 at the membrane and leads to reduced phosphorylation of Wnt co-receptor Lrp6. Finally, we present evidence that Wnt pathway activity can be modulated up (by γ-Pcdh-A1) or down (by γ-Pcdh-C3) in the cerebral cortex in vivo, using conditional transgenic alleles. Together, these data delineate opposing roles for γ-Pcdh isoforms in regulating Wnt signalling and identify Axin1 as a novel protein interactor of the widely-expressed γ-Pcdh-C3 isoform.
Collapse
Affiliation(s)
- Kar Men Mah
- Department of Biology, The University of Iowa, 143 Biology Building, Iowa City, 52242, IA, USA.,Integrated Biology Graduate Program, The University of Iowa, 143 Biology Building, Iowa City,52242, IA, USA
| | - Douglas W Houston
- Department of Biology, The University of Iowa, 143 Biology Building, Iowa City, 52242, IA, USA
| | - Joshua A Weiner
- Department of Biology, The University of Iowa, 143 Biology Building, Iowa City, 52242, IA, USA.,Department of Psychiatry, University of Iowa Carver College of Medicine, 200 Hawkins Drive, Iowa City, 52242, IA, USA
| |
Collapse
|
138
|
Hrckulak D, Kolar M, Strnad H, Korinek V. TCF/LEF Transcription Factors: An Update from the Internet Resources. Cancers (Basel) 2016; 8:cancers8070070. [PMID: 27447672 PMCID: PMC4963812 DOI: 10.3390/cancers8070070] [Citation(s) in RCA: 118] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 07/11/2016] [Accepted: 07/14/2016] [Indexed: 12/18/2022] Open
Abstract
T-cell factor/lymphoid enhancer-binding factor (TCF/LEF) proteins (TCFs) from the High Mobility Group (HMG) box family act as the main downstream effectors of the Wnt signaling pathway. The mammalian TCF/LEF family comprises four nuclear factors designated TCF7, LEF1, TCF7L1, and TCF7L2 (also known as TCF1, LEF1, TCF3, and TCF4, respectively). The proteins display common structural features and are often expressed in overlapping patterns implying their redundancy. Such redundancy was indeed observed in gene targeting studies; however, individual family members also exhibit unique features that are not recapitulated by the related proteins. In the present viewpoint, we summarized our current knowledge about the specific features of individual TCFs, namely structural-functional studies, posttranslational modifications, interacting partners, and phenotypes obtained upon gene targeting in the mouse. In addition, we employed several publicly available databases and web tools to evaluate the expression patterns and production of gene-specific isoforms of the TCF/LEF family members in human cells and tissues.
Collapse
Affiliation(s)
- Dusan Hrckulak
- Department of Cell and Developmental Biology, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Videnska 1083, Prague 4 14220, Czech Republic.
| | - Michal Kolar
- Department of Genomics and Bioinformatics, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Videnska 1083, Prague 4 14220, Czech Republic.
| | - Hynek Strnad
- Department of Genomics and Bioinformatics, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Videnska 1083, Prague 4 14220, Czech Republic.
| | - Vladimir Korinek
- Department of Cell and Developmental Biology, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Videnska 1083, Prague 4 14220, Czech Republic.
| |
Collapse
|
139
|
Chen YW, Ho CC, Huang TH, Hsu TT, Shie MY. The Ionic Products from Mineral Trioxide Aggregate–induced Odontogenic Differentiation of Dental Pulp Cells via Activation of the Wnt/β-catenin Signaling Pathway. J Endod 2016; 42:1062-9. [DOI: 10.1016/j.joen.2016.04.019] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 04/11/2016] [Accepted: 04/28/2016] [Indexed: 12/15/2022]
|
140
|
Yue Q, Zhang Y, Li X, He L, Hu Y, Wang X, Xu X, Shen Y, Zhang H. MiR-124 suppresses the chemotactic migration of rat mesenchymal stem cells toward HGF by downregulating Wnt/β-catenin signaling. Eur J Cell Biol 2016; 95:342-53. [PMID: 27377850 DOI: 10.1016/j.ejcb.2016.06.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 05/18/2016] [Accepted: 06/18/2016] [Indexed: 12/14/2022] Open
Abstract
Mesenchymal stem cells (MSCs) exhibit the potential to repair a wide variety of injured adult tissues. The migration capability of MSCs is an important determinant of the efficiency of MSC transplant therapy. MicroRNAs (miRNAs) are increasingly implicated in regulating the migration of MSCs. Herein, we show that the expression of miR-124 was downregulated in rat MSCs (rMSCs) treated with hepatocyte growth factor (HGF). Overexpression of miR-124 significantly reduced the chemotactic migration of rMSCs toward HGF, while inhibition of endogenous miR-124 promoted the chemotactic migration. A further study revealed that miR-124 directly targeted FZD4 and LRP6, which encode a receptor and co-receptor of the Wnt/β-catenin signaling pathway, respectively, thus reducing the activity of this signaling. Consistently, activation of the Wnt/β-catenin signaling pathway by LiCl and ΔN89β-catenin rescued the inhibitory effect of miR-124 on the chemotactic migration of rMSCs toward HGF, while inhibition of Wnt/β-catenin signaling by FH535 abrogated the enhanced chemotactic response achieved by the miR-124 inhibitor. Collectively, our study demonstrates that miR-124 downregulates Wnt/β-catenin signaling via targeting FZD4 and LRP6 and thus suppresses the chemotactic migration of rMSCs toward HGF.
Collapse
Affiliation(s)
- Qing Yue
- Department of Cell Biology, Jiangsu Key Laboratory of Stem Cell Research, Medical College of Soochow University, Suzhou 215123, China
| | - Yu Zhang
- Department of Orthopedics, the Second Affiliated Hospital of Soochow University, Suzhou Jiangsu, China
| | - Xianyang Li
- Department of Cell Biology, Jiangsu Key Laboratory of Stem Cell Research, Medical College of Soochow University, Suzhou 215123, China
| | - Lihong He
- Department of Cell Biology, Jiangsu Key Laboratory of Stem Cell Research, Medical College of Soochow University, Suzhou 215123, China
| | - Ya'nan Hu
- Department of Cell Biology, Jiangsu Key Laboratory of Stem Cell Research, Medical College of Soochow University, Suzhou 215123, China
| | - Xianyao Wang
- Department of Cell Biology, Jiangsu Key Laboratory of Stem Cell Research, Medical College of Soochow University, Suzhou 215123, China
| | - Xiaojing Xu
- Department of Cell Biology, Jiangsu Key Laboratory of Stem Cell Research, Medical College of Soochow University, Suzhou 215123, China
| | - Yixin Shen
- Department of Orthopedics, the Second Affiliated Hospital of Soochow University, Suzhou Jiangsu, China
| | - Huanxiang Zhang
- Department of Cell Biology, Jiangsu Key Laboratory of Stem Cell Research, Medical College of Soochow University, Suzhou 215123, China.
| |
Collapse
|
141
|
A Myc-driven self-reinforcing regulatory network maintains mouse embryonic stem cell identity. Nat Commun 2016; 7:11903. [PMID: 27301576 PMCID: PMC4912626 DOI: 10.1038/ncomms11903] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 05/10/2016] [Indexed: 01/09/2023] Open
Abstract
Stem cell identity depends on the integration of extrinsic and intrinsic signals, which directly influence the maintenance of their epigenetic state. Although Myc transcription factors play a major role in stem cell self-renewal and pluripotency, their integration with signalling pathways and epigenetic regulators remains poorly defined. We addressed this point by profiling the gene expression and epigenetic pattern in ESCs whose growth depends on conditional Myc activity. Here we show that Myc potentiates the Wnt/β-catenin signalling pathway, which cooperates with the transcriptional regulatory network in sustaining ESC self-renewal. Myc activation results in the transcriptional repression of Wnt antagonists through the direct recruitment of PRC2 on these targets. The consequent potentiation of the autocrine Wnt/β-catenin signalling induces the transcriptional activation of the endogenous Myc family members, which in turn activates a Myc-driven self-reinforcing circuit. Thus, our data unravel a Myc-dependent self-propagating epigenetic memory in the maintenance of ESC self-renewal capacity. The Myc transcription factor is a major regulator of stem cell (SC) self-renewal and pluripotency but how this integrates signals from other pathways is unclear. Here, the authors show that Myc activation triggers epigenetic memory in self renewing embryonic SCs via PRC2-mediated potentiation of the Wnt pathway.
Collapse
|
142
|
Wnt pathway activation by ADP-ribosylation. Nat Commun 2016; 7:11430. [PMID: 27138857 PMCID: PMC4857404 DOI: 10.1038/ncomms11430] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 03/23/2016] [Indexed: 01/12/2023] Open
Abstract
Wnt/β-catenin signalling directs fundamental processes during metazoan development and can be aberrantly activated in cancer. Wnt stimulation induces the recruitment of the scaffold protein Axin from an inhibitory destruction complex to a stimulatory signalosome. Here we analyse the early effects of Wnt on Axin and find that the ADP-ribose polymerase Tankyrase (Tnks)--known to target Axin for proteolysis-regulates Axin's rapid transition following Wnt stimulation. We demonstrate that the pool of ADP-ribosylated Axin, which is degraded under basal conditions, increases immediately following Wnt stimulation in both Drosophila and human cells. ADP-ribosylation of Axin enhances its interaction with the Wnt co-receptor LRP6, an essential step in signalosome assembly. We suggest that in addition to controlling Axin levels, Tnks-dependent ADP-ribosylation promotes the reprogramming of Axin following Wnt stimulation; and propose that Tnks inhibition blocks Wnt signalling not only by increasing destruction complex activity, but also by impeding signalosome assembly.
Collapse
|
143
|
SphK1 inhibitor SKI II inhibits the proliferation of human hepatoma HepG2 cells via the Wnt5A/β-catenin signaling pathway. Life Sci 2016; 151:23-29. [PMID: 26944438 DOI: 10.1016/j.lfs.2016.02.098] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Revised: 02/24/2016] [Accepted: 02/29/2016] [Indexed: 11/22/2022]
Abstract
AIM Sphingosine 1-phosphate (S1P) promotes cell growth, proliferation and survival. Sphingosine kinase 1 (SphK1), which converts sphingosine to S1P, is a key promoter in cancer. We previously found that the SphK1 inhibitor II (SKI II), suppresses the cell growth and induces apoptosis in human hepatoma HepG2 cells. However, the precise regulatory mechanism and signaling pathway on SKI II inhibiting tumor growth remains unknown. MAIN METHODS The expressions of β-catenin and related molecules of Wnt/β-catenin signal were detected by western blot in HepG2 cells. And the mRNA expression of β-catenin was detected by RT-PCR. The Wnt5A gene was silenced by siRNA. The colony formation was determined by staining with crystal violet. And the cell growth was examined by SRB assay and BrdU assay. KEY FINDINGS We found that SKI II decreased the expression of β-catenin and the downstream molecules of β-catenin signal pathway and promotes the β-catenin degradation. In addition, SKI II induced the expression of Wnt5A, and then triggered β-catenin degradation. Furthermore, silencing Wnt5A decreased the anti-tumor effects of SKI II through recovering the expressions of β-catenin and downstream molecules of β-catenin signal pathway. SIGNIFICANCE SKI II-induced downregulation of HepG2 cell proliferation was associated with Wnt signaling pathway through Wnt5A-mediated β-catenin degradation. Our study revealed that a novel signal pathway was involved in SKI II-inhibited cell proliferation in human hepatoma cells.
Collapse
|
144
|
Chen Y, Li Y, Xue J, Gong A, Yu G, Zhou A, Lin K, Zhang S, Zhang N, Gottardi CJ, Huang S. Wnt-induced deubiquitination FoxM1 ensures nucleus β-catenin transactivation. EMBO J 2016; 35:668-84. [PMID: 26912724 DOI: 10.15252/embj.201592810] [Citation(s) in RCA: 91] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 01/19/2016] [Indexed: 11/09/2022] Open
Abstract
A key step of Wnt signaling activation is the recruitment of β-catenin to the Wnt target-gene promoter in the nucleus, but its mechanisms are largely unknown. Here, we identified FoxM1 as a novel target of Wnt signaling, which is essential for β-catenin/TCF4 transactivation. GSK3 phosphorylates FoxM1 on serine 474 which induces FoxM1 ubiquitination mediated by FBXW7. Wnt signaling activation inhibits FoxM1 phosphorylation by GSK3-Axin complex and leads to interaction between FoxM1 and deubiquitinating enzyme USP5, thereby deubiquitination and stabilization of FoxM1. FoxM1 accumulation in the nucleus promotes recruitment of β-catenin to Wnt target-gene promoter and activates the Wnt signaling pathway by protecting the β-catenin/TCF4 complex from ICAT inhibition. Subsequently, the USP5-FoxM1 axis abolishes the inhibitory effect of ICAT and is required for Wnt-mediated tumor cell proliferation. Therefore, Wnt-induced deubiquitination of FoxM1 represents a novel and critical mechanism for controlling canonical Wnt signaling and cell proliferation.
Collapse
Affiliation(s)
- Yaohui Chen
- Department of Neurosurgery, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Yu Li
- Department of Neurosurgery, The University of Texas MD Anderson Cancer Center, Houston, TX, USA Cell Engineering Research Center and Department of Cell Biology, Fourth Military Medical University, Xi'an, China
| | - Jianfei Xue
- Department of Neurosurgery, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Aihua Gong
- Department of Neurosurgery, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Guanzhen Yu
- Department of Neurosurgery, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Aidong Zhou
- Department of Neurosurgery, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Kangyu Lin
- Department of Neurosurgery, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Sicong Zhang
- Department of Neurosurgery, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Nu Zhang
- Department of Neurosurgery, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Cara J Gottardi
- Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Suyun Huang
- Department of Neurosurgery, The University of Texas MD Anderson Cancer Center, Houston, TX, USA Program in Cancer Biology, The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX, USA
| |
Collapse
|
145
|
Koch S, Acebron SP, Herbst J, Hatiboglu G, Niehrs C. Post-transcriptional Wnt Signaling Governs Epididymal Sperm Maturation. Cell 2015; 163:1225-1236. [DOI: 10.1016/j.cell.2015.10.029] [Citation(s) in RCA: 162] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 09/03/2015] [Accepted: 09/23/2015] [Indexed: 01/11/2023]
|
146
|
Moselhy J, Srinivasan S, Ankem MK, Damodaran C. Natural Products That Target Cancer Stem Cells. Anticancer Res 2015; 35:5773-5788. [PMID: 26503998 PMCID: PMC7523548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The cancer stem cell model suggests that tumor initiation is governed by a small subset of distinct cells with stem-like character termed cancer stem cells (CSCs). CSCs possess properties of self-renewal and intrinsic survival mechanisms that contribute to resistance of tumors to most chemotherapeutic drugs. The failure to eradicate CSCs during the course of therapy is postulated to be the driving force for tumor recurrence and metastasis. Recent studies have focused on understanding the unique phenotypic properties of CSCs from various tumor types, as well as the signaling pathways that underlie self-renewal and drug resistance. Natural products (NPs) such as those derived from botanicals and food sources may modulate vital signaling pathways involved in the maintenance of CSC phenotype. The Wingless/Integrated (WNT), Hedgehog, Notch and PI3K/AKT/mTOR pathways have all been associated with quiescence and self-renewal of CSCs, as well as execution of CSC function including differentiation, multidrug resistance and metastasis. Recent studies evaluating NPs against CSC support the epidemiological evidence linking plant-based diets with reduced malignancy rates. This review covers the key aspects of NPs as modulators of CSC fate.
Collapse
Affiliation(s)
- Jim Moselhy
- Department of Urology, University of Louisville, Louisville, KY, U.S.A
| | | | - Murali K Ankem
- Department of Urology, University of Louisville, Louisville, KY, U.S.A
| | - Chendil Damodaran
- Department of Urology, University of Louisville, Louisville, KY, U.S.A.
| |
Collapse
|
147
|
Pronobis MI, Rusan NM, Peifer M. A novel GSK3-regulated APC:Axin interaction regulates Wnt signaling by driving a catalytic cycle of efficient βcatenin destruction. eLife 2015; 4:e08022. [PMID: 26393419 PMCID: PMC4568445 DOI: 10.7554/elife.08022] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 08/20/2015] [Indexed: 01/11/2023] Open
Abstract
APC, a key negative regulator of Wnt signaling in development and oncogenesis, acts in the destruction complex with the scaffold Axin and the kinases GSK3 and CK1 to target βcatenin for destruction. Despite 20 years of research, APC's mechanistic function remains mysterious. We used FRAP, super-resolution microscopy, functional tests in mammalian cells and flies, and other approaches to define APC's mechanistic role in the active destruction complex when Wnt signaling is off. Our data suggest APC plays two roles: (1) APC promotes efficient Axin multimerization through one known and one novel APC:Axin interaction site, and (2) GSK3 acts through APC motifs R2 and B to regulate APC:Axin interactions, promoting high-throughput of βcatenin to destruction. We propose a new dynamic model of how the destruction complex regulates Wnt signaling and how this goes wrong in cancer, providing insights into how this multiprotein signaling complex is assembled and functions via multivalent interactions. DOI:http://dx.doi.org/10.7554/eLife.08022.001 An embryo starts off as a small ball of stem cells, each of which has the potential to become any type of cell in the body. Adult organs and tissues also contain small numbers of stem cells that can replace old or damaged cells. In both of these processes, stem cells need to ‘decide’ when they should start to change into a more specialized cell type, and which cell fate to choose (e.g., liver cell vs kidney cell). A signaling pathway involving Wnt proteins helps to direct many of these decisions. But if the ‘Wnt signaling pathway’ becomes activated at the wrong time, it can lead to cancer. For example, the first step in development of colon cancer is the inappropriate activation of Wnt signaling, and is most often caused by mutations in the gene that encodes a protein called APC. The APC protein is a tumor suppressor and normally inhibits Wnt signaling. However, even after over 20 years of effort, it remains largely mysterious how APC does this. APC is known to work with another protein called Axin as part of a large protein machine. This protein complex performs one of the first steps in a process that ultimately marks a key component of the Wnt signaling pathway for destruction. Pronobis et al. have now used a range of techniques to define APC's role in this so-called ‘destruction complex’. This analysis revealed the internal structure of a complex made from APC and Axin, and showed that cable- and sheet-like assemblies of Axin were intertwined with APC cables. Further experiments then revealed how APC and Axin proteins are added into or leave these complexes, and showed that this is critical for this protein machine to work. Pronobis et al.'s data also suggest that APC plays two roles, which make the destruction complex more efficient. Firstly, it can interact with Axin via two separate interaction sites that help to assemble the destruction complex. Secondly, specific features in APC allow it to interact with a third protein (called GSK3), which can then regulate how APC interacts with Axin. One of the next challenges will be to uncover how APC helps to transfer the components of Wnt signaling to the next step of their destruction, and to clear up the role played by GSK3. DOI:http://dx.doi.org/10.7554/eLife.08022.002
Collapse
Affiliation(s)
- Mira I Pronobis
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, United States
| | - Nasser M Rusan
- Cell Biology and Physiology Center, National Heart, Lung, and Blood Institute, Bethesda, United States
| | - Mark Peifer
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, United States
| |
Collapse
|
148
|
Multiplexed 3D FRET imaging in deep tissue of live embryos. Sci Rep 2015; 5:13991. [PMID: 26387920 PMCID: PMC4585674 DOI: 10.1038/srep13991] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 07/29/2015] [Indexed: 02/03/2023] Open
Abstract
Current deep tissue microscopy techniques are mostly restricted to intensity mapping of fluorophores, which significantly limit their applications in investigating biochemical processes in vivo. We present a deep tissue multiplexed functional imaging method that probes multiple Förster resonant energy transfer (FRET) sensors in live embryos with high spatial resolution. The method simultaneously images fluorescence lifetimes in 3D with multiple excitation lasers. Through quantitative analysis of triple-channel intensity and lifetime images, we demonstrated that Ca(2+) and cAMP levels of live embryos expressing dual FRET sensors can be monitored simultaneously at microscopic resolution. The method is compatible with a broad range of FRET sensors currently available for probing various cellular biochemical functions. It opens the door to imaging complex cellular circuitries in whole live organisms.
Collapse
|
149
|
Gao C, Chen G, Kuan SF, Zhang DH, Schlaepfer DD, Hu J. FAK/PYK2 promotes the Wnt/β-catenin pathway and intestinal tumorigenesis by phosphorylating GSK3β. eLife 2015; 4. [PMID: 26274564 PMCID: PMC4558782 DOI: 10.7554/elife.10072] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 08/11/2015] [Indexed: 12/16/2022] Open
Abstract
Aberrant activation of Wnt/β-catenin signaling plays an unequivocal role in colorectal cancer, but identification of effective Wnt inhibitors for use in cancer remains a tremendous challenge. New insights into the regulation of this pathway could reveal new therapeutic point of intervention, therefore are greatly needed. Here we report a novel FAK/PYK2/GSK3β(Y216)/β-catenin regulation axis: FAK and PYK2, elevated in adenomas in APC(min/+) mice and in human colorectal cancer tissues, functioned redundantly to promote the Wnt/β-catenin pathway by phosphorylating GSK3β(Y216) to reinforce pathway output-β-catenin accumulation and intestinal tumorigenesis. We previously showed that Wnt-induced β-catenin accumulation requires Wnt-induced GSK3β/β-TrCP interaction; the current study revealed that phosphorylation of GSK3β(Y216) was a molecular determinant of GSK3β recruitment of β-TrCP. Pharmacological inhibition of FAK/PYK2 suppressed adenoma formation in APC(min/+) mice accompanied with reduced intestinal levels of phospho-GSK3β(Y216) and β-catenin, indicating that FAK/PYK2/GSK3β(Y216) axis is critical for the activation of Wnt/β-catenin signaling in APC driven intestinal tumorigenesis.
Collapse
Affiliation(s)
- Chenxi Gao
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, United States
| | - Guangming Chen
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, United States
| | - Shih-Fan Kuan
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, United States
| | | | - David D Schlaepfer
- Department of Reproductive Medicine, Moores Cancer Center, University of California, San Diego, San Diego, United States
| | - Jing Hu
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, United States
| |
Collapse
|
150
|
NF2/Merlin is required for the axial pattern formation in the Xenopus laevis embryo. Mech Dev 2015; 138 Pt 3:305-12. [PMID: 26344136 DOI: 10.1016/j.mod.2015.08.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 08/29/2015] [Accepted: 08/30/2015] [Indexed: 01/10/2023]
Abstract
The NF2 gene product Merlin is a FERM-domain protein possessing a broad tumor-suppressing function. NF2/Merlin has been implicated in regulating multiple signaling pathways critical for cell growth and survival. However, it remains unknown whether NF2/Merlin regulates Wnt/β-catenin signaling during vertebrate embryogenesis. Here we demonstrate that NF2/Merlin is required for body pattern formation in the Xenopus laevis embryo. Depletion of the maternal NF2/Merlin enhances organizer gene expression dependent on the presence of β-catenin, and causes dorsanteriorized development; Morpholino antisense oligo-mediated knockdown of the zygotic NF2/Merlin shifts posterior genes anteriorwards and reduces the anterior development. We further demonstrate that targeted depletion of NF2 in the presumptive dorsal tissues increases the levels of nuclear β-catenin in the neural epithelial cells. Biochemical analyses reveal that NF2 depletion promotes the production of active β-catenin and concurrently decreases the level of N-terminally phosphorylated β-catenin under the stimulation of the endogenous Wnt signaling. Our findings suggest that NF2/Merlin negatively regulates the Wnt/β-catenin signaling activity during the pattern formation in early X. laevis embryos.
Collapse
|