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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] [What about the content of this article? (0)] [Affiliation(s)] [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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2
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Yunir E, Kurniawan F, Rezaprasga E, Wijaya IP, Suroyo I, Matondang S, Irawan C, Soewondo P. Autologous Bone-Marrow vs. Peripheral Blood Mononuclear Cells Therapy for Peripheral Artery Disease in Diabetic Patients. Int J Stem Cells 2021; 14:21-32. [PMID: 33377454 PMCID: PMC7904521 DOI: 10.15283/ijsc20088] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 10/18/2020] [Accepted: 10/19/2020] [Indexed: 01/09/2023] Open
Abstract
Diabetes mellitus (DM) remains one of the most important risk factors for peripheral artery disease (PAD), with approximately 20% of DM patients older than 40 years old are affected with PAD. The current standard management for severe PAD is endovascular intervention with or without surgical bypass. Unfortunately, up to 40% of patients are unable to undergo these revascularization therapies due to excessive surgical risk or adverse vascular side effects. Stem cell therapy has emerged as a novel therapeutic strategy for these ‘no-option’ patients. Several types of stem cells are utilized for PAD therapy, including bone marrow mononuclear cells (BMMNC) and peripheral blood mononuclear cells (PBMNC). Many studies have reported the safety of BMMNC and PBMNC, as well as its efficacy in reducing ischemic pain, ulcer size, pain-free walking distance, ankle-brachial index (ABI), and transcutaneous oxygen pressure (TcPO2). However, the capacity to establish the efficacy of reducing major amputation rates, amputation free survival, and all-cause mortality is limited, as shown by several randomized placebo-controlled trials. The present literature review will focus on comparing safety and efficacy between BMMNC and PBMNC as cell-based management in diabetic patients with PAD who are not suitable for revascularization therapy.
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Affiliation(s)
- Em Yunir
- Department of Internal Medicine, Dr. Cipto Mangunkusumo National General Hospital, Faculty of Medicine Universitas Indonesia, Jakarta, Indonesia.,Metabolic Disorder, Cardiovascular, and Aging Cluster, Indonesian Medical Education and Research Institute, Faculty of Medicine Universitas Indonesia, Jakarta, Indonesia
| | - Farid Kurniawan
- Department of Internal Medicine, Dr. Cipto Mangunkusumo National General Hospital, Faculty of Medicine Universitas Indonesia, Jakarta, Indonesia.,Metabolic Disorder, Cardiovascular, and Aging Cluster, Indonesian Medical Education and Research Institute, Faculty of Medicine Universitas Indonesia, Jakarta, Indonesia
| | - Edo Rezaprasga
- Department of Internal Medicine, Dr. Cipto Mangunkusumo National General Hospital, Faculty of Medicine Universitas Indonesia, Jakarta, Indonesia.,Metabolic Disorder, Cardiovascular, and Aging Cluster, Indonesian Medical Education and Research Institute, Faculty of Medicine Universitas Indonesia, Jakarta, Indonesia
| | - Ika Prasetya Wijaya
- Department of Internal Medicine, Dr. Cipto Mangunkusumo National General Hospital, Faculty of Medicine Universitas Indonesia, Jakarta, Indonesia
| | - Indrati Suroyo
- Department of Radiology, Dr. Cipto Mangunkusumo National General Hospital, Faculty of Medicine Universitas Indonesia, Jakarta, Indonesia
| | - Sahat Matondang
- Department of Radiology, Dr. Cipto Mangunkusumo National General Hospital, Faculty of Medicine Universitas Indonesia, Jakarta, Indonesia
| | - Cosphiadi Irawan
- Department of Internal Medicine, Dr. Cipto Mangunkusumo National General Hospital, Faculty of Medicine Universitas Indonesia, Jakarta, Indonesia
| | - Pradana Soewondo
- Department of Internal Medicine, Dr. Cipto Mangunkusumo National General Hospital, Faculty of Medicine Universitas Indonesia, Jakarta, Indonesia.,Metabolic Disorder, Cardiovascular, and Aging Cluster, Indonesian Medical Education and Research Institute, Faculty of Medicine Universitas Indonesia, Jakarta, Indonesia
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Wang X, Liang C, Xia W, Guo C, Niu Z, Zhu W, Zhang H. VEGF165b augments NK92 cytolytic activity against human K562 leukemia cells by upregulating the levels of perforin and granzyme B via the VEGR1-PLC pathway. Mol Immunol 2020; 128:41-6. [PMID: 33068832 DOI: 10.1016/j.molimm.2020.09.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 08/17/2020] [Accepted: 09/07/2020] [Indexed: 11/21/2022]
Abstract
Pro-angiogenic Vascular endothelial growth factors (VEGFs) exert immunosuppressive functions on some immune cells by interacting with VEGF receptors. Blocking the VEGF/VEGFR pathway could reverse the tumor immunosuppressive microenvironment to some degree. We recently demonstrated that the anti-angiogenic VEGF isoform VEGF165b, similar to other anti-angiogenic agents, inhibit the accumulation immunosuppressive cells such as Tregs and MDSCs. However, whether VEGF165b affects the functions of immune effector cells remain unclear. Here, NK92 cell line was utilized as an immune effector cell model. Our results verified that NK92 cells endogenously express VEGF165 and VEGFR1. Further investigation showed that NK92 treatment with VEGF165b augments its killing ability against human K562 leukemia cells by upregulating perforin and granzyme B through the VEGFR1-PLC pathway, whereas VEGF165b had no impact on the proliferation of NK92 cells in vitro. The results of this study improve our understanding of the immunomodulatory function of VEGF165b, which may help in enhancing the efficacy of NK92-based cancer immunotherapy.
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Abstract
Vascular endothelial growth factor A (VEGF-A) and its binding to VEGFRs is an important angiogenesis regulator, especially the earliest-known isoform, VEGF-A165a. Yet several additional splice variants play prominent roles in regulating angiogenesis in health and in vascular disease, including VEGF-A121 and an anti-angiogenic variant, VEGF-A165b. Few studies have attempted to distinguish these forms from their angiogenic counterparts, experimentally. Previous studies of VEGF-A:VEGFR binding have measured binding kinetics for VEGFA165 and VEGF-A121, but binding kinetics of the other two pro- and all anti-angiogenic splice variants are not known. We measured the binding kinetics for VEGF-A165, -A165b, and -A121 with VEGFR1 and VEGF-R2 using surface plasmon resonance. We validated our methods by reproducing the known affinities between VEGF-A165a:VEGFR1 and VEGF-A165a:VEGFR2, 1.0 pM and 10 pM respectively, and validated the known affinity VEGF-A121:VEGFR2 as KD = 0.66 nM. We found that VEGF-A121 also binds VEGFR1 with an affinity KD = 3.7 nM. We further demonstrated that the anti-angiogenic variant, VEGF-A165b selectively prefers VEGFR2 binding at an affinity = 0.67 pM while binding VEGFR1 with a weaker affinity-KD = 1.4 nM. These results suggest that the - A165b anti-angiogenic variant would preferentially bind VEGFR2. These discoveries offer a new paradigm for understanding VEGF-A, while further stressing the need to take care in differentiating the splice variants in all future VEGF-A studies.
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Affiliation(s)
- Spencer B Mamer
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
| | - Ashley Wittenkeller
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - P I Imoukhuede
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
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5
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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6
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Abstract
Vascular endothelial cell growth factor A (VEGF-A) signaling promotes the endothelial cell proliferation, macrophage infiltration and foam cell formation, which play pivotal roles in the pathogenesis of atherosclerosis (AS). However, the role of alternative splicing of VEGF here is not known. Here, ApoE (-/-) mice supplied high-fat diet (HFD mice) were used to generate AS, while ApoE (-/-) mice supplied with normal diet (NOR mice) were used as a control. Aortic endothelial cells (AECs) and infiltrated macrophages were purified and quantified by flow cytometry. Alternative splicing of VEGF and the regulator of VEGF splicing, SRPK1, were assessed by RT-qPCR and immunoblotting in both AECs and aortic macrophages. We found that HFD mice developed AS in 12 weeks, while the NOR did not. Compared to NOR mice, HFD mice possessed significantly more AECs and AEC proliferation, and had significantly more aortic infiltrated macrophages and more apoptosis of them. Significant shift of VEGF-A splicing to pro-angiogenic VEGF165 was detected in both AECs and macrophages from HFD mice, seemingly through upregulation of SRPK1. In vitro, SRPK1 overexpression significantly increased EC proliferation and macrophage apoptosis. Thus, our data suggest that alternative splicing of VEGF-A to pro-angiogenic VEGF165 may contribute to the development of AS.
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Affiliation(s)
- Naishi Zhao
- Department of Cardiovascular Surgery, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Jianfeng Zhang
- Department of Cardiovascular Surgery, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai 200030, China
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7
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Błochowiak K, Sokalski J, Golusińska E, Trzybulska D, Witmanowski H, Bodnar M, Marszałek A. Salivary levels and immunohistochemical expression of selected angiogenic factors in benign and malignant parotid gland tumours. Clin Oral Investig 2018; 23:995-1006. [DOI: 10.1007/s00784-018-2524-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 06/11/2018] [Indexed: 01/06/2023]
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8
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Lomet D, Piégu B, Wood SH, Dardente H. Anti-angiogenic VEGFAxxxb transcripts are not expressed in the medio-basal hypothalamus of the seasonal sheep. PLoS One 2018; 13:e0197123. [PMID: 29746548 DOI: 10.1371/journal.pone.0197123] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 04/25/2018] [Indexed: 12/15/2022] Open
Abstract
This study investigated Vegfa expression in the pars tuberalis (PT) of the pituitary and medio-basal hypothalamus (MBH) of sheep, across seasons and reproductive states. It has recently been proposed that season impacts alternative splicing of Vegfa mRNA in the PT, which shifts the balance between angiogenic VEGFAxxx and anti-angiogenic VEGFAxxxb isoforms (with xxx the number of amino acids of the mature VEGFA proteins) to modulate seasonal breeding. Here, we used various RT-PCR methodologies and analysis of RNAseq datasets to investigate seasonal variation in expression and splicing of the ovine Vegfa gene. Collectively, we identify 5 different transcripts for Vegfa within the ewe PT/MBH, which correspond to splicing events previously described in mouse and human. All identified transcripts encode angiogenic VEGFAxxx isoforms, with no evidence for alternative splicing within exon 8. These findings led us to investigate in detail how "Vegfaxxxb-like" PCR products could be generated by RT-PCR and misidentified as endogenous transcripts, in sheep and human HEK293 cells. In conclusion, our findings do not support the existence of anti-angiogenic VEGFAxxxb isoforms in the ovine PT/MBH and shed new light on the interpretation of prior studies, which claimed to identify Vegfaxxxb isoforms by RT-PCR.
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Bridgett S, Dellett M, Simpson DA. RNA-Sequencing data supports the existence of novel VEGFA splicing events but not of VEGFA xxxb isoforms. Sci Rep 2017; 7:58. [PMID: 28246395 DOI: 10.1038/s41598-017-00100-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [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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11
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Kikuchi R, Nakamura K, MacLauchlan S, Ngo DT, Shimizu I, Fuster JJ, Katanasaka Y, Yoshida S, Qiu Y, Yamaguchi TP, Matsushita T, Murohara T, Gokce N, Bates DO, Hamburg NM, Walsh K. An antiangiogenic isoform of VEGF-A contributes to impaired vascularization in peripheral artery disease. Nat Med 2014; 20:1464-71. [PMID: 25362254 DOI: 10.1038/nm.3703] [Citation(s) in RCA: 140] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 08/28/2014] [Indexed: 11/17/2022]
Abstract
Peripheral artery disease (PAD) generates tissue ischemia through arterial occlusions and insufficient collateral vessel formation. Vascular insufficiency in PAD occurs despite higher circulating levels of vascular endothelial growth factor A (VEGF-A),1,2 a key regulator of angiogenesis. Here, we show that clinical PAD is associated with elevated anti-angiogenic VEGF-A splice isoform (VEGF-A165b), and a corresponding reduction of the pro-angiogenic VEGF-A165a isoform. In a murine model of PAD, VEGF-A165b was upregulated by conditions associated with impaired limb revascularization, including leptin-deficiency, diet-induced obesity, genetic ablation of the secreted frizzled-related protein 5 (Sfrp5) adipokine and transgenic overexpression of Wnt5a in myeloid cells. In PAD models, delivery of VEGF-A165b inhibited revascularization of ischemic hind limbs, whereas treatment with an isoform-specific neutralizing antibody reversed the impaired revascularization phenotype caused by metabolic dysfunction or perturbations in the Wnt5a/Sfrp5 regulatory system. These results indicate that inflammation driven expression of the anti-angiogenic VEGF-A isoform can contribute to impaired collateralization in ischemic cardiovascular disease.
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Vempati P, Popel AS, Mac Gabhann F. Extracellular regulation of VEGF: isoforms, proteolysis, and vascular patterning. Cytokine Growth Factor Rev 2013; 25:1-19. [PMID: 24332926 DOI: 10.1016/j.cytogfr.2013.11.002] [Citation(s) in RCA: 198] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Revised: 11/14/2013] [Accepted: 11/19/2013] [Indexed: 12/15/2022]
Abstract
The regulation of vascular endothelial growth factor A (VEGF) is critical to neovascularization in numerous tissues under physiological and pathological conditions. VEGF has multiple isoforms, created by alternative splicing or proteolytic cleavage, and characterized by different receptor-binding and matrix-binding properties. These isoforms are known to give rise to a spectrum of angiogenesis patterns marked by differences in branching, which has functional implications for tissues. In this review, we detail the extensive extracellular regulation of VEGF and the ability of VEGF to dictate the vascular phenotype. We explore the role of VEGF-releasing proteases and soluble carrier molecules on VEGF activity. While proteases such as MMP9 can 'release' matrix-bound VEGF and promote angiogenesis, for example as a key step in carcinogenesis, proteases can also suppress VEGF's angiogenic effects. We explore what dictates pro- or anti-angiogenic behavior. We also seek to understand the phenomenon of VEGF gradient formation. Strong VEGF gradients are thought to be due to decreased rates of diffusion from reversible matrix binding, however theoretical studies show that this scenario cannot give rise to lasting VEGF gradients in vivo. We propose that gradients are formed through degradation of sequestered VEGF. Finally, we review how different aspects of the VEGF signal, such as its concentration, gradient, matrix-binding, and NRP1-binding can differentially affect angiogenesis. We explore how this allows VEGF to regulate the formation of vascular networks across a spectrum of high to low branching densities, and from normal to pathological angiogenesis. A better understanding of the control of angiogenesis is necessary to improve upon limitations of current angiogenic therapies.
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Affiliation(s)
- Prakash Vempati
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Aleksander S Popel
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Feilim Mac Gabhann
- Institute for Computational Medicine and Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA.
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13
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Finley SD, Dhar M, Popel AS. Compartment model predicts VEGF secretion and investigates the effects of VEGF trap in tumor-bearing mice. Front Oncol 2013; 3:196. [PMID: 23908970 PMCID: PMC3727077 DOI: 10.3389/fonc.2013.00196] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Accepted: 07/13/2013] [Indexed: 12/19/2022] Open
Abstract
Angiogenesis, the formation of new blood vessels from existing vasculature, is important in tumor growth and metastasis. A key regulator of angiogenesis is vascular endothelial growth factor (VEGF), which has been targeted in numerous anti-angiogenic therapies aimed at inhibiting tumor angiogenesis. Systems biology approaches, including computational modeling, are useful for understanding this complex biological process and can aid in the development of novel and effective therapeutics that target the VEGF family of proteins and receptors. We have developed a computational model of VEGF transport and kinetics in the tumor-bearing mouse, which includes three-compartments: normal tissue, blood, and tumor. The model simulates human tumor xenografts and includes human (VEGF121 and VEGF165) and mouse (VEGF120 and VEGF164) isoforms. The model incorporates molecular interactions between these VEGF isoforms and receptors (VEGFR1 and VEGFR2), as well as co-receptors (NRP1 and NRP2). We also include important soluble factors: soluble VEGFR1 (sFlt-1) and α-2-macroglobulin. The model accounts for transport via macromolecular transendothelial permeability, lymphatic flow, and plasma clearance. We have fit the model to available in vivo experimental data on the plasma concentration of free VEGF Trap and VEGF Trap bound to mouse and human VEGF in order to estimate the rates at which parenchymal cells (myocytes and tumor cells) and endothelial cells secrete VEGF. Interestingly, the predicted tumor VEGF secretion rates are significantly lower (0.007-0.023 molecules/cell/s, depending on the tumor microenvironment) than most reported in vitro measurements (0.03-2.65 molecules/cell/s). The optimized model is used to investigate the interstitial and plasma VEGF concentrations and the effect of the VEGF-neutralizing agent, VEGF Trap (aflibercept). This work complements experimental studies performed in mice and provides a framework with which to examine the effects of anti-VEGF agents, aiding in the optimization of such anti-angiogenic therapeutics as well as analysis of clinical data. The model predictions also have implications for biomarker discovery with anti-angiogenic therapies.
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Affiliation(s)
- Stacey D Finley
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine , Baltimore, MD , USA
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Finley SD, Popel AS. Effect of tumor microenvironment on tumor VEGF during anti-VEGF treatment: systems biology predictions. J Natl Cancer Inst 2013; 105:802-11. [PMID: 23670728 DOI: 10.1093/jnci/djt093] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Vascular endothelial growth factor (VEGF) is known to be a potent promoter of angiogenesis under both physiological and pathological conditions. Given its role in regulating tumor vascularization, VEGF has been targeted in various cancer treatments, and anti-VEGF therapy has been used clinically for treatment of several types of cancer. Systems biology approaches, particularly computational models, provide insight into the complexity of tumor angiogenesis. These models complement experimental studies and aid in the development of effective therapies targeting angiogenesis. METHODS We developed an experiment-based, molecular-detailed compartment model of VEGF kinetics and transport to investigate the distribution of two major VEGF isoforms (VEGF121 and VEGF165) in the body. The model is applied to predict the dynamics of tumor VEGF and, importantly, to gain insight into how tumor VEGF responds to an intravenous injection of an anti-VEGF agent. RESULTS The model predicts that free VEGF in the tumor interstitium is seven to 13 times higher than plasma VEGF and is predominantly in the form of VEGF121 (>70%), predictions that are validated by experimental data. The model also predicts that tumor VEGF can increase or decrease with anti-VEGF treatment depending on tumor microenvironment, pointing to the importance of personalized medicine. CONCLUSIONS This computational study suggests that the rate of VEGF secretion by tumor cells may serve as a biomarker to predict the patient population that is likely to respond to anti-VEGF treatment. Thus, the model predictions have important clinical relevance and may aid clinicians and clinical researchers seeking interpretation of pharmacokinetic and pharmacodynamic observations and optimization of anti-VEGF therapies.
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Affiliation(s)
- Stacey D Finley
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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Zhu RY, Xin X, Dai HY, Li Q, Lei JY, Chen Y, Jin J. Expression and purification of recombinant human serum albumin fusion protein with VEGF165b in Pichia pastoris. Protein Expr Purif 2012; 85:32-7. [PMID: 22750397 DOI: 10.1016/j.pep.2012.06.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Revised: 05/26/2012] [Accepted: 06/18/2012] [Indexed: 11/16/2022]
Abstract
VEGF165b is an endogenous transcriptional splice variant of VEGF and has been shown to have a therapeutic potency as an anti-cancer agent. In this report, a fusion gene consisting of a human VEGF165b and a human albumin (HSA) gene was constructed and then inserted into a pPIC9k vector. The recombinant fusion protein, rhHSA-VEGF165b, was over expressed in the methylotrophic yeast Pichia pastoris under the control of AOX1 promoter. After induction with methanol, the expression level of rhHSA-VEGF165b was 275 mg/L in broth. The fusion protein rhHSA-VEGF165b was purified to more than 95% purity by using Blue Sepharose Fast Flow and SP Sepharose Fast Flow. Biological activity of the prepared rhHSA-VEGF165b was characterized by transwell migration assay, retaining about 9% of that of unmodified rhVEGF165b on a molar basis. Data from mice show that the serum half-life time of rhHSA-VEGF165b was nearly 20 times longer than that of rhVEGF165b.
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Affiliation(s)
- Rui-Yu Zhu
- Molecular Pharmacol Laboratory, Sch Med and Pharmaceut, Jiangnan University, Wuxi 214122, PR China.
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Finley SD, Popel AS. Predicting the effects of anti-angiogenic agents targeting specific VEGF isoforms. AAPS J 2012; 14:500-9. [PMID: 22547351 DOI: 10.1208/s12248-012-9363-4] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Accepted: 04/13/2012] [Indexed: 01/04/2023]
Abstract
Vascular endothelial growth factor (VEGF) is a key mediator of angiogenesis, whose effect on cancer growth and development is well characterized. Alternative splicing of VEGF leads to several different isoforms, which are differentially expressed in various tumor types and have distinct functions in tumor blood vessel formation. Many cancer therapies aim to inhibit angiogenesis by targeting VEGF and preventing intracellular signaling leading to tumor vascularization; however, the effects of targeting specific VEGF isoforms have received little attention in the clinical setting. In this work, we investigate the effects of selectively targeting a single VEGF isoform, as compared with inhibiting all isoforms. We utilize a molecular-detailed whole-body compartment model of VEGF transport and kinetics in the presence of breast tumor. The model includes two major VEGF isoforms, VEGF(121) and VEGF(165), receptors VEGFR1 and VEGFR2, and co-receptors Neuropilin-1 and Neuropilin-2. We utilize the model to predict the concentrations of free VEGF, the number of VEGF/VEGFR2 complexes (considered to be pro-angiogenic), and the receptor occupancy profiles following inhibition of VEGF using isoform-specific anti-VEGF agents. We predict that targeting VEGF(121) leads to a 54% and 84% reduction in free VEGF in tumors that secrete both VEGF isoforms or tumors that overexpress VEGF(121), respectively. Additionally, 21% of the VEGFR2 molecules in the blood are ligated following inhibition of VEGF(121), compared with 88% when both isoforms are targeted. Targeting VEGF(121) reduces tumor free VEGF and is an effective treatment strategy. Our results provide a basis for clinical investigation of isoform-specific anti-VEGF agents.
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Affiliation(s)
- Stacey D Finley
- Department of Biomedical Engineering, School of Medicine, Johns Hopkins University, Baltimore, Maryland 21205, USA.
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Jones WS, Duscha BD, Robbins JL, Duggan NN, Regensteiner JG, Kraus WE, Hiatt WR, Dokun AO, Annex BH. Alteration in angiogenic and anti-angiogenic forms of vascular endothelial growth factor-A in skeletal muscle of patients with intermittent claudication following exercise training. Vasc Med 2012; 17:94-100. [PMID: 22402934 DOI: 10.1177/1358863x11436334] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The aims of this study were twofold: (1) to identify whether peripheral artery disease (PAD) patients had increased muscle concentration of angiogenic VEGF-A, anti-angiogenic VEGF₁₆₅b or VEGF receptor 1 (VEGF-R1) when compared with control subjects, and (2) to evaluate whether exercise training in PAD patients was associated with changes in muscle concentration of VEGF-A, VEGF₁₆₅b or VEGF-R1. At baseline, 22 PAD and 30 control subjects underwent gastrocnemius muscle biopsy. Twelve PAD patients were treated with supervised exercise training (SET) and underwent muscle biopsy after 3 weeks and 12 weeks of training and had sufficient tissue to measure VEGF-A, VEGF₁₆₅b and VEGF-R1 concentrations in skeletal muscle lysates by ELISA. Muscle concentrations of VEGF-A and VEGF₁₆₅b were similar in PAD patients versus controls at baseline. At both time points after the start of SET, VEGF-A levels decreased and there was a trend towards increased VEGF₁₆₅b concentrations. At baseline, VEGF-R1 concentrations were lower in PAD patients when compared with controls but did not change after SET. Skeletal muscle concentrations of VEGF-A are not different in PAD patients when compared with controls at baseline. SET is associated with a significant reduction in VEGF-A levels and a trend towards increased VEGF₁₆₅b levels. These somewhat unexpected findings suggest that further investigation into the mechanism of vascular responses to exercise training in PAD patients is warranted.
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Affiliation(s)
- W Schuyler Jones
- Division of Cardiology, Duke University Medical Center, Durham, NC, USA.
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Manetti M, Guiducci S, Ibba-manneschi L, Matucci-cerinic M. 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] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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