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Ortiz JR, Lewis SM, Ciccone M, Chatterjee D, Henry S, Siepel A, Dos Santos CO. Single-Cell Transcription Mapping of Murine and Human Mammary Organoids Responses to Female Hormones. J Mammary Gland Biol Neoplasia 2024; 29:3. [PMID: 38289401 PMCID: PMC10827859 DOI: 10.1007/s10911-023-09553-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 12/18/2023] [Indexed: 02/01/2024] Open
Abstract
During female adolescence and pregnancy, rising levels of hormones result in a cyclic source of signals that control the development of mammary tissue. While such alterations are well understood from a whole-gland perspective, the alterations that such hormones bring to organoid cultures derived from mammary glands have yet to be fully mapped. This is of special importance given that organoids are considered suitable systems to understand cross species breast development. Here we utilized single-cell transcriptional profiling to delineate responses of murine and human normal breast organoid systems to female hormones across evolutionary distinct species. Collectively, our study represents a molecular atlas of epithelial dynamics in response to estrogen and pregnancy hormones.
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Affiliation(s)
| | - Steven M Lewis
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, 11724, USA
- Graduate Program in Genetics, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Michael Ciccone
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, 11724, USA
| | | | - Samantha Henry
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, 11724, USA
- Graduate Program in Genetics, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Adam Siepel
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, 11724, USA
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2
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Do MH, Shi W, Ji L, Ladewig E, Zhang X, Srivastava RM, Capistrano KJ, Edwards C, Malik I, Nixon BG, Stamatiades EG, Liu M, Li S, Li P, Chou C, Xu K, Hsu TW, Wang X, Chan TA, Leslie CS, Li MO. Reprogramming tumor-associated macrophages to outcompete endovascular endothelial progenitor cells and suppress tumor neoangiogenesis. Immunity 2023; 56:2555-2569.e5. [PMID: 37967531 PMCID: PMC11284818 DOI: 10.1016/j.immuni.2023.10.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Revised: 07/03/2023] [Accepted: 10/18/2023] [Indexed: 11/17/2023]
Abstract
Tumors develop by invoking a supportive environment characterized by aberrant angiogenesis and infiltration of tumor-associated macrophages (TAMs). In a transgenic model of breast cancer, we found that TAMs localized to the tumor parenchyma and were smaller than mammary tissue macrophages. TAMs had low activity of the metabolic regulator mammalian/mechanistic target of rapamycin complex 1 (mTORC1), and depletion of negative regulator of mTORC1 signaling, tuberous sclerosis complex 1 (TSC1), in TAMs inhibited tumor growth in a manner independent of adaptive lymphocytes. Whereas wild-type TAMs exhibited inflammatory and angiogenic gene expression profiles, TSC1-deficient TAMs had a pro-resolving phenotype. TSC1-deficient TAMs relocated to a perivascular niche, depleted protein C receptor (PROCR)-expressing endovascular endothelial progenitor cells, and rectified the hyperpermeable blood vasculature, causing tumor tissue hypoxia and cancer cell death. TSC1-deficient TAMs were metabolically active and effectively eliminated PROCR-expressing endothelial cells in cell competition experiments. Thus, TAMs exhibit a TSC1-dependent mTORC1-low state, and increasing mTORC1 signaling promotes a pro-resolving state that suppresses tumor growth, defining an innate immune tumor suppression pathway that may be exploited for cancer immunotherapy.
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Affiliation(s)
- Mytrang H Do
- Immunology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA; Immunology and Microbial Pathogenesis Program, Weill Cornell Graduate School of Medical Sciences, Cornell University, New York, NY 10065, USA
| | - Wei Shi
- Immunology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Liangliang Ji
- Immunology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Erik Ladewig
- Computational and Systems Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Xian Zhang
- Immunology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Raghvendra M Srivastava
- Immunogenomics & Precision Oncology Platform (IPOP), Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Kristelle J Capistrano
- Immunology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Chaucie Edwards
- Immunology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Isha Malik
- Immunology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Briana G Nixon
- Immunology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA; Immunology and Microbial Pathogenesis Program, Weill Cornell Graduate School of Medical Sciences, Cornell University, New York, NY 10065, USA
| | - Efstathios G Stamatiades
- Immunology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Ming Liu
- Immunology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Shun Li
- Immunology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Peng Li
- Immunology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Chun Chou
- Immunology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Ke Xu
- Immunology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA; Immunology and Microbial Pathogenesis Program, Weill Cornell Graduate School of Medical Sciences, Cornell University, New York, NY 10065, USA
| | - Ting-Wei Hsu
- Immunology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA; Graduate Program in Biochemistry and Structural Biology, Cell and Developmental Biology, and Molecular Biology, Weill Cornell Graduate School of Medical Sciences, Cornell University, New York, NY 10065, USA
| | - Xinxin Wang
- Immunology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA; Immunology and Microbial Pathogenesis Program, Weill Cornell Graduate School of Medical Sciences, Cornell University, New York, NY 10065, USA
| | - Timothy A Chan
- Immunogenomics & Precision Oncology Platform (IPOP), Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Christina S Leslie
- Computational and Systems Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Ming O Li
- Immunology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA; Immunology and Microbial Pathogenesis Program, Weill Cornell Graduate School of Medical Sciences, Cornell University, New York, NY 10065, USA.
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3
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Ortiz JR, Lewis SM, Ciccone MF, Chatterjee D, Henry S, Siepel A, Dos Santos CO. Single-cell transcription mapping of murine and human mammary organoids responses to female hormones. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.28.559971. [PMID: 37808747 PMCID: PMC10557705 DOI: 10.1101/2023.09.28.559971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
During female adolescence and pregnancy, rising levels of hormones result in a cyclic source of signals that control the development of mammary tissue. While such alterations are well understood from a whole-gland perspective, the alterations that such hormones bring to organoid cultures derived from mammary glands have yet to be fully mapped. This is of special importance given that organoids are considered suitable systems to understand cross species breast development. Here we utilized single-cell transcriptional profiling to delineate responses of murine and human normal breast organoid systems to female hormones across evolutionary distinct species. Collectively, our study represents a molecular atlas of epithelial dynamics in response to estrogen and pregnancy hormones.
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Wimberger P, Gerber MJ, Pfisterer J, Erdmann K, Füssel S, Link T, du Bois A, Kommoss S, Heitz F, Sehouli J, Kimmig R, de Gregorio N, Schmalfeldt B, Park-Simon TW, Baumann K, Hilpert F, Grube M, Schröder W, Burges A, Belau A, Hanker L, Kuhlmann JD. Bevacizumab May Differentially Improve Prognosis of Advanced Ovarian Cancer Patients with Low Expression of VEGF-A165b, an Antiangiogenic VEGF-A Splice Variant. Clin Cancer Res 2022; 28:4660-4668. [PMID: 36001383 DOI: 10.1158/1078-0432.ccr-22-1326] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 07/07/2022] [Accepted: 08/22/2022] [Indexed: 01/24/2023]
Abstract
PURPOSE The identification of a robust IHC marker to predict the response to antiangiogenic bevacizumab in ovarian cancer is of high clinical interest. VEGF-A, the molecular target of bevacizumab, is expressed as multiple isoforms with pro- or antiangiogenic properties, of which VEGF-A165b is the most dominant antiangiogenic isoform. The balance of VEGF-A isoforms is closely related to the angiogenic capacity of a tumor and may define its vulnerability to antiangiogenic therapy. We investigated whether the expression of VEGF-A165b could be related to the effect of bevacizumab in advanced ovarian cancer patients. EXPERIMENTAL DESIGN Formalin-fixed paraffin-embedded tissues from 413 patients of the ICON7 multicenter phase III trial, treated with standard platinum-based chemotherapy with or without bevacizumab, were probed for VEGF-A165b expression by IHC. RESULTS In patients with low VEGF-A165b expression, the addition of bevacizumab to standard platinum-based chemotherapy significantly improved progression-free (HR: 0.727; 95% CI, 0.538-0.984; P = 0.039) and overall survival (HR: 0.662; 95% CI, 0.458-0.958; P = 0.029). Multivariate analysis showed that the addition of bevacizumab in low VEGF-A165b-expressing patients conferred significant improvements in progression-free survival (HR: 0.610; 95% CI, 0.446-0.834; P = 0.002) and overall survival (HR: 0.527; 95% CI, 0.359-0.775; P = 0.001), independently from established risk factors. CONCLUSIONS We demonstrate for the first time that bevacizumab may differentially improve the prognosis of advanced ovarian cancer patients with low expression of VEGF-A165b, an antiangiogenic VEGF-A splice variant. We envision that this novel biomarker could be implemented into routine diagnostics and may have direct clinical implications for guiding bevacizumab-related treatment decisions in advanced ovarian cancer patients.
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Affiliation(s)
- Pauline Wimberger
- Department of Gynecology and Obstetrics, Medical Faculty and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.,National Center for Tumour Diseases (NCT), Dresden, Germany: German Cancer Research Center (DKFZ), Heidelberg, Germany; Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany; Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany.,German Cancer Consortium (DKTK), Dresden and German Cancer Research Center (DKFZ), Heidelberg, Germany.,AGO Study Group, Wiesbaden, Germany
| | - Mara Julia Gerber
- Department of Gynecology and Obstetrics, Medical Faculty and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.,National Center for Tumour Diseases (NCT), Dresden, Germany: German Cancer Research Center (DKFZ), Heidelberg, Germany; Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany; Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany.,German Cancer Consortium (DKTK), Dresden and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Jacobus Pfisterer
- AGO Study Group, Wiesbaden, Germany.,Gynecologic Oncology Center, Kiel, Germany
| | - Kati Erdmann
- National Center for Tumour Diseases (NCT), Dresden, Germany: German Cancer Research Center (DKFZ), Heidelberg, Germany; Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany; Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany.,German Cancer Consortium (DKTK), Dresden and German Cancer Research Center (DKFZ), Heidelberg, Germany.,Department of Urology, Medical Faculty and University Hospital Carl Gustav Carus Dresden, Technische Universität Dresden, Dresden, Germany
| | - Susanne Füssel
- German Cancer Consortium (DKTK), Dresden and German Cancer Research Center (DKFZ), Heidelberg, Germany.,Department of Urology, Medical Faculty and University Hospital Carl Gustav Carus Dresden, Technische Universität Dresden, Dresden, Germany
| | - Theresa Link
- Department of Gynecology and Obstetrics, Medical Faculty and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.,National Center for Tumour Diseases (NCT), Dresden, Germany: German Cancer Research Center (DKFZ), Heidelberg, Germany; Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany; Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany.,German Cancer Consortium (DKTK), Dresden and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Andreas du Bois
- Department of Gynecology and Gynecologic Oncology, Kliniken Essen-Mitte (KEM), Essen, Germany
| | - Stefan Kommoss
- Department Gynecology and Gynecologic Oncology, University of Tuebingen, Tübingen, Germany
| | - Florian Heitz
- AGO Study Group, Wiesbaden, Germany.,Department of Gynecology and Gynecologic Oncology, Kliniken Essen-Mitte (KEM), Essen, Germany
| | - Jalid Sehouli
- AGO Study Group, Wiesbaden, Germany.,Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Rainer Kimmig
- AGO Study Group, Wiesbaden, Germany.,University Hospital Essen, Essen, Germany
| | - Nikolaus de Gregorio
- AGO Study Group, Wiesbaden, Germany.,University Hospital Ulm, Ulm, Germany and SLK-Kliniken Heilbronn, Klinikum am Gesundbrunnen, Heilbronn, Germany
| | - Barbara Schmalfeldt
- AGO Study Group, Wiesbaden, Germany.,University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | - Klaus Baumann
- AGO Study Group, Wiesbaden, Germany.,University Hospital Gießen and Marburg, Marburg, Germany; Hospital Ludwigshafen, Ludwigshafen, Germany
| | - Felix Hilpert
- AGO Study Group, Wiesbaden, Germany.,University Hospital Schleswig-Holstein, Kiel, Germany; Krankenhaus Jerusalem, Mammazentrum Hamburg, Hamburg, Germany
| | - Marcel Grube
- AGO Study Group, Wiesbaden, Germany.,Department Gynecology and Gynecologic Oncology, University of Tuebingen, Tübingen, Germany
| | - Willibald Schröder
- AGO Study Group, Wiesbaden, Germany.,Klinikum Bremen-Mitte, Bremen, Germany; GYNAEKOLOGICUM Bremen, Bremen, Germany
| | - Alexander Burges
- AGO Study Group, Wiesbaden, Germany.,University Hospital LMU Munich, Munich, Germany
| | - Antje Belau
- AGO Study Group, Wiesbaden, Germany.,University Hospital Greifswald, Greifswald, Germany; Frauenarztpraxis Dr. Belau, Greifswald, Germany
| | - Lars Hanker
- AGO Study Group, Wiesbaden, Germany.,Department of Gynecology and Obstetrics University Hospital Frankfurt, Frankfurt, Germany; Department of Gynecology and Obstetrics University Hospital Schleswig-Holstein, Lübeck, Germany
| | - Jan Dominik Kuhlmann
- Department of Gynecology and Obstetrics, Medical Faculty and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.,National Center for Tumour Diseases (NCT), Dresden, Germany: German Cancer Research Center (DKFZ), Heidelberg, Germany; Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany; Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany.,German Cancer Consortium (DKTK), Dresden and German Cancer Research Center (DKFZ), Heidelberg, Germany
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5
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Al Kawas H, Saaid I, Jank P, Westhoff CC, Denkert C, Pross T, Weiler KBS, Karsten MM. How VEGF-A and its splice variants affect breast cancer development - clinical implications. Cell Oncol (Dordr) 2022; 45:227-239. [PMID: 35303290 PMCID: PMC9050780 DOI: 10.1007/s13402-022-00665-w] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/16/2022] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Altered expression levels and structural variations in the vascular endothelial growth factor (VEGF) have been found to play important roles in cancer development and to be associated with the overall survival and therapy response of cancer patients. Particularly VEGF-A and its splice variants have been found to affect physiological and pathological angiogenic processes, including tumor angiogenesis, correlating with tumor progression, mostly caused by overexpression. This review focuses on the expression and impact of VEGF-A splice variants under physiologic conditions and in tumors and, in particular, the distribution and role of isoform VEGF165b in breast cancer. CONCLUSIONS AND PERSPECTIVES Many publications already highlighted the importance of VEGF-A and its splice variants in tumor therapy, especially in breast cancer, which are summarized in this review. Furthermore, we were able to demonstrate that cytoplasmatic VEGFA/165b expression is higher in invasive breast cancer tumor cells than in normal tissues or stroma. These examples show that the detection of VEGF splice variants can be performed also on the protein level in formalin fixed tissues. Although no quantitative conclusions can be drawn, these results may be the starting point for further studies at a quantitative level, which can be a major step towards the design of targeted antibody-based (breast) cancer therapies.
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Affiliation(s)
- Hivin Al Kawas
- Department of Gynecology with Breast Center, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Inas Saaid
- Department of Gynecology with Breast Center, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Paul Jank
- Institute of Pathology, Philipps-Universität Marburg, 35043, Marburg, Germany
| | | | - Carsten Denkert
- Institute of Pathology, Philipps-Universität Marburg, 35043, Marburg, Germany
| | - Therese Pross
- Department of Gynecology with Breast Center, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | | | - Maria Margarete Karsten
- Department of Gynecology with Breast Center, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Charitéplatz 1, 10117, Berlin, Germany.
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Dardente H, English WR, Valluru MK, Kanthou C, Simpson D. Debunking the Myth of the Endogenous Antiangiogenic Vegfaxxxb Transcripts. Trends Endocrinol Metab 2020; 31:398-409. [PMID: 32396842 DOI: 10.1016/j.tem.2020.01.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 11/28/2019] [Accepted: 01/14/2020] [Indexed: 12/19/2022]
Abstract
In this opinion article we critically assess evidence for the existence of a family of antiangiogenic vascular endothelial growth factor (Vegfaxxxb) transcripts, arising from the use of a phylogenetically conserved alternative distal splice site within exon 8 of the VEGFA gene. We explain that prior evidence for Vegfaxxxb transcripts in tissues rests heavily upon flawed RT-PCR methodologies, with the extensive use of 5'-tailing in primer design being the main issue. Furthermore, our analysis of large RNA-seq data sets (human and ovine) fails to identify a single Vegfaxxxb transcript. Therefore, we challenge the very existence of Vegfaxxxb transcripts, which further questions the physiological relevance of studies based on the use of 'anti-VEGFAxxxb' antibodies. Our analysis has implications for the proposed therapeutic use of isoform-specific anti-VEGFA strategies for treating cancer and retinopathies.
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Affiliation(s)
- Hugues Dardente
- PRC, INRA, CNRS, IFCE, Université de Tours, 37380 Nouzilly, France.
| | - William R English
- Department of Oncology and Metabolism, Tumour Microcirculation Group, University of Sheffield, School of Medicine, Beech Hill Road, Sheffield, S10 2RX, UK
| | - Manoj K Valluru
- Department of Oncology and Metabolism, Tumour Microcirculation Group, University of Sheffield, School of Medicine, Beech Hill Road, Sheffield, S10 2RX, UK
| | - Chryso Kanthou
- Department of Oncology and Metabolism, Tumour Microcirculation Group, University of Sheffield, School of Medicine, Beech Hill Road, Sheffield, S10 2RX, UK
| | - David Simpson
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, BT7 1NN, UK
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7
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Contribution of the VEGF system to the follicular persistence associated with bovine cystic ovaries. Theriogenology 2019; 138:52-65. [DOI: 10.1016/j.theriogenology.2019.07.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 06/05/2019] [Accepted: 07/02/2019] [Indexed: 01/09/2023]
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8
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Knockdown of P4HA1 inhibits neovascularization via targeting glioma stem cell-endothelial cell transdifferentiation and disrupting vascular basement membrane. Oncotarget 2018; 8:35877-35889. [PMID: 28415787 PMCID: PMC5482624 DOI: 10.18632/oncotarget.16270] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 02/28/2017] [Indexed: 11/25/2022] Open
Abstract
Emerging evidence has demonstrated transdifferentiation process of glioma stem cells (GSCs) into endothelial cells (ECs) in glioma neovascularization. Herein, we focused on screening for genes that were differentially expressed in the transdifferentiation process using microarray analysis. Bioinformatics analysis revealed differential expression of the prolyl 4-hydroxylase subunit alpha-1 (P4HA1) gene. We determined that P4HA1 expression was correlated with histological grade, the level of Ki67 and microvessel density (MVD) in human glioma specimens. Knockdown of P4HA1 inhibited the proliferation, migration and tube formation of GSCs in vitro. In vivo studies revealed that the downregulation of P4HA1 inhibited intracranial tumor growth, prolonged the overall survival time of xenograft mice and suppressed the neovascularization in brain tumors. Moreover, P4HA1 regulates the expression of vascular endothelial growth factor A (VEGF-A), especially an anti-angiogenic isoform-VEGF165b. Additionally, knockdown of P4HA1 inhibited the synthesis of collagen IV, and hence disrupted the structures of vascular basement membranes (BMs) in gliomas. Our study indicates that P4HA1 plays a pivotal role in the process of GSC-EC transdifferentiation and the structural formation of vascular BMs.
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9
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Barratt SL, Blythe T, Jarrett C, Ourradi K, Shelley-Fraser G, Day MJ, Qiu Y, Harper S, Maher TM, Oltean S, Hames TJ, Scotton CJ, Welsh GI, Bates DO, Millar AB. Differential Expression of VEGF-A xxx Isoforms Is Critical for Development of Pulmonary Fibrosis. Am J Respir Crit Care Med 2017; 196:479-493. [PMID: 28661183 DOI: 10.1164/rccm.201603-0568oc] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Fibrosis after lung injury is related to poor outcome, and idiopathic pulmonary fibrosis (IPF) can be regarded as an exemplar. Vascular endothelial growth factor (VEGF)-A has been implicated in this context, but there are conflicting reports as to whether it is a contributory or protective factor. Differential splicing of the VEGF-A gene produces multiple functional isoforms including VEGF-A165a and VEGF-A165b, a member of the inhibitory family. To date there is no clear information on the role of VEGF-A in IPF. OBJECTIVES To establish VEGF-A isoform expression and functional effects in IPF. METHODS We used tissue sections, plasma, and lung fibroblasts from patients with IPF and control subjects. In a bleomycin-induced lung fibrosis model we used wild-type MMTV mice and a triple transgenic mouse SPC-rtTA+/-TetoCre+/-LoxP-VEGF-A+/+ to conditionally induce VEGF-A isoform deletion specifically in the alveolar type II (ATII) cells of adult mice. MEASUREMENTS AND MAIN RESULTS IPF and normal lung fibroblasts differentially expressed and responded to VEGF-A165a and VEGF-A165b in terms of proliferation and matrix expression. Increased VEGF-A165b was detected in plasma of progressing patients with IPF. In a mouse model of pulmonary fibrosis, ATII-specific deficiency of VEGF-A or constitutive overexpression of VEGF-A165b inhibited the development of pulmonary fibrosis, as did treatment with intraperitoneal delivery of VEGF-A165b to wild-type mice. CONCLUSIONS These results indicate that changes in the bioavailability of VEGF-A sourced from ATII cells, namely the ratio of VEGF-Axxxa to VEGF-Axxxb, are critical in development of pulmonary fibrosis and may be a paradigm for the regulation of tissue repair.
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Affiliation(s)
| | - Thomas Blythe
- 1 Academic Respiratory Unit, School of Clinical Sciences
| | | | | | - Golda Shelley-Fraser
- 2 Department of Histopathology, Cheltenham and Gloucestershire NHS Trust, Cheltenham, United Kingdom
| | | | | | | | - Toby M Maher
- 5 NIHR Respiratory Biomedical Research Unit, Royal Brompton Hospital, London, United Kingdom
| | - Sebastian Oltean
- 6 Department of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom
| | - Thomas J Hames
- 7 University of Exeter Medical School, Exeter, United Kingdom; and
| | - Chris J Scotton
- 7 University of Exeter Medical School, Exeter, United Kingdom; and
| | | | - David O Bates
- 8 Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Nottingham, United Kingdom
| | - Ann B Millar
- 1 Academic Respiratory Unit, School of Clinical Sciences
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10
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Biselli-Chicote PM, Biselli JM, Cunha BR, Castro R, Maniglia JV, Neto DDS, Tajara EH, Góis Filho JFD, Fukuyama EE, Pavarino ÉC, Goloni-Bertollo EM. Overexpression of Antiangiogenic Vascular Endothelial Growth Factor Isoform and Splicing Regulatory Factors in Oral, Laryngeal and Pharyngeal Squamous Cell Carcinomas. Asian Pac J Cancer Prev 2017; 18:2171-2177. [PMID: 28843252 PMCID: PMC5697477 DOI: 10.22034/apjcp.2017.18.8.2171] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Background: Overexpression of proangiogenic vascular endothelial growth factor A family VEGFAxxx is associated with tumor growth and metastasis. The role of the alternatively spliced antiangiogenic family VEGFAxxxb is poorly investigated in head and neck squamous cell carcinomas (HNSCCs). The antiangiogenic isoform binds to bevacizumab and its expression level could influence the treatment response and progression-free survival. In this study, the relative expression of VEGFAxxx and VEGFA165b isoforms and splicing regulatory factors genes was investigated in a series of HNSCCs. Methods: VEGFAxxx, VEGFA165b, SRSF6, SRSF5, SRSF1 and SRPK1 gene expression was quantified by quantitative real time PCR in 53 tissue samples obtained by surgery from HNSCC patients. Protein expression was evaluated by immunohistochemistry. Results: VEGFAxxx and VEGFA165b were overexpressed in HNSCCs. Elevated protein expression was also confirmed. However, VEGFA isoforms demonstrated differential expression according to anatomical sites. VEGFAxxx was overexpressed in pharyngeal tumors while the VEGFA165b isoform was up-regulated in oral tumors. The VEGFA165b isoform was also positively correlated with expression of the splicing regulatory genes SRSF1, SRSF6 and SRSF5. Conclusions: We concluded that VEGFAxxx and VEGFA165b isoforms are overexpressed in HNSCCs and the splicing regulatory factors SRSF1, SRSF6, SRSF5 and SRPK1 may contribute to alternative splicing of the VEGFA gene. The findings for the differential expression of the antiangiogenic isoform in HNSCCs could facilitate effective therapeutic strategies for the management of these tumors.
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RNA-Sequencing data supports the existence of novel VEGFA splicing events but not of VEGFA xxxb isoforms. Sci Rep 2017; 7:58. [PMID: 28246395 PMCID: PMC5427905 DOI: 10.1038/s41598-017-00100-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 02/06/2017] [Indexed: 01/08/2023] Open
Abstract
Vascular endothelial growth factor (VEGFA), a pivotal regulator of angiogenesis and valuable therapeutic target, is characterised by alternative splicing which generates three principal isoforms, VEGFA121, VEGFA165 and VEGFA189. A second set of anti-angiogenic isoforms termed VEGFAxxxb that utilise an alternative splice site in the final exon have been widely reported, with mRNA detection based principally upon RT-PCR assays. We sought confirmation of the existence of the VEGFAxxxb isoforms within the abundant RNA sequencing data available publicly. Whilst sequences derived specifically from each of the canonical VEGFA isoforms were present in many tissues, there were no sequences derived from VEGFAxxxb isoforms. Sequencing of approximately 50,000 RT-PCR products spanning the exon 7–8 junction in 10 tissues did not identify any VEGFAxxxb transcripts. The absence or extremely low expression of these transcripts in vivo indicates that VEGFAxxxb isoforms are unlikely to play a role in normal physiology. Our analyses also revealed multiple novel splicing events supported by more reads than previously reported for VEGFA145 and VEGFA148 isoforms, including three from novel first exons consistent with existing transcription start site data. These novel VEGFA isoforms may play significant roles in specific cell types.
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13
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Guyot M, Pagès G. VEGF Splicing and the Role of VEGF Splice Variants: From Physiological-Pathological Conditions to Specific Pre-mRNA Splicing. Methods Mol Biol 2015; 1332:3-23. [PMID: 26285742 DOI: 10.1007/978-1-4939-2917-7_1] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
During this past decade, the vascular endothelial growth factor (VEGF) pathway has been extensively studied. VEGF is a paradigm of molecular regulation since its expression is controlled at all possible steps including transcription, mRNA stability, translation, and pre-mRNA splicing. The latter form of molecular regulation is probably the least studied. This field has been neglected; yet different forms of VEGF with different sizes and different physiological properties issued from alternative splicing have been described a long time ago. Recently a new level of complexity was added to the field of splicing of VEGF pre-mRNA. Whereas thousands of publications have described VEGF as a pro-angiogenic factor, an alternative splicing event generates specific anti-angiogenic forms of VEGF that only differ from the others by a modification in the last six amino acids of the protein. According to the scientists who discovered these isoforms, which are indistinguishable from the pro-angiogenic ones with pan VEGF antibodies, some of the literature on VEGF is at least inexact if not completely false. Moreover, the presence of anti-angiogenic forms of VEGF may explain the disappointing efficacy of anti-VEGF therapies on the overall survival of patients with different forms of cancers and with wet age-related macular degeneration. This review focuses on the existence of the different alternative splice variants of VEGF and the molecular mechanisms associated with their expression and function.
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Affiliation(s)
- Mélanie Guyot
- Institute for Research on Cancer and Aging of Nice (IRCAN), University of Nice Sophia Antipolis, Centre Antoine Lacassagne 33 Avenue de Valombrose, UMR CNRS 7284/INSERM U 1081, Nice, 06189, France
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Orief YI, Karkor TAE, Aly Saleh H, El Hadidy AS, Badr N. Comparative evaluation of vascular endothelial growth factor-A expression in pre-ovulatory follicular fluid in normogonadotrophic and endometriotic patients undergoing assisted reproductive techniques. MIDDLE EAST FERTILITY SOCIETY JOURNAL 2014. [DOI: 10.1016/j.mefs.2013.06.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
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Carter JG, Gammons MVR, Damodaran G, Churchill AJ, Harper SJ, Bates DO. The carboxyl terminus of VEGF-A is a potential target for anti-angiogenic therapy. Angiogenesis 2014; 18:23-30. [PMID: 25274272 PMCID: PMC4280485 DOI: 10.1007/s10456-014-9444-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Accepted: 09/10/2014] [Indexed: 11/25/2022]
Abstract
Anti-VEGF-A therapy has become a mainstay of treatment for ocular neovascularisation and in cancer; however, their effectiveness is not universal, in some cases only benefiting a minority of patients. Anti-VEGF-A therapies bind and block both pro-angiogenic VEGF-Axxx and the partial agonist VEGF-Axxxb isoforms, but their anti-angiogenic benefit only comes about from targeting the pro-angiogenic isoforms. Therefore, antibodies that exclusively target the pro-angiogenic isoforms may be more effective. To determine whether C-terminal-targeted antibodies could inhibit angiogenesis, we generated a polyclonal antibody to the last nine amino acids of VEGF-A165 and tested it in vitro and in vivo. The exon8a polyclonal antibody (Exon8apab) did not bind VEGF-A165b even at greater than 100-fold excess concentration, and dose dependently inhibited VEGF-A165 induced endothelial migration in vitro at concentrations similar to the VEGF-A antibody fragment ranibizumab. Exon8apab can inhibit tumour growth of LS174t cells implanted in vivo and blood vessel growth in the eye in models of age-related macular degeneration, with equal efficacy to non-selective anti-VEGF-A antibodies. It also showed that it was the VEGF-Axxx levels specifically that were upregulated in plasma from patients with proliferative diabetic retinopathy. These results suggest that VEGF-A165-specific antibodies can be therapeutically useful.
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Affiliation(s)
- James G. Carter
- Microvascular Research Laboratories, School of Physiology and Pharmacology, University of Bristol, Preclinical Veterinary Sciences Building, Southwell Street, Bristol, BS2 8EJ UK
- Cancer Biology, Queens Medical Centre, University of Nottingham, D Floor West Block, Nottingham, NG7 2UH UK
| | - Melissa V. R. Gammons
- Microvascular Research Laboratories, School of Physiology and Pharmacology, University of Bristol, Preclinical Veterinary Sciences Building, Southwell Street, Bristol, BS2 8EJ UK
| | - Gopinath Damodaran
- Microvascular Research Laboratories, School of Physiology and Pharmacology, University of Bristol, Preclinical Veterinary Sciences Building, Southwell Street, Bristol, BS2 8EJ UK
| | - Amanda J. Churchill
- Microvascular Research Laboratories, School of Physiology and Pharmacology, University of Bristol, Preclinical Veterinary Sciences Building, Southwell Street, Bristol, BS2 8EJ UK
| | - Steven J. Harper
- Microvascular Research Laboratories, School of Physiology and Pharmacology, University of Bristol, Preclinical Veterinary Sciences Building, Southwell Street, Bristol, BS2 8EJ UK
| | - David O. Bates
- Microvascular Research Laboratories, School of Physiology and Pharmacology, University of Bristol, Preclinical Veterinary Sciences Building, Southwell Street, Bristol, BS2 8EJ UK
- Cancer Biology, Queens Medical Centre, University of Nottingham, D Floor West Block, Nottingham, NG7 2UH UK
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Eswarappa SM, Potdar AA, Koch WJ, Fan Y, Vasu K, Lindner D, Willard B, Graham LM, DiCorleto PE, Fox PL. Programmed translational readthrough generates antiangiogenic VEGF-Ax. Cell 2014; 157:1605-18. [PMID: 24949972 DOI: 10.1016/j.cell.2014.04.033] [Citation(s) in RCA: 150] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Revised: 02/21/2014] [Accepted: 04/04/2014] [Indexed: 12/20/2022]
Abstract
Translational readthrough, observed primarily in less complex organisms from viruses to Drosophila, expands the proteome by translating select transcripts beyond the canonical stop codon. Here, we show that vascular endothelial growth factor A (VEGFA) mRNA in mammalian endothelial cells undergoes programmed translational readthrough (PTR) generating VEGF-Ax, an isoform containing a unique 22-amino-acid C terminus extension. A cis-acting element in the VEGFA 3' UTR serves a dual function, not only encoding the appended peptide but also directing the PTR by decoding the UGA stop codon as serine. Heterogeneous nuclear ribonucleoprotein (hnRNP) A2/B1 binds this element and promotes readthrough. Remarkably, VEGF-Ax exhibits antiangiogenic activity in contrast to the proangiogenic activity of VEGF-A. Pathophysiological significance of VEGF-Ax is indicated by robust expression in multiple human tissues but depletion in colon adenocarcinoma. Furthermore, genome-wide analysis revealed AGO1 and MTCH2 as authentic readthrough targets. Overall, our studies reveal a novel protein-regulated PTR event in a vertebrate system.
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Affiliation(s)
- Sandeepa M Eswarappa
- Department of Cellular and Molecular Medicine, The Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Alka A Potdar
- Department of Cellular and Molecular Medicine, The Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA; Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA
| | - William J Koch
- Department of Cellular and Molecular Medicine, The Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Yi Fan
- Department of Cellular and Molecular Medicine, The Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Kommireddy Vasu
- Department of Cellular and Molecular Medicine, The Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Daniel Lindner
- Taussig Cancer Center, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Belinda Willard
- Mass Spectrometry Laboratory for Protein Sequencing, The Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Linda M Graham
- Department of Biomedical Engineering, The Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Paul E DiCorleto
- Department of Cellular and Molecular Medicine, The Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Paul L Fox
- Department of Cellular and Molecular Medicine, The Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
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Liu S, Cheng C. Alternative RNA splicing and cancer. WILEY INTERDISCIPLINARY REVIEWS. RNA 2013; 4:547-66. [PMID: 23765697 PMCID: PMC4426271 DOI: 10.1002/wrna.1178] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2013] [Revised: 05/10/2013] [Accepted: 05/11/2013] [Indexed: 01/04/2023]
Abstract
Alternative splicing of pre-messenger RNA (mRNA) is a fundamental mechanism by which a gene can give rise to multiple distinct mRNA transcripts, yielding protein isoforms with different, even opposing, functions. With the recognition that alternative splicing occurs in nearly all human genes, its relationship with cancer-associated pathways has emerged as a rapidly growing field. In this review, we summarize recent findings that have implicated the critical role of alternative splicing in cancer and discuss current understandings of the mechanisms underlying dysregulated alternative splicing in cancer cells.
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Affiliation(s)
- Sali Liu
- Department of Medicine, Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
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Gammons MVR, Dick AD, Harper SJ, Bates DO. SRPK1 inhibition modulates VEGF splicing to reduce pathological neovascularization in a rat model of retinopathy of prematurity. Invest Ophthalmol Vis Sci 2013; 54:5797-806. [PMID: 23761094 PMCID: PMC6485497 DOI: 10.1167/iovs.13-11634] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE We tested the hypothesis that recombinant human VEGF-A165b and the serine arginine protein kinase (SRPK) inhibitor, SRPIN340, which controls splicing of the VEGF-A pre-mRNA, prevent neovascularization in a rodent model of retinopathy of prematurity (ROP). METHODS In the 50/10 oxygen-induced retinopathy (50/10 OIR) model that exposes newborn rats to repeated cycles of 24 hours of 50% oxygen alternating with 24 hours of 10% oxygen, pups received intraocular injections of SRPIN340, vehicle, VEGF165b, anti-VEGF antibody, or saline. Whole mounts of retinas were prepared for isolectin immunohistochemistry, and preretinal or intravitreal neovascularization (PRNV) determined by clock hour analysis. RESULTS The anti-VEGF antibody (P < 0.04), rhVEGF165b (P < 0.001), and SRPIN340 (P < 0.05) significantly reduced PRNV compared with control eyes. SRPIN340 reduced the expression of proangiogenic VEGF165 without affecting VEGF165b expression. CONCLUSIONS These results suggest that splicing regulation through selective downregulation of proangiogenic VEGF isoforms (via SRPK1 inhibition) or competitive inhibition of VEGF signaling by rhVEGF165b has the potential to be an effective alternative to potential cyto- and neurotoxic anti-VEGF agents in the treatment of pathological neovascularization in the eye.
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Affiliation(s)
- Melissa V R Gammons
- Microvascular Research Laboratories, School of Physiology and Pharmacology, University of Bristol, Bristol, UK
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Arcondéguy T, Lacazette E, Millevoi S, Prats H, Touriol C. VEGF-A mRNA processing, stability and translation: a paradigm for intricate regulation of gene expression at the post-transcriptional level. Nucleic Acids Res 2013; 41:7997-8010. [PMID: 23851566 PMCID: PMC3783158 DOI: 10.1093/nar/gkt539] [Citation(s) in RCA: 175] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Vascular Endothelial Growth Factor A (VEGF-A) is a potent secreted mitogen crucial for physiological and pathological angiogenesis. Post-transcriptional regulation of VEGF-A occurs at multiple levels. Firstly, alternative splicing gives rise to different transcript variants encoding diverse isoforms that exhibit distinct biological properties with regard to receptor binding and extra-cellular localization. Secondly, VEGF-A mRNA stability is regulated by effectors such as hypoxia or growth factors through the binding of stabilizing and destabilizing proteins at AU-rich elements located in the 3′-untranslated region. Thirdly, translation of VEGF-A mRNA is a controlled process involving alternative initiation codons, internal ribosome entry sites (IRESs), an upstream open reading frame (uORF), miRNA targeting and a riboswitch in the 3′ untranslated region. These different levels of regulation cooperate for the crucial fine-tuning of the expression of VEGF-A variants. This review will be focused on our current knowledge of the complex post-transcriptional regulatory switches that modulate the cellular VEGF-A level, a paradigmatic model of post-transcriptional regulation.
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Affiliation(s)
- Tania Arcondéguy
- Inserm UMR1037, Centre de Recherches en Cancérologie de Toulouse, CHU Rangueil, BP84225, 31432 Toulouse Cedex 4, France and Université Toulouse III Paul-Sabatier, 118 Route de Narbonne, 31400 Toulouse, France
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20
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Bates DO, Catalano PJ, Symonds KE, Varey AHR, Ramani P, O'Dwyer PJ, Giantonio BJ, Meropol NJ, Benson AB, Harper SJ. Association between VEGF splice isoforms and progression-free survival in metastatic colorectal cancer patients treated with bevacizumab. Clin Cancer Res 2012; 18:6384-91. [PMID: 23104894 DOI: 10.1158/1078-0432.ccr-12-2223] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Bevacizumab improves survival for patients with metastatic colorectal cancer with chemotherapy, but no proven predictive markers exist. The VEGF-A splice form, VEGF(165)b, anti-angiogenic in animal models, binds bevacizumab. We tested the hypothesis that prolonged progression-free survival (PFS) would occur only in patients with low relative VEGF(165)b levels treated with bevacizumab. EXPERIMENTAL DESIGN Blinded tumor samples from the phase III trial of FOLFOX4 ± bevacizumab were assessed for VEGF(165)b and VEGF(total) by immunohistochemistry and scored relative to normal tissue. A predictive index (PI) was derived from the ratio of VEGF(165)b:VEGF(total) for 44 samples from patients treated with FOLFOX + bevacizumab (arm A) and 53 samples from patients treated with FOLFOX4 (arm B), and PFS, and overall survival (OS) analyzed on the basis of PI relative to median ratio. RESULTS Unadjusted analysis of PFS showed significantly better outcome for individuals with VEGF(165)b:VEGF(total) ratio scores below median treated with FOLFOX4 + bevacizumab compared with FOLFOX4 alone (median, 8.0 vs. 5.2 months; P < 0.02), but no effect of bevacizumab on PFS in patients with VEGF(165)b:VEGF(total) ratio >median (5.9 vs. 6.3 months). These findings held after adjustment for other clinical and demographic features. OS was increased in arm A (median, 13.6 months) compared with arm B (10.6 months) in the low VEGF(165)b group, but this did not reach statistical significance. There was no difference in the high VEGF(165)b:VEGF(total) group between FOLFOX + bevacizumab (10.8 months) and FOLFOX alone (11.3 months). CONCLUSION Low VEGF(165)b:VEGF(total) ratio may be a predictive marker for bevacizumab in metastatic colorectal cancer, and individuals with high relative levels may not benefit.
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Affiliation(s)
- David O Bates
- Microvascular Research Laboratories, Department of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom.
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21
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Abstract
Anti-angiogenic vascular endothelial growth factor A (VEGF) 165b and pro-angiogenic VEGF 165 are generated from the same transcript, and their relative amounts are dependent on alternative splicing. The role of VEGF 165b has not been investigated in as much detail as VEGF 165, although it appears to be highly expressed in non-angiogenic tissues and, in contrast with VEGF 165, is downregulated in tumors and other pathologies associated with abnormal neovascularization such as diabetic retinopathy or Denys Drash syndrome. VEGF 165b inhibits VEGFR2 signaling by inducing differential phosphorylation, and it can be used to block angiogenesis in in vivo models of tumorigenesis and angiogenesis-related eye disease. Recent reports have identified three serine/arginine-rich proteins, SRSF1, SRSF2 and SRSF6, and studied their role in regulating terminal splice-site selection. Since the balance of VEGF isoforms is lost in cancer and angiogenesis-related conditions, control of VEGF splicing could also be used as a basis for therapy in these diseases.
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Affiliation(s)
- Maria Peiris-Pagès
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY, USA
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22
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Do anti-angiogenic VEGF (VEGFxxxb) isoforms exist? A cautionary tale. PLoS One 2012; 7:e35231. [PMID: 22567098 PMCID: PMC3342274 DOI: 10.1371/journal.pone.0035231] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Accepted: 03/14/2012] [Indexed: 12/28/2022] Open
Abstract
Splicing of the human vascular endothelial growth factor-A (VEGF-A) gene has been reported to generate angiogenic (VEGFxxx) and anti-angiogenic (VEGFxxxb) isoforms. Corresponding VEGFxxxb isoforms have also been reported in rat and mouse. We examined VEGFxxxb expression in mouse fibrosarcoma cell lines expressing all or individual VEGF isoforms (VEGF120, 164 or 188), grown in vitro and in vivo, and compared results with those from normal mouse and human tissues. Importantly, genetic construction of VEGF164 and VEGF188 expressing fibrosarcomas, in which exon 7 is fused to the conventional exon 8, precludes VEGFxxxb splicing from occurring. Thus, these two fibrosarcoma cell lines provided endogenous negative controls. Using RT-PCR we show that primers designed to simultaneously amplify VEGFxxx and VEGFxxxb isoforms amplified only VEGFxxx variants in both species. Moreover, only VEGFxxx species were generated when mouse podocytes were treated with TGFβ-1, a reported activator of VEGFxxxb splice selection in human podocytes. A VEGF164/120 heteroduplex species was identified as a PCR artefact, specifically in mouse. VEGFxxxb isoform-specific PCR did amplify putative VEGFxxxb species in mouse and human tissues, but unexpectedly also in VEGF188 and VEGF164 fibrosarcoma cells and tumours, where splicing to produce true VEGFxxxb isoforms cannot occur. Moreover, these products were only consistently generated using reverse primers spanning more than 5 bases across the 8b/7 or 8b/5 splice junctions. Primer annealing to VEGFxxx transcripts and amplification of exon 8b primer ‘tails’ explained the artefactual generation of VEGFxxxb products, since the same products were generated when the PCR reactions were performed with cDNA from VEGF164/VEGF188 ‘knock-in’ vectors used in the generation of single VEGF isoform-expressing transgenic mice from which the fibrosarcoma lines were developed. Collectively, our results highlight important pitfalls in data interpretation associated with detecting VEGFxxxb isoforms using current methods, and demonstrate that anti-angiogenic isoforms are not commonly expressed in mouse or human tissues.
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23
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Clapp C, Martínez de la Escalera L, Martínez de la Escalera G. Prolactin and blood vessels: a comparative endocrinology perspective. Gen Comp Endocrinol 2012; 176:336-40. [PMID: 22245261 DOI: 10.1016/j.ygcen.2011.12.033] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Revised: 12/25/2011] [Accepted: 12/27/2011] [Indexed: 01/13/2023]
Abstract
The hormone prolactin (PRL), fundamental for lactation in mammals, is known to exert a wide diversity of actions in the various vertebrate groups. Blood vessels are surfacing as important PRL targets, contributing to these hormonal functions. PRL promotes the growth of new blood vessels (angiogenesis) and is proteolytically cleaved to vasoinhibins, a family of peptides (including 16-kDa PRL) with potent antiangiogenic and blood vessel regression effects. These opposing actions point to the regulation of the proteases responsible for PRL cleavage as an efficient way to balance blood vessel growth and involution. This review briefly summarizes the effects of PRL and vasoinhibins on blood vessels in mammals and discusses whether similar vascular actions could contribute to the effects of PRL on the development, growth, and reproduction of lower vertebrates. A comparative study in diverse species may lead to a better understanding of blood vessels as a driving force for the biological actions of PRL.
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Affiliation(s)
- Carmen Clapp
- Instituto de Neurobiología, Universidad Nacional Autónoma de México (UNAM), Campus UNAM-Juriquilla, 76230 Querétaro, Mexico.
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24
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Qiu Y, Seager M, Osman A, Castle-Miller J, Bevan H, Tortonese DJ, Murphy D, Harper SJ, Fraser HM, Donaldson LF, Bates DO. Ovarian VEGF(165)b expression regulates follicular development, corpus luteum function and fertility. Reproduction 2012; 143:501-11. [PMID: 22232745 PMCID: PMC3325318 DOI: 10.1530/rep-11-0091] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 12/07/2011] [Accepted: 01/09/2012] [Indexed: 12/22/2022]
Abstract
Angiogenesis and vascular regression are critical for the female ovulatory cycle. They enable progression and regression of follicular development, and corpora lutea formation and regression. Angiogenesis in the ovary occurs under the control of the vascular endothelial growth factor-A (VEGFA) family of proteins, which are generated as both pro-(VEGF(165)) and anti(VEGF(165)b)-angiogenic isoforms by alternative splicing. To determine the role of the VEGF(165)b isoforms in the ovulatory cycle, we measured VEGF(165)b expression in marmoset ovaries by immunohistochemistry and ELISA, and used transgenic mice over-expressing VEGF(165)b in the ovary. VEGF(165)b was expressed in the marmoset ovaries in granulosa cells and theca, and the balance of VEGF(165)b:VEGF(165) was regulated during luteogenesis. Mice over-expressing VEGF(165)b in the ovary were less fertile than wild-type littermates, had reduced secondary and tertiary follicles after mating, increased atretic follicles, fewer corpora lutea and generated fewer embryos in the oviduct after mating, and these were more likely not to retain the corona radiata. These results indicate that the balance of VEGFA isoforms controls follicle progression and luteogenesis, and that control of isoform expression may regulate fertility in mammals, including in primates.
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Affiliation(s)
- Y Qiu
- Microvascular Research LaboratoriesSchool of Physiology and Pharmacology, Bristol Heart InstitutePre-clinical Veterinary Sciences Building, Southwell Street, Bristol, BS2 8EJUK
| | - M Seager
- Microvascular Research LaboratoriesSchool of Physiology and Pharmacology, Bristol Heart InstitutePre-clinical Veterinary Sciences Building, Southwell Street, Bristol, BS2 8EJUK
| | - A Osman
- Microvascular Research LaboratoriesSchool of Physiology and Pharmacology, Bristol Heart InstitutePre-clinical Veterinary Sciences Building, Southwell Street, Bristol, BS2 8EJUK
| | - J Castle-Miller
- Microvascular Research LaboratoriesSchool of Physiology and Pharmacology, Bristol Heart InstitutePre-clinical Veterinary Sciences Building, Southwell Street, Bristol, BS2 8EJUK
- Centre for Comparative and Clinical AnatomyUniversity of BristolPre-clinical Veterinary Sciences Building, Southwell Street, Bristol, BS2 8EJUK
| | - H Bevan
- Microvascular Research LaboratoriesSchool of Physiology and Pharmacology, Bristol Heart InstitutePre-clinical Veterinary Sciences Building, Southwell Street, Bristol, BS2 8EJUK
| | - D J Tortonese
- Centre for Comparative and Clinical AnatomyUniversity of BristolPre-clinical Veterinary Sciences Building, Southwell Street, Bristol, BS2 8EJUK
| | - D Murphy
- Henry Wellcome Laboratories for Integrative Neuroscience and EndocrinologyUniversity of BristolBristolUK
| | - S J Harper
- Microvascular Research LaboratoriesSchool of Physiology and Pharmacology, Bristol Heart InstitutePre-clinical Veterinary Sciences Building, Southwell Street, Bristol, BS2 8EJUK
| | - H M Fraser
- MRC Human Reproductive Sciences UnitQueen's Medical Research Institute47 Little France Crescent, Edinburgh, EH16 4TJUK
| | - L F Donaldson
- School of Physiology and PharmacologyMedical Sciences Building, University Walk, Bristol, BS8 1TDUK
| | - D O Bates
- Microvascular Research LaboratoriesSchool of Physiology and Pharmacology, Bristol Heart InstitutePre-clinical Veterinary Sciences Building, Southwell Street, Bristol, BS2 8EJUK
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25
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Amin EM, Oltean S, Hua J, Gammons MVR, Hamdollah-Zadeh M, Welsh GI, Cheung MK, Ni L, Kase S, Rennel ES, Symonds KE, Nowak DG, Royer-Pokora B, Saleem MA, Hagiwara M, Schumacher VA, Harper SJ, Hinton DR, Bates DO, Ladomery MR. WT1 mutants reveal SRPK1 to be a downstream angiogenesis target by altering VEGF splicing. Cancer Cell 2011; 20:768-80. [PMID: 22172722 PMCID: PMC3574979 DOI: 10.1016/j.ccr.2011.10.016] [Citation(s) in RCA: 195] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Revised: 06/10/2011] [Accepted: 10/17/2011] [Indexed: 12/19/2022]
Abstract
Angiogenesis is regulated by the balance of proangiogenic VEGF(165) and antiangiogenic VEGF(165)b splice isoforms. Mutations in WT1, the Wilms' tumor suppressor gene, suppress VEGF(165)b and cause abnormal gonadogenesis, renal failure, and Wilms' tumors. In WT1 mutant cells, reduced VEGF(165)b was due to lack of WT1-mediated transcriptional repression of the splicing-factor kinase SRPK1. WT1 bound to the SRPK1 promoter, and repressed expression through a specific WT1 binding site. In WT1 mutant cells SRPK1-mediated hyperphosphorylation of the oncogenic RNA binding protein SRSF1 regulated splicing of VEGF and rendered WT1 mutant cells proangiogenic. Altered VEGF splicing was reversed by wild-type WT1, knockdown of SRSF1, or SRPK1 and inhibition of SRPK1, which prevented in vitro and in vivo angiogenesis and associated tumor growth.
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Affiliation(s)
- Elianna M Amin
- Centre for Research in Biomedicine, University of the West of England, Bristol, UK
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Abstract
After decades of research, the mechanism by which estrogens stimulate the proliferation of epithelial cells in the endometrium and mammary gland, and in the carcinomas that arise in those tissues, is still not understood. Cells do not proliferate in response to 17β-estradiol (E2) alone, and although it is widely recognized that growth factors play a role in E2's proliferative effect, exactly how they are involved is unclear. It has long been known that the proliferation of endometrial epithelial cells is preceded by dramatic increases in blood flow and microvascular permeability, filling the subepithelial stroma with plasma and the proteins it contains, such as IGF-I, which is known to synergize with E2 in the induction of cell proliferation. The hyperpermeability is caused by vascular endothelial growth factor (VEGF), which is rapidly induced by E2, via the transcription factors hypoxia-inducible factor 1 and estrogen receptor α, in luminal epithelial cells in vivo. As we recently showed, VEGF is also strongly induced in endometrial cancer cells in vitro when excessive degradation of hypoxia-inducible factor 1α, caused by the abnormally high oxygen level to which cultured cells are exposed, is prevented. Putting these facts together, we now propose a new model of E2-induced proliferation in which VEGF-induced vascular hyperpermeability plays an essential role. E2 first induces the expression by endometrial epithelial cells of VEGF, which then acts in a paracrine manner to induce interendothelial cell gaps in subepithelial blood vessels, through which plasma and the proteins therein enter the adjacent stroma. Plasma carries even more E2, which circulates bound to proteins, and IGF-l, which together drive epithelial cells completely through the cell cycle.
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Affiliation(s)
- Robert D Koos
- Department of Physiology, University of Maryland School of Medicine, 655 West Baltimore Street, Baltimore, Maryland 21201-1559, USA.
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Zhao M, Shi X, Liang J, Miao Y, Xie W, Zhang Y, Li X. Expression of pro- and anti-angiogenic isoforms of VEGF in the mouse model of oxygen-induced retinopathy. Exp Eye Res 2011; 93:921-6. [PMID: 22067127 DOI: 10.1016/j.exer.2011.10.013] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2011] [Revised: 09/21/2011] [Accepted: 10/18/2011] [Indexed: 11/30/2022]
Abstract
Retinopathy of prematurity (ROP) has become one of the leading causes of blindness and visual loss in children over the last half century. Vascular endothelial growth factor (VEGF-A) is the principal stimulator of angiogenesis. Recently, it has been identified that VEGF was differentially spliced from exons 8 to exons 8a and 8b to form two families: the pro-angiogenic VEGFxxx family and the anti-angiogenic VEGFxxxb family. This alternate splicing produced VEGFxxxb proteins of the same length as VEGFxxx family, but with different C terminal amino acid sequences. VEGFxxxb appeared to be able to inhibit VEGFxxx-dependent angiogenesis. In our study, we investigated the protein expression course of VEGFxxx and VEGFxxxb by Western-blot in a mouse model of Oxygen-induced Retinopathy (OIR) from postnatal day 1 (P1) to postnatal day 21 (P21). We also analyzed the relative protein expression level of VEGF(165)b isoform in the OIR mouse model. We found that both VEGFxxx and VEGFxxxb were present in the mouse retina, among which, VEGF(164) and VEGF(165)b appeared to be predominant VEGFxxx and VEGFxxxb isoforms respectively in the mouse retina. We also found that the two family had different expression pattern correlated with neovascularization development and that the relative expression level of VEGF(165)b isoform switched during the neovascularization development in the OIR mouse model. In OIR group, the protein level of total VEGF isoforms (a mix of VEGF(164) and VEGF(165)b, detected by pan-VEGF antibody) continuously increased and peaked at P17 while VEGF(165)b continuously decreased from P9 which was well related with the vessel obliteration and neovascularization development in the mouse model of OIR. The neovascularization development correlates with an increase of total VEGF isoforms and the decrease of VEGF(165)b, indicating that there is a pro-angiogenic VEGF shift. Therefore, anti-angiogenic therapy that could alter the ratio of VEGFxxxb/VEGFxxx may be more effective.
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Affiliation(s)
- Min Zhao
- Department of Ophthalmology, Peking University People's Hospital, Beijing, China
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Biselli-Chicote PM, Oliveira ARCP, Pavarino EC, Goloni-Bertollo EM. VEGF gene alternative splicing: pro- and anti-angiogenic isoforms in cancer. J Cancer Res Clin Oncol 2011; 138:363-70. [PMID: 22045472 DOI: 10.1007/s00432-011-1073-2] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Accepted: 09/21/2011] [Indexed: 12/28/2022]
Abstract
Tumor growth and progression depend on angiogenesis, a process of new blood vessels formation from a preexisting vascular endothelium. Tumors promote angiogenesis by secreting or activating angiogenic factors that stimulate endothelial proliferation and migration and capillary morphogenesis. The newly formed blood vessels provide nutrients and oxygen to the tumor, increasing its growth. Thus, angiogenesis plays a key role in cancer progression and development of metastases. An important growth factor that promotes angiogenesis and participates in a variety of physiological and pathological processes is the vascular endothelial growth factor (VEGF-A or VEGF). Overexpression of VEGF results in increased angiogenesis in normal and pathological conditions. The existence of an alternative site of splicing at the 3' untranslated region of the mRNA results in the expression of isoforms with a C-terminal region which are downregulated in tumors and may have differential inhibitory effects. This suggests that control of splicing can be an important regulatory mechanism of angiogenesis in cancer.
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Affiliation(s)
- P M Biselli-Chicote
- Genetics and Molecular Biology Research Unit - UPGEM, Medical School of Sao Jose do Rio Preto - FAMERP, Av. Brigadeiro Faria Lima, 5416, Bloco U6, Sao Jose do Rio Preto, SP 15090-000, Brazil
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29
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Chen J, Li Z, Zhang S, Zhang R, Dassarath M, Wu G. Effects of exogenous VEGF(165)b on invasion and migration of human lung adenocarcinoma A549 cells. ACTA ACUST UNITED AC 2011; 31:619. [PMID: 22038350 DOI: 10.1007/s11596-011-0571-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2011] [Indexed: 01/19/2023]
Abstract
Vascular endothelial growth factor 165 (VEGF(165))-mediated autocrine stimulation of tumor cells enhances the progression to a malignant phenotype. VEGF(165)b competes with VEGF(165) and binds to vascular endothelial growth factor receptor (VEGFR), resulting in inhibition of downstream signal transduction pathways. This study was designed to investigate the role of VEGF(165)b in the migration and invasion of human lung adenocarcinoma A549 cells. The full-length of VEGF(165)b was constructed and cloned into an expression plasmid (pVEGF(165)b), and then transfected into A549 cells. Dimethylthiazolyl- 1 -2, 5-diphenyltetrazolium bromide (MTT) assay was used to detect the effect of VEGF(165)b on proliferation of transfected cells. Reverse transcription polymerase chain reaction (RT-PCR) was employed to examine the effect of VEGF(165)b on the expression of VEGF(165) in transfected cells. Wound-healing assays were used to investigate the effect of VEGF(165)b on migration of transfected cells. Matrix metalloproteinase (MMPs) activity assay and in vitro invasion assay were used to determine the role of VEGF(165)b in invasion of transfected cells. There was no significant change in proliferation of A549 cells after transfection of pVEGF(165)b, but the expression of VEGF(165), migration and invasion in A549 cells were inhibited. Furthermore, exogenous VEGF(165)b inhibited the activity of MMP9 in the supernatant of A549 cells and the subsequent invasion capacity of those cells. We therefore conclude that exogenous VEGF(165)b can inhibit the expression of VEGF(165), as well as the migration and invasion of A549 cells, but has no effect on the proliferation of A549 cells.
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Affiliation(s)
- Jing Chen
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Zhenyu Li
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Sheng Zhang
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Ruiguang Zhang
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Meera Dassarath
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.,Department of Oncology, Queen Victoria Hospital, Candos, Quatre-Bornes, Mauritius
| | - Gang Wu
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
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Impaired Angiogenesis in Systemic Sclerosis: The Emerging Role of the Antiangiogenic VEGF165b Splice Variant. Trends Cardiovasc Med 2011; 21:204-10. [DOI: 10.1016/j.tcm.2012.05.011] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Bills VL, Salmon AH, Harper SJ, Overton TG, Neal CR, Jeffery B, Soothill PW, Bates DO. Impaired vascular permeability regulation caused by the VEGF165b splice variant in pre-eclampsia. BJOG 2011; 118:1253-61. [DOI: 10.1111/j.1471-0528.2011.02925.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Liu K, Cheng L, Flesken-Nikitin A, Huang L, Nikitin AY, Pauli BU. Conditional knockout of fibronectin abrogates mouse mammary gland lobuloalveolar differentiation. Dev Biol 2010; 346:11-24. [PMID: 20624380 PMCID: PMC2937099 DOI: 10.1016/j.ydbio.2010.07.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2010] [Revised: 06/29/2010] [Accepted: 07/02/2010] [Indexed: 11/16/2022]
Abstract
Fibronectin (Fn) plays an important part in the branching morphogenesis of salivary gland, lung, and kidney. Here, we examine the effect of the conditional knockout of Fn in the mammary epithelium [Fn(MEp-/-)] on postnatal mammary gland development, using Cre-loxP-mediated gene knockout technology. Our data show that Fn deletion causes a moderate retardation in outgrowth and branching of the ductal tree in 5-week-old mice. These defects are partially compensated in virgin 16-week-old mice. However, mammary glands consisting of Fn-deficient epithelial cells fail to undergo normal lobuloalveolar differentiation during pregnancy. The severity of lobuloalveolar impairment ranged from lobular hypoplasia to aplasia in some cases and was associated with the amount of Fn protein recovered from these glands. Decreased rates of mammary epithelial cell proliferation accounted for delayed ductal outgrowth in virgin and lack of alveologenesis in pregnant Fn(MEp-/-) mice. Concomitant decreased expression of integrin beta(1) (Itgb1) and lack of autophosphorylation of focal adhesion kinase (Fak) suggest that this pathology might, at least in part, be mediated by disruption of the Fn/Itgb1/Fak signaling pathway.
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Affiliation(s)
- Keyi Liu
- Department of Molecular Medicine, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA
| | - Le Cheng
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA
| | - Andrea Flesken-Nikitin
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA
| | - Lynn Huang
- Department of Molecular Medicine, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA
| | - Alexander Y. Nikitin
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA
| | - Bendicht U. Pauli
- Department of Molecular Medicine, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA
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Niu G, Chen X. Vascular endothelial growth factor as an anti-angiogenic target for cancer therapy. Curr Drug Targets 2010; 11:1000-17. [PMID: 20426765 DOI: 10.2174/138945010791591395] [Citation(s) in RCA: 265] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2009] [Accepted: 04/14/2010] [Indexed: 12/12/2022]
Abstract
New blood vessel formation (angiogenesis) is fundamental to tumor growth, invasion, and metastatic dissemination. The vascular endothelial growth factor (VEGF) signaling pathway plays pivotal roles in regulating tumor angiogenesis. VEGF as a therapeutic target has been validated in various types of human cancers. Different agents including antibodies, aptamers, peptides, and small molecules have been extensively investigated to block VEGF and its pro-angiogenic functions. Some of these agents have been approved by FDA and some are currently in clinical trials. Combination therapies are also being pursued for better tumor control. By providing comprehensive real-time information, molecular imaging of VEGF pathway may accelerate the drug development process. Moreover, the imaging will be of great help for patient stratification and therapeutic effect monitoring, which will promote effective personalized molecular cancer therapy. This review summarizes the current status of tumor therapeutic agents targeting to VEGF and the applications of VEGF related molecular imaging.
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Affiliation(s)
- Gang Niu
- Laboratory of Molecular Imaging and Nanomedicine, National Institute of Biomedical Imaging and Bioengineering, National Institute of Health, 9 Memorial Drive, Bethesda, MD 20892, USA.
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34
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Andres AC, Djonov V. The mammary gland vasculature revisited. J Mammary Gland Biol Neoplasia 2010; 15:319-28. [PMID: 20706777 DOI: 10.1007/s10911-010-9186-9] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2010] [Accepted: 08/04/2010] [Indexed: 12/11/2022] Open
Abstract
Concomitant with the extensive growth and differentiation of the mammary epithelium during pregnancy and lactation, and epithelial involution after weaning, the vasculature of the mammary gland undergoes repeated cycles of expansion and regression. Vascular expansion is effected by sprouting angiogenesis, intussusception and conceivably also vasculogenesis. The capacity of the epithelial cells to stimulate vascular growth and differentiation is dependent on the constellation of systemic and local hormones and growth factors as well as the changing demands for oxygenation and nutrient supply. This results in the release of angiogenic factors which stimulate endothelial cell growth and regulate vascular architecture. In contrast to the angiogenic phase of the mammary gland cycle, little is known about the control of vascular regression although this would possibly offer new insights into therapeutic possibilities against breast cancer. In this review we summarize knowledge regarding the mechanisms regulating the vasculature of the mammary gland and delineate the importance of the vasculature in the attainment of organ function. In addition, we discuss the angiogenic mechanisms observed during mammary carcinogenesis and their consequences for breast cancer therapy.
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Affiliation(s)
- Anne-Catherine Andres
- Department of Clinical Research, University of Bern, Tiefenaustrasse 120c, Bern, Switzerland.
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35
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Qiu Y, Ferguson J, Oltean S, Neal CR, Kaura A, Bevan H, Wood E, Sage LM, Lanati S, Nowak DG, Salmon AHJ, Bates D, Harper SJ. Overexpression of VEGF165b in podocytes reduces glomerular permeability. J Am Soc Nephrol 2010; 21:1498-509. [PMID: 20688932 DOI: 10.1681/asn.2009060617] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
The observation that therapeutic agents targeting vascular endothelial growth factor-A (VEGF-A) associate with renal toxicity suggests that VEGF plays a role in the maintenance of the glomerular filtration barrier. Alternative mRNA splicing produces the VEGF(xxx)b family, which consists of antiangiogenic peptides that reduce permeability and inhibit tumor growth; the contribution of these peptides to normal glomerular function is unknown. Here, we established and characterized heterozygous and homozygous transgenic mice that overexpress VEGF(165)b specifically in podocytes. We confirmed excess production of glomerular VEGF(165)b by reverse transcriptase-PCR, immunohistochemistry, and ELISA in both heterozygous and homozygous animals. Macroscopically, the mice seemed normal up to 18 months of age, unlike the phenotype of transgenic podocyte-specific VEGF(164)-overexpressing mice. Animals overexpressing VEGF(165)b, however, had a significantly reduced normalized glomerular ultrafiltration fraction with accompanying changes in ultrastructure of the glomerular filtration barrier on the vascular side of the glomerular basement membrane. These data highlight the contrasting properties of VEGF splice variants and their impact on glomerular function and phenotype.
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Affiliation(s)
- Yan Qiu
- Microvascular Research Laboratories, Department Physiology and Pharmacology, Bristol Heart Institute, Preclinical Veterinary School, Southwell Street, Bristol, BS2 8EJ, UK
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Marlow R, Binnewies M, Sorensen LK, Monica SD, Strickland P, Forsberg EC, Li DY, Hinck L. Vascular Robo4 restricts proangiogenic VEGF signaling in breast. Proc Natl Acad Sci U S A 2010; 107:10520-5. [PMID: 20498081 PMCID: PMC2890778 DOI: 10.1073/pnas.1001896107] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Formation of the vascular system within organs requires the balanced action of numerous positive and negative factors secreted by stromal and epithelial cells. Here, we used a genetic approach to determine the role of SLITs in regulating the growth and organization of blood vessels in the mammary gland. We demonstrate that vascularization of the gland is not affected by loss of Slit expression in the epithelial compartment. Instead, we identify a stromal source of SLIT, mural cells encircling blood vessels, and show that loss of Slit in the stroma leads to elevated blood vessel density and complexity. We examine candidate SLIT receptors, Robo1 and Robo4, and find that increased vessel angiogenesis is phenocopied by loss of endothelial-specific Robo4, as long as it is combined with the presence of an angiogenic stimulus such as preneoplasia or pregnancy. In contrast, loss of Robo1 does not affect blood vessel growth. The enhanced growth of blood vessels in Robo4(-/-) endothelium is due to activation of vascular endothelial growth factor (VEGF)-R2 signaling through the Src and FAK kinases. Thus, our studies present a genetic dissection of SLIT/ROBO signaling during organ development. We identify a stromal, rather than epithelial, source of SLITs that inhibits blood vessel growth by signaling through endothelial ROBO4 to down-regulate VEGF/VEGFR2 signaling.
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Affiliation(s)
- Rebecca Marlow
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, CA 95064
| | - Mikhail Binnewies
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, CA 95064
| | - Lise K. Sorensen
- Department of Oncological Sciences, University of Utah, Salt Lake City, UT 84112; and
| | - Stefanie D. Monica
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, CA 95064
| | - Phyllis Strickland
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, CA 95064
| | - E. Camilla Forsberg
- Department of BioMolecular Engineering, University of California, Santa Cruz, CA 95064
| | - Dean Y. Li
- Department of Oncological Sciences, University of Utah, Salt Lake City, UT 84112; and
| | - Lindsay Hinck
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, CA 95064
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Hua J, Spee C, Kase S, Rennel ES, Magnussen AL, Qiu Y, Varey A, Dhayade S, Churchill AJ, Harper SJ, Bates DO, Hinton DR. Recombinant human VEGF165b inhibits experimental choroidal neovascularization. Invest Ophthalmol Vis Sci 2010; 51:4282-8. [PMID: 20237252 DOI: 10.1167/iovs.09-4360] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
PURPOSE Vascular endothelial growth factor (VEGF-A) is the principal stimulator of angiogenesis in wet age-related macular degeneration (AMD). However, VEGF-A is generated by alternate splicing into two families, the proangiogenic VEGF-A(xxx) family and the antiangiogenic VEGF-A(xxx)b family. It is the proangiogenic family that is responsible for the blood vessel growth seen in AMD. METHODS To determine the role of antiangiogenic isoforms of VEGF-A as inhibitors of choroidal neovascularization, the authors used a model of laser-induced choroidal neovascularization in the mouse eye and investigated VEGF-A(165)b effects on endothelial cells and VEGFRs in vitro. RESULTS VEGF-A(165)b inhibited VEGF-A(165)-mediated endothelial cell migration with a dose effect similar to that of ranibizumab and bevacizumab and 200-fold more potent than that of pegaptanib. VEGF-A(165)b bound both VEGFR1 and VEGFR2 with affinity similar to that of VEGF-A(165). After laser injury, mice were injected either intraocularly or subcutaneously with recombinant human VEGF-A(165)b. Intraocular injection of rhVEGF-A(165)b gave a pronounced dose-dependent inhibition of fluorescein leakage, with an IC(50) of 16 pg/eye, neovascularization (IC(50), 0.8 pg/eye), and lesion as assessed by histologic staining (IC(50), 8 pg/eye). Subcutaneous administration of 100 microg twice a week also inhibited fluorescein leakage and neovascularization and reduced lesion size. CONCLUSIONS These results show that VEGF-A(165)b is a potent antiangiogenic agent in a mouse model of age-related macular degeneration and suggest that increasing the ratio of antiangiogenic-to-proangiogenic isoforms may be therapeutically effective in this condition.
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Affiliation(s)
- Jing Hua
- Microvascular Research Laboratories, Department of Physiology and Pharmacology, Bristol Heart Institute, School of Veterinary Sciences, University of Bristol, Bristol, UK
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Magnussen AL, Rennel ES, Hua J, Bevan HS, Beazley Long N, Lehrling C, Gammons M, Floege J, Harper SJ, Agostini HT, Bates DO, Churchill AJ. VEGF-A165b is cytoprotective and antiangiogenic in the retina. Invest Ophthalmol Vis Sci 2010; 51:4273-81. [PMID: 20237249 DOI: 10.1167/iovs.09-4296] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
PURPOSE A number of key ocular diseases, including diabetic retinopathy and age-related macular degeneration, are characterized by localized areas of epithelial or endothelial damage, which can ultimately result in the growth of fragile new blood vessels, vitreous hemorrhage, and retinal detachment. VEGF-A(165), the principal neovascular agent in ocular angiogenic conditions, is formed by proximal splice site selection in its terminal exon 8. Alternative splicing of this exon results in an antiangiogenic isoform, VEGF-A(165)b, which is downregulated in diabetic retinopathy. Here the authors investigate the antiangiogenic activity of VEGF(165)b and its effect on retinal epithelial and endothelial cell survival. METHODS VEGF-A(165)b was injected intraocularly in a mouse model of retinal neovascularization (oxygen-induced retinopathy [OIR]). Cytotoxicity and cell migration assays were used to determine the effect of VEGF-A(165)b. RESULTS VEGF-A(165)b dose dependently inhibited angiogenesis (IC(50), 12.6 pg/eye) and retinal endothelial migration induced by 1 nM VEGF-A(165) across monolayers in culture (IC(50), 1 nM). However, it also acts as a survival factor for endothelial cells and retinal epithelial cells through VEGFR2 and can stimulate downstream signaling. Furthermore, VEGF-A(165)b injection, while inhibiting neovascular proliferation in the eye, reduced the ischemic insult in OIR (IC(50), 2.6 pg/eye). Unlike bevacizumab, pegaptanib did not interact directly with VEGF-A(165)b. CONCLUSIONS The survival effects of VEGF-A(165)b signaling can protect the retina from ischemic damage. These results suggest that VEGF-A(165)b may be a useful therapeutic agent in ischemia-induced angiogenesis and a cytoprotective agent for retinal pigment epithelial cells.
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Affiliation(s)
- Anette L Magnussen
- Microvascular Research Laboratories, Bristol Heart Institute, Department of Physiology and Pharmacology, School of Veterinary Sciences, University of Bristol, Bristol, UK
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Molitoris KH, Kazi AA, Koos RD. Inhibition of oxygen-induced hypoxia-inducible factor-1alpha degradation unmasks estradiol induction of vascular endothelial growth factor expression in ECC-1 cancer cells in vitro. Endocrinology 2009; 150:5405-14. [PMID: 19819950 PMCID: PMC2795708 DOI: 10.1210/en.2009-0884] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Estradiol (E(2)) rapidly and strongly induces vascular endothelial growth factor (VEGF) transcription in uterine endometrial epithelial cells in vivo. We have shown that this is mediated by both the estrogen receptor-alpha and hypoxia-inducible factor (HIF)-1alpha. By contrast, E(2) induces little or no VEGF expression in cultured breast or endometrial cancer cells, which lack HIF-1alpha due to the abnormally high concentration of oxygen ( approximately 20%) to which they are exposed. To test the hypothesis that restoring HIF-1alpha in cultured cells would restore the ability of E(2) to induce VEGF expression, we treated human endometrial cancer cells (ECC-1) with cobalt chloride (CoCl(2);100 microm), which prevents oxygen-induced HIF-1alpha degradation. HIF-1alpha was absent in untreated ECC-1 cells but detectable by 4 h after treatment with CoCl(2) alone, as was a significant increase in VEGF mRNA. E(2) plus CoCl(2) induced detectable HIF-1alpha expression at 2 h and an even higher level than that induced by CoCl(2) alone at 4 h; this HIF-1alpha was localized in the nuclei. This was accompanied by increasing VEGF expression, with the increase at 4 h severalfold higher than that induced by CoCl(2) alone and was concurrent with recruitment of both HIF-1alpha and estrogen receptor-alpha to the VEGF promoter. These results confirm that HIF-1alpha plays an essential role in E(2)-induced expression of VEGF. Through the induction of increased microvascular permeability and the consequent exudation of plasma growth factors, VEGF in turn may play an essential role in cancer cell proliferation in vivo.
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Affiliation(s)
- Kristin Happ Molitoris
- Department of Physiology, University of Maryland School of Medicine, 655 West Baltimore Street, Baltimore, Maryland 21201-1559, USA
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Qiu Y, Hoareau-Aveilla C, Oltean S, Harper SJ, Bates DO. The anti-angiogenic isoforms of VEGF in health and disease. Biochem Soc Trans 2009; 37:1207-13. [PMID: 19909248 PMCID: PMC2882696 DOI: 10.1042/bst0371207] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Anti-angiogenic VEGF (vascular endothelial growth factor) isoforms, generated from differential splicing of exon 8, are widely expressed in normal human tissues but down-regulated in cancers and other pathologies associated with abnormal angiogenesis (cancer, diabetic retinopathy, retinal vein occlusion, the Denys-Drash syndrome and pre-eclampsia). Administration of recombinant VEGF(165)b inhibits ocular angiogenesis in mouse models of retinopathy and age-related macular degeneration, and colorectal carcinoma and metastatic melanoma. Splicing factors and their regulatory molecules alter splice site selection, such that cells can switch from the anti-angiogenic VEGF(xxx)b isoforms to the pro-angiogenic VEGF(xxx) isoforms, including SRp55 (serine/arginine protein 55), ASF/SF2 (alternative splicing factor/splicing factor 2) and SRPK (serine arginine domain protein kinase), and inhibitors of these molecules can inhibit angiogenesis in the eye, and splice site selection in cancer cells, opening up the possibility of using splicing factor inhibitors as novel anti-angiogenic therapeutics. Endogenous anti-angiogenic VEGF(xxx)b isoforms are cytoprotective for endothelial, epithelial and neuronal cells in vitro and in vivo, suggesting both an improved safety profile and an explanation for unpredicted anti-VEGF side effects. In summary, C-terminal distal splicing is a key component of VEGF biology, overlooked by the vast majority of publications in the field, and these findings require a radical revision of our understanding of VEGF biology in normal human physiology.
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Affiliation(s)
- Yan Qiu
- Microvascular Research Laboratories, Bristol Heart Institute, Department of Physiology and Pharmacology, School of Veterinary Sciences, University of Bristol, Southwell Street, Bristol BS2 8EJ, U.K
| | - Coralie Hoareau-Aveilla
- Microvascular Research Laboratories, Bristol Heart Institute, Department of Physiology and Pharmacology, School of Veterinary Sciences, University of Bristol, Southwell Street, Bristol BS2 8EJ, U.K
| | - Sebastian Oltean
- Microvascular Research Laboratories, Bristol Heart Institute, Department of Physiology and Pharmacology, School of Veterinary Sciences, University of Bristol, Southwell Street, Bristol BS2 8EJ, U.K
| | - Steven J. Harper
- Microvascular Research Laboratories, Bristol Heart Institute, Department of Physiology and Pharmacology, School of Veterinary Sciences, University of Bristol, Southwell Street, Bristol BS2 8EJ, U.K
| | - David O. Bates
- Microvascular Research Laboratories, Bristol Heart Institute, Department of Physiology and Pharmacology, School of Veterinary Sciences, University of Bristol, Southwell Street, Bristol BS2 8EJ, U.K
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Woolard J, Bevan HS, Harper SJ, Bates DO. Molecular diversity of VEGF-A as a regulator of its biological activity. Microcirculation 2009; 16:572-92. [PMID: 19521900 PMCID: PMC2929464 DOI: 10.1080/10739680902997333] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The vascular endothelial growth factor (VEGF) family of proteins regulates blood flow, growth, and function in both normal physiology and disease processes. VEGF-A is alternatively spliced to form multiple isoforms, in two subfamilies, that have specific, novel functions. Alternative splicing of exons 5-7 of the VEGF gene generates forms with differing bioavailability and activities, whereas alternative splice-site selection in exon 8 generates proangiogenic, termed VEGF(xxx), or antiangiogenic proteins, termed VEGF(xxx)b. Despite its name, emerging roles for VEGF isoforms on cell types other than endothelium have now been identified. Although VEGF-A has conventionally been considered to be a family of proangiogenic, propermeability vasodilators, the identification of effects on nonendothelial cells, and the discovery of the antiangiogenic subfamily of splice isoforms, has added further complexity to their regulation of microvascular function. The distally spliced antiangiogenic isoforms are expressed in normal human tissue, but downregulated in angiogenic diseases, such as cancer and proliferative retinopathy, and in developmental pathologies, such as Denys Drash syndrome and preeclampsia. Here, we examine the molecular diversity of VEGF-A as a regulator of its biological activity and compare the role of the pro- and antiangiogenic VEGF-A splice isoforms in both normal and pathophysiological processes.
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Affiliation(s)
- Jeanette Woolard
- Department of Physiology and Pharmacology, Bristol Heart Institute, School of Veterinary Sciences, University of Bristol, Bristol, UK.
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Rennel ES, Harper SJ, Bates DO. Therapeutic potential of manipulating VEGF splice isoforms in oncology. Future Oncol 2009; 5:703-12. [PMID: 19519209 DOI: 10.2217/fon.09.33] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Anti-angiogenic therapies currently revolve around targeting vascular endothelial growth factor-A (VEGF-A) or its receptors. These therapies are effective to some degree, but have low response rates and poor side-effect profiles. Part of these problems is likely to be due to their lack of specificity between pro- and anti-angiogenic isoforms, and their nonspecific effects on proactive, pleiotropic survival and maintenance roles of VEGF-A in endothelial and other cell types. An alternative approach, and one which has recently been shown to be effective in animal models of neovascularization in the eye, is to target the mechanisms by which the cell generates pro-angiogenic splice forms of VEGF-A, its receptors and, co-incidentally, by targeting the upstream processes, other oncogenes that have antagonistic splice isoforms. The concept here is to target the splicing mechanisms that control splice site choice in the VEGF-A mRNA. Recent evidence on the pharmacological possibilities of such splice factors is described.
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Affiliation(s)
- Emma S Rennel
- Microvascular Research Laboratories, Department of Physiology and Pharmacology, School of Veterinary Sciences, University of Bristol, Bristol, UK.
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VEGF(121)b, a new member of the VEGF(xxx)b family of VEGF-A splice isoforms, inhibits neovascularisation and tumour growth in vivo. Br J Cancer 2009; 101:1183-93. [PMID: 19707198 PMCID: PMC2768092 DOI: 10.1038/sj.bjc.6605249] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Background: The key mediator of new vessel formation in cancer and other diseases is VEGF-A. VEGF-A exists as alternatively spliced isoforms - the pro-angiogenic VEGFxxx family generated by exon 8 proximal splicing, and a sister family, termed VEGFxxxb, exemplified by VEGF165b, generated by distal splicing of exon 8. However, it is unknown whether this anti-angiogenic property of VEGF165b is a general property of the VEGFxxxb family of isoforms. Methods: The mRNA and protein expression of VEGF121b was studied in human tissue. The effect of VEGF121b was analysed by saturation binding to VEGF receptors, endothelial migration, apoptosis, xenograft tumour growth, pre-retinal neovascularisation and imaging of biodistribution in tumour-bearing mice with radioactive VEGF121b. Results: The existence of VEGF121b was confirmed in normal human tissues. VEGF121b binds both VEGF receptors with similar affinity as other VEGF isoforms, but inhibits endothelial cell migration and is cytoprotective to endothelial cells through VEGFR-2 activation. Administration of VEGF121b normalised retinal vasculature by reducing both angiogenesis and ischaemia. VEGF121b reduced the growth of xenografted human colon tumours in association with reduced microvascular density, and an intravenous bolus of VEGF121b is taken up into colon tumour xenografts. Conclusion: Here we identify a second member of the family, VEGF121b, with similar properties to those of VEGF165b, and underline the importance of the six amino acids of exon 8b in the anti-angiogenic activity of the VEGFxxxb isoforms.
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Kazi AA, Molitoris KH, Koos RD. Estrogen rapidly activates the PI3K/AKT pathway and hypoxia-inducible factor 1 and induces vascular endothelial growth factor A expression in luminal epithelial cells of the rat uterus. Biol Reprod 2009; 81:378-87. [PMID: 19420388 PMCID: PMC2849827 DOI: 10.1095/biolreprod.109.076117] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2009] [Revised: 02/10/2009] [Accepted: 04/29/2009] [Indexed: 11/01/2022] Open
Abstract
We have previously shown that 17beta-estradiol (E(2)) increases vascular endothelial growth factor A (Vegfa) gene expression in the rat uterus, resulting in increased microvascular permeability, and that this involves the simultaneous recruitment of hypoxia-inducible factor 1 (HIF1) and estrogen receptor alpha (ESR1) to the Vegfa gene promoter. Both events require the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) pathway. However, those studies were carried out using whole uterine tissue, and while most evidence indicates that the likely site of E(2)-induced Vegfa expression is luminal epithelial (LE) cells, other studies have identified stromal cells as the site of that expression. To address this question, the pathway regulating Vegfa expression was reexamined using LE cells rapidly isolated after E(2) treatment. In addition, we further characterized the nature of the receptor through which E(2) triggers the signaling events that lead to Vegfa expression using the specific ESR1 antagonist ICI 182,780. In agreement with previous results in the whole uterus, E(2) stimulated Vegfa mRNA expression in LE cells, peaking at 1 h (4- to 14-fold) and returning to basal levels by 4 h. Treatment with E(2) also increased phosphorylation of AKT in LE cells, as well as of the downstream mediators FRAP1 (mTOR), GSK3B, and MDM2. The alpha subunit of HIF1 (HIF1A) was present in LE cells before E(2) treatment, was unchanged 1 h after E(2), but was >2-fold higher by 4 h. Chromatin immunoprecipitation analysis showed that HIF1A was recruited to the Vegfa promoter by 1 h and was absent again by 4 h. The E(2) activation of the PI3K/AKT pathway, HIF1A recruitment to the Vegfa promoter, and Vegfa expression were all blocked by ICI 182,780. In summary, the rapid E(2)-induced signaling events that lead to the expression of Vegfa observed previously using the whole uterus occur in LE cells and appear to be initiated via a membrane form of ESR1.
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Affiliation(s)
- Armina A. Kazi
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Kristin Happ Molitoris
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Robert D. Koos
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland
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Failure to up-regulate VEGF165b in maternal plasma is a first trimester predictive marker for pre-eclampsia. Clin Sci (Lond) 2009; 116:265-72. [PMID: 18826376 PMCID: PMC2635543 DOI: 10.1042/cs20080270] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Pre-eclampsia is a pregnancy-related condition characterized by hypertension,
proteinuria and endothelial dysfunction. VEGF165b, formed by
alternative splicing of VEGF (vascular endothelial growth factor) pre-mRNA,
inhibits VEGF165-mediated vasodilation and angiogenesis, but has not
been quantified in pregnancy. ELISAs were used to measure
means±S.E.M. plasma VEGF165b, sEng (soluble endoglin) and
sFlt-1 (soluble fms-like tyrosine kinase-1). At 12 weeks of
gestation, the plasma VEGF165b concentration was significantly
up-regulated in plasma from women who maintained normal blood pressure
throughout their pregnancy (normotensive group,
4.90±1.6 ng/ml; P<0.01, as
determined using a Mann-Whitney U test) compared with
non-pregnant women (0.40±0.22 ng/ml). In contrast, in
patients who later developed pre-eclampsia, VEGF165b levels were
lower than in the normotensive group (0.467±0.209 ng/ml),
but were no greater than non-pregnant women. At term, plasma VEGF165b
concentrations were greater than normal in both pre-eclamptic
(3.75±2.24 ng/ml) and normotensive
(10.58 ng/ml±3.74 ng/ml;
P>0.1 compared with pre-eclampsia) pregnancies.
Patients with a lower than median plasma VEGF165b at
12 weeks had elevated sFlt-1 and sEng pre-delivery. Concentrations of
sFlt-1 (1.20±0.07 and 1.27±0.18 ng/ml) and sEng
(4.4±0.18 and 4.1±0.5 ng/ml) were similar at
12 weeks of gestation in the normotensive and pre-eclamptic groups
respectively. Plasma VEGF165b levels were elevated in pregnancy, but
this increase is delayed in women that subsequently develop pre-eclampsia. In
conclusion, low VEGF165b may therefore be a clinically useful first
trimester plasma marker for increased risk of pre-eclampsia.
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Nowak DG, Woolard J, Amin EM, Konopatskaya O, Saleem MA, Churchill AJ, Ladomery MR, Harper SJ, Bates DO. Expression of pro- and anti-angiogenic isoforms of VEGF is differentially regulated by splicing and growth factors. J Cell Sci 2009; 121:3487-95. [PMID: 18843117 DOI: 10.1242/jcs.016410] [Citation(s) in RCA: 249] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Vascular endothelial growth factor A (VEGFA; hereafter referred to as VEGF) is a key regulator of physiological and pathological angiogenesis. Two families of VEGF isoforms are generated by alternate splice-site selection in the terminal exon. Proximal splice-site selection (PSS) in exon 8 results in pro-angiogenic VEGFxxx isoforms (xxx is the number of amino acids), whereas distal splice-site selection (DSS) results in anti-angiogenic VEGFxxxb isoforms. To investigate control of PSS and DSS, we investigated the regulation of isoform expression by extracellular growth factor administration and intracellular splicing factors. In primary epithelial cells VEGFxxxb formed the majority of VEGF isoforms (74%). IGF1, and TNFalpha treatment favoured PSS (increasing VEGFxxx) whereas TGFbeta1 favoured DSS, increasing VEGFxxxb levels. TGFbeta1 induced DSS selection was prevented by inhibition of p38 MAPK and the Clk/sty (CDC-like kinase, CLK1) splicing factor kinase family, but not ERK1/2. Clk phosphorylates SR protein splicing factors ASF/SF2, SRp40 and SRp55. To determine whether SR splicing factors alter VEGF splicing, they were overexpressed in epithelial cells, and VEGF isoform production assessed. ASF/SF2, and SRp40 both favoured PSS, whereas SRp55 upregulated VEGFxxxb (DSS) isoforms relative to VEGFxxx. SRp55 knockdown reduced expression of VEGF165b. Moreover, SRp55 bound to a 35 nucleotide region of the 3'UTR immediately downstream of the stop codon in exon 8b. These results identify regulation of splicing by growth and splice factors as a key event in determining the relative pro-versus anti-angiogenic expression of VEGF isoforms, and suggest that p38 MAPK-Clk/sty kinases are responsible for the TGFbeta1-induced DSS selection, and identify SRp55 as a key regulatory splice factor.
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Affiliation(s)
- Dawid G Nowak
- Microvascular Research Laboratories, Bristol Heart Institute, Department of Physiology and Pharmacology, School of Veterinary Sciences, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK
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47
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Bott RC, Clopton DT, Cupp AS. A proposed role for VEGF isoforms in sex-specific vasculature development in the gonad. Reprod Domest Anim 2008; 43 Suppl 2:310-6. [PMID: 18638140 DOI: 10.1111/j.1439-0531.2008.01179.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Many scientists have expended efforts to determine what regulates development of an indifferent gonad into either a testis or ovary. Expression of Sry and upregulation of Sox9 are factors that initiate formation of the testis-specific pathway to allow for both sex-specific vasculature and seminiferous cord formation. Migration of mesonephric precursors of peritubular myoid cells and endothelial cells into the differentiating testis is a critical step in formation of both of these structures. Furthermore, these events appear to be initiated downstream from Sry expression. Sertoli cell secretion of growth factors acts to attract these mesonephric cells. One hypothesis is that a growth factor specific for these cell linages act in concert to coordinate migration of both peritubular and endothelial cells. A second hypothesis is that several growth factors stimulate migration and differentiation of mesonephric 'stem-like' cells to result in migration and differentiation into several different cell lineages. While the specific mechanism is unclear, several growth factors have been implicated in the initiation of mesonephric cell migration. This review will focus on the proposed mechanisms of a growth factor, Vascular Endothelial Growth Factor, and how different angiogenic and inhibitory isoforms from this single gene may aid in development of testis-specific vascular development.
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Affiliation(s)
- R C Bott
- Animal Science Department, University of Nebraska-Lincoln, Lincoln, NE 68583-0908, USA
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48
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Abstract
The physiology of microvessels limits the growth and development of tumours. Tumours gain nutrients and excrete waste through growth-associated microvessels. New anticancer therapies target this microvasculature by inhibiting vascular endothelial growth factor A (VEGF-A) splice isoforms that promote microvessel growth. However, certain VEGF-A splice isoforms in normal tissues inhibit growth of microvessels. Thus, it is the VEGF-A isoform balance, which is controlled by mRNA splicing, that orchestrates angiogenesis. Here, we highlight the functional differences between the pro-angiogenic and the anti-angiogenic VEGF-A isoform families and the potential to harness the synthetic capacity of cancer cells to produce factors that inhibit, rather than aid, cancer growth.
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Affiliation(s)
- Steven J Harper
- Microvascular Research Laboratories, Department of Physiology & Pharmacology, Bristol Heart Institute, School of Veterinary Science, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK.
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49
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Jin P, Zhang J, Sumariwalla PF, Ni I, Jorgensen B, Crawford D, Phillips S, Feldmann M, Shepard HM, Paleolog EM. Novel splice variants derived from the receptor tyrosine kinase superfamily are potential therapeutics for rheumatoid arthritis. Arthritis Res Ther 2008; 10:R73. [PMID: 18593464 PMCID: PMC2575619 DOI: 10.1186/ar2447] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2008] [Revised: 06/25/2008] [Accepted: 07/01/2008] [Indexed: 12/21/2022] Open
Abstract
INTRODUCTION Despite the advent of biological therapies for the treatment of rheumatoid arthritis, there is a compelling need to develop alternative therapeutic targets for nonresponders to existing treatments. Soluble receptors occur naturally in vivo, such as the splice variant of the cell surface receptor for vascular endothelial growth factor (VEGF)--a key regulator of angiogenesis in rheumatoid arthritis. Bioinformatics analyses predict that the majority of human genes undergo alternative splicing, generating proteins--many of which may have regulatory functions. The objective of the present study was to identify alternative splice variants (ASV) from cell surface receptor genes, and to determine whether the novel proteins encoded exert therapeutic activity in an in vivo model of arthritis. METHODS To identify novel splice variants, we performed RT-PCR using an mRNA pool representing major human tissue types and tumors. Novel ASV were identified by alignment of each cloned sequence to its respective genomic sequence in comparison with full-length transcripts. To test whether these ASV have biologic activity, we characterized a subset of them for ligand binding, and for efficacy in an animal model of arthritis. The in vivo study was accomplished using adenoviruses expressing secreted ASV. RESULTS We cloned 60 novel human ASV from 21 genes, encoding cell surface receptors--many of which are known to be important in the regulation of angiogenesis. The ASV were characterized by exon extension, intron retention and alternative exon utilization. Efficient expression and secretion of selected ASV--corresponding to VEGF receptor type 1, VEGF receptor type 2, VEGF receptor type 3, angiopoietin receptor Tie1, Met (receptor for hepatocyte growth factor), colony-stimulating factor 1 receptor, platelet-derived growth factor receptor beta, fibroblast growth factor receptor 1, Kit, and RAGE--was demonstrated, together with binding to their cognate ligands. Importantly, ASV derived from VEGF receptor type 1 and Tie1, and to a lesser extent from VEGF receptor type 2 and fibroblast growth factor receptor 1, reduced clinical signs of arthritis in vivo. The reduction was paralleled by decreased joint inflammation and destruction. CONCLUSION The present study shows that unique ASV derived from receptors that play key roles in angiogenesis--namely, VEGF receptor type 1 and, for the first time, Tie1--can markedly reduce arthritis severity. More broadly, our results demonstrate that ASV are a source of novel proteins with therapeutic potential in diseases in which angiogenesis and cellular hyperplasia play a central role, such as rheumatoid arthritis.
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MESH Headings
- Angiopoietin-1/metabolism
- Animals
- Arthritis, Rheumatoid/drug therapy
- Arthritis, Rheumatoid/metabolism
- Cells, Cultured
- Disease Models, Animal
- Endothelium, Vascular/cytology
- Endothelium, Vascular/metabolism
- Humans
- Mice
- Mice, Inbred DBA
- Neovascularization, Physiologic/physiology
- Protein Binding/physiology
- Protein Isoforms/metabolism
- Protein Isoforms/therapeutic use
- RNA, Messenger/metabolism
- Receptor Protein-Tyrosine Kinases/metabolism
- Receptor Protein-Tyrosine Kinases/therapeutic use
- Receptor, TIE-1/metabolism
- Receptor, TIE-1/therapeutic use
- Severity of Illness Index
- Umbilical Veins/cytology
- Umbilical Veins/metabolism
- Vascular Endothelial Growth Factor Receptor-1/metabolism
- Vascular Endothelial Growth Factor Receptor-1/therapeutic use
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Affiliation(s)
- Pei Jin
- Receptor BioLogix, Inc., Palo Alto, CA 94303, USA
| | - Juan Zhang
- Receptor BioLogix, Inc., Palo Alto, CA 94303, USA
| | - Percy F Sumariwalla
- Kennedy Institute of Rheumatology, Faculty of Medicine, Imperial College London, London W6 8LH, UK
| | - Irene Ni
- Receptor BioLogix, Inc., Palo Alto, CA 94303, USA
| | | | - Damian Crawford
- Kennedy Institute of Rheumatology, Faculty of Medicine, Imperial College London, London W6 8LH, UK
| | | | - Marc Feldmann
- Kennedy Institute of Rheumatology, Faculty of Medicine, Imperial College London, London W6 8LH, UK
| | | | - Ewa M Paleolog
- Kennedy Institute of Rheumatology, Faculty of Medicine, Imperial College London, London W6 8LH, UK
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