1
|
Ji Y, Huang PH, Woolfenden S, Myers A. Model-based dose selection to inform translational clinical oncology development of WNT974, a first-in-class Porcupine inhibitor. Clin Transl Sci 2022; 15:1713-1722. [PMID: 35620969 PMCID: PMC9283749 DOI: 10.1111/cts.13287] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 04/01/2022] [Accepted: 04/07/2022] [Indexed: 11/30/2022] Open
Abstract
WNT974 is a potent, selective, and orally bioavailable first‐in‐class inhibitor of Porcupine, a membrane‐bound O‐acyltransferase required for Wnt secretion, currently under clinical development in oncology. A phase I clinical trial is being conducted in patients with advanced solid tumors. During the dose‐escalation part, various dosing regimens, including once or twice daily continuous and intermittent dosing at a dose range of 5–45 mg WNT974 were studied, however, the protocol‐defined maximum tolerated dose (MTD) was not established based on dose‐limiting toxicity. To assist in the selection of the recommended dose for expansion (RDE), a model‐based approach was utilized. It integrated population pharmacokinetic (PK) modeling and exposure–response analyses of a target‐inhibition biomarker, skin AXIN2 mRNA expression, and the occurrence of the adverse event, dysgeusia. The target exposure range of WNT974 that would provide a balance between target inhibition and tolerability was estimated based on exposure–response analyses. The dose that was predicted to yield an exposure within the target exposure range was selected as RDE. This model‐based approach integrated PK, biomarker, and safety data to determine the RDE and represented an alternative as opposed to the conventional MTD approach for selecting an optimal biological dose. The strategy can be broadly applied to select doses in early oncology trials and inform translational clinical oncology drug development.
Collapse
Affiliation(s)
- Yan Ji
- Novartis Pharmaceuticals Corporation, East Hanover, New Jersey, USA
| | - Pai-Hsi Huang
- Novartis Pharmaceuticals Corporation, East Hanover, New Jersey, USA
| | - Steve Woolfenden
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts, USA
| | - Andrea Myers
- Novartis Pharmaceuticals Corporation, East Hanover, New Jersey, USA
| |
Collapse
|
2
|
Rodon J, Argilés G, Connolly RM, Vaishampayan U, de Jonge M, Garralda E, Giannakis M, Smith DC, Dobson JR, McLaughlin ME, Seroutou A, Ji Y, Morawiak J, Moody SE, Janku F. Phase 1 study of single-agent WNT974, a first-in-class Porcupine inhibitor, in patients with advanced solid tumours. Br J Cancer 2021; 125:28-37. [PMID: 33941878 PMCID: PMC8257624 DOI: 10.1038/s41416-021-01389-8] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 03/17/2021] [Accepted: 03/31/2021] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND This Phase 1 study assessed the safety and efficacy of the Porcupine inhibitor, WNT974, in patients with advanced solid tumours. METHODS Patients (n = 94) received oral WNT974 at doses of 5-30 mg once-daily, plus additional dosing schedules. RESULTS The maximum tolerated dose was not established; the recommended dose for expansion was 10 mg once-daily. Dysgeusia was the most common adverse event (50% of patients), likely resulting from on-target Wnt pathway inhibition. No responses were seen by Response Evaluation Criteria in Solid Tumors (RECIST) v1.1; 16% of patients had stable disease (median duration 19.9 weeks). AXIN2 expression by RT-PCR was reduced in 94% of paired skin biopsies (n = 52) and 74% of paired tumour biopsies (n = 35), confirming inhibition of the Wnt pathway. In an exploratory analysis, an inverse association was observed between AXIN2 change and immune signature change in paired tumour samples (n = 8). CONCLUSIONS Single-agent WNT974 treatment was generally well tolerated. Biomarker analyses suggest that WNT974 may influence immune cell recruitment to tumours, and may enhance checkpoint inhibitor activity. CLINICAL TRIAL REGISTRATION NCT01351103.
Collapse
Affiliation(s)
- Jordi Rodon
- grid.411083.f0000 0001 0675 8654Vall d’Hebron University Hospital and Universitat Autònoma de Barcelona, Barcelona, Spain ,grid.240145.60000 0001 2291 4776Present Address: The University of Texas MD Anderson Cancer Center, Houston, TX USA
| | - Guillem Argilés
- grid.411083.f0000 0001 0675 8654Vall d’Hebron University Hospital and Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Roisin M. Connolly
- grid.21107.350000 0001 2171 9311Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine, Baltimore, MD USA ,grid.7872.a0000000123318773Present Address: CancerResearch@UCC, College of Medicine and Health, University College Cork, Cork, Ireland
| | - Ulka Vaishampayan
- grid.477517.70000 0004 0396 4462Department of Oncology, Karmanos Cancer Institute, Wayne State University, Detroit, MI USA
| | - Maja de Jonge
- grid.5645.2000000040459992XDepartment of Medical Oncology, Erasmus Medical Center Cancer Institute, Rotterdam, The Netherlands
| | - Elena Garralda
- grid.488453.60000000417724902START Madrid, Hospital Universitario Madrid Sanchinarro, Madrid, Spain
| | - Marios Giannakis
- grid.38142.3c000000041936754XDana Farber Cancer Institute, Harvard Medical School, Boston, MA USA
| | - David C. Smith
- grid.214458.e0000000086837370University of Michigan, Ann Arbor, MI USA
| | - Jason R. Dobson
- grid.418424.f0000 0004 0439 2056Novartis Institutes for BioMedical Research, Cambridge, MA USA
| | - Margaret E. McLaughlin
- grid.418424.f0000 0004 0439 2056Novartis Institutes for BioMedical Research, Cambridge, MA USA
| | | | - Yan Ji
- grid.418424.f0000 0004 0439 2056Novartis Institutes for BioMedical Research, East Hanover, NJ USA
| | - Jennifer Morawiak
- grid.418424.f0000 0004 0439 2056Novartis Institutes for BioMedical Research, Cambridge, MA USA
| | - Susan E. Moody
- grid.418424.f0000 0004 0439 2056Novartis Institutes for BioMedical Research, Cambridge, MA USA
| | - Filip Janku
- grid.240145.60000 0001 2291 4776Department of Investigational Cancer Therapeutics (Phase 1 Clinical Trials Program), The University of Texas MD Anderson Cancer Center, Houston, TX USA
| |
Collapse
|
3
|
Park J, Yoo HJ, Yu AR, Kim HO, Park SC, Jang YP, Lee C, Choe W, Kim SS, Kang I, Yoon KS. Non-Polar Myxococcus fulvus KYC4048 Metabolites Exert Anti-Proliferative Effects via Inhibition of Wnt/β-Catenin Signaling in MCF-7 Breast Cancer Cells. J Microbiol Biotechnol 2021; 31:540-549. [PMID: 33746192 PMCID: PMC9705865 DOI: 10.4014/jmb.2012.12015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 03/15/2021] [Accepted: 03/16/2021] [Indexed: 12/15/2022]
Abstract
The Wnt/β-catenin signaling pathway is involved in breast cancer and Myxococcus fulvus KYC4048 is a myxobacterial strain that can produce a variety of bioactive secondary metabolites. Although a previous study revealed that KYC4048 metabolites exhibit anti-proliferative effects on breast cancer, the biochemical mechanism involved in their effects remains unclear. In the present study, KYC4048 metabolites were separated into polar and non-polar (ethyl acetate and n-hexane) fractions via liquid-liquid extraction. The effects of these polar and non-polar KYC4048 metabolites on the viability of breast cancer cells were then determined by MTT assay. Expression levels of Wnt/β-catenin pathway proteins were determined by Western blot analysis. Cell cycle and apoptosis were measured via fluorescence-activated cell sorting (FACS). The results revealed that non-polar KYC4048 metabolites induced cell death of breast cancer cells and decreased expression levels of WNT2B, β-catenin, and Wnt target genes (c-Myc and cyclin D1). Moreover, the n-hexane fraction of non-polar KYC4048 metabolites was found most effective in inducing apoptosis, necrosis, and cell cycle arrest, leading us to conclude that it can induce apoptosis of breast cancer cells through the Wnt/β-catenin pathway. These findings provide evidence that the n-hexane fraction of non-polar KYC4048 metabolites can be developed as a potential therapeutic agent for breast cancer via inhibition of the Wnt/β-catenin pathway.
Collapse
Affiliation(s)
- Juha Park
- Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Hee-Jin Yoo
- Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Ah-Ran Yu
- Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Hye Ok Kim
- Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Sang Cheol Park
- Department of Oriental Pharmaceutical Science, College of Pharmacy, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Young Pyo Jang
- Department of Life and Nanopharmaceutical Sciences, Graduate School, Kyung Hee University, Seoul 02447, Republic of Korea,Department of Oriental Pharmaceutical Science, College of Pharmacy, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Chayul Lee
- Lifetogether Co., Ltd., Chuncheon 24232, Republic of Korea
| | - Wonchae Choe
- Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Sung Soo Kim
- Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Insug Kang
- Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Kyung-Sik Yoon
- Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, Seoul 02447, Republic of Korea,Corresponding author Phone: +82-2-961-0388 Fax: +82-2-965-6349 E-mail:
| |
Collapse
|
4
|
Al-Bari AA, Al Mamun A. Current advances in regulation of bone homeostasis. FASEB Bioadv 2020; 2:668-679. [PMID: 33205007 PMCID: PMC7655096 DOI: 10.1096/fba.2020-00058] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Revised: 08/18/2020] [Accepted: 08/21/2020] [Indexed: 02/06/2023] Open
Abstract
Bone homeostasis is securely controlled by the dynamic well‐balanced actions among osteoclasts, osteoblasts and osteocytes. Osteoclasts are large multinucleated cells that degrade bone matrix and involve in the bone remodelling in conjunction with other bone cells, osteoblasts and osteocytes, the completely matured form of osteoblasts. Disruption of this controlling balance among these cells or any disparity in bone remodelling caused by a higher rate of resorption by osteoclasts over construction of bone by osteoblasts results in a reduction of bone matrix including bone mineral density (BMD) and bone marrow cells (BMCs). The dominating effect of osteoclasts results in advanced risk of bone crack and joint destruction in several diseases including osteoporosis and rheumatoid arthritis (RA). However, the boosted osteoblastic activity produces osteosclerotic phenotype and weakened its action primes to osteomalacia or rickets. On the other hand, senescent osteocytes predominately progress the senescence associated secretory phenotype (SASP) and may contribute to age related bone loss. Here, we discuss an advanced level work on newly identified cellular mechanisms controlling the remodelling of bone and crosstalk among bone cells as these relate to the therapeutic targeting of the skeleton.
Collapse
Affiliation(s)
| | - Abdullah Al Mamun
- Department of Genetic Engineering and Biotechnology Shahjalal University of Science and Technology Sylhet Bangladesh
| |
Collapse
|
5
|
Lin CC, Lo MC, Moody R, Jiang H, Harouaka R, Stevers N, Tinsley S, Gasparyan M, Wicha M, Sun D. Targeting LRP8 inhibits breast cancer stem cells in triple-negative breast cancer. Cancer Lett 2018; 438:165-173. [PMID: 30227220 DOI: 10.1016/j.canlet.2018.09.022] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 08/23/2018] [Accepted: 09/11/2018] [Indexed: 12/30/2022]
Abstract
Triple-negative breast cancer (TNBC) is the most difficult subtype of breast cancer to treat due to a paucity of effective targeted therapies. Many studies have reported that breast cancer stem cells (BCSCs) are enriched in TNBC and are responsible for chemoresistance and metastasis. In this study, we identify LRP8 as a novel positive regulator of BCSCs in TNBC. LRP8 is highly expressed in TNBC compared to other breast cancer subtypes and its genomic locus is amplified in 24% of TNBC tumors. Knockdown of LRP8 in TNBC cell lines inhibits Wnt/β-catenin signaling, decreases BCSCs, and suppresses tumorigenic potential in xenograft models. LRP8 knockdown also induces a more differentiated, luminal-epithelial phenotype and thus sensitizes the TNBC cells to chemotherapy. Together, our study highlights LRP8 as a novel therapeutic target for TNBC as inhibition of LRP8 can attenuate Wnt/β-catenin signaling to suppress BCSCs.
Collapse
Affiliation(s)
- Chang-Ching Lin
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Miao-Chia Lo
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, MI, 48109, USA.
| | - Rebecca Moody
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, MI, 48109, USA; Chemical Biology Program, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Hui Jiang
- Department of Biostatistics, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Ramdane Harouaka
- Department of Internal Medicine, University of Michigan Comprehensive Cancer Center, Ann Arbor, MI, 48109, USA
| | - Nicholas Stevers
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Samantha Tinsley
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Mari Gasparyan
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Max Wicha
- Department of Internal Medicine, University of Michigan Comprehensive Cancer Center, Ann Arbor, MI, 48109, USA
| | - Duxin Sun
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, MI, 48109, USA; Chemical Biology Program, University of Michigan, Ann Arbor, MI, 48109, USA.
| |
Collapse
|
6
|
Abstract
PURPOSE OF REVIEW The goal of this paper is to evaluate critically the literature published over the past 3 years regarding the Wnt signaling pathway. The Wnt pathway was found to be involved in bone biology in 2001-2002 with the discovery of a (G171V) mutation in the lipoprotein receptor-related protein 5 (LRP5) that resulted in high bone mass and another mutation that completely inactivated Lrp5 function and resulted in osteoporosis pseudoglioma syndrome (OPPG). The molecular biology has been complex, and very interesting. It has provided many opportunities for exploitation to develop new clinical treatments, particularly for osteoporosis. More clinical possibilities include: treatments for fracture healing, corticosteroid osteoporosis, osteogenesis imperfecta, and others. In addition, we wish to provide historical information coming from distant publications (~350 years ago) regarding bone biology that have been confirmed by study of Wnt signaling. RECENT FINDINGS A recent finding is the development of an antibody to sclerostin that is under study as a treatment for osteoporosis. Development of treatments for other forms of osteoporosis, such as corticosteroid osteoporosis, is also underway. The full range of the applications of the work is not yet been achieved.
Collapse
Affiliation(s)
- Mark L Johnson
- Department of Oral and Craniofacial Sciences, UMKC School of Dentistry, 650 East 25th Street, Kansas City, MO, 64108, USA
| | - Robert R Recker
- Creighton University, 601 N 30th St., Ste 4841, Omaha, NE, 68131, USA.
| |
Collapse
|
7
|
Williams BO. Genetically engineered mouse models to evaluate the role of Wnt secretion in bone development and homeostasis. AMERICAN JOURNAL OF MEDICAL GENETICS. PART C, SEMINARS IN MEDICAL GENETICS 2016; 172C:24-6. [PMID: 26818176 DOI: 10.1002/ajmg.c.31474] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2024]
Abstract
Alterations in components of the Wnt signaling pathway are associated with altered bone development and homeostasis in several human diseases. We created genetically engineered mouse models (GEMMs) that mimic the cellular defect associated with the Porcupine mutations in patients with Goltz Syndrome/Focal Dermal Hypoplasia. These GEMMs were established by utilizing mice containing a conditionally inactivatable allele of Wntless/GPR177 (a gene encoding a protein required for the transport of Porcupine-modified ligand to the plasma membrane for secretion). We crossed this strain to another which drives cre-mediated gene deletion in mature osteoblasts (Osteocalcin-cre) resulted in mice lacking the ability to secrete Wnt ligands in this cell type. These mice displayed severely reduced bone mass and provide a model to understand the effects of disrupting the ability to secrete Wnt ligands on the skeletal system.
Collapse
|
8
|
Thouverey C, Caverzasio J. Sclerostin inhibits osteoblast differentiation without affecting BMP2/SMAD1/5 or Wnt3a/β-catenin signaling but through activation of platelet-derived growth factor receptor signaling in vitro. BONEKEY REPORTS 2015; 4:757. [PMID: 26587226 DOI: 10.1038/bonekey.2015.126] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 09/29/2015] [Indexed: 01/18/2023]
Abstract
Sclerostin inhibits bone formation mostly by antagonizing LRP5/6, thus inhibiting Wnt signaling. However, experiments with genetically modified mouse models suggest that a significant part of sclerostin-mediated inhibition of bone formation is due to interactions with other binding partners. The objective of the present work was to identify signaling pathways affected by sclerostin in relation with its inhibitory action on osteogenic differentiation of C3H10T1/2 cells, MC3T3-E1 cells and primary osteoblasts. Sclerostin inhibited BMP2-induced osteoblast differentiation without altering SMAD1/5 phosphorylation and transcriptional activity. Moreover, sclerostin prevented Wnt3a-mediated osteoblastogenesis without affecting LRP5/6 phosphorylation or β-catenin transcriptional activity. In addition, sclerostin inhibited mineralization promoted by GSK3 inhibition, which mimics canonical Wnt signaling without activation of LRP5/6, suggesting that sclerostin can prevent osteoblast differentiation without antagonizing LRP5/6. Finally, we found that sclerostin could activate platelet-derived growth factor receptor (PDGFR) and its downstream signaling pathways PLCγ, PKC, Akt and ERK1/2. PDGFR inhibition could reverse sclerostin-mediated inhibitory activity on BMP2-induced osteoblast differentiation. Therefore, our data suggest that sclerostin can activate PDGFR signaling by itself, and this functional interaction may be involved in the negative effect of sclerostin on osteoblast differentiation.
Collapse
Affiliation(s)
- Cyril Thouverey
- Service of Bone Diseases, Department of Internal Medicine Specialties, University Hospital of Geneva , Geneva, Switzerland
| | - Joseph Caverzasio
- Service of Bone Diseases, Department of Internal Medicine Specialties, University Hospital of Geneva , Geneva, Switzerland
| |
Collapse
|
9
|
Abstract
Wnt signaling plays key roles in many aspects of development. In this review, we will briefly describe the components of signaling pathways induced by Wnt ligands and then describe the current state of research as this applies to aspects of development and disease as it relates to skeletal muscle and bone. We will conclude with a discussion of the parallels and differences in Wnt signaling in these two contexts and how these pathways are being (or could potentially be) targeted for therapeutic treatment of musculoskeletal diseases. This article is part of a Special Issue entitled "Muscle Bone Interactions".
Collapse
Affiliation(s)
- Michael A Rudnicki
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada; Department Medicine, University of Ottawa, Ottawa, Ontario, Canada.
| | - Bart O Williams
- Center for Skeletal Disease and Tumor Metastasis, Van Andel Research Institute, Grand Rapids, MI, USA.
| |
Collapse
|
10
|
Abstract
A dozen years ago the identification of causal mutations in the low-density lipoprotein receptor-related protein 5 (LRP5) gene involved in two rare bone disorders propelled research in the bone field in totally new directions. Since then, there have been an explosion in the number of reports that highlight the role of the Wnt/β-catenin pathway in the regulation of bone homeostasis. In this review we discuss some of the most recent reports (in the past 2 years) highlighting the involvement of the members of the LRP family (LRP5, LRP6, LRP4, and more recently LRP8) in the maintenance of bone and their implications in bone diseases. These reports include records of new single nucleotides polymorphisms (SNPs) and haplotypes that suggest variants in these genes can contribute to subtle variation in bone traits to mutations that give rise to extreme bone phenotypes. All of these serve to further support and reinforce the importance of this tightly regulated pathway in bone. Furthermore, we discuss provocative reports suggesting novel approaches through inhibitors of this pathway to treat rarer diseases such as Osteoporosis-Pseudoglioma Syndrome (OPPG), Osteogenesis Imperfecta (OI), and Sclerosteosis/Van Buchem disease. It is hoped that by understanding the role of each component of the pathway and their involvement in bone diseases that this knowledge will allow us to develop new, more effective therapeutic approaches for more common diseases such as post-menopausal osteoporosis, osteoarthritis, and rheumatoid arthritis as well as these rarer bone diseases.
Collapse
Affiliation(s)
- N Lara-Castillo
- Department of Oral and Craniofacial Sciences, UMKC School of Dentistry, 650 East 25th Street, Kansas City, MO, 64108, USA,
| | | |
Collapse
|
11
|
Lee K, Shin Y, Cheng R, Park K, Hu Y, McBride J, He X, Takahashi Y, Ma JX. Receptor heterodimerization as a novel mechanism for the regulation of Wnt/β-catenin signaling. J Cell Sci 2014; 127:4857-69. [PMID: 25271056 DOI: 10.1242/jcs.149302] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The Wnt pathway plays important roles in multiple physiological and pathophysiological processes. Here, we report a novel mechanism that regulates the Wnt pathway through heterodimerization of the Wnt co-receptor low-density lipoprotein-receptor-related protein 6 (LRP6) and very low-density lipoprotein receptor (VLDLR); the latter belongs to the same protein family as LRP6 and was originally known as a receptor for lipoproteins. Knockdown of Vldlr expression elevated LRP6 protein levels and activated Wnt/β-catenin signaling, whereas overexpression of Vldlr suppressed Wnt signaling. Moreover, we demonstrate that the VLDLR ectodomain is essential and sufficient for inhibition of Wnt signaling. The VLDLR ectodomain accelerated internalization and degradation of LRP6 through heterodimerization with the LRP6 extracellular domain. Monoclonal antibodies specific for the VLDLR ectodomain blocked VLDLR-LRP6 heterodimerization, resulting in enhanced Wnt/β-catenin signaling in vitro and in vivo. Taken together, these findings suggest that heterodimerization of receptors in the membrane accelerates the turnover of LRP6, and represent a new mechanism for the regulation of Wnt/β-catenin signaling.
Collapse
Affiliation(s)
- Kyungwon Lee
- Department of Cell Biology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Younghwa Shin
- Department of Physiology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Rui Cheng
- Department of Physiology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Kyoungmin Park
- Department of Cell Biology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Yang Hu
- Department of Physiology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Jeffrey McBride
- Department of Cell Biology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Xuemin He
- Department of Physiology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Yusuke Takahashi
- Department of Medicine, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Jian-Xing Ma
- Department of Physiology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| |
Collapse
|
12
|
Zhong Z, Ethen NJ, Williams BO. WNT signaling in bone development and homeostasis. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2014; 3:489-500. [PMID: 25270716 DOI: 10.1002/wdev.159] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2014] [Revised: 08/16/2014] [Accepted: 08/25/2014] [Indexed: 01/29/2023]
Abstract
The balance between bone formation and bone resorption controls postnatal bone homeostasis. Research over the last decade has provided a vast amount of evidence that WNT signaling plays a pivotal role in regulating this balance. Therefore, understanding how the WNT signaling pathway regulates skeletal development and homeostasis is of great value for human skeletal health and disease.
Collapse
Affiliation(s)
- Zhendong Zhong
- Center for Skeletal Disease and Tumor Microenvironment, Van Andel Research Institute, Grand Rapids, MI, USA
| | | | | |
Collapse
|
13
|
Abstract
Osteogenesis and bone remodeling are complex biological processes that are essential for the formation of new bone tissue and its correct functioning. When the balance between bone resorption and formation is disrupted, bone diseases and disorders such as Paget's disease, fibrous dysplasia, osteoporosis and fragility fractures may result. Recent advances in bone cell biology have revealed new specific targets for the treatment of bone loss that are based on the inhibition of bone resorption by osteoclasts or the stimulation of bone formation by osteoblasts. Bisphosphonates, antiresorptive agents that reduce bone resorption, are usually recommended as first-line therapy in women with postmenopausal osteoporosis. Numerous studies have shown that bisphosphonates are able to significantly reduce the risk of femoral and vertebral fractures. Other antiresorptive agents indicated for the treatment of osteoporosis include selective estrogen receptor modulators, such as raloxifene. Denosumab, a human monoclonal antibody, is another antiresorptive agent that has been approved in Europe and the USA. This agent blocks the RANK/RANKL/OPG system, which is responsible for osteoclastic activation, thus reducing bone resorption. Other approved agents include bone anabolic agents, such as teriparatide, a recombinant parathyroid hormone that improves bone microarchitecture and strength, and strontium ranelate, considered to be a dual-action drug that acts by both osteoclastic inhibition and osteoblastic stimulation. Currently, anti-catabolic drugs that act through the Wnt-β catenin signaling pathway, serving as Dickkopf-related protein 1 inhibitors and sclerostin antagonists, are also in development. This concise review provides an overview of the drugs most commonly used for the control of osteogenesis in bone diseases.
Collapse
|
14
|
Ke J, Harikumar KG, Erice C, Chen C, Gu X, Wang L, Parker N, Cheng Z, Xu W, Williams BO, Melcher K, Miller LJ, Xu HE. Structure and function of Norrin in assembly and activation of a Frizzled 4-Lrp5/6 complex. Genes Dev 2013; 27:2305-19. [PMID: 24186977 PMCID: PMC3828517 DOI: 10.1101/gad.228544.113] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Norrin is an important growth factor and Wnt ligand required for angiogenesis in the eye, ear, brain, and female reproductive organs. Structural and functional studies by Ke et al. now reveal that Norrin forms a unique dimer required for binding and activation of the Frizzled 4 (Fz4) receptor. Interestingly, Norrin contains separate binding sites for Wnt ligand coreceptors Lrp5/6 and induces the formation of a ternary complex with Fz4 and Lrp5/6 extracellular domains. This study provides critical new insight into the Wnt and Norrin signaling pathways. Norrin is a cysteine-rich growth factor that is required for angiogenesis in the eye, ear, brain, and female reproductive organs. It functions as an atypical Wnt ligand by specifically binding to the Frizzled 4 (Fz4) receptor. Here we report the crystal structure of Norrin, which reveals a unique dimeric structure with each monomer adopting a conserved cystine knot fold. Functional studies demonstrate that the novel Norrin dimer interface is required for Fz4 activation. Furthermore, we demonstrate that Norrin contains separate binding sites for Fz4 and for the Wnt ligand coreceptor Lrp5 (low-density lipoprotein-related protein 5) or Lrp6. Instead of inducing Fz4 dimerization, Norrin induces the formation of a ternary complex with Fz4 and Lrp5/6 by binding to their respective extracellular domains. These results provide crucial insights into the assembly and activation of the Norrin–Fz4–Lrp5/6 signaling complex.
Collapse
Affiliation(s)
- Jiyuan Ke
- Laboratory of Structural Sciences, Van Andel Research Institute, Grand Rapids, Michigan 49503, USA
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Abstract
Osteoporosis is a skeletal system pathology characterized by low bone mineral density and tissue structural deterioration. This malady is associated with high fracture risk that severely compromises quality of life. Osteoporosis incidence is becoming more significant with increasing lifespan worldwide. However, current approaches for treating osteoporosis cannot and do not treat the disease in the most ideal manner for diverse reasons. Substantial research has sought both the discovery of new targets and new therapies. In this review, emerging possible RNAi-mediated therapeutic opportunities for osteoporosis are identified and associated challenges discussed. Targeted delivery strategies capable of more reliable and efficient delivery to skeletal tissue are described, as well as possibilities to treat bone-forming cells with siRNA to produce cell-based therapy.
Collapse
Affiliation(s)
- Yuwei Wang
- Department of Pharmaceutics & Pharmaceutical Chemistry, University of Utah, Salt Lake City, UT 84112 USA
| | - David W Grainger
- Department of Pharmaceutics & Pharmaceutical Chemistry, University of Utah, Salt Lake City, UT 84112 USA
| |
Collapse
|
16
|
Robling AG. The expanding role of Wnt signaling in bone metabolism. Bone 2013; 55:256-7. [PMID: 23500458 PMCID: PMC4516055 DOI: 10.1016/j.bone.2013.03.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Revised: 03/01/2013] [Accepted: 03/02/2013] [Indexed: 11/30/2022]
Affiliation(s)
- Alexander G Robling
- Department of Anatomy & Cell Biology, Department of Biomedical Engineering, Indiana University School of Medicine, 635 Barnhill Dr., MS 5035, Indianapolis, IN 46202, USA.
| |
Collapse
|
17
|
Abe T, Zhou P, Jackman K, Capone C, Casolla B, Hochrainer K, Kahles T, Ross ME, Anrather J, Iadecola C. Lipoprotein receptor-related protein-6 protects the brain from ischemic injury. Stroke 2013; 44:2284-2291. [PMID: 23743975 DOI: 10.1161/strokeaha.113.001320] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Loss-of-function mutations of the lipoprotein receptor-related protein-6 (LRP6), a coreceptor in the Wingless-related integration site-β-catenin prosurvival pathway, have been implicated in myocardial ischemia and neurodegeneration. However, it remains to be established whether LRP6 is also involved in ischemic brain injury. We used LRP6+/- mice to examine the role of this receptor in the mechanisms of focal cerebral ischemia. METHODS Focal cerebral ischemia was induced by transient occlusion of the middle cerebral artery. Motor deficits and infarct volume were assessed 3 days later. Glycogen-synthase-kinase-3β (GSK-3β) phosphorylation was examined by Western blotting with phosphospecific antibodies, and the mitochondrial membrane potential changes induced by Ca2+ were also assessed. RESULTS LRP6+/- mice have larger stroke and more severe motor deficits, effects that were independent of intraischemic cerebral blood flow, vascular factors, or cytosolic β-catenin levels. Rather, LRP6 haploinsufficiency increased the activating phosphorylation and decreased the inhibitory phosphorylation of GSK-3β, a kinase involved in proinflammatory signaling and mitochondrial dysfunction. Accordingly, postischemic inflammatory gene expression was enhanced in LRP6+/- mice. Furthermore, the association of mitochondria with activated GSK-3β was increased in LRP6+/- mice, resulting in a reduction in the Ca2+ handling ability of mitochondria. The mitochondrial dysfunction was reversed by pharmacological inhibition of GSK-3β. CONCLUSIONS LRP6 activates an endogenous neuroprotective pathway that acts independently of β-catenin by controlling GSK-3β activity and preventing its deleterious mitochondrial and proinflammatory effects. The findings raise the possibility that emerging treatment strategies for diseases attributable to LRP6 loss-of-function mutations could also lead to new therapeutic avenues for ischemic stroke.
Collapse
Affiliation(s)
- Takato Abe
- Brain and Mind Research Institute, Weill Cornell Medical College, New York, NY
| | - Ping Zhou
- Brain and Mind Research Institute, Weill Cornell Medical College, New York, NY
| | - Katherine Jackman
- Brain and Mind Research Institute, Weill Cornell Medical College, New York, NY
| | - Carmen Capone
- Brain and Mind Research Institute, Weill Cornell Medical College, New York, NY
| | - Barbara Casolla
- Brain and Mind Research Institute, Weill Cornell Medical College, New York, NY
| | - Karin Hochrainer
- Brain and Mind Research Institute, Weill Cornell Medical College, New York, NY
| | - Timo Kahles
- Brain and Mind Research Institute, Weill Cornell Medical College, New York, NY
| | | | - Josef Anrather
- Brain and Mind Research Institute, Weill Cornell Medical College, New York, NY
| | - Costantino Iadecola
- Brain and Mind Research Institute, Weill Cornell Medical College, New York, NY
| |
Collapse
|
18
|
Dissecting Major Signaling Pathways throughout the Development of Prostate Cancer. Prostate Cancer 2013; 2013:920612. [PMID: 23738079 PMCID: PMC3657461 DOI: 10.1155/2013/920612] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 03/25/2013] [Accepted: 03/28/2013] [Indexed: 01/28/2023] Open
Abstract
Prostate cancer (PCa) is one of the most common malignancies found in males. The development of PCa involves several mutations in prostate epithelial cells, usually linked to developmental changes, such as enhanced resistance to apoptotic death, constitutive proliferation, and, in some cases, to differentiation into an androgen deprivation-resistant phenotype, leading to the appearance of castration-resistant PCa (CRPCa), which leads to a poor prognosis in patients. In this review, we summarize recent findings concerning the main deregulations into signaling pathways that will lead to the development of PCa and/or CRPCa. Key mutations in some pathway molecules are often linked to a higher prevalence of PCa, by directly affecting the respective cascade and, in some cases, by deregulating a cross-talk node or junction along the pathways. We also discuss the possible environmental and nonenvironmental inducers for these mutations, as well as the potential therapeutic strategies targeting these signaling pathways. A better understanding of how some risk factors induce deregulation of these signaling pathways, as well as how these deregulated pathways affect the development of PCa and CRPCa, will further help in the development of new treatments and prevention strategies for this disease.
Collapse
|
19
|
Maupin KA, Droscha CJ, Williams BO. A Comprehensive Overview of Skeletal Phenotypes Associated with Alterations in Wnt/β-catenin Signaling in Humans and Mice. Bone Res 2013; 1:27-71. [PMID: 26273492 DOI: 10.4248/br201301004] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Accepted: 01/20/2013] [Indexed: 12/23/2022] Open
Abstract
The Wnt signaling pathway plays key roles in differentiation and development and alterations in this signaling pathway are causally associated with numerous human diseases. While several laboratories were examining roles for Wnt signaling in skeletal development during the 1990s, interest in the pathway rose exponentially when three key papers were published in 2001-2002. One report found that loss of the Wnt co-receptor, Low-density lipoprotein related protein-5 (LRP5), was the underlying genetic cause of the syndrome Osteoporosis pseudoglioma (OPPG). OPPG is characterized by early-onset osteoporosis causing increased susceptibility to debilitating fractures. Shortly thereafter, two groups reported that individuals carrying a specific point mutation in LRP5 (G171V) develop high-bone mass. Subsequent to this, the causative mechanisms for these observations heightened the need to understand the mechanisms by which Wnt signaling controlled bone development and homeostasis and encouraged significant investment from biotechnology and pharmaceutical companies to develop methods to activate Wnt signaling to increase bone mass to treat osteoporosis and other bone disease. In this review, we will briefly summarize the cellular mechanisms underlying Wnt signaling and discuss the observations related to OPPG and the high-bone mass disorders that heightened the appreciation of the role of Wnt signaling in normal bone development and homeostasis. We will then present a comprehensive overview of the core components of the pathway with an emphasis on the phenotypes associated with mice carrying genetically engineered mutations in these genes and clinical observations that further link alterations in the pathway to changes in human bone.
Collapse
Affiliation(s)
- Kevin A Maupin
- Program for Skeletal Pathobiology and Center for Tumor Metastasis, Van Andel Research Institute , 333 Bostwick NE, Grand Rapids, MI 49503, USA
| | - Casey J Droscha
- Program for Skeletal Pathobiology and Center for Tumor Metastasis, Van Andel Research Institute , 333 Bostwick NE, Grand Rapids, MI 49503, USA
| | - Bart O Williams
- Program for Skeletal Pathobiology and Center for Tumor Metastasis, Van Andel Research Institute , 333 Bostwick NE, Grand Rapids, MI 49503, USA
| |
Collapse
|
20
|
Cottrell JA, Keshav V, Mitchell A, O'Connor JP. Local inhibition of 5-lipoxygenase enhances bone formation in a rat model. Bone Joint Res 2013; 2:41-50. [PMID: 23610701 PMCID: PMC3626215 DOI: 10.1302/2046-3758.22.2000066] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Accepted: 01/09/2013] [Indexed: 12/20/2022] Open
Abstract
Objectives Recent studies have shown that modulating inflammation-related
lipid signalling after a bone fracture can accelerate healing in
animal models. Specifically, decreasing 5-lipoxygenase (5-LO) activity
during fracture healing increases cyclooxygenase-2 (COX-2) expression
in the fracture callus, accelerates chondrogenesis and decreases
healing time. In this study, we test the hypothesis that 5-LO inhibition
will increase direct osteogenesis. Methods Bilateral, unicortical femoral defects were used in rats to measure
the effects of local 5-LO inhibition on direct osteogenesis. The
defect sites were filled with a polycaprolactone (PCL) scaffold
containing 5-LO inhibitor (A-79175) at three dose levels, scaffold
with drug carrier, or scaffold only. Drug release was assessed in
vitro. Osteogenesis was assessed by micro-CT and histology
at two endpoints of ten and 30 days. Results Using micro-CT, we found that A-79175, a 5-LO inhibitor, increased
bone formation in an apparent dose-related manner. Conclusions These results indicate that 5-LO inhibition could be used therapeutically
to enhance treatments that require the direct formation of bone.
Collapse
Affiliation(s)
- J A Cottrell
- University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Department of Biochemistry & Molecular Biology, Newark, New Jersey, USA
| | | | | | | |
Collapse
|
21
|
Valkenburg KC, Steensma MR, Williams BO, Zhong Z. Skeletal metastasis: treatments, mouse models, and the Wnt signaling. CHINESE JOURNAL OF CANCER 2013; 32:380-96. [PMID: 23327798 PMCID: PMC3845601 DOI: 10.5732/cjc.012.10218] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Skeletal metastases result in significant morbidity and mortality. This is particularly true of cancers with a strong predilection for the bone, such as breast, prostate, and lung cancers. There is currently no reliable cure for skeletal metastasis, and palliative therapy options are limited. The Wnt signaling pathway has been found to play an integral role in the process of skeletal metastasis and may be an important clinical target. Several experimental models of skeletal metastasis have been used to find new biomarkers and test new treatments. In this review, we discuss pathologic process of bone metastasis, the roles of the Wnt signaling, and the available experimental models and treatments.
Collapse
Affiliation(s)
- Kenneth C Valkenburg
- Center for Skeletal Disease Research, Van Andel Research Institute, Grand Rapids, MI 49503, USA
| | | | | | | |
Collapse
|
22
|
Joiner DM, Ke J, Zhong Z, Xu HE, Williams BO. LRP5 and LRP6 in development and disease. Trends Endocrinol Metab 2013; 24:31-9. [PMID: 23245947 PMCID: PMC3592934 DOI: 10.1016/j.tem.2012.10.003] [Citation(s) in RCA: 156] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Revised: 10/09/2012] [Accepted: 10/15/2012] [Indexed: 11/21/2022]
Abstract
Low-density lipoprotein-related receptors 5 and 6 (LRP5/6) are highly homologous proteins with key functions in canonical Wnt signaling. Alterations in the genes encoding these receptors or their interacting proteins are linked to human diseases, and as such they have been a major focus of drug development efforts to treat several human conditions including osteoporosis, cancer, and metabolic disease. Here, we discuss the links between alterations in LRP5/6 and disease, proteins that interact with them, and insights gained into their function from mouse models. We also highlight current drug development related to LRP5/6 as well as how the recent elucidation of their crystal structures may allow further refinement of our ability to target them for therapeutic benefit.
Collapse
Affiliation(s)
- Danese M. Joiner
- Center for Skeletal Disease Research, Laboratory of Cell Signaling and Carcinogenesis, Van Andel Research Institute, 333 Bostwick NE, Grand Rapids, MI 49503, USA
| | - Jiyuan Ke
- Center for Structural Biology and Drug Discovery, Laboratory of Structural Sciences, Van Andel Research Institute, 333 Bostwick NE, Grand Rapids, MI 49503, USA
| | - Zhendong Zhong
- Center for Skeletal Disease Research, Laboratory of Cell Signaling and Carcinogenesis, Van Andel Research Institute, 333 Bostwick NE, Grand Rapids, MI 49503, USA
| | - H. Eric Xu
- Center for Structural Biology and Drug Discovery, Laboratory of Structural Sciences, Van Andel Research Institute, 333 Bostwick NE, Grand Rapids, MI 49503, USA
| | - Bart O. Williams
- Center for Skeletal Disease Research, Laboratory of Cell Signaling and Carcinogenesis, Van Andel Research Institute, 333 Bostwick NE, Grand Rapids, MI 49503, USA
| |
Collapse
|
23
|
Nagaoka T, Karasawa H, Turbyville T, Rangel MC, Castro NP, Gonzales M, Baker A, Seno M, Lockett S, Greer YE, Rubin JS, Salomon DS, Bianco C. Cripto-1 enhances the canonical Wnt/β-catenin signaling pathway by binding to LRP5 and LRP6 co-receptors. Cell Signal 2013; 25:178-89. [PMID: 23022962 PMCID: PMC3508164 DOI: 10.1016/j.cellsig.2012.09.024] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Revised: 09/18/2012] [Accepted: 09/24/2012] [Indexed: 12/21/2022]
Abstract
Cripto-1 is implicated in multiple cellular events, including cell proliferation, motility and angiogenesis, through the activation of an intricate network of signaling pathways. A crosstalk between Cripto-1 and the canonical Wnt/β-catenin signaling pathway has been previously described. In fact, Cripto-1 is a downstream target gene of the canonical Wnt/β-catenin signaling pathway in the embryo and in colon cancer cells and T-cell factor (Tcf)/lymphoid enhancer factor binding sites have been identified in the promoter and the first intronic region of the mouse and human Cripto-1 genes. We now demonstrate that Cripto-1 modulates signaling through the canonical Wnt/β-catenin/Tcf pathway by binding to the Wnt co-receptors low-density lipoprotein receptor-related protein (LRP) 5 and LRP6, which facilitates Wnt3a binding to LRP5 and LRP6. Cripto-1 functionally enhances Wnt3a signaling through cytoplasmic stabilization of β-catenin and elevated β-catenin/Tcf transcriptional activation. Conversely, Wnt3a further increases Cripto-1 stimulation of migration, invasion and colony formation in soft agar of HC11 mouse mammary epithelial cells, indicating that Cripto-1 and the canonical Wnt/β-catenin signaling co-operate in regulating motility and in vitro transformation of mammary epithelial cells.
Collapse
Affiliation(s)
- Tadahiro Nagaoka
- Tumor Growth Factor Section, Laboratory of Cancer Prevention, Frederick National Laboratory for Cancer Research, 1050 Boyles St., Bldg 560/ Room 12-46, Frederick, MD 21702, USA
| | - Hideaki Karasawa
- Tumor Growth Factor Section, Laboratory of Cancer Prevention, Frederick National Laboratory for Cancer Research, 1050 Boyles St., Bldg 560/ Room 12-46, Frederick, MD 21702, USA
| | - Thomas Turbyville
- Optical Microscopy and Analysis Laboratory, SAIC-Frederick, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, USA
| | - Maria-Cristina Rangel
- Tumor Growth Factor Section, Laboratory of Cancer Prevention, Frederick National Laboratory for Cancer Research, 1050 Boyles St., Bldg 560/ Room 12-46, Frederick, MD 21702, USA
| | - Nadia P. Castro
- Tumor Growth Factor Section, Laboratory of Cancer Prevention, Frederick National Laboratory for Cancer Research, 1050 Boyles St., Bldg 560/ Room 12-46, Frederick, MD 21702, USA
| | - Monica Gonzales
- Tumor Growth Factor Section, Laboratory of Cancer Prevention, Frederick National Laboratory for Cancer Research, 1050 Boyles St., Bldg 560/ Room 12-46, Frederick, MD 21702, USA
| | - Alyson Baker
- Tumor Growth Factor Section, Laboratory of Cancer Prevention, Frederick National Laboratory for Cancer Research, 1050 Boyles St., Bldg 560/ Room 12-46, Frederick, MD 21702, USA
| | - Masaharu Seno
- Laboratory of Nano-Biotechnology, Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima-Naka, Okayama 700-8530, Japan
| | - Stephen Lockett
- Optical Microscopy and Analysis Laboratory, SAIC-Frederick, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, USA
| | - Yoshimi E. Greer
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, 37 Convent Drive, Bldg 37/Room 2066, Bethesda, MD 20892, USA
| | - Jeffrey S. Rubin
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, 37 Convent Drive, Bldg 37/Room 2066, Bethesda, MD 20892, USA
| | - David S. Salomon
- Tumor Growth Factor Section, Laboratory of Cancer Prevention, Frederick National Laboratory for Cancer Research, 1050 Boyles St., Bldg 560/ Room 12-46, Frederick, MD 21702, USA
| | - Caterina Bianco
- Tumor Growth Factor Section, Laboratory of Cancer Prevention, Frederick National Laboratory for Cancer Research, 1050 Boyles St., Bldg 560/ Room 12-46, Frederick, MD 21702, USA
| |
Collapse
|
24
|
Regard JB, Zhong Z, Williams BO, Yang Y. Wnt signaling in bone development and disease: making stronger bone with Wnts. Cold Spring Harb Perspect Biol 2012; 4:4/12/a007997. [PMID: 23209148 DOI: 10.1101/cshperspect.a007997] [Citation(s) in RCA: 142] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The skeleton as an organ is widely distributed throughout the entire vertebrate body. Wnt signaling has emerged to play major roles in almost all aspects of skeletal development and homeostasis. Because abnormal Wnt signaling causes various human skeletal diseases, Wnt signaling has become a focal point of intensive studies in skeletal development and disease. As a result, promising effective therapeutic agents for bone diseases are being developed by targeting the Wnt signaling pathway. Understanding the functional mechanisms of Wnt signaling in skeletal biology and diseases highlights how basic and clinical studies can stimulate each other to push a quick and productive advancement of the entire field. Here we review the current understanding of Wnt signaling in critical aspects of skeletal biology such as bone development, remodeling, mechanotransduction, and fracture healing. We took special efforts to place fundamentally important discoveries in the context of human skeletal diseases.
Collapse
Affiliation(s)
- Jean B Regard
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | | | | | | |
Collapse
|
25
|
Abstract
The crystal structure of a Wnt morphogen bound to its Frizzled receptor ectodomain provides insights into the evolutionary provenance of this complex fold and offers an explanation for why Wnts utilize both lipid- and protein-mediated contacts to engage Frizzleds.
Collapse
|
26
|
Zhong Z, Williams BO. Integration of cellular adhesion and Wnt signaling: Interactions between N-cadherin and LRP5 and their role in regulating bone mass. J Bone Miner Res 2012; 27:1849-51. [PMID: 22903578 PMCID: PMC3904542 DOI: 10.1002/jbmr.1715] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Zhendong Zhong
- Center for Skeletal Disease Research, Van Andel Research Institute, Grand Rapids, MI 49503, USA
| | | |
Collapse
|
27
|
Abstract
Recent genome-wide association studies of individuals of Asian and European descent have found that SNPs located within the genomic region (1p31.3) encoding the Wntless (Wls)/Gpr177 protein are associated significantly with reduced bone mineral density. Wls/Gpr177 is a newly identified chaperone protein that specifically escorts Wnt ligands for secretion. Given the strong functional association between the Wnt signaling pathways and bone development and homeostasis, we generated osteoblast-specific Wls-deficient (Ocn-Cre;Wls-flox) mice. Homozygous conditional knockout animals were born at a normal Mendelian frequency. Whole-body dual-energy X-ray absorptiometry scanning revealed that bone-mass accrual was significantly inhibited in homozygotes as early as 20 d of age. These homozygotes had spontaneous fractures and a high frequency of premature lethality at around 2 mo of age. Microcomputed tomography analysis and histomorphometric data revealed a dramatic reduction of both trabecular and cortical bone mass in homozygous mutants. Bone formation in homozygotes was severely impaired, but no obvious phenotypic change was observed in mice heterozygous for the conditional deletion. In vitro studies showed that Wls-deficient osteoblasts had a defect in differentiation and mineralization, with significant reductions in the expression of key osteoblast differentiation regulators. In summary, these results reveal a surprising and crucial role of osteoblast-secreted Wnt ligands in bone-mass accrual.
Collapse
|
28
|
King TD, Zhang W, Suto MJ, Li Y. Frizzled7 as an emerging target for cancer therapy. Cell Signal 2012; 24:846-51. [PMID: 22182510 PMCID: PMC3268941 DOI: 10.1016/j.cellsig.2011.12.009] [Citation(s) in RCA: 102] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Accepted: 12/04/2011] [Indexed: 02/09/2023]
Abstract
Wnt proteins are secreted glycoproteins that bind to the N-terminal extra-cellular cysteine-rich domain of the Frizzled (Fzd) receptor family. The Fzd receptors can respond to Wnt proteins in the presence of Wnt co-receptors to activate the canonical and non-canonical Wnt pathways. Recent studies indicated that, among the Fzd family, Fzd7 is the Wnt receptor most commonly upregulated in a variety of cancers including colorectal cancer, hepatocellular carcinoma and triple negative breast cancer. Fzd7 plays an important role in stem cell biology and cancer development and progression. In addition, it has been demonstrated that siRNA knockdown of Fzd7, the anti-Fzd7 antibody or the extracellular peptide of Fzd7 (soluble Fzd7 peptide) displayed anti-cancer activity in vitro and in vivo mainly due to the inhibition of the canonical Wnt signaling pathway. Furthermore, pharmacological inhibition of Fzd7 by small interfering peptides or a small molecule inhibitor suppressed β-catenin-dependent tumor cell growth. Therefore, targeted inhibition of Fzd7 represents a rational and promising new approach for cancer therapy.
Collapse
Affiliation(s)
- Taj D. King
- Department of Biochemistry and Molecular Biology, Drug Discovery Division, Southern Research Institute, 2000 Ninth Avenue South, Birmingham, AL 35205, USA
| | - Wei Zhang
- Department of Medicinal Chemistry, Drug Discovery Division, Southern Research Institute, 2000 Ninth Avenue South, Birmingham, AL 35205, USA
| | - Mark J. Suto
- Department of Biochemistry and Molecular Biology, Drug Discovery Division, Southern Research Institute, 2000 Ninth Avenue South, Birmingham, AL 35205, USA
- Department of Medicinal Chemistry, Drug Discovery Division, Southern Research Institute, 2000 Ninth Avenue South, Birmingham, AL 35205, USA
| | - Yonghe Li
- Department of Biochemistry and Molecular Biology, Drug Discovery Division, Southern Research Institute, 2000 Ninth Avenue South, Birmingham, AL 35205, USA
| |
Collapse
|
29
|
Palsgaard J, Emanuelli B, Winnay JN, Sumara G, Karsenty G, Kahn CR. Cross-talk between insulin and Wnt signaling in preadipocytes: role of Wnt co-receptor low density lipoprotein receptor-related protein-5 (LRP5). J Biol Chem 2012; 287:12016-26. [PMID: 22337886 DOI: 10.1074/jbc.m111.337048] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Disturbed Wnt signaling has been implicated in numerous diseases, including type 2 diabetes and the metabolic syndrome. In the present study, we have investigated cross-talk between insulin and Wnt signaling pathways using preadipocytes with and without knockdown of the Wnt co-receptors LRP5 and LRP6 and with and without knock-out of insulin and IGF-1 receptors. We find that Wnt stimulation leads to phosphorylation of insulin signaling key mediators, including Akt, GSK3β, and ERK1/2, although with a lower fold stimulation and slower time course than observed for insulin. These Wnt effects are insulin/IGF-1 receptor-dependent and are lost in insulin/IGF-1 receptor double knock-out cells. Conversely, in LRP5 knockdown preadipocytes, insulin-induced phosphorylation of IRS1, Akt, GSK3β, and ERK1/2 is highly reduced. This effect is specific to insulin, as compared with IGF-1, stimulation and appears to be due to an inducible interaction between LRP5 and the insulin receptor as demonstrated by co-immunoprecipitation. These data demonstrate that Wnt and insulin signaling pathways exhibit cross-talk at multiple levels. Wnt induces phosphorylation of Akt, ERK1/2, and GSK3β, and this is dependent on insulin/IGF-1 receptors. Insulin signaling also involves the Wnt co-receptor LRP5, which has a positive effect on insulin signaling. Thus, altered Wnt and LRP5 activity can serve as modifiers of insulin action and insulin resistance in the pathophysiology of diabetes and metabolic syndrome.
Collapse
Affiliation(s)
- Jane Palsgaard
- Section on Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts 02215, USA
| | | | | | | | | | | |
Collapse
|
30
|
Keefe MD, Wang H, De La O JP, Khan A, Firpo MA, Murtaugh LC. β-catenin is selectively required for the expansion and regeneration of mature pancreatic acinar cells in mice. Dis Model Mech 2012; 5:503-14. [PMID: 22266944 PMCID: PMC3380713 DOI: 10.1242/dmm.007799] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The size of the pancreas is determined by intrinsic factors, such as the number of progenitor cells, and by extrinsic signals that control the fate and proliferation of those progenitors. Both the exocrine and endocrine compartments of the pancreas undergo dramatic expansion after birth and are capable of at least partial regeneration following injury. Whether the expansion of these lineages relies on similar mechanisms is unknown. Although we have shown that the Wnt signaling component β-catenin is selectively required in mouse embryos for the generation of exocrine acinar cells, this protein has been ascribed various functions in the postnatal pancreas, including proliferation and regeneration of islet as well as acinar cells. To address whether β-catenin remains important for the maintenance and expansion of mature acinar cells, we have established a system to follow the behavior and fate of β-catenin-deficient cells during postnatal growth and regeneration in mice. We find that β-catenin is continuously required for the establishment and maintenance of acinar cell mass, extending from embryonic specification through juvenile and adult self-renewal and regeneration. This requirement is not shared with islet cells, which proliferate and function normally in the absence of β-catenin. These results make distinct predictions for the relative role of Wnt–β-catenin signaling in the etiology of human endocrine and exocrine disease. We suggest that loss of Wnt–β-catenin activity is unlikely to drive islet dysfunction, as occurs in type 2 diabetes, but that β-catenin is likely to promote human acinar cell proliferation following injury, and might therefore contribute to the resolution of acute or chronic pancreatitis.
Collapse
Affiliation(s)
- Matthew D Keefe
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | | | | | | | | | | |
Collapse
|
31
|
Lu W, Lin C, Roberts MJ, Waud WR, Piazza GA, Li Y. Niclosamide suppresses cancer cell growth by inducing Wnt co-receptor LRP6 degradation and inhibiting the Wnt/β-catenin pathway. PLoS One 2011; 6:e29290. [PMID: 22195040 PMCID: PMC3241710 DOI: 10.1371/journal.pone.0029290] [Citation(s) in RCA: 162] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Accepted: 11/24/2011] [Indexed: 12/18/2022] Open
Abstract
The Wnt/β-catenin signaling pathway is important for tumor initiation and progression. The low density lipoprotein receptor-related protein-6 (LRP6) is an essential Wnt co-receptor for Wnt/β-catenin signaling and represents a promising anticancer target. Recently, the antihelminthic drug, niclosamide was found to inhibit Wnt/β-catenin signaling, although the mechanism was not well defined. We found that niclosamide was able to suppress LRP6 expression and phosphorylation, block Wnt3A-induced β-catenin accumulation, and inhibit Wnt/β-catenin signaling in HEK293 cells. Furthermore, the inhibitory effects of niclosamide on LRP6 expression/phosphorylation and Wnt/β-catenin signaling were conformed in human prostate PC-3 and DU145 and breast MDA-MB-231 and T-47D cancer cells. Moreover, we showed that the mechanism by which niclosamide suppressed LRP6 resulted from increased degradation as evident by a shorter half-life. Finally, we demonstrated that niclosamide was able to induce cancer cell apoptosis, and displayed excellent anticancer activity with IC50 values less than 1 µM for prostate PC-3 and DU145 and breast MDA-MB-231 and T-47D cancer cells. The IC50 values are comparable to those shown to suppress the activities of Wnt/β-catenin signaling in prostate and breast cancer cells. Our data indicate that niclosamide is a unique small molecule Wnt/β-catenin signaling inhibitor targeting the Wnt co-receptor LRP6 on the cell surface, and that niclosamide has a potential to be developed a novel chemopreventive or therapeutic agent for human prostate and breast cancer.
Collapse
Affiliation(s)
- Wenyan Lu
- Drug Discovery Division, Department of Biochemistry and Molecular Biology, Southern Research Institute, Birmingham, Alabama, United States of America
| | - Cuihong Lin
- Drug Discovery Division, Department of Biochemistry and Molecular Biology, Southern Research Institute, Birmingham, Alabama, United States of America
| | - Michael J. Roberts
- Drug Development Division, Department of Cell Biology and Immunology, Southern Research Institute, Birmingham, Alabama, United States of America
| | - William R. Waud
- Drug Development Division, Department of Cancer Therapeutics, Southern Research Institute, Birmingham, Alabama, United States of America
| | - Gary A. Piazza
- Mitchell Cancer Institute, University of South Alabama, Mobile, Alabama, United States of America
| | - Yonghe Li
- Drug Discovery Division, Department of Biochemistry and Molecular Biology, Southern Research Institute, Birmingham, Alabama, United States of America
- * E-mail:
| |
Collapse
|
32
|
Wijenayaka AR, Kogawa M, Lim HP, Bonewald LF, Findlay DM, Atkins GJ. Sclerostin stimulates osteocyte support of osteoclast activity by a RANKL-dependent pathway. PLoS One 2011; 6:e25900. [PMID: 21991382 PMCID: PMC3186800 DOI: 10.1371/journal.pone.0025900] [Citation(s) in RCA: 345] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Accepted: 09/13/2011] [Indexed: 02/06/2023] Open
Abstract
Sclerostin is a product of mature osteocytes embedded in mineralised bone and is a negative regulator of bone mass and osteoblast differentiation. While evidence suggests that sclerostin has an anti-anabolic role, the possibility also exists that sclerostin has catabolic activity. To test this we treated human primary pre-osteocyte cultures, cells we have found are exquisitely sensitive to sclerostin, or mouse osteocyte-like MLO-Y4 cells, with recombinant human sclerostin (rhSCL) and measured effects on pro-catabolic gene expression. Sclerostin dose-dependently up-regulated the expression of receptor activator of nuclear factor kappa B (RANKL) mRNA and down-regulated that of osteoprotegerin (OPG) mRNA, causing an increase in the RANKL∶OPG mRNA ratio. To examine the effects of rhSCL on resulting osteoclastic activity, MLO-Y4 cells plated onto a bone-like substrate were primed with rhSCL for 3 days and then either mouse splenocytes or human peripheral blood mononuclear cells (PBMC) were added. This resulted in cultures with elevated osteoclastic resorption (approximately 7-fold) compared to untreated co-cultures. The increased resorption was abolished by co-addition of recombinant OPG. In co-cultures of MLO-Y4 cells with PBMC, SCL also increased the number and size of the TRAP-positive multinucleated cells formed. Importantly, rhSCL had no effect on TRAP-positive cell formation from monocultures of either splenocytes or PBMC. Further, rhSCL did not induce apoptosis of MLO-Y4 cells, as determined by caspase activity assays, demonstrating that the osteoclastic response was not driven by dying osteocytes. Together, these results suggest that sclerostin may have a catabolic action through promotion of osteoclast formation and activity by osteocytes, in a RANKL-dependent manner.
Collapse
Affiliation(s)
- Asiri R. Wijenayaka
- Bone Cell Biology Group, Discipline of Orthopaedics and Trauma, University of Adelaide, and the Hanson Institute, Adelaide, Australia
| | - Masakazu Kogawa
- Bone Cell Biology Group, Discipline of Orthopaedics and Trauma, University of Adelaide, and the Hanson Institute, Adelaide, Australia
| | - Hui Peng Lim
- Bone Cell Biology Group, Discipline of Orthopaedics and Trauma, University of Adelaide, and the Hanson Institute, Adelaide, Australia
| | - Lynda F. Bonewald
- University of Missouri - Kansas City School of Dentistry, Department of Oral Biology, Kansas City, Missouri, United States of America
| | - David M. Findlay
- Bone Cell Biology Group, Discipline of Orthopaedics and Trauma, University of Adelaide, and the Hanson Institute, Adelaide, Australia
| | - Gerald J. Atkins
- Bone Cell Biology Group, Discipline of Orthopaedics and Trauma, University of Adelaide, and the Hanson Institute, Adelaide, Australia
- * E-mail:
| |
Collapse
|
33
|
Galat A. Common structural traits for cystine knot domain of the TGFβ superfamily of proteins and three-fingered ectodomain of their cellular receptors. Cell Mol Life Sci 2011; 68:3437-51. [PMID: 21369710 PMCID: PMC11114550 DOI: 10.1007/s00018-011-0643-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2010] [Revised: 01/08/2011] [Accepted: 02/15/2011] [Indexed: 01/22/2023]
Abstract
The transforming growth factor-β (TGFβ) superfamily of proteins and their receptors are crucial developmental factors for all metazoan organisms. Cystine-knot (CK) motif is a spatial feature of the TGFβ superfamily of proteins whereas the extra-cellular domains (ectodomains) of their respective receptors form three-fingered protein domain (TFPD), both stabilized by tight cystine networks. Analyses of multiple sequence alignments of these two domains encoded in various genomes revealed that the cystines forming the CK and TFPD folds are conserved, whereas the remaining polypeptide patches are diversified. Orthologues of the human TGFβs and their respective receptors expressed in diverse vertebrates retain high sequence conservation. Examination of 3D structures of various TGFβ factors bound to their receptors have revealed that the CK and TFPD domains display several similar spatial traits suggesting that these two different protein folds might have been acquired from a common ancestor.
Collapse
Affiliation(s)
- A Galat
- Commissariat à l'Energie Atomique, Direction des Sciences du Vivant, Institut de Biologie et de Technologies de Saclay, Service d'Ingénierie Moléculaire des Protéines, Bat. 152, 91191 Gif-sur-Yvette, France.
| |
Collapse
|
34
|
Lewiecki EM. New targets for intervention in the treatment of postmenopausal osteoporosis. Nat Rev Rheumatol 2011; 7:631-8. [PMID: 21931340 DOI: 10.1038/nrrheum.2011.130] [Citation(s) in RCA: 96] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Postmenopausal osteoporosis is a disease of high bone remodeling, with an imbalance of bone resorption over bone formation, resulting in decreased bone mineral density and disruption of bone microarchitecture. With our improved understanding of the molecular and cellular regulators and mediators of bone remodeling, new targets for therapeutic intervention have been identified. Receptor activator of nuclear factor κB ligand (RANKL) is the principal regulator of osteoclast differentiation, activity, and survival; denosumab, a fully human monoclonal antibody to RANKL, inhibits bone resorption and is approved for the treatment of women with postmenopausal osteoporosis at high risk of fractures. Cathepsin K is a protease produced by activated osteoclasts that degrades the protein matrix of bone. An inhibitor of cathepsin K, odanacatib, is in phase III clinical trials for the treatment of postmenopausal osteoporosis; it decreases bone resorption while seeming to suppress bone formation less than other antiresorptive agents. Sclerostin is a cytokine produced by osteocytes that inhibits osteoblastic bone formation; investigational monoclonal antibodies to sclerostin, such as AMG 785, have osteoanabolic properties with the potential to improve clinical outcomes in patients with osteoporosis. These and other novel interventions that target newly recognized regulators of bone remodeling are promising agents for the treatment of osteoporosis.
Collapse
Affiliation(s)
- E Michael Lewiecki
- New Mexico Clinical Research & Osteoporosis Center, 300 Oak Street NE, Albuquerque, NM 87106, USA.
| |
Collapse
|
35
|
Atkins GJ, Rowe PS, Lim HP, Welldon KJ, Ormsby R, Wijenayaka AR, Zelenchuk L, Evdokiou A, Findlay DM. Sclerostin is a locally acting regulator of late-osteoblast/preosteocyte differentiation and regulates mineralization through a MEPE-ASARM-dependent mechanism. J Bone Miner Res 2011; 26:1425-36. [PMID: 21312267 PMCID: PMC3358926 DOI: 10.1002/jbmr.345] [Citation(s) in RCA: 193] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The identity of the cell type responsive to sclerostin, a negative regulator of bone mass, is unknown. Since sclerostin is expressed in vivo by mineral-embedded osteocytes, we tested the hypothesis that sclerostin would regulate the behavior of cells actively involved in mineralization in adult bone, the preosteocyte. Differentiating cultures of human primary osteoblasts exposed to recombinant human sclerostin (rhSCL) for 35 days displayed dose- and time-dependent inhibition of in vitro mineralization, with late cultures being most responsive in terms of mineralization and gene expression. Treatment of advanced (day 35) cultures with rhSCL markedly increased the expression of the preosteocyte marker E11 and decreased the expression of mature markers DMP1 and SOST. Concomitantly, matrix extracellular phosphoglycoprotein (MEPE) expression was increased by rhSCL at both the mRNA and protein levels, whereas PHEX was decreased, implying regulation through the MEPE-ASARM axis. We confirmed that mineralization by human osteoblasts is exquisitely sensitive to the triphosphorylated ASARM-PO4 peptide. Immunostaining revealed that rhSCL increased the endogenous levels of MEPE-ASARM. Importantly, antibody-mediated neutralization of endogenous MEPE-ASARM antagonized the effect of rhSCL on mineralization, as did the PHEX synthetic peptide SPR4. Finally, we found elevated Sost mRNA expression in the long bones of HYP mice, suggesting that sclerostin may drive the increased MEPE-ASARM levels and mineralization defect in this genotype. Our results suggest that sclerostin acts through regulation of the PHEX/MEPE axis at the preosteocyte stage and serves as a master regulator of physiologic bone mineralization, consistent with its localization in vivo and its established role in the inhibition of bone formation.
Collapse
Affiliation(s)
- Gerald J Atkins
- Bone Cell Biology Group, Discipline of Orthopaedics and Trauma, University of Adelaide, and the Hanson Institute, Adelaide, Australia.
| | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Valkenburg KC, Graveel CR, Zylstra-Diegel CR, Zhong Z, Williams BO. Wnt/β-catenin Signaling in Normal and Cancer Stem Cells. Cancers (Basel) 2011; 3:2050-79. [PMID: 24212796 PMCID: PMC3757404 DOI: 10.3390/cancers3022050] [Citation(s) in RCA: 97] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Revised: 04/12/2011] [Accepted: 04/13/2011] [Indexed: 12/23/2022] Open
Abstract
The ability of Wnt ligands to initiate a signaling cascade that results in cytoplasmic stabilization of, and nuclear localization of, β-catenin underlies their ability to regulate progenitor cell differentiation. In this review, we will summarize the current knowledge of the mechanisms underlying Wnt/β-catenin signaling and how the pathway regulates normal differentiation of stem cells in the intestine, mammary gland, and prostate. We will also discuss how dysregulation of the pathway is associated with putative cancer stem cells and the potential therapeutic implications of regulating Wnt signaling.
Collapse
Affiliation(s)
- Kenneth C Valkenburg
- Van Andel Research Institute, 333 Bostwick Ave. N.E., Grand Rapids, MI 49503, USA.
| | | | | | | | | |
Collapse
|
37
|
Zhang B, Ma JX. Wnt pathway antagonists and angiogenesis. Protein Cell 2010; 1:898-906. [PMID: 21204016 DOI: 10.1007/s13238-010-0112-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2010] [Accepted: 09/27/2010] [Indexed: 11/26/2022] Open
Abstract
Dysregulation of the Wnt pathway has been extensively studied in multiple diseases, including some angiogenic disorders. Wnt signaling activation is a major stimulator in pathological angiogenesis and thus, Wnt antagonists are believed to have therapeutic potential for neovascular disorders. Actually, some Wnt antagonists have been identified directly from the anti-angiogenic factor family. This review summarizes the recent progress toward understanding of the roles of Wnt pathway antagonists in angiogenic regulation and their mechanism of action, and exploring their therapeutic potential.
Collapse
Affiliation(s)
- Bin Zhang
- Department of Physiology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | | |
Collapse
|
38
|
Curtin JC, Lorenzi MV. Drug discovery approaches to target Wnt signaling in cancer stem cells. Oncotarget 2010; 1:563-577. [PMID: 21317452 PMCID: PMC3248130 DOI: 10.18632/oncotarget.191] [Citation(s) in RCA: 128] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2010] [Accepted: 10/27/2010] [Indexed: 12/18/2022] Open
Abstract
Cancer stem cells (CSCs) represent a unique subset of cells within a tumor that possess self-renewal capacity and pluripotency, and can drive tumor initiation and maintenance. First identified in hematological malignancies, CSCs are now thought to play an important role in a wide variety of solid tumors such as NSCLC, breast and colorectal cancer. The role of CSCs in driving tumor formation illustrates the dysregulation of differentiation in tumorigenesis. The Wnt, Notch and Hedgehog (HH) pathways are developmental pathways that are commonly activated in many types of cancer. While substantial progress has been made in developing therapeutics targeting Notch and HH, the Wnt pathway has remained an elusive therapeutic target. This review will focus on the clinical relevance of the Wnt pathway in CSCs and tumor cell biology, as well as points of therapeutic intervention and recent advances in targeting Wnt/β-catenin signaling.
Collapse
Affiliation(s)
- Joshua C Curtin
- Oncology Drug Discovery, Research and Development, Bristol-Myers Squibb, Princeton, NJ, USA
| | | |
Collapse
|
39
|
Mason JJ, Williams BO. SOST and DKK: Antagonists of LRP Family Signaling as Targets for Treating Bone Disease. J Osteoporos 2010; 2010:460120. [PMID: 20948575 PMCID: PMC2951123 DOI: 10.4061/2010/460120] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2010] [Revised: 04/27/2010] [Accepted: 05/26/2010] [Indexed: 11/22/2022] Open
Abstract
The study of rare human genetic disorders has often led to some of the most significant advances in biomedical research. One such example was the body of work that resulted in the identification of the Low Density Lipoprotein-Related Protein (LRP5) as a key regulator of bone mass. Point mutations were identified that encoded forms of LRP5 associated with very high bone mass (HBM). HBM patients live to a normal age and do not appear to have increased susceptibility to carcinogenesis or other disease. Thus, devising methods to mimic the molecular consequences of this mutation to treat bone diseases associated with low bone mass is a promising avenue to pursue. Two groups of agents related to putative LRP5/6 functions are under development. One group, the focus of this paper, is based on antagonizing the functions of putative inhibitors of Wnt signaling, Dickkopf-1 (DKK1), and Sclerostin (SOST). Another group of reagents under development is based on the observation that LRP5 may function to control bone mass by regulating the secretion of serotonin from the enterrochromaffin cells of the duodenum.
Collapse
Affiliation(s)
- James J. Mason
- Center for Skeletal Disease Research, Van Andel Research Institute, 333 Bostwick NE, Grand Rapids, MI 49503, USA,Laboratory of Orthopaedic Cell and Tissue Mechanics, Van Andel Research Institute, 333 Bostwick NE, Grand Rapids, MI 49503, USA
| | - Bart O. Williams
- Center for Skeletal Disease Research, Van Andel Research Institute, 333 Bostwick NE, Grand Rapids, MI 49503, USA,Laboratory of Cell Signaling and Carcinogenesis, Van Andel Research Institute, 333 Bostwick NE, Grand Rapids, MI 49503, USA,*Bart O. Williams:
| |
Collapse
|
40
|
Camilli TC, Weeraratna AT. Striking the target in Wnt-y conditions: intervening in Wnt signaling during cancer progression. Biochem Pharmacol 2010; 80:702-11. [PMID: 20211149 DOI: 10.1016/j.bcp.2010.03.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2010] [Revised: 02/25/2010] [Accepted: 03/01/2010] [Indexed: 12/30/2022]
Abstract
Wnt signaling can be divided into three pathways, namely the canonical Wnt/beta-catenin pathway, and the non-canonical (or heretical) Wnt/Ca(2+) and planar cell polarity (PCP) pathways. Although the canonical Wnt/beta-catenin pathway is the best described in cancer, increasing data points to the importance of the heretical Wnt pathways in several aspects of tumor progression. The recent advances in understanding the players and mechanisms by which these Wnt pathways contribute to cancer progression have led to the identification of numerous molecules that are already, or could be considered, targets for cancer therapy.
Collapse
Affiliation(s)
- Tura C Camilli
- Laboratory of Immunology and Research Resources Branch, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | | |
Collapse
|