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Schulz E, Holtzman NG, Ostojic A, Pirsl F, Steinberg SM, Curtis LM, Shaffer BC, Heller T, Carpenter A, Beshensky D, Rubin JS, Gress RE, Pavletic DSZ. Phase 2 Study of Single High-Dose Palifermin for Graft-Versus-Host Disease Prevention after Matched Unrelated Donor Transplantation. Transplant Cell Ther 2023. [DOI: 10.1016/s2666-6367(23)00407-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Burgess TL, Amason JD, Rubin JS, Duveau DY, Lamy L, Roberts DD, Farrell CL, Inglese J, Thomas CJ, Miller TW. A homogeneous SIRPα-CD47 cell-based, ligand-binding assay: Utility for small molecule drug development in immuno-oncology. PLoS One 2020; 15:e0226661. [PMID: 32240171 PMCID: PMC7117682 DOI: 10.1371/journal.pone.0226661] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 03/06/2020] [Indexed: 01/08/2023] Open
Abstract
CD47 is an immune checkpoint protein that downregulates both the innate and adaptive anti-tumor immune response via its counter receptor SIRPα. Biologics, including humanized CD47 monoclonal antibodies and decoy SIRPα receptors, that block the SIRPα-CD47 interaction, are currently being developed as cancer immunotherapy agents. However, adverse side effects and limited penetration of tumor tissue associated with their structure and large size may impede their clinical application. We recently developed a quantitative high throughput screening assay platform to identify small molecules that disrupt the binding of SIRPα and CD47 as an alternative approach to these protein-based therapeutics. Here, we report on the development and optimization of a cell-based binding assay to validate active small molecules from our biochemical screening effort. This assay has a low volume, high capacity homogenous format that relies on laser scanning cytometry (LSC) and associated techniques to enhance signal to noise measurement of cell surface binding. The LSC assay is specific, concentration dependent, and validated for the two major human SIRPα variants (V1 and V2), with results that parallel those of our biochemical data as well as published studies. We also utilized the LSC assay to confirm published studies showing that the inhibition of amino-terminal pyroglutamate formation on CD47 using the glutaminyl cyclase inhibitor SEN177 disrupts SIRPα binding. The SIRPα-CD47 interaction could be quantitatively measured in live and fixed tumor cells. Use of fixed cells reduces the burden of cell maintenance and provides stable cell standards to control for inter- and intra-assay variations. We also demonstrate the utility of the assay to characterize the activity of the first reported small molecule antagonists of the SIRPα-CD47 interaction. This assay will support the screening of thousands of compounds to identify or validate active small molecules as hits, develop structure activity relationships and assist in the optimization of hits to leads by a typical iterative medicinal chemistry campaign.
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Affiliation(s)
- Teresa L. Burgess
- Paradigm Shift Therapeutics LLC, Rockville, Maryland, United States of America
| | - Joshua D. Amason
- Paradigm Shift Therapeutics LLC, Rockville, Maryland, United States of America
- Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Jeffrey S. Rubin
- Paradigm Shift Therapeutics LLC, Rockville, Maryland, United States of America
| | - Damien Y. Duveau
- Division of Preclinical Innovation, National Center for Advancing Translational Studies, National Institutes of Health, Rockville, Maryland, United States of America
| | - Laurence Lamy
- Division of Preclinical Innovation, National Center for Advancing Translational Studies, National Institutes of Health, Rockville, Maryland, United States of America
| | - David D. Roberts
- Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | | | - James Inglese
- Division of Preclinical Innovation, National Center for Advancing Translational Studies, National Institutes of Health, Rockville, Maryland, United States of America
| | - Craig J. Thomas
- Division of Preclinical Innovation, National Center for Advancing Translational Studies, National Institutes of Health, Rockville, Maryland, United States of America
| | - Thomas W. Miller
- Paradigm Shift Therapeutics LLC, Rockville, Maryland, United States of America
- Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
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Miller TW, Amason JD, Garcin ED, Lamy L, Dranchak PK, Macarthur R, Braisted J, Rubin JS, Burgess TL, Farrell CL, Roberts DD, Inglese J. Quantitative high-throughput screening assays for the discovery and development of SIRPα-CD47 interaction inhibitors. PLoS One 2019; 14:e0218897. [PMID: 31276567 PMCID: PMC6611588 DOI: 10.1371/journal.pone.0218897] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 06/11/2019] [Indexed: 02/06/2023] Open
Abstract
CD47 is an immune checkpoint molecule that downregulates key aspects of both the innate and adaptive anti-tumor immune response via its counter receptor SIRPα, and it is expressed at high levels in a wide variety of tumor types. This has led to the development of biologics that inhibit SIRPα engagement including humanized CD47 antibodies and a soluble SIRPα decoy receptor that are currently undergoing clinical trials. Unfortunately, toxicological issues, including anemia related to on-target mechanisms, are barriers to their clinical advancement. Another potential issue with large biologics that bind CD47 is perturbation of CD47 signaling through its high-affinity interaction with the matricellular protein thrombospondin-1 (TSP1). One approach to avoid these shortcomings is to identify and develop small molecule molecular probes and pretherapeutic agents that would (1) selectively target SIRPα or TSP1 interactions with CD47, (2) provide a route to optimize pharmacokinetics, reduce on-target toxicity and maximize tissue penetration, and (3) allow more flexible routes of administration. As the first step toward this goal, we report the development of an automated quantitative high-throughput screening (qHTS) assay platform capable of screening large diverse drug-like chemical libraries to discover novel small molecules that inhibit CD47-SIRPα interaction. Using time-resolved Förster resonance energy transfer (TR-FRET) and bead-based luminescent oxygen channeling assay formats (AlphaScreen), we developed biochemical assays, optimized their performance, and individually tested them in small-molecule library screening. Based on performance and low false positive rate, the LANCE TR-FRET assay was employed in a ~90,000 compound library qHTS, while the AlphaScreen oxygen channeling assay served as a cross-validation orthogonal assay for follow-up characterization. With this multi-assay strategy, we successfully eliminated compounds that interfered with the assays and identified five compounds that inhibit the CD47-SIRPα interaction; these compounds will be further characterized and later disclosed. Importantly, our results validate the large library qHTS for antagonists of CD47-SIRPα interaction and suggest broad applicability of this approach to screen chemical libraries for other protein-protein interaction modulators.
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Affiliation(s)
- Thomas W. Miller
- Paradigm Shift Therapeutics LLC, Rockville, Maryland, United States of America
- Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Joshua D. Amason
- Paradigm Shift Therapeutics LLC, Rockville, Maryland, United States of America
- Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Elsa D. Garcin
- Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Catonsville, Maryland, United States of America
| | - Laurence Lamy
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland, United States of America
| | - Patricia K. Dranchak
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland, United States of America
| | - Ryan Macarthur
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland, United States of America
| | - John Braisted
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland, United States of America
| | - Jeffrey S. Rubin
- Paradigm Shift Therapeutics LLC, Rockville, Maryland, United States of America
| | - Teresa L. Burgess
- Paradigm Shift Therapeutics LLC, Rockville, Maryland, United States of America
| | | | - David D. Roberts
- Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - James Inglese
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland, United States of America
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Tripurani SK, Wang Y, Fan YX, Rahimi M, Wong L, Lee MH, Starost MF, Rubin JS, Johnson GR. Suppression of Wnt/β-catenin signaling by EGF receptor is required for hair follicle development. Mol Biol Cell 2018; 29:2784-2799. [PMID: 30188763 PMCID: PMC6249831 DOI: 10.1091/mbc.e18-08-0488] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Mice that lack the epidermal growth factor receptor (EGFR) fail to develop a hair coat, but the mechanism responsible for this deficit is not completely understood. Here, we show that EGFR plays a critical role to attenuate wingless-type MMTV integration site family member (Wnt)/β-catenin signaling during postnatal hair follicle development. Genetic ablation of EGFR in mice resulted in increased mitotic activity in matrix cells, apoptosis in hair follicles, and impaired differentiation of epithelial lineages that form hair. EGFR is activated in wild-type hair follicle stem cells marked with SOX9 or NFATc1 and is essential to restrain proliferation and support stem cell numbers and their quiescence. We observed elevated levels of Wnt4, 6, 7b, 10a, 10b, and 16 transcripts and hyperactivation of the β-catenin pathway in EGFR knockout follicles. Using primary keratinocytes, we linked ligand-induced EGFR activation to suppression of nascent mRNA synthesis of Wnt genes. Overexpression of the Wnt antagonist sFRP1 in mice lacking EGFR demonstrated that elevated Wnts are a major cause for the hair follicle defects. Colocalization of transforming growth factor α and Wnts regulated by EGFR in stem cells and progeny indicates that EGFR autocrine loops control Wnts. Our findings define a novel mechanism that integrates EGFR and Wnt/β-catenin pathways to coordinate the delicate balance between proliferation and differentiation during development.
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Affiliation(s)
- Swamy K Tripurani
- Division of Biotechnology Review and Research IV, Office of Biotechnology Products, Office of Pharmaceutical Quality, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, MD 20993
| | - Yan Wang
- Division of Biotechnology Review and Research IV, Office of Biotechnology Products, Office of Pharmaceutical Quality, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, MD 20993
| | - Ying-Xin Fan
- Division of Biotechnology Review and Research IV, Office of Biotechnology Products, Office of Pharmaceutical Quality, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, MD 20993
| | - Massod Rahimi
- Division of Biotechnology Review and Research IV, Office of Biotechnology Products, Office of Pharmaceutical Quality, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, MD 20993
| | - Lily Wong
- Division of Biotechnology Review and Research IV, Office of Biotechnology Products, Office of Pharmaceutical Quality, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, MD 20993
| | - Min-Hyung Lee
- Division of Biotechnology Review and Research IV, Office of Biotechnology Products, Office of Pharmaceutical Quality, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, MD 20993
| | - Matthew F Starost
- Diagnostic and Research Services Branch, Office of the Director, National Institutes of Health, Bethesda, MD 20892
| | - Jeffrey S Rubin
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Institutes of Health, Bethesda, MD 20892
| | - Gibbes R Johnson
- Division of Biotechnology Review and Research IV, Office of Biotechnology Products, Office of Pharmaceutical Quality, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, MD 20993
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Greer YE, Gao B, Yang Y, Nussenzweig A, Rubin JS. Lack of Casein Kinase 1 Delta Promotes Genomic Instability - The Accumulation of DNA Damage and Down-Regulation of Checkpoint Kinase 1. PLoS One 2017; 12:e0170903. [PMID: 28125685 PMCID: PMC5268481 DOI: 10.1371/journal.pone.0170903] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 01/12/2017] [Indexed: 12/18/2022] Open
Abstract
Casein kinase 1 delta (CK1δ) is a conserved serine/threonine protein kinase that regulates diverse cellular processes. Mice lacking CK1δ have a perinatal lethal phenotype and typically weigh 30% less than their wild type littermates. However, the causes of death and small size are unknown. We observed cells with abnormally large nuclei in tissue from Csnk1d null embryos, and multiple centrosomes in mouse embryo fibroblasts (MEFs) deficient in CK1δ (MEFCsnk1d null). Results from γ-H2AX staining and the comet assay demonstrated significant DNA damage in MEFCsnk1d null cells. These cells often contain micronuclei, an indicator of genomic instability. Similarly, abrogation of CK1δ expression in control MEFs stimulated micronuclei formation after doxorubicin treatment, suggesting that CK1δ loss increases vulnerability to genotoxic stress. Cellular levels of total and activated checkpoint kinase 1 (Chk1), which functions in the DNA damage response and mitotic checkpoints, and its downstream effector, Cdc2/CDK1 kinase, were often decreased in MEFCsnk1d null cells as well as in control MEFs transfected with CK1δ siRNA. Hydroxyurea-induced Chk1 activation, as measured by Ser345 phosphorylation, and nuclear localization also were impaired in MEF cells following siRNA knockdown of CK1δ. Similar results were observed in the MCF7 human breast cancer cell line. The decreases in phosphorylated Chk1 were rescued by concomitant expression of siRNA-resistant CK1δ. Experiments with cycloheximide demonstrated that the stability of Chk1 protein was diminished in cells subjected to CK1δ knockdown. Together, these findings suggest that CK1δ contributes to the efficient repair of DNA damage and the proper functioning of mitotic checkpoints by maintaining appropriate levels of Chk1.
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Affiliation(s)
- Yoshimi Endo Greer
- Laboratory of Cellular and Molecular Biology, National Cancer Institute, Bethesda, Maryland, United States of America
- Women’s Malignancies Branch, National Cancer Institute, Bethesda, Maryland, United States of America
- * E-mail: (YEG); (JSR)
| | - Bo Gao
- Genetic Disease Research Branch, National Human Genome Research Institute, Bethesda, Maryland, United States of America
| | - Yingzi Yang
- Genetic Disease Research Branch, National Human Genome Research Institute, Bethesda, Maryland, United States of America
| | - Andre Nussenzweig
- Laboratory of Genome Integrity, National Cancer Institute, Bethesda, Maryland, United States of America
| | - Jeffrey S. Rubin
- Laboratory of Cellular and Molecular Biology, National Cancer Institute, Bethesda, Maryland, United States of America
- * E-mail: (YEG); (JSR)
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Reinherz BJ, Rubin JS. Spontaneous Closure of a Full-Thickness Macular Hole Associated with Proliferative Diabetic Retinopathy and Persistent Vitreomacular Traction. Case Rep Ophthalmol 2016; 7:163-6. [PMID: 27099607 PMCID: PMC4836124 DOI: 10.1159/000444657] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Diabetic retinopathy worsens the prognosis of macular holes compared to those of idiopathic etiology. While spontaneous closure of idiopathic macular holes is a well-documented phenomenon, spontaneous closure of macular holes associated with proliferative diabetic retinopathy is rare. We report a case of spontaneous closure of a macular hole associated with proliferative diabetic retinopathy and persistent vitreomacular traction.
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Affiliation(s)
| | - Jeffrey S Rubin
- New York Eye and Ear Infirmary of Mount Sinai School of Medicine, New York, N.Y., USA
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Mat Baki M, Wood G, Alston M, Ratcliffe P, Sandhu G, Rubin JS, Birchall MA. Reliability of OperaVOX against Multidimensional Voice Program (MDVP). Clin Otolaryngol 2015; 40:22-8. [PMID: 25263076 DOI: 10.1111/coa.12313] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/07/2014] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To evaluate the agreement between OperaVOX and MDVP. DESIGN Cross sectional reliability study. SETTING University teaching hospital. METHODS Fifty healthy volunteers and 50 voice disorder patients had supervised recordings in a quiet room using OperaVOX by the iPod's internal microphone with sampling rate of 45 kHz. A five-seconds recording of vowel/a/was used to measure fundamental frequency (F0), jitter, shimmer and noise-to-harmonic ratio (NHR). All healthy volunteers and 21 patients had a second recording. The recorded voices were also analysed using the MDVP. The inter- and intrasoftware reliability was analysed using intraclass correlation (ICC) test and Bland-Altman (BA) method. Mann-Whitney test was used to compare the acoustic parameters between healthy volunteers and patients. RESULTS Nine of 50 patients had severe aperiodic voice. The ICC was high with a confidence interval of >0.75 for the inter- and intrasoftware reliability except for the NHR. For the intersoftware BA analysis, excluding the severe aperiodic voice data sets, the bias (95% LOA) of F0, jitter, shimmer and NHR was 0.81 (11.32, -9.71); -0.13 (1.26, -1.52); -0.52 (1.68, -2.72); and 0.08 (0.27, -0.10). For the intrasoftware reliability, it was -1.48 (18.43, -21.39); 0.05 (1.31, -1.21); -0.01 (2.87, -2.89); and 0.005 (0.20, -0.18), respectively. Normative data from the healthy volunteers were obtained. There was a significant difference in all acoustic parameters between volunteers and patients measured by the Opera-VOX (P < 0.001) except for F0 in females (P = 0.87). CONCLUSION OperaVOX is comparable to MDVP and has high internal consistency for measuring the F0, jitter and shimmer of voice except for the NHR.
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Affiliation(s)
- M Mat Baki
- Ear Institute, University College London, London, UK; Royal National Throat Nose Ear Hospital, University College London Hospital NHS Trust, London, UK; Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
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Dijksterhuis JP, Baljinnyam B, Stanger K, Sercan HO, Ji Y, Andres O, Rubin JS, Hannoush RN, Schulte G. Systematic mapping of WNT-FZD protein interactions reveals functional selectivity by distinct WNT-FZD pairs. J Biol Chem 2015; 290:6789-98. [PMID: 25605717 DOI: 10.1074/jbc.m114.612648] [Citation(s) in RCA: 105] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The seven-transmembrane-spanning receptors of the FZD1-10 class are bound and activated by the WNT family of lipoglycoproteins, thereby inducing a complex network of signaling pathways. However, the specificity of the interaction between mammalian WNT and FZD proteins and the subsequent signaling cascade downstream of the different WNT-FZD pairs have not been systematically addressed to date. In this study, we determined the binding affinities of various WNTs for different members of the FZD family by using bio-layer interferometry and characterized their functional selectivity in a cell system. Using purified WNTs, we show that different FZD cysteine-rich domains prefer to bind to distinct WNTs with fast on-rates and slow off-rates. In a 32D cell-based system engineered to overexpress FZD2, FZD4, or FZD5, we found that WNT-3A (but not WNT-4, -5A, or -9B) activated the WNT-β-catenin pathway through FZD2/4/5 as measured by phosphorylation of LRP6 and β-catenin stabilization. Surprisingly, different WNT-FZD pairs showed differential effects on phosphorylation of DVL2 and DVL3, revealing a previously unappreciated DVL isoform selectivity by different WNT-FZD pairs in 32D cells. In summary, we present extensive mapping of WNT-FZD cysteine-rich domain interactions complemented by analysis of WNT-FZD pair functionality in a unique cell system expressing individual FZD isoforms. Differential WNT-FZD binding and selective functional readouts suggest that endogenous WNT ligands evolved with an intrinsic natural bias toward different downstream signaling pathways, a phenomenon that could be of great importance in the design of FZD-targeting drugs.
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Affiliation(s)
- Jacomijn P Dijksterhuis
- From the Section of Receptor Biology and Signaling, Department of Physiology and Pharmacology, Karolinska Institutet, S-171 77 Stockholm, Sweden, the Laboratory of Cellular and Molecular Biology, Center for Cancer Research, NCI, National Institutes of Health, Bethesda, Maryland 20892
| | - Bolormaa Baljinnyam
- the Laboratory of Cellular and Molecular Biology, Center for Cancer Research, NCI, National Institutes of Health, Bethesda, Maryland 20892
| | - Karen Stanger
- the Department of Early Discovery Biochemistry, Genentech, South San Francisco, California 94080, and
| | - Hakki O Sercan
- the Laboratory of Cellular and Molecular Biology, Center for Cancer Research, NCI, National Institutes of Health, Bethesda, Maryland 20892
| | - Yun Ji
- the Laboratory of Cellular and Molecular Biology, Center for Cancer Research, NCI, National Institutes of Health, Bethesda, Maryland 20892
| | - Osler Andres
- the Laboratory of Cellular and Molecular Biology, Center for Cancer Research, NCI, National Institutes of Health, Bethesda, Maryland 20892
| | - Jeffrey S Rubin
- the Laboratory of Cellular and Molecular Biology, Center for Cancer Research, NCI, National Institutes of Health, Bethesda, Maryland 20892
| | - Rami N Hannoush
- the Department of Early Discovery Biochemistry, Genentech, South San Francisco, California 94080, and
| | - Gunnar Schulte
- From the Section of Receptor Biology and Signaling, Department of Physiology and Pharmacology, Karolinska Institutet, S-171 77 Stockholm, Sweden, the Faculty of Science, Institute of Experimental Biology, Masaryk University, 611 37 Brno, Czech Republic
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Posokhova E, Shukla A, Seaman S, Volate S, Hilton MB, Wu B, Morris H, Swing DA, Zhou M, Zudaire E, Rubin JS, St Croix B. GPR124 functions as a WNT7-specific coactivator of canonical β-catenin signaling. Cell Rep 2014; 10:123-30. [PMID: 25558062 DOI: 10.1016/j.celrep.2014.12.020] [Citation(s) in RCA: 117] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Revised: 11/25/2014] [Accepted: 12/09/2014] [Indexed: 01/08/2023] Open
Abstract
G protein-coupled receptor 124 (GPR124) is an orphan receptor in the adhesion family of GPCRs, and previous global or endothelial-specific disruption of Gpr124 in mice led to defective CNS angiogenesis and blood-brain barriergenesis. Similar developmental defects were observed following dual deletion of Wnt7a/Wnt7b or deletion of β-catenin in endothelial cells, suggesting a possible relationship between GPR124 and canonical WNT signaling. Here, we show using in vitro reporter assays, mutation analysis, and genetic interaction studies in vivo that GPR124 functions as a WNT7A/WNT7B-specific costimulator of β-catenin signaling in brain endothelium. WNT7-stimulated β-catenin signaling was dependent upon GPR124's intracellular PDZ binding motif and a set of leucine-rich repeats in its extracellular domain. This study reveals a vital role for GPR124 in potentiation of WNT7-induced canonical β-catenin signaling with important implications for understanding and manipulating CNS-specific angiogenesis and blood-brain barrier-genesis.
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Affiliation(s)
- Ekaterina Posokhova
- Tumor Angiogenesis Section, Mouse Cancer Genetics Program (MCGP), National Cancer Institute (NCI) at Frederick, National Institutes of Health (NIH), Frederick, MD 21702, USA
| | - Animesh Shukla
- Tumor Angiogenesis Section, Mouse Cancer Genetics Program (MCGP), National Cancer Institute (NCI) at Frederick, National Institutes of Health (NIH), Frederick, MD 21702, USA
| | - Steven Seaman
- Tumor Angiogenesis Section, Mouse Cancer Genetics Program (MCGP), National Cancer Institute (NCI) at Frederick, National Institutes of Health (NIH), Frederick, MD 21702, USA
| | - Suresh Volate
- Tumor Angiogenesis Section, Mouse Cancer Genetics Program (MCGP), National Cancer Institute (NCI) at Frederick, National Institutes of Health (NIH), Frederick, MD 21702, USA
| | - Mary Beth Hilton
- Tumor Angiogenesis Section, Mouse Cancer Genetics Program (MCGP), National Cancer Institute (NCI) at Frederick, National Institutes of Health (NIH), Frederick, MD 21702, USA; Basic Research Program, Frederick National Laboratory for Cancer Research (FNLCR), Leidos, Inc., Frederick, MD 21702, USA
| | - Bofan Wu
- Tumor Angiogenesis Section, Mouse Cancer Genetics Program (MCGP), National Cancer Institute (NCI) at Frederick, National Institutes of Health (NIH), Frederick, MD 21702, USA
| | - Holly Morris
- Transgenic Core Facility, MCGP, NCI, Frederick, MD 21702, USA
| | - Deborah A Swing
- Transgenic Core Facility, MCGP, NCI, Frederick, MD 21702, USA
| | - Ming Zhou
- Laboratory of Proteomics and Analytical Technologies, FNLCR, Leidos, Inc., Frederick, MD 21702, USA
| | - Enrique Zudaire
- Tumor Angiogenesis Section, Mouse Cancer Genetics Program (MCGP), National Cancer Institute (NCI) at Frederick, National Institutes of Health (NIH), Frederick, MD 21702, USA
| | - Jeffrey S Rubin
- Laboratory of Cellular and Molecular Biology, NCI, NIH, Bethesda, MD 20892, USA
| | - Brad St Croix
- Tumor Angiogenesis Section, Mouse Cancer Genetics Program (MCGP), National Cancer Institute (NCI) at Frederick, National Institutes of Health (NIH), Frederick, MD 21702, USA.
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Abstract
Abstract
Casein kinase 1 delta (CK1δ) is a conserved serine/threonine protein kinase that regulates diverse cellular processes including vesicle trafficking, cell cycle progression, chromosomal segregation, DNA repair, circadian rhythm, neurite outgrowth and ciliogenesis. CK1δ has been reported to phosphorylate Mdm2, the E3 ubiquitin ligase for p53, resulting in Mdm2 ubiquitination/degradation and concomitant accumulation of p53, the latter functioning as a mediator of cell cycle checkpoints and DNA repair. Mice that lack Csnk1d exhibit a perinatal lethal phenotype and typically weigh 30-50% less than their wild type littermates. The exact causes of death and small size are unknown. We hypothesized that the absence of CK1δ initiates cellular stresses that adversely affect cell survival. To examine this idea, we collected mouse embryonic fibroblasts (MEFs) from mice homozygous for a Csnk1d floxed allele, and generated MEF Csnk1d null cells by infection with adenovirus expressing Cre. Endogenous p53 protein level was significantly lower in MEF Csnk1d null cells relative to MEF Ctl cells infected with adenovirus-GFP. Substantial DNA damage also was detected in MEF Csnk1d null cells, as measured by γ-H2AX staining. Flow cytometric analysis revealed that early passage (P3) MEF Csnk1d null cells exhibited a larger sub-G0 fraction (64%) than MEF Ctl cells (34%). The sub-G0 fraction decreased sharply with increasing passage number, becoming negligible by P10. In addition to the decline in sub-G0 fraction, we observed a transient population of MEF Csnk1d null cells with multiple DAPI-stained micronuclei containing both γ-H2AX and membranes positive for the autophagosomal marker LC3 and lysosomal marker LAMP1. These features were preceded by and coincided with mTORC1 pathway inactivation, as indicated by low concentrations of phospho-Akt, phospho-mTOR and phospho-S6K, consistent with the view that mTORC1 inhibition facilitates the induction of autophagy. Subsequently, these differences between MEF Csnk1d null and MEF Ctl cells subsided. Our findings demonstrate that loss of CK1δ expression in proliferating MEF cells results in DNA damage and initially a large sub-G0 peak, followed by a wave of nucleophagy and ultimately cell survival in culture. Ongoing investigation will explore whether similar processes occur in embryonic tissues from Csnk1d null mice and contribute to their pathologic phenotype.
Citation Format: Yoshimi Endo Greer, Bo Gao, Yingzi Yang, Jeffrey S. Rubin. Lack of casein kinase 1 delta induces DNA damage, inhibition of mTORC1 signaling and nucleophagy. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1335. doi:10.1158/1538-7445.AM2014-1335
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Affiliation(s)
| | - Bo Gao
- 2NHGRI, NIH, Bethesda, MD
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Gao W, Kim H, Feng M, Phung Y, Xavier CP, Rubin JS, Ho M. Inactivation of Wnt signaling by a human antibody that recognizes the heparan sulfate chains of glypican-3 for liver cancer therapy. Hepatology 2014; 60:576-87. [PMID: 24492943 PMCID: PMC4083010 DOI: 10.1002/hep.26996] [Citation(s) in RCA: 126] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Accepted: 12/23/2013] [Indexed: 12/21/2022]
Abstract
UNLABELLED Wnt signaling is important for cancer pathogenesis and is often up-regulated in hepatocellular carcinoma (HCC). Heparan sulfate proteoglycans (HSPGs) function as coreceptors or modulators of Wnt activation. Glypican-3 (GPC3) is an HSPG that is highly expressed in HCC, where it can attract Wnt proteins to the cell surface and promote cell proliferation. Thus, GPC3 has emerged as a candidate therapeutic target in liver cancer. While monoclonal antibodies to GPC3 are currently being evaluated in preclinical and clinical studies, none have shown an effect on Wnt signaling. Here, we first document the expression of Wnt3a, multiple Wnt receptors, and GPC3 in several HCC cell lines, and demonstrate that GPC3 enhanced the activity of Wnt3a/β-catenin signaling in these cells. Then we report the identification of HS20, a human monoclonal antibody against GPC3, which preferentially recognized the heparan sulfate chains of GPC3, both the sulfated and nonsulfated portions. HS20 disrupted the interaction of Wnt3a and GPC3 and blocked Wnt3a/β-catenin signaling. Moreover, HS20 inhibited Wnt3a-dependent cell proliferation in vitro and HCC xenograft growth in nude mice. In addition, HS20 had no detectable undesired toxicity in mice. Taken together, our results show that a monoclonal antibody primarily targeting the heparin sulfate chains of GPC3 inhibited Wnt/β-catenin signaling in HCC cells and had potent antitumor activity in vivo. CONCLUSION An antibody directed against the heparan sulfate of a proteoglycan shows efficacy in blocking Wnt signaling and HCC growth, suggesting a novel strategy for liver cancer therapy.
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Affiliation(s)
- Wei Gao
- Laboratory of Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Heungnam Kim
- Laboratory of Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Mingqian Feng
- Laboratory of Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Yen Phung
- Laboratory of Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Charles P. Xavier
- Laboratory of Cellular and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Jeffrey S. Rubin
- Laboratory of Cellular and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Mitchell Ho
- Laboratory of Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892,Corresponding Author: Dr. Mitchell Ho, Antibody Therapy Section, Laboratory of Molecular Biology, National Cancer Institute, National Institutes of Health, 37 Convent Drive, Room 5002C, Bethesda, MD 20892-4264. Tel: (301)451-8727; Fax: (301)402-1344;
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13
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Greer YE, Westlake CJ, Gao B, Bharti K, Shiba Y, Xavier CP, Pazour GJ, Yang Y, Rubin JS. Casein kinase 1δ functions at the centrosome and Golgi to promote ciliogenesis. Mol Biol Cell 2014; 25:1629-40. [PMID: 24648492 PMCID: PMC4019494 DOI: 10.1091/mbc.e13-10-0598] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
CK1δ acts at the centrosome and Golgi to support polarized transport for ciliogenesis. It controls distribution of ciliary effectors Rab11, Rab8, CEP290, PCM1, and IFT20 and also promotes MT nucleation at the Golgi and positioning and integrity of the Golgi. Interaction of CK1δ with AKAP450 mediates Golgi MT nucleation and ciliogenesis. Inhibition of casein kinase 1 delta (CK1δ) blocks primary ciliogenesis in human telomerase reverse transcriptase immortalized retinal pigmented epithelial and mouse inner medullary collecting duct cells-3. Mouse embryonic fibroblasts (MEFs) and retinal cells from Csnk1d (CK1δ)-null mice also exhibit ciliogenesis defects. CK1δ catalytic activity and centrosomal localization signal (CLS) are required to rescue cilia formation in MEFsCsnk1d null. Furthermore, expression of a truncated derivative containing the CLS displaces full-length CK1δ from the centrosome and decreases ciliary length in control MEFs, suggesting that centrosomal CK1δ has a role in ciliogenesis. CK1δ inhibition also alters pericentrosomal or ciliary distribution of several proteins involved in ciliary transport, including Ras-like in rat brain-11A, Ras-like in rat brain-8A, centrosomal protein of 290 kDa, pericentriolar material protein 1, and polycystin-2, as well as the Golgi distribution of its binding partner, A-kinase anchor protein 450 (AKAP450). As reported for AKAP450, CK1δ was required for microtubule nucleation at the Golgi and maintenance of Golgi integrity. Overexpression of an AKAP450 fragment containing the CK1δ-binding site inhibits Golgi-derived microtubule nucleation, Golgi distribution of intraflagellar transport protein 20 homologue, and ciliogenesis. Our results suggest that CK1δ mediates primary ciliogenesis by multiple mechanisms, one involving its centrosomal function and another dependent on its interaction with AKAP450 at the Golgi, where it is important for maintaining Golgi organization and polarized trafficking of multiple factors that mediate ciliary transport.
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Affiliation(s)
- Yoshimi Endo Greer
- Laboratory of Cellular and Molecular Biology, National Cancer Institute, Bethesda, MD 20892
| | - Christopher J Westlake
- Laboratory of Cell and Developmental Signaling, National Cancer Institute, Frederick, MD 21702
| | - Bo Gao
- Genetic Disease Research Branch, National Human Genome Research Institute, Bethesda, MD 20892
| | - Kapil Bharti
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, Bethesda, MD 20892
| | - Yoko Shiba
- Laboratory of Cellular and Molecular Biology, National Cancer Institute, Bethesda, MD 20892
| | - Charles P Xavier
- Laboratory of Cellular and Molecular Biology, National Cancer Institute, Bethesda, MD 20892
| | - Gregory J Pazour
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605
| | - Yingzi Yang
- Genetic Disease Research Branch, National Human Genome Research Institute, Bethesda, MD 20892
| | - Jeffrey S Rubin
- Laboratory of Cellular and Molecular Biology, National Cancer Institute, Bethesda, MD 20892
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Xavier CP, Melikova M, Chuman Y, Üren A, Baljinnyam B, Rubin JS. Secreted Frizzled-related protein potentiation versus inhibition of Wnt3a/β-catenin signaling. Cell Signal 2013; 26:94-101. [PMID: 24080158 DOI: 10.1016/j.cellsig.2013.09.016] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Revised: 09/18/2013] [Accepted: 09/23/2013] [Indexed: 01/22/2023]
Abstract
Wnt signaling regulates a variety of cellular processes during embryonic development and in the adult. Many of these activities are mediated by the Frizzled family of seven-pass transmembrane receptors, which bind Wnts via a conserved cysteine-rich domain (CRD). Secreted Frizzled-related proteins (sFRPs) contain an amino-terminal, Frizzled-like CRD and a carboxyl-terminal, heparin-binding netrin-like domain. Previous studies identified sFRPs as soluble Wnt antagonists that bind directly to Wnts and prevent their interaction with Frizzleds. However, subsequent observations suggested that sFRPs and Frizzleds form homodimers and heterodimers via their respective CRDs, and that sFRPs can stimulate signal transduction. Here, we present evidence that sFRP1 either inhibits or enhances signaling in the Wnt3a/β-catenin pathway, depending on its concentration and the cellular context. Nanomolar concentrations of sFRP1 increased Wnt3a signaling, while higher concentrations blocked it in HEK293 cells expressing a SuperTopFlash reporter. sFRP1 primarily augmented Wnt3a/β-catenin signaling in C57MG cells, but it behaved as an antagonist in L929 fibroblasts. sFRP1 enhanced reporter activity in L cells that were engineered to stably express Frizzled 5, though not Frizzled 2. This implied that the Frizzled expression pattern could determine the response to sFRP1. Similar results were obtained with sFRP2 in HEK293, C57MG and L cell reporter assays. CRDsFRP1 mimicked the potentiating effect of sFRP1 in multiple settings, contradicting initial expectations that this domain would inhibit Wnt signaling. Moreover, CRDsFRP1 showed little avidity for Wnt3a compared to sFRP1, implying that the mechanism for potentiation by CRDsFRP1 probably does not require an interaction with Wnt protein. Together, these findings demonstrate that sFRPs can either promote or suppress Wnt/β-catenin signaling, depending on cellular context, concentration and most likely the expression pattern of Fzd receptors.
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Affiliation(s)
- Charles P Xavier
- Laboratory of Cellular and Molecular Biology, National Cancer Institute, Bethesda, MD 20892, United States
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15
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Rubin JS. Recent developments in palifermin basic, pre-clinical and clinical research. J Cell Mol Med 2013; 17:1063-4. [PMID: 24151974 PMCID: PMC4118165 DOI: 10.1111/jcmm.12132] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 08/15/2013] [Indexed: 11/30/2022] Open
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González-Sancho JM, Greer YE, Abrahams CL, Takigawa Y, Baljinnyam B, Lee KH, Lee KS, Rubin JS, Brown AMC. Functional consequences of Wnt-induced dishevelled 2 phosphorylation in canonical and noncanonical Wnt signaling. J Biol Chem 2013; 288:9428-37. [PMID: 23396967 DOI: 10.1074/jbc.m112.448480] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Dishevelled (Dvl) proteins are intracellular effectors of Wnt signaling that have essential roles in both canonical and noncanonical Wnt pathways. It has long been known that Wnts stimulate Dvl phosphorylation, but relatively little is known about its functional significance. We have previously reported that both Wnt3a and Wnt5a induce Dvl2 phosphorylation that is associated with an electrophoretic mobility shift and loss of recognition by monoclonal antibody 10B5. In the present study, we mapped the 10B5 epitope to a 16-amino acid segment of human Dvl2 (residues 594-609) that contains four Ser/Thr residues. Alanine substitution of these residues (P4m) eliminated the mobility shift induced by either Wnt3a or Wnt5a. The Dvl2 P4m mutant showed a modest increase in canonical Wnt/β-catenin signaling activity relative to wild type. Consistent with this finding, Dvl2 4Pm preferentially localized to cytoplasmic puncta. In contrast to wild-type Dvl2, however, the P4m mutant was unable to rescue Wnt3a-dependent neurite outgrowth in TC-32 cells following suppression of endogenous Dvl2/3. Earlier work has implicated casein kinase 1δ/ε as responsible for the Dvl mobility shift, and a CK1δ in vitro kinase assay confirmed that Ser(594), Thr(595), and Ser(597) of Dvl2 are CK1 targets. Alanine substitution of these three residues was sufficient to abrogate the Wnt-dependent mobility shift. Thus, we have identified a cluster of Ser/Thr residues in the C-terminal domain of Dvl2 that are Wnt-induced phosphorylation (WIP) sites. Our results indicate that phosphorylation at the WIP sites reduces Dvl accumulation in puncta and attenuates β-catenin signaling, whereas it enables noncanonical signaling that is required for neurite outgrowth.
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Affiliation(s)
- José M González-Sancho
- Department of Cell and Developmental Biology, Weill Cornell Medical College, New York, NY 10065, USA
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Greer YE, Fields AP, Brown AMC, Rubin JS. Atypical protein kinase Cι is required for Wnt3a-dependent neurite outgrowth and binds to phosphorylated dishevelled 2. J Biol Chem 2013; 288:9438-46. [PMID: 23396968 DOI: 10.1074/jbc.m112.448282] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Previously we reported that Wnt3a-dependent neurite outgrowth in Ewing sarcoma family tumor cell lines was mediated by Frizzled3, Dishevelled (Dvl), and c-Jun N-terminal kinase (Endo, Y., Beauchamp, E., Woods, D., Taylor, W. G., Toretsky, J. A., Uren, A., and Rubin, J. S. (2008) Mol. Cell. Biol. 28, 2368-2379). Subsequently, we observed that Dvl2/3 phosphorylation correlated with neurite outgrowth and that casein kinase 1δ, one of the enzymes that mediate Wnt3a-dependent Dvl phosphorylation, was required for neurite extension (Greer, Y. E., and Rubin, J. S. (2011) J. Cell Biol. 192, 993-1004). However, the functional relevance of Dvl phosphorylation in neurite outgrowth was not established. Dvl1 has been shown by others to be important for axon specification in hippocampal neurons via an interaction with atypical PKCζ, but the role of Dvl phosphorylation was not evaluated. Here we report that Ewing sarcoma family tumor cells express PKCι but not PKCζ. Wnt3a stimulated PKCι activation and caused a punctate distribution of pPKCι in the neurites and cytoplasm, with a particularly intense signal at the centrosome. Knockdown of PKCι expression with siRNA reagents blocked neurite formation in response to Wnt3a. Aurothiomalate, a specific inhibitor of PKCι/Par6 binding, also suppressed neurite extension. Wnt3a enhanced the co-immunoprecipitation of endogenous PKCι and Dvl2. Although FLAG-tagged wild-type Dvl2 immunoprecipitated with PKCι, a phosphorylation-deficient Dvl2 derivative did not. This derivative also was unable to rescue neurite outgrowth when endogenous Dvl2/3 was suppressed by siRNA (González-Sancho, J. M., Greer, Y. E., Abrahams, C. L., Takigawa, Y., Baljinnyam, B., Lee, K. H., Lee, K. S., Rubin, J. S., and Brown, A. M. (2013) J. Biol. Chem. 288, 9428-9437). Taken together, these results suggest that site-specific Dvl2 phosphorylation is required for Dvl2 association with PKCι. This interaction is likely to be one of the mechanisms essential for Wnt3a-dependent neurite outgrowth.
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Affiliation(s)
- Yoshimi Endo Greer
- From the Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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18
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Mao W, Millar JC, Wang WH, Silverman SM, Liu Y, Wordinger RJ, Rubin JS, Pang IH, Clark AF. Existence of the canonical Wnt signaling pathway in the human trabecular meshwork. Invest Ophthalmol Vis Sci 2012; 53:7043-51. [PMID: 22956608 DOI: 10.1167/iovs.12-9664] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
PURPOSE We previously discovered elevated levels of secreted frizzled-related protein 1 (sFRP1), the Wnt signaling pathway inhibitor, in the glaucomatous trabecular meshwork (GTM), and found that key canonical Wnt signaling pathway genes are expressed in the trabecular meshwork (TM). The purpose of our study was to determine whether a functional canonical Wnt signaling pathway exists in the human TM (HTM). METHODS Western immunoblotting and/or immunofluorescent microscopy were used to study β-catenin translocation as well as the actin cytoskeleton in transformed and primary HTM cells. A TCF/LEF luciferase assay was used to study functional canonical Wnt signaling, which was confirmed further by WNT3a-induced expression of a pathway target gene, AXIN2, via quantitative PCR. Intravitreal injection of an Ad5 adenovirus expressing Dickkopf-related protein-1 (DKK1) was used to study the in vivo effect of canonical Wnt signaling on IOP in mice. RESULTS WNT3a induced β-catenin translocation in the HTM, which was blocked by co-treatment with sFRP1. Similarly, WNT3a enhanced luciferase levels in TCF/LEF luciferase assays, which also were blocked by sFRP1. Furthermore, AXIN2 expression was elevated significantly by WNT3a. However, neither WNT3a nor sFRP1 affected actin cytoskeleton organization, which theoretically could be regulated by noncanonical Wnt signaling in HTM cells. Exogenous DKK1, a specific inhibitor for the canonical Wnt signaling pathway, or sFRP1 elevated mouse IOP to equivalent levels. CONCLUSIONS There is a canonical Wnt signaling pathway in the TM, and this canonical Wnt pathway, but not the noncanonical Wnt signaling pathway, regulates IOP.
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Affiliation(s)
- Weiming Mao
- Department of Cell Biology and Anatomy, North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas 76107, USA.
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Kele J, Andersson ER, Villaescusa JC, Cajanek L, Parish CL, Bonilla S, Toledo EM, Bryja V, Rubin JS, Shimono A, Arenas E. SFRP1 and SFRP2 dose-dependently regulate midbrain dopamine neuron development in vivo and in embryonic stem cells. Stem Cells 2012; 30:865-75. [PMID: 22290867 DOI: 10.1002/stem.1049] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Secreted Frizzled related proteins (sFRPs) are a family of proteins that modulate Wnt signaling, which in turn regulates multiple aspects of ventral midbrain (VM) and dopamine (DA) neuron development. However, it is not known which Wnt signaling branch and what aspects of midbrain DA neuron development are regulated by sFRPs. Here, we show that sFRP1 and sFRP2 activate the Wnt/planar-cell-polarity/Rac1 pathway in DA cells. In the developing VM, sFRP1 and sFRP2 are expressed at low levels, and sFRP1-/- or sFRP2-/- mice had no detectable phenotype. However, compound sFRP1-/-;sFRP2-/- mutants revealed a Wnt/PCP phenotype similar to that previously described for Wnt5a-/- mice. This included an anteroposterior shortening of the VM, a lateral expansion of the Shh domain and DA lineage markers (Lmx1a and Th), as well as an accumulation of Nurr1+ precursors in the VM. In vitro experiments showed that, while very high concentrations of SFRP1 had a negative effect on cell survival, low/medium concentrations of sFRP1 or sFRP2 promoted the DA differentiation of progenitors derived from primary VM cultures or mouse embryonic stem cells (ESCs), mimicking the effects of Wnt5a. We thus conclude that the main function of sFRP1 and sFRP2 is to enhance Wnt/PCP signaling in DA cells and to regulate Wnt/PCP-dependent functions in midbrain development. Moreover, we suggest that low-medium concentrations of sFRPs may be used to enhance the DA differentiation of ESCs and improve their therapeutic application.
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Affiliation(s)
- Julianna Kele
- Laboratory of Molecular Neurobiology, Medical Biochemistry and Biophysics, Karolinska Institute, Scheeleväg 1, Stockholm, Sweden
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Klauzinska M, Baljinnyam B, Raafat A, Rodriguez-Canales J, Strizzi L, Greer YE, Rubin JS, Callahan R. Rspo2/Int7 regulates invasiveness and tumorigenic properties of mammary epithelial cells. J Cell Physiol 2012; 227:1960-71. [PMID: 21732367 DOI: 10.1002/jcp.22924] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Rspo2 was identified as a novel common integration site (CIS) for the mouse mammary tumor virus (MMTV) in viral induced mouse mammary tumors. Here we show that Rspo2 modulates Wnt signaling in mouse mammary epithelial cells. Co-expression of both genes resulted in an intermediate growth phenotype on plastic and had minor effects on the growth-promoting properties of Wnt1 in soft agar. However, individual Rspo2 and Wnt1 HC11 transfectants as well as the double transfectant were tumorigenic in athymic nude mice, with tumors from each line having distinctive histological characteristics. Rspo2 and Rspo2/Wnt1 tumors contained many spindle cells, consistent with an epithelial-mesenchymal transformation (EMT) phenotype. When Rspo2 and Rspo2/Wnt1 tumor cells were transferred into naïve mice, they exhibited greater metastatic activity than cells derived from Wnt1 tumors. For comparison, C57MG/Wnt1/Rspo2 co-transfectants exhibited invasive properties in three-dimensional (3D) Matrigel cultures that were not seen with cells transfected only with Wnt1 or Rspo2. Use of Dickkopf-1, a specific antagonist of the Wnt/β-catenin pathway, or short hairpin RNA targeting β-catenin expression demonstrated that the invasive activity was not mediated by β-catenin. Our results indicate that Rspo2 and Wnt1 have mutually distinct effects on mammary epithelial cell growth and these effects are context-dependent. While Rspo2 and Wnt1 act synergistically in the β-catenin pathway, other mechanisms are responsible for the invasive properties of stable double transfectants observed in 3D Matrigel cultures.
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Affiliation(s)
- Malgorzata Klauzinska
- Oncogenetics Section, Mammary Biology and Tumorigenesis Laboratory, National Cancer Institute, Bethesda, MD 20892, USA
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Mao W, Rubin JS, Anoruo N, Wordinger RJ, Clark AF. SFRP1 promoter methylation and expression in human trabecular meshwork cells. Exp Eye Res 2012; 97:130-6. [PMID: 22248913 DOI: 10.1016/j.exer.2012.01.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2011] [Revised: 12/21/2011] [Accepted: 01/03/2012] [Indexed: 11/15/2022]
Abstract
Glaucoma is a leading cause of blindness worldwide. In primary open angle glaucoma (POAG) patients, impaired trabecular meshwork (TM) function results in elevated intraocular pressure (IOP), which is the primary risk factor of developing optic neuropathy. Our previous studies showed that Wnt signaling pathway components are expressed in the human TM (HTM), and the Wnt inhibitor, secreted frizzled-related protein 1 (SFRP1) is elevated in the glaucomatous TM (GTM). Elevated SFRP1 increased IOP in mice eyes and in perfusion cultured anterior segments of the human eye. However, the cause of elevated SFRP1 in the GTM remains unknown. Promoter methylation plays a key role in regulating SFRP1 expression in certain cancer cells. In light of this, we studied whether promoter methylation is also involved in SFRP1 differential expression in the TM. Two normal TM (NTM) and two GTM cell strains were cultured for an additional 7 days after they were confluent. RNA and genomic DNA (gDNA) were isolated simultaneously to compare SFRP1 expression levels by quantitative PCR (qPCR) and to determine SFRP1 promoter methylation status by bisulfite conversion and methylation-sensitive high resolution melting analysis (MS-HRM). To study whether DNA methylation inhibitors affect SFRP1 expression in TM cells, the four TM cell strains were treated with or without 2 μM 5-aza-2'-deoxycytidine (AZA-dC) for 4 days. RNA was isolated to compare SFRP1 expression by qPCR. In addition, a human cancer cell line, NCI-H460, was used as a positive control. We found that the two GTM cell strains had significantly higher expression levels of SFRP1 than the two NTM cell strains. However, the SFRP1 promoter of all four TM cell strains was unmethylated. In addition, AZA-dC treatment did not affect SFRP1 expression in any of the TM cell strains (n = 3, p > 0.05). In contrast, the hypermethylated SFRP1 promoter of NCI-H460 cells was partially demethylated by the same treatment. AZA-dC treatment also elevated SFRP1 expression by approximately two fold in NCI-H460 cells (n = 3, p < 0.01). Our data suggest that the differential expression of SFRP1 in HTM cells is not due to differential promoter methylation.
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Affiliation(s)
- Weiming Mao
- North Texas Eye Research Institute, Department of Cell Biology & Anatomy, University of North Texas Health Science Center, CBH440, Fort Worth, TX 76107, USA.
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Baljinnyam B, Klauzinska M, Saffo S, Callahan R, Rubin JS. Recombinant R-spondin2 and Wnt3a up- and down-regulate novel target genes in C57MG mouse mammary epithelial cells. PLoS One 2012; 7:e29455. [PMID: 22238613 PMCID: PMC3251591 DOI: 10.1371/journal.pone.0029455] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Accepted: 11/29/2011] [Indexed: 01/05/2023] Open
Abstract
R-spondins (Rspos) comprise a family of four secreted proteins that have important roles in cell proliferation, cell fate determination and organogenesis. Rspos typically exert their effects by potentiating the Wnt/β-catenin signaling pathway. To systematically investigate the impact of Rspo/Wnt on gene expression, we performed a microarray analysis using C57MG mouse mammary epithelial cells treated with recombinant Rspo2 and/or Wnt3a. We observed the up- and down-regulation of several previously unidentified target genes, including ones that encode proteins involved in immune responses, effectors of other growth factor signaling pathways and transcription factors. Dozens of these changes were validated by quantitative real time RT-PCR. Time course experiments showed that Rspo2 typically had little or no effect on Wnt-dependent gene expression at 3 or 6 h, but enhanced expression at 24 h, consistent with biochemical data indicating that Rspo2 acts primarily to sustain rather than acutely increase Wnt pathway activation. Up-regulation of gene expression was inhibited by pre-treatment with Dickkopf1, a Wnt/β-catenin pathway antagonist, and by siRNA knockdown of β-catenin expression. While Dickkopf1 blocked Rspo2/Wnt3a-dependent down-regulation, a number of down-regulated genes were not affected by β-catenin knockdown, suggesting that in these instances down-regulation was mediated by a β-catenin-independent mechanism.
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Affiliation(s)
- Bolormaa Baljinnyam
- Laboratory of Cellular and Molecular Biology, National Cancer Institute, Bethesda, Maryland, United States of America
| | - Malgorzata Klauzinska
- Oncogenetics Section, Mammary Biology and Tumorigenesis Laboratory, National Cancer Institute, Bethesda, Maryland, United States of America
| | - Saad Saffo
- Laboratory of Cellular and Molecular Biology, National Cancer Institute, Bethesda, Maryland, United States of America
| | - Robert Callahan
- Oncogenetics Section, Mammary Biology and Tumorigenesis Laboratory, National Cancer Institute, Bethesda, Maryland, United States of America
| | - Jeffrey S. Rubin
- Laboratory of Cellular and Molecular Biology, National Cancer Institute, Bethesda, Maryland, United States of America
- * E-mail:
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Abstract
Previously we determined that Dishevelled-2/3 (Dvl) mediate Wnt-3a-dependent neurite outgrowth in Ewing sarcoma family tumor cells. Here we report that neurite extension was associated with Dvl phosphorylation and that both were inhibited by the casein kinase 1 (CK1) δ/ε inhibitor IC261. Small interfering RNAs targeting either CK1δ or CK1ε decreased Dvl phosphorylation, but only knockdown of CK1δ blocked neurite outgrowth. CK1δ but not CK1ε was detected at the centrosome, an organelle associated with neurite formation. Deletion analysis mapped the centrosomal localization signal (CLS) of CK1δ to its C-terminal domain. A fusion protein containing the CLS and EGFP displaced full-length CK1δ from the centrosome and inhibited Wnt-3a-dependent neurite outgrowth. In contrast to wild-type CK1ε, a chimera comprised of the kinase domain of CK1ε and the CLS of CK1δ localized to the centrosome and rescued Wnt-3a-dependent neurite outgrowth suppressed by CK1δ knockdown. These results provide strong evidence that the centrosomal localization of CK1δ is required for Wnt-3a-dependent neuritogenesis.
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Affiliation(s)
- Yoshimi Endo Greer
- Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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Martin-Manso G, Calzada MJ, Chuman Y, Sipes JM, Xavier CP, Wolf V, Kuznetsova SA, Rubin JS, Roberts DD. sFRP-1 binds via its netrin-related motif to the N-module of thrombospondin-1 and blocks thrombospondin-1 stimulation of MDA-MB-231 breast carcinoma cell adhesion and migration. Arch Biochem Biophys 2011; 509:147-56. [PMID: 21402050 DOI: 10.1016/j.abb.2011.03.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2010] [Revised: 03/03/2011] [Accepted: 03/04/2011] [Indexed: 11/24/2022]
Abstract
Secreted frizzled-related protein (sFRP)-1 is a Wnt antagonist that inhibits breast carcinoma cell motility, whereas the secreted glycoprotein thrombospondin-1 stimulates adhesion and motility of the same cells. We examined whether thrombospondin-1 and sFRP-1 interact directly or indirectly to modulate cell behavior. Thrombospondin-1 bound sFRP-1 with an apparent K(d)=48nM and the related sFRP-2 with a K(d)=95nM. Thrombospondin-1 did not bind to the more distantly related sFRP-3. The association of thrombospondin-1 and sFRP-1 is primarily mediated by the amino-terminal N-module of thrombospondin-1 and the netrin domain of sFRP-1. sFRP-1 inhibited α3β1 integrin-mediated adhesion of MDA-MB-231 breast carcinoma cells to a surface coated with thrombospondin-1 or recombinant N-module, but not adhesion of the cells on immobilized fibronectin or type I collagen. sFRP-1 also inhibited thrombospondin-1-mediated migration of MDA-MB-231 and MDA-MB-468 breast carcinoma cells. Although sFRP-2 binds similarly to thrombospondin-1, it did not inhibit thrombospondin-1-stimulated adhesion. Thus, sFRP-1 binds to thrombospondin-1 and antagonizes stimulatory effects of thrombospondin-1 on breast carcinoma cell adhesion and motility. These results demonstrate that sFRP-1 can modulate breast cancer cell responses by interacting with thrombospondin-1 in addition to its known effects on Wnt signaling.
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Affiliation(s)
- Gema Martin-Manso
- Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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Jones MB, Chu CH, Pendleton JC, Betenbaugh MJ, Shiloach J, Baljinnyam B, Rubin JS, Shamblott MJ. Proliferation and pluripotency of human embryonic stem cells maintained on type I collagen. Stem Cells Dev 2010; 19:1923-35. [PMID: 20367282 DOI: 10.1089/scd.2009.0326] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Human embryonic stem cells (hESC) require a balance of growth factors and signaling molecules to proliferate and retain pluripotency. Conditioned medium (CM) from a human embryonic germ-cell-derived cell culture, SDEC, was observed to support the growth of hESC on type I collagen (COL I) and on Matrigel (MAT) biomatricies. After 1 month, the population doubling of hESC grown in SDEC CM on COL I was equivalent to that of hESC grown in mouse embryonic fibroblast (MEF) CM on MAT. hESC grown in SDEC CM on COL I expressed OCT4, NANOG, SSEA-4, alkaline phosphatase (AP), and TRA-1-60; retained a normal karyotype; and were capable of forming teratomas. DNA microarray analysis was used to compare the transcriptional profiles of SDEC and the less supportive WI38 and Detroit 551 human cell lines. The mRNA level of secreted frizzled-related protein (sFRP-1), a known antagonist of the WNT/β-catenin signaling pathway, was significantly reduced in SDEC as compared with the other 2 cell lines, whereas the mRNA levels of prostaglandin-endoperoxide synthase 2 (PTGS2 or COX-2) and prostaglandin I₂ synthase (PGIS), two prostaglandin biosynthesis genes, were significantly increased in SDEC. The level of sFRP-1 protein was significantly reduced, and levels of 2 prostaglandins that are downstream products of PTGS2 and PGIS, prostaglandin E₂ and 6-keto-prostaglandin F(1α), were significantly elevated in SDEC CM compared with WI38, Detroit 551, and MEF CM. Further, addition of purified sFRP-1 to SDEC CM reduced the proliferation of hESC grown on COL I as well as MAT in a dose-dependent manner.
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Affiliation(s)
- Meredith B Jones
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland, USA
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Nagaoka T, Watanabe K, Gonzales M, Castro N, Rangel MC, Rollman K, Rubin JS, Salomon DS, Bianco C. Abstract 1053: Modulation of Wnt/β-catenin signaling pathway by Cripto-1 in mouse embryonal carcinoma F9 cells. Cancer Res 2010. [DOI: 10.1158/1538-7445.am10-1053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Cripto-1 is a membrane bound protein that belongs to the epidermal growth factor (EGF)-CFC (Cripto/FRL-1/cryptic) protein family. Cripto-1 is a co-receptor for the transforming growth factor-β related protein Nodal and together with Nodal induces Smad-2/3 phosphorylation through the serine-threonine kinase receptor ALK-4. Furthermore, Cripto-1 can also bind to Glypican-1, Caveolin-1, GRP78, TGFβ1, Activin, Notch and Wnt11 proteins. In the present study, 3xFLAG-tagged human Cripto-1 and HA-tagged Wnt proteins (Wnt-1, 3a, 5a and 11) were co-expressed in 293T cells and co-immunoprecipitation was carried out using anti-FLAG or anti-HA antibodies. All four Wnt proteins were found to bind to Cripto-1. We also evaluated whether Cripto-1 could bind to the Wnt receptor, Frizzled-8 cysteine rich domain and the Wnt co-receptor, LRP5 in 293T cells. LRP5 was found to co-immunoprecipitate with Cripto-1 in transiently transfected 293T cells, while no binding of Cripto-1 to Frizzled-8 was detected. Finally, we investigated the biological significance of the interaction between various Wnts and Cripto-1 using mouse embryonal carcinoma F9 cells that express high levels of endogenous Cripto-1 protein and Cripto-1 gene null F9 (F9 Cr-1-/-) cells. Interestingly, we found that F9 cells contained more stabilized cytoplasmic β-catenin than F9 Cr-1-/- cells after the cells were treated with Wnt3a protein. Super TOP-FLASH reporter assays also revealed a significant increase in luciferase activity in F9 cells compared to F9 Cr-1-/- cells following Wnt3a treatment. In conclusion, our results demonstrate that Cripto-1 can enhance the canonical Wnt/β-catenin signaling pathway in mouse embryonal carcinoma cells. Therefore, modulation of the canonical Wnt/β-catenin pathway by Cripto-1 might perform an important role in embryonic stem cells and embryonal carcinoma cells that are expressing high levels of Cripto-1.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1053.
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Rubin JS, Macdonald I, Blake E. The putative involvement of the transabdominal muscles in dysphonia: a preliminary study and thoughts. J Voice 2010; 25:218-22. [PMID: 20381309 DOI: 10.1016/j.jvoice.2009.09.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2009] [Accepted: 09/03/2009] [Indexed: 11/30/2022]
Abstract
OBJECTIVES/HYPOTHESIS Real-time ultrasound was used as an adjunct to assess patterns of periabdominal musculature in 14 individual with dysphonia and muscle tension dysphonia. MATERIALS Fourteen individuals with muscle tension dysphonia were evaluated with real-time ultrasound as a part of their initial evaluation and management. RESULTS In 13 of 14 individuals, there was an imbalance found during phonation between the transversus abdominis muscles (TAs) and internal oblique muscles (IOs), whereby the IOs were found to be overactive and the TAs underactive. After physiotherapy, this pattern was reversed. CONCLUSION The abdominal muscle pattern of overactivity of the internal oblique and underactivity of the TA during phonation was found to be present in the large majority of patients in this pilot sample who had presented with muscle tension dysphonia. The significance of this is unclear but deserves further review.
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Affiliation(s)
- J S Rubin
- Royal National Throat Nose and Ear Hospital, Royal Free Hampstead NHS Trust, London, UK.
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Beauchamp E, Bulut G, Abaan O, Chen K, Merchant A, Matsui W, Endo Y, Rubin JS, Toretsky J, Uren A. GLI1 is a direct transcriptional target of EWS-FLI1 oncoprotein. J Biol Chem 2009; 284:9074-82. [PMID: 19189974 DOI: 10.1074/jbc.m806233200] [Citation(s) in RCA: 131] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Ewing sarcoma family of tumors (ESFT) is an undifferentiated neoplasm of the bone and soft tissue. ESFT is characterized by a specific chromosomal translocation occurring between chromosome 22 and (in most cases) chromosome 11, which generates an aberrant transcription factor, EWS-FLI1. The function of EWS-FLI1 is essential for the maintenance of ESFT cell survival and tumorigenesis. The Hedgehog pathway is activated in several cancers. Oncogenic potential of the Hedgehog pathway is mediated by increasing the activity of the GLI family of transcription factors. Recent evidence suggests that EWS-FLI1 increases expression of GLI1 by an unknown mechanism. Our data from chromatin immunoprecipitation and promoter reporter studies indicated GLI1 as a direct transcriptional target of EWS-FLI1. Expression of EWS-FLI1 in non-ESFT cells increased GLI1 expression and GLI-dependent transcription. We also detected high levels of GLI1 protein in ESFT cell lines. Pharmacological inhibition of GLI1 protein function decreased proliferation and soft agar colony formation of ESFT cells. Our results establish GLI1 as a direct transcriptional target of EWS-FLI1 and suggest a potential role for GLI1 in ESFT tumorigenesis.
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Affiliation(s)
- Elspeth Beauchamp
- Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, D C 20057, USA
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Linehan WM, Rubin JS, Bottaro DP. VHL loss of function and its impact on oncogenic signaling networks in clear cell renal cell carcinoma. Int J Biochem Cell Biol 2008; 41:753-6. [PMID: 18950731 DOI: 10.1016/j.biocel.2008.09.024] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2008] [Revised: 09/11/2008] [Accepted: 09/15/2008] [Indexed: 11/28/2022]
Abstract
Loss of von Hippel-Lindau tumor suppressor gene function occurs in familial and most sporadic clear cell renal cell carcinoma, resulting in the aberrant expression of genes that control cell proliferation, metabolism, invasion and angiogenesis. The molecular mechanisms by which loss of function leads to tumorigenesis are not yet fully defined. The von Hippel-Lindau gene product is part of an ubiquitin ligase complex that targets hypoxia inducible factors for polyubiquitination and proteasomal degradation, linking hypoxia response genes to renal cell carcinoma oncogenesis. Loss von Hippel-Lindau gene function also promotes cell invasiveness in response to hepatocyte growth factor, an important regulator of kidney development and renal homeostasis. Increased cell invasiveness is mediated by another ubiquitin ligase target with relevance to the molecular pathogenesis of renal cell carcinoma: beta-catenin. This discovery and other recent insights into kidney cancer oncogenesis implicate convergent developmental and homeostatic signaling pathways in tumorigenesis, tumor invasiveness and metastasis.
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Affiliation(s)
- W Marston Linehan
- Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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Wang WH, McNatt LG, Pang IH, Millar JC, Hellberg PE, Hellberg MH, Steely HT, Rubin JS, Fingert JH, Sheffield VC, Stone EM, Clark AF. Increased expression of the WNT antagonist sFRP-1 in glaucoma elevates intraocular pressure. J Clin Invest 2008; 118:1056-64. [PMID: 18274669 DOI: 10.1172/jci33871] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2007] [Accepted: 12/19/2007] [Indexed: 12/19/2022] Open
Abstract
Elevated intraocular pressure (IOP) is the principal risk factor for glaucoma and results from excessive impedance of the fluid outflow from the eye. This abnormality likely originates from outflow pathway tissues such as the trabecular meshwork (TM), but the associated molecular etiology is poorly understood. We discovered what we believe to be a novel role for secreted frizzled-related protein-1 (sFRP-1), an antagonist of Wnt signaling, in regulating IOP. sFRP1 was overexpressed in human glaucomatous TM cells. Genes involved in the Wnt signaling pathway were expressed in cultured TM cells and human TM tissues. Addition of recombinant sFRP-1 to ex vivo perfusion-cultured human eyes decreased outflow facility, concomitant with reduced levels of beta-catenin, the Wnt signaling mediator, in the TM. Intravitreal injection of an adenoviral vector encoding sFRP1 in mice produced a titer-dependent increase in IOP. Five days after vector injection, IOP increased 2 fold, which was significantly reduced by topical ocular administration of an inhibitor of a downstream suppressor of Wnt signaling. Thus, these data indicate that increased expression of sFRP1 in the TM appears to be responsible for elevated IOP in glaucoma and restoring Wnt signaling in the TM may be a novel disease intervention strategy for treating glaucoma.
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Joesting MS, Cheever TR, Volzing KG, Yamaguchi TP, Wolf V, Naf D, Rubin JS, Marker PC. Secreted frizzled related protein 1 is a paracrine modulator of epithelial branching morphogenesis, proliferation, and secretory gene expression in the prostate. Dev Biol 2008; 317:161-73. [PMID: 18371946 DOI: 10.1016/j.ydbio.2008.02.021] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2007] [Revised: 01/23/2008] [Accepted: 02/06/2008] [Indexed: 10/22/2022]
Abstract
Previous in vitro studies identified secreted frizzled related protein 1 (SFRP1) as a candidate pro-proliferative signal during prostatic development and cancer progression. This study determined the in vivo roles of SFRP1 in the prostate using expression studies in mice and by creating loss- and gain-of-function mouse genetic models. Expression studies using an Sfrp1(lacZ) knock-in allele showed that Sfrp1 is expressed in the developing mesenchyme/stroma of the prostate. Nevertheless, Sfrp1 null prostates exhibited multiple prostatic developmental defects in the epithelium including reduced branching morphogenesis, delayed proliferation, and increased expression of genes encoding prostate-specific secretory proteins. Interestingly, over-expression of SFRP1 in the adult prostates of transgenic mice yielded opposite effects including prolonged epithelial proliferation and decreased expression of genes encoding secretory proteins. These data demonstrated a previously unrecognized role for Sfrp1 as a stromal-to-epithelial paracrine modulator of epithelial growth, branching morphogenesis, and epithelial gene expression. To clarify the mechanism of SFRP1 action in the prostate, the response of WNT signaling pathways to SFRP1 was examined. Forced expression of SFRP1 in prostatic epithelial cells did not alter canonical WNT/beta-catenin signaling or the activation of CamKII. However, forced expression of SFRP1 led to sustained activation of JNK, and inhibition of JNK activity blocked the SFRP1-induced proliferation of prostatic epithelial cells, suggesting that SFRP1 acts through the non-canonical WNT/JNK pathway in the prostate.
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Affiliation(s)
- Margaret S Joesting
- Department of Genetics, Cellular Biology, and Development, University of Minnesota, Minneapolis, MN 55455, USA
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Abstract
Recombinant expression of secreted Frizzled-related proteins (sFRPs) in mammalian expression systems is a convenient source of these proteins for biological studies. Yields of protein vary; screening of clonal lines for high expression is usually worthwhile. Heparin affinity chromatography is an easy step that provides a major enrichment, particularly for sFRP-1 and sFRP-2. Alternatively, sFRP derivatives tagged with poly-histidine at their carboxyl termini are functional and can be readily isolated by chelating chromatography. Once purified, the proteins are stable indefinitely if stored frozen and they tolerate multiple rounds of freeze-thawing. Pre-incubation of Wnt samples with sFRP protein for 30 min at 37 degrees C is sufficient to inhibit Wnt activity in various assays. The concentration of sFRP required to block Wnt signaling should be determined empirically, as it will vary with the Wnt preparation and cellular context.
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Tchou-Wong KM, Fok SYY, Rubin JS, Pixley F, Condeelis J, Braet F, Rom W, Soon LL. Erratum to: Rapid chemokinetic movement and the invasive potential of lung cancer cells; a functional molecular study. BMC Cancer 2007. [PMCID: PMC1819389 DOI: 10.1186/1471-2407-7-32] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
This is a correction of an earlier published article.
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Mathieson L, Hirani SP, Epstein R, Baken RJ, Wood G, Rubin JS. Laryngeal manual therapy: a preliminary study to examine its treatment effects in the management of muscle tension dysphonia. J Voice 2007; 23:353-66. [PMID: 18036777 DOI: 10.1016/j.jvoice.2007.10.002] [Citation(s) in RCA: 199] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2007] [Accepted: 10/01/2007] [Indexed: 11/24/2022]
Abstract
The objectives of this study were to determine appropriate acoustic and outcome measures for the evaluation of a method of laryngeal manual therapy (LMT) used in the treatment of patients with muscle tension dysphonia (MTD). The effects of this technique were also investigated. The study was based on the hypotheses that the vertical position of the larynx in the vocal tract would lower, that the quality of the voice would normalize, and that a reduction in any vocal tract discomfort (VTD) would occur after LMT. This was a small, prospective, repeated measures pilot study in which each member of the research team was "blinded" to all other stages of the study and during which all data were anonymized until the final stage of data analysis. Ten subjects presenting with MTD completed outcome measures and provided audiorecordings immediately before, immediately after, and 1 week after LMT. The Kay CSL 4150 was used for signal acquisition and for some acoustic measurements. Spectrographic evaluation was accomplished with Praat. A new perceptual, self-rating scale, the VTD scale, and a new proforma for use by the clinician for palpatory evaluation, were developed for the study. Relative average perturbation during connected speech was significantly reduced after LMT, indicating a reduction in abnormal vocal function. The severity and frequency of VTD was shown to have reduced after LMT. This pilot study showed positive evidence for LMT as a method of therapy in the treatment of hyperfunctional voice disorders. Its effects were shown to be measurable with both acoustical analysis and the VTD scale.
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Affiliation(s)
- L Mathieson
- The Ear Institute, University College London, London, United Kingdom.
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Affiliation(s)
- Jeffrey S Rubin
- Laboratory of Cellular and Molecular Biology and Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland 20892-1107, USA
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Abstract
Wnt signaling consists of a highly conserved set of biochemical pathways that have a multitude of functions during embryonic development and in the adult. The Wnt proteins are extracellular agents that often act as gradient morphogens, indicating that their distribution in tissues is tightly controlled. This attribute is also characteristic of factors that regulate neurite outgrowth and guide axons precisely to their specific destinations. Several studies in various species now have established that Wnts and their receptors have an important role in axonal guidance. Different ligand/receptor combinations have been identified that mediate this activity in many of the experimental models. Clues about downstream effector molecules have come from in vitro systems. In this article, the authors review the results from many of these models, evaluate what is known about the associated signaling pathways and speculate about the direction of future research.
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Affiliation(s)
- Yoshimi Endo
- National Cancer Institute, 37 Convent Drive, Bethesda, MD 20892-4256, USA
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Rubin JS, Wendler J, Woisard V, Dejonckere PH, Wellens W, Kotby N. Phoniatric provision and training: current European perspectives. J Laryngol Otol 2006; 121:427-30. [PMID: 17156513 DOI: 10.1017/s0022215106004920] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 07/01/2006] [Indexed: 11/06/2022]
Abstract
Communication disorders represent a major and growing problem worldwide. In Europe, the specialty of phoniatrics has developed partly in response to this important issue. This article reviews training and workforce issues in phoniatrics and raises key questions and issues that need resolution in the future.
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Affiliation(s)
- J S Rubin
- Royal National Throat, Nose and Ear Hospital, London, UK.
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Abstract
Dysregulation of Wnt signaling is common in a variety of human malignancies. Activation of the canonical Wnt or beta-catenin pathway has been especially well documented in cancer, although other non-canonical Wnt signaling pathways also have been implicated in neoplasia. In most instances, constitutive signaling through the beta-catenin pathway involves activation of effector molecules or loss of tumor suppressor function downstream of Wnt binding to its cell surface receptors. Nonetheless, in recent years increasing evidence suggests that secreted Wnt antagonists act as tumor suppressors, with their expression often silenced by promoter hypermethylation. This implies that maximal constitutive signaling in cancer requires unimpaired Wnt stimulation at the cell surface as well as enhanced signal propagation within the cell. However, an understanding of the role secreted Wnt antagonists may play in cancer is complicated by the multiplicity of these proteins, their potential Wnt-independent activities and observations indicating that sometimes they may promote tumor growth. Just as the particular function of Wnt signaling in development and homeostasis varies with the setting, the impact of secreted Wnt antagonists on neoplasia depends on the molecular, cellular and tissue context.
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Affiliation(s)
- Jeffrey S Rubin
- Laboratory of Cellular and Molecular Biology, National Cancer Institute, Bethesda, MD 20892, USA.
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Abstract
Keratinocyte growth factor (KGF) is a locally acting epithelial mitogen that is produced by cells of mesenchymal origin and has an important role in protecting and repairing epithelial tissues. Use of recombinant human KGF (palifermin) in patients with hematologic malignancies reduces the incidence and duration of severe oral mucositis experienced after intensive chemoradiotherapy. These results suggest that KGF may be useful in the treatment of patients with other kinds of tumors, including those of epithelial origin. However, its application in this context raises issues that were not pertinent to its use in hematologic cancer because epithelial tumor cells, unlike blood cells, often express the KGF receptor (FGFR2b). Thus, it is important to examine whether KGF could promote the growth of epithelial tumors or protect such tumor cells from the effects of chemotherapy agents. Analyses of KGF and FGFR2b expression in tumor specimens and of KGF activity on transformed cells in vitro and in vivo do not indicate a definitive role for KGF in tumorigenesis. On the contrary, restoring FGFR2b expression to certain malignant cells can induce cell differentiation or apoptosis. However, other observations suggest that, in specific situations, KGF may contribute to epithelial tumorigenesis. Thus, further studies are warranted to examine the nature and extent of KGF involvement in these settings. In addition, clinical trials in patients with solid tumors are underway to assess the potential benefits of using KGF to protect normal tissue from the adverse effects of chemoradiotherapy and its possible impact on clinical outcome.
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Affiliation(s)
- Paul W Finch
- Laboratory of Cellular and Molecular Biology, National Cancer Institute, Building 37, Room 2042, 37 Convent Drive, MSC 4256, Bethesda, MD 20892-4256, USA
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Liu X, Rubin JS, Kimmel AR. Rapid, Wnt-induced changes in GSK3beta associations that regulate beta-catenin stabilization are mediated by Galpha proteins. Curr Biol 2006; 15:1989-97. [PMID: 16303557 DOI: 10.1016/j.cub.2005.10.050] [Citation(s) in RCA: 163] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2004] [Revised: 10/23/2005] [Accepted: 10/25/2005] [Indexed: 10/25/2022]
Abstract
BACKGROUND In the absence of Wnt stimulation, the transcriptional cofactor beta-catenin is destabilized via phosphorylation by protein kinase GSK3beta in complex with Axin family members. In the "canonical" Wnt signaling pathway, Disheveled (Dvl) is required to functionally inhibit the activity of the GSK3beta/Axin complex and thereby stabilize beta-catenin. Yet, the mechanisms that underlie Wnt regulation of GSK3 and stabilization of beta-catenin are still not fully appreciated. RESULTS Here, we examine time-dependent changes in protein-protein interactions that occur in response to Wnt treatment. We show that GSK3beta/Axin complexes are rapidly (t1/2 < 3 min) disrupted upon Wnt stimulation and that changes in GSK3beta/Axin association substantially precede both beta-catenin stabilization and Axin degradation. We further demonstrate that depletion of Galpha(o) or Galpha(q) will inhibit, respectively, the Wnt-induced disruption of GSK3beta/Axin2 and GSK3beta/Axin complexes and diminish Wnt stabilization of beta-catenin. We also show that direct activation of G proteins in vivo with GTPgammaS in the absence of exogenous Wnt will disrupt GSK3beta/Axin2 complexes and stabilize beta-catenin. Finally, we demonstrate an association of Galpha(o) with Fz that is also very rapidly (t1/2 < 1 min) perturbed upon Wnt-3a stimulation and that the Wnt-dependent effects on both GSK3beta/Axin2 and Galpha(o)/Fz are pertussis-toxin sensitive. Collectively, these data implicate a role for G proteins in the regulation of Wnt-mediated protein-protein interactions and signaling to beta-catenin. CONCLUSIONS We conclude that rapid disruption of GSK3beta/Axin interactions in response to Wnt leads to the initial stabilization of beta-catenin and that Galpha(o) and Galpha(q) signaling contributes to Wnt-mediated GSK3beta/Axin disruption and the ultimate stabilization of beta-catenin.
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Affiliation(s)
- Xunxian Liu
- Laboratory of Cellular and Developmental Biology, NIDDK, National Institutes of Health, Bethesda, Maryland 20892, USA
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Fok SYY, Rubin JS, Pixley F, Condeelis J, Braet F, Soon LL. Rapid chemokinetic movement and the invasive potential of lung cancer cells; a functional molecular study. BMC Cancer 2006; 6:151. [PMID: 16756685 PMCID: PMC1501041 DOI: 10.1186/1471-2407-6-151] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2005] [Accepted: 06/07/2006] [Indexed: 11/13/2022] Open
Abstract
Background Non-small cell lung cancer is the most common cause of early casualty from malignant disease in western countries. The heterogeneous nature of these cells has been identified by histochemical and microarray biomarker analyses. Unfortunately, the morphological, molecular and biological variation within cell lines used as models for invasion and metastasis are not well understood. In this study, we test the hypothesis that heterogeneous cancer cells exhibit variable motility responses such as chemokinesis and chemotaxis that can be characterized molecularly. Methods A subpopulation of H460 lung cancer cells called KINE that migrated under chemokinetic (no gradient) conditions was harvested from Boyden chambers and cultured. Time-lapsed microscopy, immunofluorescence microscopy and microarray analyses were then carried out comparing chemokinetic KINE cells with the unselected CON cell population. Results Time-lapsed microscopy and analysis showed that KINE cells moved faster but less directionally than the unselected control population (CON), confirming their chemokinetic character. Of note was that chemokinetic KINE cells also chemotaxed efficiently. KINE cells were less adhesive to substrate than CON cells and demonstrated loss of mature focal adhesions at the leading edge and the presence of non-focalized cortical actin. These characteristics are common in highly motile amoeboid cells that may favour faster motility speeds. KINE cells were also significantly more invasive compared to CON. Gene array studies and real-time PCR showed the downregulation of a gene called, ROM, in highly chemokinetic KINE compared to mainly chemotactic CON cells. ROM was also reduced in expression in a panel of lung cancer cell lines compared to normal lung cells. Conclusion This study shows that cancer cells that are efficient in both chemokinesis and chemotaxis demonstrate high invasion levels. These cells possess different morphological, cytoskeletal and adhesive properties from another population that are only efficient at chemotaxis, indicating a loss in polarity. Understanding the regulation of polarity in the context of cell motility is important in order to improve control and inhibition of invasion and metastasis.
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Affiliation(s)
- Sandra YY Fok
- Electron Microscope Unit, Australian Key Centre for Microscopy and Microanalysis, University of Sydney, Sydney, NSW, 2006, Australia
| | - Jeffrey S Rubin
- Laboratory of Cellular and Molecular Biology, NCI, National Institutes of Health, Bethesda, MD 20892, USA
| | - Fiona Pixley
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine of Yeshiva University, Bronx, NY 10461, USA
| | - John Condeelis
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine of Yeshiva University, Bronx, NY 10461, USA
| | - Filip Braet
- Electron Microscope Unit, Australian Key Centre for Microscopy and Microanalysis, University of Sydney, Sydney, NSW, 2006, Australia
| | - Lilian L Soon
- Electron Microscope Unit, Australian Key Centre for Microscopy and Microanalysis, University of Sydney, Sydney, NSW, 2006, Australia
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Wang H, Charles PC, Wu Y, Ren R, Pi X, Moser M, Barshishat-Kupper M, Rubin JS, Perou C, Bautch V, Patterson C. Gene expression profile signatures indicate a role for Wnt signaling in endothelial commitment from embryonic stem cells. Circ Res 2006; 98:1331-9. [PMID: 16601226 DOI: 10.1161/01.res.0000220650.26555.1d] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We have used global gene expression analysis to establish a comprehensive list of candidate genes in the developing vasculature during embryonic (ES) cell differentiation in vitro. A large set of genes, including growth factors, cell surface molecules, transcriptional factors, and members of several signal transduction pathways that are known to be involved in vasculogenesis or angiogenesis, were found to have expression patterns as expected. Some unknown or functionally uncharacterized genes were differentially regulated in flk1+ cells compared with flk1- cells, suggesting possible roles for these genes in vascular commitment. Particularly, multiple components of the Wnt signaling pathway were differentially regulated in flk1+ cells, including Wnt proteins, their receptors, downstream transcriptional factors, and other components belonging to this pathway. Activation of the Wnt signal was able to expand vascular progenitor populations whereas suppression of Wnt activity reduced flk1+ populations. Suppression of Wnt signaling also inhibited the formation of matured vascular capillary-like structures during late stages of embryoid body differentiation. These data indicate a requisite and ongoing role for Wnt activity during vascular development, and the gene expression profiles identify candidate components of this pathway that participate in vascular cell differentiation.
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Affiliation(s)
- Hong Wang
- Carolina Cardiovascular Biology Center, University of North Carolina, Chapel Hill, USA
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Joesting MS, Perrin S, Elenbaas B, Fawell SE, Rubin JS, Franco OE, Hayward SW, Cunha GR, Marker PC. Identification of SFRP1 as a candidate mediator of stromal-to-epithelial signaling in prostate cancer. Cancer Res 2006; 65:10423-30. [PMID: 16288033 DOI: 10.1158/0008-5472.can-05-0824] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Genetic changes in epithelial cells initiate the development of prostatic adenocarcinomas. As nascent tumors grow and undergo progression, epithelial tumor cells are intimately associated with stromal cells. Stromal cells within the tumor microenvironment acquire new properties, including the capacity to promote phenotypic and genetic progression in adjacent epithelial cells. Affymetrix microarrays were used to identify 119 genes differentially expressed between normal-derived and carcinoma-derived prostatic stromal cells. These included 31 genes encoding extracellular proteins that may act as stromal-to-epithelial paracrine signals. Further investigation of one of these genes, secreted frizzled related protein 1 (SFRP1), revealed that its expression parallels prostatic growth with high expression during prostatic development, low expression in the adult prostate, and elevated expression in prostatic tumor stroma. In addition, as prostatic epithelial cells progressed to a tumorigenic state under the influence of tumor stroma, SFRP1 became overexpressed in the progressed epithelial cells. To further understand the roles of SFRP1 in the prostate, we tested the affects of increased SFRP1 levels on prostatic tissues and cells. Treatment of developing prostates with SFRP1 in culture led to increased organ growth. Treatment of a human prostatic epithelial cell line with SFRP1 led to increased proliferation, decreased apoptosis, and decreased signaling through the Wnt/beta-catenin pathway in vitro and increased proliferation in vivo. These data suggest that overexpression of SFRP1 by prostatic tumor stroma may account for the previously reported capacity of prostatic tumor stroma to provide a pro-proliferative paracrine signal to adjacent epithelial cells.
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Affiliation(s)
- Margaret S Joesting
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, Minnesota 55455, USA
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Abstract
Multiple myeloma is an incurable form of lymphoid cancer characterized by accumulation of neoplastic plasma cells in the bone marrow cavity. Little is known about the mechanisms regulating myeloma cell movement within the bone marrow and metastasis to secondary sites. Herein, we identify multiple members of the wingless/int (Wnt) family as promoters of myeloma cell migration/invasion. Wnt-mediated migration was associated with the Wnt/RhoA pathway and did not necessitate signaling through beta-catenin. Activation of both RhoA and members of the protein kinase C (PKC) family, including PKCalpha, PKCbeta, and PKCmu, were required for induction of migration. Activated RhoA and PKCalpha, PKCbeta, and PKCmu appear to assemble in macromolecular signaling complexes that are associated with the cell membrane. These results suggest that Wnt responsiveness of myeloma plasma cells may be a significant factor in disease progression.
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Affiliation(s)
- Ya-Wei Qiang
- Laboratory of Cellular and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-4255, USA
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45
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Mohammed FF, Pennington CJ, Kassiri Z, Rubin JS, Soloway PD, Ruther U, Edwards DR, Khokha R. Metalloproteinase inhibitor TIMP-1 affects hepatocyte cell cycle via HGF activation in murine liver regeneration. Hepatology 2005; 41:857-67. [PMID: 15726641 DOI: 10.1002/hep.20618] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Liver regeneration depends on timely restoration of cellular mass while orchestrating structural matrix remodeling. Matrix metalloproteinases (MMPs) and their endogenous inhibitors (TIMPs) are known to regulate the extracellular matrix (ECM) turnover and, more recently, the processing of growth factors and cytokines. We have previously demonstrated that TIMP-1 inhibits preneoplastic hepatocyte proliferation by attenuating growth factor bioavailability. In the present study, we examined the role of TIMP-1 in de novo hepatocyte cell division during liver regeneration. Comprehensive real-time reverse-transcriptase polymerase chain reaction analyses of regenerating livers revealed significant inductions in the messenger RNA of TIMP-1, TIMP-3, TIMP-4, MMP-2, MMP-9, MMP-13, MMP-14, and MMP-24, while MMP-15 expression was significantly reduced. Induction of TIMP-1 occurred during the peak of hepatocyte DNA synthesis. Studies using genetically altered mice revealed that TIMP-1 loss of function accelerated hepatocyte cell cycle progression. This finding was demonstrated by earlier expression of cyclin D1, proliferating cell nuclear antigen, and phosphorylated histone H3, which mark the G(1)-S, S, and M phase, respectively. Conversely, TIMP-1 gain of function delayed cell cycle progression. MMP activity was increased in the absence of Timp-1. Examination of hepatocyte growth factor (HGF), and its receptor Met, both of which provide a mitogenic signal for hepatocyte division, showed increased HGF activity in Timp-1(-/-)-regenerating livers. HGF is released from the ECM and is proteolytically processed to its active form. Active HGF was elevated in Timp-1(-/-) mice, leading to increased immunostaining of phosphorylated Met as well as activation of a downstream effector, p38. In conclusion, TIMP-1 is a novel negative regulator of HGF activity during liver regeneration.
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Affiliation(s)
- Fazilat F Mohammed
- Department of Medical Biophysics, Ontario Cancer Institute, Toronto, Ontario M5G 2M9, Canada
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46
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Finch PW, Rubin JS. Keratinocyte growth factor/fibroblast growth factor 7, a homeostatic factor with therapeutic potential for epithelial protection and repair. Adv Cancer Res 2004; 91:69-136. [PMID: 15327889 DOI: 10.1016/s0065-230x(04)91003-2] [Citation(s) in RCA: 170] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Keratinocyte growth factor (KGF) is a paracrine-acting, epithelial mitogen produced by cells of mesenchymal origin. It is a member of the fibroblast growth factor (FGF) family, and acts exclusively through a subset of FGF receptor isoforms (FGFR2b) expressed predominantly by epithelial cells. The upregulation of KGF after epithelial injury suggested it had an important role in tissue repair. This hypothesis was reinforced by evidence that intestinal damage was worse and healing impaired in KGF null mice. Preclinical data from several animal models demonstrated that recombinant human KGF could enhance the regenerative capacity of epithelial tissues and protect them from a variety of toxic exposures. These beneficial effects are attributed to multiple mechanisms that collectively act to strengthen the integrity of the epithelial barrier, and include the stimulation of cell proliferation, migration, differentiation, survival, DNA repair, and induction of enzymes involved in the detoxification of reactive oxygen species. KGF is currently being evaluated in clinical trials to test its ability to ameliorate severe oral mucositis (OM) that results from cancer chemoradiotherapy. In a phase 3 trial involving patients who were treated with myeloablative chemoradiotherapy before autologous peripheral blood progenitor cell transplantation for hematologic malignancies, KGF significantly reduced both the incidence and duration of severe OM. Similar investigations are underway in patients being treated for solid tumors. On the basis of its success in ameliorating chemoradiotherapy-induced OM in humans and tissue damage in a variety of animal models, additional clinical applications of KGF are worthy of investigation.
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Affiliation(s)
- Paul W Finch
- Laboratory of Cellular and Molecular Biology, National Cancer Institute, Bethesda, Maryland 20892, USA
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Häusler KD, Horwood NJ, Chuman Y, Fisher JL, Ellis J, Martin TJ, Rubin JS, Gillespie MT. Secreted frizzled-related protein-1 inhibits RANKL-dependent osteoclast formation. J Bone Miner Res 2004; 19:1873-81. [PMID: 15476588 DOI: 10.1359/jbmr.040807] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2003] [Revised: 04/06/2004] [Accepted: 05/27/2004] [Indexed: 12/25/2022]
Abstract
UNLABELLED We determined that sFRP-1 mRNA was differentially expressed by osteoblast/stromal cell lines and that sFRP-1 neutralizing antibodies and siRNA complementary to sFRP-1 coding sequence enhanced, while recombinant sFRP-1 inhibited, osteoclast formation. In studying the mechanism of action for sFRP-1, we found that sFRP-1 could bind recombinant RANKL. These results suggest potential cross-talk between Wnt and RANKL pathways. INTRODUCTION Osteoclast formation in normal bone remodeling requires the presence of osteoblast lineage cells that express RANKL and macrophage-colony-stimulating factor (M-CSF), which interact with their cognate receptors on the osteoclast precursor. We identified secreted Frizzled-related protein-1 (sFRP-1), which is known to bind to Wnt and inhibit the Wnt signaling pathway, as an osteoblast-derived factor that impinges on osteoclast formation and activity. MATERIALS AND METHODS Differential display of mRNA from osteoblast lineage cell lines established sFRP-1 to be highly expressed in an osteoclast supporting cell line. sFRP-1 expression in bone was determined by in situ hybridization, and the effects of sFRP-1 on osteoclast formation were determined using a neutralizing antibody, siRNA, for sFRP-1 and recombinant protein. RESULTS In situ hybridization revealed sFRP-1 mRNA expression in osteoblasts and chondrocytes in murine bone. sFRP-1 mRNA expression could be elevated in calvarial primary osteoblasts in response to prostaglandin E2 (PGE2) or interleukin (IL)-11, whereas many other osteotropic agents (e.g., IL-1, IL-6, calcitrol, parathyroid hormone) were without any effect. In vitro assays of osteoclast formation established sFRP-1 to be an inhibitor of osteoclast formation. Neutralizing antibodies against sFRP-1 enhanced TRACP+ mononuclear and multinuclear osteoclast formation (3- and 2-fold, respectively) in co-cultures of murine osteoblasts with spleen cells, whereas siRNA complementary to sFRP-1 coding sequence significantly enhanced osteoclast formation in co-cultures of KUSA O (osteoblast/stromal cell line) and bone marrow cells, cultured in the presence of PGE2 and 1,25(OH)2 vitamin D3. Recombinant sFRP-1 dose-dependently inhibited osteoclast formation in osteoblast/spleen co-cultures, RANKL + M-CSF-treated splenic cultures, and RANKL-treated RAW264.7 cell cultures, indicating a direct action of sFRP-1 on hematopoietic cells. Consistent with this, sFRP-1 was found to bind to RANKL in ELISAs. CONCLUSION sFRP-1 is expressed by osteoblasts and inhibits osteoclast formation. While sFRP-1 activity might involve the blocking of endogenous Wnt signaling, our results suggest that, alternatively, it could be because of direct binding to RANKL. This study describes a new mechanism whereby osteoblasts regulate osteoclastogenesis through the expression and release of sFRP-1.
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Affiliation(s)
- Karl D Häusler
- Bone, Joint, and Cancer Unit, St Vincent's Institute of Medical Research, Fitzroy, Victoria, Australia
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Chuman Y, Uren A, Cahill J, Regan C, Wolf V, Kay BK, Rubin JS. Identification of a peptide binding motif for secreted frizzled-related protein-1. Peptides 2004; 25:1831-8. [PMID: 15501513 DOI: 10.1016/j.peptides.2004.07.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2004] [Accepted: 07/13/2004] [Indexed: 02/06/2023]
Abstract
Secreted Frizzled-related proteins (sFRPs) bind Wnts and modulate their activity. To identify putative sFRP-1 binding motifs, we screened an M13 phage displayed combinatorial peptide library. A predominant motif, L/V-VDGRW-L/V, was present in approximately 70% of the phage that bound sFRP-1. Use of peptide/alkaline phosphatase chimeras and alanine scanning confirmed that the conserved motif was important for sFRP-1 recognition. The dissociation constant for a peptide/sFRP-1 complex was 3.9 microM. Additional analysis revealed that DGR was the core of the binding motif. Although Wnt proteins lack this sequence, other proteins possessing the DGR motif may function as novel binding partners for sFRP-1.
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Affiliation(s)
- Yoshiro Chuman
- Laboratory of Cellular and Molecular Biology, National Cancer Institute, Bethesda, MD 20892-4256, USA
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Endo Y, Wolf V, Muraiso K, Kamijo K, Soon L, Uren A, Barshishat-Küpper M, Rubin JS. Wnt-3a-dependent cell motility involves RhoA activation and is specifically regulated by dishevelled-2. J Biol Chem 2004; 280:777-86. [PMID: 15509575 DOI: 10.1074/jbc.m406391200] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Wnts stimulate cell migration, although the mechanisms responsible for this effect are not fully understood. To investigate the pathways that mediate Wnt-dependent cell motility, we treated Chinese hamster ovary cells with Wnt-3a-conditioned medium and monitored changes in cell shape and movement. Wnt-3a induced cell spreading, formation of protrusive structures, reorganization of stress fibers and migration. Although Wnt-3a stabilized beta-catenin, two inhibitors of the beta-catenin/canonical pathway, Dickkopf-1 and a dominant-negative T cell factor construct, did not reduce motility. The small GTPase RhoA also was activated by Wnt-3a. In contrast to beta-catenin signaling, inhibition of Rho kinase partially blocked motility. Because Dishevelled (Dvl) proteins are effectors of both canonical and noncanonical Wnt signaling, we used immunofluorescent analysis and small interference RNA technology to evaluate the role of Dvl in cell motility. Specific knock-down of Dvl-2 expression markedly reduced Wnt-3a-dependent changes in cell shape and movement, suggesting that this Dvl isoform had a predominant role in mediating Wnt-3a-dependent motility in Chinese hamster ovary cells.
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Affiliation(s)
- Yoshimi Endo
- Laboratories of Cellular and Molecular Biology, NCI, National Institutes of Health, Bethesda, Maryland 20892, USA
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50
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Abstract
BACKGROUND The Ewing sarcoma family of tumors (ESFT) is a set of neuroectodermal malignancies that typically presents in the second decade and has a poor prognosis due to metastatic disease. Wnt signaling has a critical role in the normal development of multiple neuroectodermal tissues and also contributes to the neoplastic properties of tumor cells of neuroectodermal origin. PROCEDURE We surveyed the expression of Wnts and their receptors in nine ESFT cell lines by RT-PCR analysis. We also tested biological response of ESFT cell lines to exogenous Wnts in beta-catenin stabilization, actin stress fiber formation, and chemotaxis assays. RESULTS We detected Wnt-10b in all the lines, and most also expressed Wnt-5a, Wnt-11, and Wnt-13. Several Frizzleds (Fz) and the Wnt co-receptors, low density lipoprotein-receptor-like proteins 5 and 6 were also expressed. We observed a marked stimulation of the beta-catenin/canonical Wnt pathway in ESFT cells treated with Wnt-3a. Wnt-3a induced morphologic changes characterized by the formation of long cytoplasmic extensions in ESFT cells. We also observed chemotaxis of ESFT cells in response to Wnt-3a. CONCLUSIONS These results provide evidence that components of Wnt/Fz pathway are expressed and an intact Wnt/Frizzled signaling pathway exists in ESFT cell lines. Activation of the Wnt pathway in ESFT suggests that Wnt modulates cell motility rather than cell proliferation. Hence, activation of this pathway may influence metastatic potential of ESFT.
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Affiliation(s)
- Aykut Uren
- Georgetown University Medical Center, Lombardi Cancer Center, Research Building, Washington, DC 20057-1469, USA.
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