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Mapunda JA, Pareja J, Vladymyrov M, Bouillet E, Hélie P, Pleskač P, Barcos S, Andrae J, Vestweber D, McDonald DM, Betsholtz C, Deutsch U, Proulx ST, Engelhardt B. VE-cadherin in arachnoid and pia mater cells serves as a suitable landmark for in vivo imaging of CNS immune surveillance and inflammation. Nat Commun 2023; 14:5837. [PMID: 37730744 PMCID: PMC10511632 DOI: 10.1038/s41467-023-41580-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 09/01/2023] [Indexed: 09/22/2023] Open
Abstract
Meninges cover the surface of the brain and spinal cord and contribute to protection and immune surveillance of the central nervous system (CNS). How the meningeal layers establish CNS compartments with different accessibility to immune cells and immune mediators is, however, not well understood. Here, using 2-photon imaging in female transgenic reporter mice, we describe VE-cadherin at intercellular junctions of arachnoid and pia mater cells that form the leptomeninges and border the subarachnoid space (SAS) filled with cerebrospinal fluid (CSF). VE-cadherin expression also marked a layer of Prox1+ cells located within the arachnoid beneath and separate from E-cadherin+ arachnoid barrier cells. In vivo imaging of the spinal cord and brain in female VE-cadherin-GFP reporter mice allowed for direct observation of accessibility of CSF derived tracers and T cells into the SAS bordered by the arachnoid and pia mater during health and neuroinflammation, and detection of volume changes of the SAS during CNS pathology. Together, the findings identified VE-cadherin as an informative landmark for in vivo imaging of the leptomeninges that can be used to visualize the borders of the SAS and thus potential barrier properties of the leptomeninges in controlling access of immune mediators and immune cells into the CNS during health and neuroinflammation.
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Affiliation(s)
| | - Javier Pareja
- Theodor Kocher Institute, University of Bern, Bern, Switzerland
| | | | - Elisa Bouillet
- Theodor Kocher Institute, University of Bern, Bern, Switzerland
| | - Pauline Hélie
- Theodor Kocher Institute, University of Bern, Bern, Switzerland
| | - Petr Pleskač
- Theodor Kocher Institute, University of Bern, Bern, Switzerland
| | - Sara Barcos
- Theodor Kocher Institute, University of Bern, Bern, Switzerland
| | - Johanna Andrae
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | | | - Donald M McDonald
- Cardiovascular Research Institute, UCSF Helen Diller Family Comprehensive Cancer Center, and Department of Anatomy, University of California San Francisco, San Francisco, CA, USA
| | - Christer Betsholtz
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
- Department of Medicine-Huddinge, Karolinska Institute, Campus Flemingsberg, Huddinge, Sweden
| | - Urban Deutsch
- Theodor Kocher Institute, University of Bern, Bern, Switzerland
| | - Steven T Proulx
- Theodor Kocher Institute, University of Bern, Bern, Switzerland
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2
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D'Alessandris QG, Pacioni S, Stumpo V, Buccarelli M, Lauretti L, Giordano M, Di Bonaventura R, Martini M, Larocca LM, Giannetti S, Montano N, Falchetti ML, Ricci-Vitiani L, Pallini R. Dilation of Brain Veins and Perivascular Infiltration by Glioblastoma Cells in an In Vivo Assay of Early Tumor Angiogenesis. BIOMED RESEARCH INTERNATIONAL 2021; 2021:8891045. [PMID: 33748283 PMCID: PMC7960033 DOI: 10.1155/2021/8891045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 02/22/2021] [Accepted: 02/27/2021] [Indexed: 01/22/2023]
Abstract
The cranial window (CW) technique provides a simple and low-cost method to assess tumor angiogenesis in the brain. The CW combined with histology using selective markers for tumor and endothelial cells can allow a sensitive monitoring of novel antiangiogenesis therapies in preclinical models. The CW was established in cyclosporine immunosuppressed rats that were stereotactically grafted with fluorescent U87MG glioblastoma cells. One to 3 weeks after grafting, brain vasculature was visualized in vivo and assessed by immunofluorescence microscopy using antibodies against endothelial and smooth-muscle cells and blood brain barrier. At 1-2 weeks after grafting, the CW reliably detected the hypertrophy of venous-venous anastomoses and cortical veins. These structures increased highly significantly their pregrafting diameter. Arterialized veins and hemorrhages were seen by three weeks after grafting. Immunofluorescence microscopy showed significant branching and dilation of microvessels, particularly those surrounded by tumor cells. Mechanistically, these changes lead to loss of vascular resistance, increased venous outflow, and opening of venous-venous anastomoses on the cortical surface. Data from the present study, namely, the hypertrophy of cortical venous-venous anastomoses, microvessel branching, and dilation of the microvessels surrounded by tumor cells, indicate the power of this in vivo model for the sensitive monitoring of early tumor angiogenesis.
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Affiliation(s)
- Quintino Giorgio D'Alessandris
- Institute of Neurosurgery, Department of Neuroscience, Fondazione Policlinico Universitario A. Gemelli IRCCS, Università Cattolica del Sacro Cuore, Rome 00168, Italy
| | - Simone Pacioni
- Institute of Neurosurgery, Department of Neuroscience, Fondazione Policlinico Universitario A. Gemelli IRCCS, Università Cattolica del Sacro Cuore, Rome 00168, Italy
| | - Vittorio Stumpo
- Institute of Neurosurgery, Department of Neuroscience, Fondazione Policlinico Universitario A. Gemelli IRCCS, Università Cattolica del Sacro Cuore, Rome 00168, Italy
| | - Mariachiara Buccarelli
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome 0061, Italy
| | - Liverana Lauretti
- Institute of Neurosurgery, Department of Neuroscience, Fondazione Policlinico Universitario A. Gemelli IRCCS, Università Cattolica del Sacro Cuore, Rome 00168, Italy
| | - Martina Giordano
- Institute of Neurosurgery, Department of Neuroscience, Fondazione Policlinico Universitario A. Gemelli IRCCS, Università Cattolica del Sacro Cuore, Rome 00168, Italy
| | - Rina Di Bonaventura
- Institute of Neurosurgery, Department of Neuroscience, Fondazione Policlinico Universitario A. Gemelli IRCCS, Università Cattolica del Sacro Cuore, Rome 00168, Italy
| | - Maurizio Martini
- Institute of Pathology, Fondazione Policlinico Universitario A. Gemelli IRCCS, Università Cattolica del Sacro Cuore, Rome 00168, Italy
| | - Luigi M. Larocca
- Institute of Pathology, Fondazione Policlinico Universitario A. Gemelli IRCCS, Università Cattolica del Sacro Cuore, Rome 00168, Italy
| | - Stefano Giannetti
- Institute of Human Anatomy, Università Cattolica del Sacro Cuore, Rome 00168, Italy
| | - Nicola Montano
- Institute of Neurosurgery, Department of Neuroscience, Fondazione Policlinico Universitario A. Gemelli IRCCS, Università Cattolica del Sacro Cuore, Rome 00168, Italy
| | - Maria Laura Falchetti
- CNR-IBBC, Institute of Biochemistry and Cell Biology, Consiglio Nazionale delle Ricerche, 00015 Rome, Italy
| | - Lucia Ricci-Vitiani
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome 0061, Italy
| | - Roberto Pallini
- Institute of Neurosurgery, Department of Neuroscience, Fondazione Policlinico Universitario A. Gemelli IRCCS, Università Cattolica del Sacro Cuore, Rome 00168, Italy
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3
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Uhl C, Markel M, Broggini T, Nieminen M, Kremenetskaia I, Vajkoczy P, Czabanka M. EphB4 mediates resistance to antiangiogenic therapy in experimental glioma. Angiogenesis 2018; 21:873-881. [PMID: 29987450 PMCID: PMC6208883 DOI: 10.1007/s10456-018-9633-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 07/01/2018] [Indexed: 12/15/2022]
Abstract
INTRODUCTION Alterations in vascular morphogenesis are hallmarks of antiangiogenesis-resistant tumor vessels. Vascular morphogenesis is regulated by ephrinB2-EphB4 system which may induce different biological effects depending on the oncological and molecular contexts. It was the aim of the current study to characterize the influence of EphB4 on tumor microcirculation after antiangiogenic treatment using different SF126 glioma models. MATERIALS AND METHODS Using an ecotropic transfection system, empty vector (pLXSN) or EphB4 (EphB4OE) overexpressing Phoenix-ECO cells were coimplanted with SF126 glioma cells subcutaneously (dorsal skinfold chamber, DSC) and orthotopically (cranial window, CW). Tumor volume was assessed by MRI. Intravital microscopy (IVM) allowed microcirculatory analysis (total {TVD} and functional vessel density {FVD}, diameter {D}, and permeability index {PI}) before and after antiangiogenic treatment (Sunitinib: DSC: 40 mg/kg BW, 6 days; CW: 80 mg/kg BW, 4 days). Immunohistochemistry included Pecam-Desmin, Ki67, TUNEL, and Caspase 3 stainings. RESULTS EphB4OE induced large and treatment-resistant tumor vessels (FVD: Control/Su: 110 ± 23 cm/cm2 vs. EphB4OE/Su: 103 ± 42 cm/cm2). Maintenance of pericyte-endothelial cell interactions (Control: 80 ± 12 vs. Control/Su: 47 ± 26%; EphB4OE: 88 ± 9 vs. EphB4OE/Su: 74 ± 25%) and reduced antiproliferative (Control: 637 ± 80 vs. Control/Su: 110 ± 22; EphB4OE: 298 ± 108 vs. EphB4OE/Su: 213 ± 80) and proapoptotic responses (Control: 196 ± 25 vs. Control / Su: 404 ± 60; EphB4OE: 183 ± 20 vs. EphB4OE/Su: 270 ± 66) were observed under EphB4 overexpression. CONCLUSION EphB4 overexpression leads to vascular resistance by altering vascular morphogenesis, pericyte coverage, and cellular proliferation/apoptosis in experimental SF126 glioma models.
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MESH Headings
- Angiogenesis Inhibitors/pharmacology
- Animals
- Apoptosis/drug effects
- Apoptosis/genetics
- Cell Line, Tumor
- Cell Proliferation/drug effects
- Cell Proliferation/genetics
- Drug Resistance, Neoplasm/genetics
- Glioma/blood supply
- Glioma/drug therapy
- Glioma/genetics
- Glioma/pathology
- Humans
- Mice
- Mice, Nude
- Neoplasms, Experimental/blood supply
- Neoplasms, Experimental/genetics
- Neoplasms, Experimental/metabolism
- Neoplasms, Experimental/pathology
- Neovascularization, Pathologic/drug therapy
- Neovascularization, Pathologic/genetics
- Neovascularization, Pathologic/metabolism
- Neovascularization, Pathologic/pathology
- Receptor, EphB4/genetics
- Receptor, EphB4/metabolism
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Affiliation(s)
- Christian Uhl
- Department of Neurosurgery, Universitätsmedizin Charite - Campus Mitte, Luisenstrasse 46, 10117, Berlin, Germany
| | - Moritz Markel
- Department of Neurosurgery, Universitätsmedizin Charite - Campus Mitte, Luisenstrasse 46, 10117, Berlin, Germany
| | - Thomas Broggini
- Department of Neurosurgery, Universitätsmedizin Charite - Campus Mitte, Luisenstrasse 46, 10117, Berlin, Germany
| | - Melina Nieminen
- Department of Neurosurgery, Universitätsmedizin Charite - Campus Mitte, Luisenstrasse 46, 10117, Berlin, Germany
| | - Irina Kremenetskaia
- Department of Neurosurgery, Universitätsmedizin Charite - Campus Mitte, Luisenstrasse 46, 10117, Berlin, Germany
| | - Peter Vajkoczy
- Department of Neurosurgery, Universitätsmedizin Charite - Campus Mitte, Luisenstrasse 46, 10117, Berlin, Germany.
| | - Marcus Czabanka
- Department of Neurosurgery, Universitätsmedizin Charite - Campus Mitte, Luisenstrasse 46, 10117, Berlin, Germany.
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4
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Takano S, Ishikawa E, Matsuda M, Yamamoto T, Matsumura A. Interferon-β inhibits glioma angiogenesis through downregulation of vascular endothelial growth factor and upregulation of interferon inducible protein 10. Int J Oncol 2014; 45:1837-46. [PMID: 25175315 PMCID: PMC4203325 DOI: 10.3892/ijo.2014.2620] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 07/04/2014] [Indexed: 02/06/2023] Open
Abstract
Interferon-β (IFN-β) has been used clinically for malignant glioma growth inhibition. Recently IFN-β is re-evaluated for its sensitization mechanism to the chemotherapeutic agent temozolomide, because angiogenesis is essential for malignant glioma growth. In this study, we investigated new mechanisms of inhibition of glioma angiogenesis by IFN-β. Three malignant glioma cell lines, U87, TK2 and Becker, were used for in vitro study. The effect of IFN-β for these cell lines were evaluated by means of proliferation (MTT assay), conditioned medium induced HUVEC migration, VEGF and interferon inducible protein 10 (IP10, angiogenesis inhibitor) expression by RT-PCR and western blot analysis. SCID mouse U87 subcutaneous model and U87 implant cranial window model were used for in vivo study. The effect of IFN-β with the models was evaluated by means of tumor growth, tumor tissue expression for VEGF and IP10, tumor tissue CD31 positive vessel densities, apoptosis and tumor microcirculation (blood velocity, interaction between leukocytes and endothelial cells). In vitro, IFN-β upregulated IP10 expression and downregulated VEGF expression time- (4–48 h) and dose- (10–5,000 U/ml) dependently. At the same dose, glioma cell-induced HUVEC migration was inhibited, but cell proliferation was not affected. IFN-β local and systemic injection at 105 U and at 5×105 U/day, for 15 days inhibited U87 subcutaneous growth significantly. In the tumor tissues, VEGF expression and vessel densities were downregulated, but IP10 expression and apoptosis index upregulated. In addition, IFN-β local injection increased collagen fiber deposition in the tumor tissues. IFN-β 5×105 U/day, s.c. injection for 7 days reversed the decreased leukocyte adhesion to endothelial cells, but did not affect blood velocity and vessel images. One of the important roles of IFN-β for malignant glioma growth inhibition was anti-angiogenesis by directly inhibiting angiogenesis through downregulation of VEGF and upregulation of IP-10 and indirectly changing the tumor microcirculation and regulating the interstitial pressure.
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Affiliation(s)
- Shingo Takano
- Department of Neurosurgery, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Eiichi Ishikawa
- Department of Neurosurgery, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Masahide Matsuda
- Department of Neurosurgery, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Tetsuya Yamamoto
- Department of Neurosurgery, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Akira Matsumura
- Department of Neurosurgery, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
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5
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Li SC, Lee KL, Luo J, Zhong JF, Loudon WG. Convergence of normal stem cell and cancer stem cell developmental stage: Implication for differential therapies. World J Stem Cells 2011; 3:83-8. [PMID: 22007273 PMCID: PMC3192222 DOI: 10.4252/wjsc.v3.i9.83] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2011] [Revised: 09/16/2011] [Accepted: 09/21/2011] [Indexed: 02/06/2023] Open
Abstract
Increased evidence shows that normal stem cells may contribute to cancer development and progression by acting as cancer-initiating cells through their interactions with abnormal environmental elements. We postulate that normal stem cells and cancer stem cells (CSC) possess similar mechanisms of self-renewal and differentiation. CSC can be the key to the elaboration of anti-cancer-based therapy. In this article, we focus on a controversial new theme relating to CSC. Tumorigenesis may have a critical stage characterized as a "therapeutic window", which can be identified by association of molecular, biochemical and biological events. Identifying such a stage can allow the production of more effective therapies (e.g. manipulated stem cells) to treat several cancers. More importantly, confirming the existence of a similar therapeutic window during the conversion of normal stem cells to malignant CSC may lead to targeted therapy specifically against CSC. This conversion information may be derived from investigating the biological behaviour of both normal stem cells and cancerous stem cells. Currently, there is little knowledge about the cellular and molecular mechanisms that govern the initiation and maintenance of CSC. Studies on co-evolution and interdependence of cancer with normal tissues may lead to a useful treatment paradigm of cancer. The crosstalk between normal stem cells and cancer formation may converge developmental stages of different types of stem cells (e.g. normal stem cells, CSC and embryonic stem cells). The differential studies of the convergence may result in novel therapies for treating cancers.
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Affiliation(s)
- Shengwen Calvin Li
- Shengwen Calvin Li, Katherine L Lee, William G Loudon, Neuro-Oncology Research Laboratory, Center for Neuroscience and Stem Cell Research, Children's Hospital of Orange County, University of California Irvine, 455 South Main Street, Orange, CA 92868, United States
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6
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Orringer DA, Chen T, Huang DL, Armstead WM, Hoff BA, Koo YEL, Keep RF, Philbert MA, Kopelman R, Sagher O. The brain tumor window model: a combined cranial window and implanted glioma model for evaluating intraoperative contrast agents. Neurosurgery 2010; 66:736-43. [PMID: 20305495 DOI: 10.1227/01.neu.0000367631.02903.50] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE Optical contrast agents for brain tumor delineation have been previously evaluated in ex vivo specimens from animals with implanted gliomas and may not reflect the true visual parameters encountered during surgery. This study describes a novel model system designed to evaluate optical contrast agents for tumor delineation in vivo. METHODS Biparietal craniectomies were performed on 8-week-old Sprague-Dawley rats. 9L glioma cells were injected intraparenchymally. A cover slip was bonded to the cranial defect with cyanoacrylate glue. When the tumor radius reached 1 mm, Coomassie Blue was administered intravenously while the appearance of the cortical surface was recorded. Computerized image analysis of the red/green/blue color components was used to quantify visible differences between tumor and nonneoplastic tissue and to compare delineation in the brain tumor window (BTW) model with the conventional 9L glioma model. RESULTS The tumor margin in the BTW model was poorly defined before contrast administration but readily apparent after contrast administration. Based on red component intensity, tumor delineation improved 4-fold at 50 minutes after contrast administration in the BTW model (P < .002). The conventional 9L glioma model overestimated the degree of delineation compared with the BTW model at the same dose of Coomassie Blue (P < .03). CONCLUSION Window placement overlying an implanted glioma is technically possible and well tolerated in the rat. The BTW model is a valid system for evaluating optical contrast agents designed to delineate brain tumor margins. To our knowledge, we have described the first in vivo model system for evaluating optical contrast agents for tumor delineation.
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Affiliation(s)
- Daniel A Orringer
- Department of Neurosurgery, University of Michigan Health System, Ann Arbor, Michigan, USA
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7
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Zennadi R, Moeller BJ, Whalen EJ, Batchvarova M, Xu K, Shan S, Delahunty M, Dewhirst MW, Telen MJ. Epinephrine-induced activation of LW-mediated sickle cell adhesion and vaso-occlusion in vivo. Blood 2007; 110:2708-17. [PMID: 17609430 PMCID: PMC1988948 DOI: 10.1182/blood-2006-11-056101] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Sickle red cell (SS RBC) adhesion is believed to contribute to the process of vaso-occlusion in sickle cell disease (SCD). We previously found that the LW RBC adhesion receptor can be activated by epinephrine to mediate SS RBC adhesion to endothelial alphavbeta3 integrin. To determine the contribution of LW activation to vaso-occlusive events in vivo, we investigated whether in vitro treatment of SS RBCs by epinephrine resulted in vaso-occlusion in intact microvasculature after RBC infusion into nude mice. Epinephrine enhanced human SS but not normal RBC adhesion to murine endothelial cells in vitro and to endothelium in vivo, promoting vaso-occlusion and RBC organ sequestration. Murine sickle RBCs also responded to epinephrine with increased adhesion to postcapillary endothelium in nude mice. Epinephrine-induced SS RBC adhesion, vaso-occlusion, and RBC organ trapping could be prevented by the beta-adrenergic receptor (beta-AR) antagonist, propranolol. Infusion of soluble recombinant LW also significantly reduced adhesion and vaso-occlusion. In addition, epinephrine-treated SS RBCs induced activation of murine leukocyte adhesion to endothelium as well. We conclude that LW activation by epinephrine via beta-AR stimulation can promote both SS RBC and leukocyte adhesion as well as vaso-occlusion, suggesting that both epinephrine and LW play potentially pathophysiological roles in SCD.
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Affiliation(s)
- Rahima Zennadi
- Division of Hematology and Duke Comprehensive Sickle Cell Center, Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
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8
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Farhadi MR, Capelle HH, Erber R, Ullrich A, Vajkoczy P. Combined inhibition of vascular endothelial growth factor and platelet-derived growth factor signaling: effects on the angiogenesis, microcirculation, and growth of orthotopic malignant gliomas. J Neurosurg 2005; 102:363-70. [PMID: 15739567 DOI: 10.3171/jns.2005.102.2.0363] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Object. The goal of this study was to determine the effects of SU6668, a polyvalent receptor tyrosine kinase inhibitor against vascular endothelial growth factor receptor—2, platelet-derived growth factor receptor—β, and fibroblast growth factor—1 on tumor growth, angiogenesis, and microcirculation in an orthotopic malignant glioma model.
Methods. Fluorescently labeled C6 malignant glioma cells were implanted into a long-term cranial window, which had been prepared in nude mice. The animals were treated with intraperitoneal injections of SU6668 (75 mg/kg/day) immediately (five animals) or 7 days (five animals) following tumor implantation. Control mice received intraperitoneal injections of vehicle (50 µl dimethylsulfoxide) immediately (five animals) or 7 days (four animals) after tumor implantation. Tumor growth, angiogenesis, and microcirculation were assessed by performing intravital fluorescence videomicroscopy over a 14-day observation period. To assess the effects of SU6668 on overall survival, C6 glioma cells were implanted stereotactically into the brains of 24 additional animals and treatment was initiated on Day 7.
In both the immediate and delayed experimental setting, SU6668 treatment resulted in a significant reduction of total and functional tumor vessel densities (both p < 0.05), reflecting a suppression of angiogenesis and impairment of tumor perfusion. As a consequence, tumor growth was significantly inhibited (p < 0.05). Histological analysis demonstrated reduced tumor growth and less mass effect on the adjacent brain of treated animals. The survival experiments confirmed the importance of our results in that survival was significantly prolonged following SU6668 therapy (p < 0.05).
Conclusions. Targeting of multiple angiogenic signaling pathways by polyvalent tyrosine kinase inhibitors represents a promising strategy to interfere with the vascularization, microcirculation, and growth of angiogenesis-dependent tumors. This also applies to malignant gliomas, despite the uniqueness of the cerebral microenvironment and the singular pathobiology of this tumor entity.
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MESH Headings
- Animals
- Apoptosis/drug effects
- Apoptosis/physiology
- Brain/drug effects
- Brain/pathology
- Brain Neoplasms/blood supply
- Cell Division/drug effects
- Cell Division/physiology
- Cell Line, Tumor
- Cell Transformation, Neoplastic/drug effects
- Cell Transformation, Neoplastic/pathology
- Glioma/blood supply
- Indoles/pharmacology
- Mice
- Mice, Nude
- Microcirculation/drug effects
- Microcirculation/physiology
- Microscopy, Fluorescence
- Microscopy, Video
- Neoplasm Transplantation
- Neovascularization, Pathologic/pathology
- Neovascularization, Pathologic/physiopathology
- Oxindoles
- Platelet-Derived Growth Factor/antagonists & inhibitors
- Platelet-Derived Growth Factor/physiology
- Propionates
- Protein-Tyrosine Kinases/antagonists & inhibitors
- Pyrroles/pharmacology
- Rats
- Receptor, Platelet-Derived Growth Factor beta/antagonists & inhibitors
- Receptor, Platelet-Derived Growth Factor beta/physiology
- Signal Transduction/drug effects
- Signal Transduction/physiology
- Transplantation, Heterologous
- Vascular Endothelial Growth Factor A/antagonists & inhibitors
- Vascular Endothelial Growth Factor A/physiology
- Vascular Endothelial Growth Factor Receptor-2/antagonists & inhibitors
- Vascular Endothelial Growth Factor Receptor-2/physiology
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Affiliation(s)
- Mohammad Reza Farhadi
- Department of Neurosurgery, University Hospital, Faculty of Clinical Medicine, University of Heidelberg, Mannheim, Germany
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9
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Roberts RL, Lin PC. Structural and Functional Optical Imaging of Angiogenesis in Animal Models. Methods Enzymol 2004; 386:105-22. [PMID: 15120248 DOI: 10.1016/s0076-6879(04)86004-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
MESH Headings
- Animals
- Arthritis/pathology
- Blood Flow Velocity/physiology
- Blood Vessels/pathology
- Blood Vessels/physiopathology
- Capillary Permeability/physiology
- Cell Line, Tumor
- Corneal Neovascularization/pathology
- Diagnostic Imaging/methods
- Dilatation, Pathologic/pathology
- Erythrocytes/chemistry
- Female
- Fluorescent Dyes/analysis
- Green Fluorescent Proteins
- Hypoxia/physiopathology
- Luminescent Proteins/genetics
- Luminescent Proteins/metabolism
- Mammary Neoplasms, Experimental/pathology
- Mammary Neoplasms, Experimental/physiopathology
- Mice
- Mice, Transgenic
- Microscopy/methods
- Microscopy, Confocal
- Microscopy, Fluorescence, Multiphoton
- Models, Animal
- Neoplasms/blood supply
- Neoplasms/pathology
- Neoplasms/therapy
- Neovascularization, Pathologic/pathology
- Neovascularization, Pathologic/physiopathology
- Rats
- Receptor, TIE-1/genetics
- Receptor, TIE-1/metabolism
- Receptor, TIE-2/genetics
- Receptor, TIE-2/metabolism
- Receptors, Vascular Endothelial Growth Factor/genetics
- Receptors, Vascular Endothelial Growth Factor/metabolism
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Affiliation(s)
- Richard L Roberts
- Department of Pathology, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee 37232, USA
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10
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Chomas JE, Pollard RE, Sadlowski AR, Griffey SM, Wisner ER, Ferrara KW. Contrast-enhanced US of Microcirculation of Superficially Implanted Tumors in Rats. Radiology 2003; 229:439-46. [PMID: 14526091 DOI: 10.1148/radiol.2292020536] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To determine the ability of contrast material-enhanced ultrasonography (US) to assess replenishment time in a rat kidney and adenocarcinoma tumor model. MATERIALS AND METHODS Mammary adenocarcinoma cells were implanted into the subcutaneous tissues of the flank of 11 rats. Resultant tumors were imaged serially with contrast-enhanced US and compared with images of the rat kidney, a highly perfused normal organ. The US acquisition and processing methods yield images of perfused tumor regions and the times required to achieve 80% replenishment. Findings at contrast-enhanced computed tomography (CT) and light microscopy of hematoxylin-eosin-stained tumor tissue were compared. Paired Student t test was performed to compare the accuracy of US with that of histologic examination and CT in the detection of viable tumor regions. RESULTS Replenishment of the kidney cortex microvasculature requires 1-5 seconds compared with a replenishment time of 6-14 seconds in tumors. Over the time course of tumor growth, the mean perfusion time becomes progressively longer, and a wider range of perfusion times is detected. Comparison of findings at US, CT, and histologic examination suggested that all three methods yield correlated estimates of the percentage of viable perfused tumor cells. Results of the t test suggested that the viable tumor percentages observed at US are not significantly different from those observed at CT and histologic examination (US vs CT, P =.92; US vs histologic examination, P =.94). CONCLUSION Repeated measurements of microvascular flow rate can be accomplished in a rat animal model with a minimally invasive technique.
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Affiliation(s)
- James E Chomas
- Department of Biomedical Engineering, University of California-Davis, 1021 Academic Surge, Davis, CA 95616, USA
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11
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Shan S, Sorg B, Dewhirst MW. A novel rodent mammary window of orthotopic breast cancer for intravital microscopy. Microvasc Res 2003; 65:109-17. [PMID: 12686168 DOI: 10.1016/s0026-2862(02)00017-1] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Orthotopic and ectopic organ environments differentially influence tumor growth, metastasis, and sensitivity to therapy. In this study we present a novel rodent mammary window of orthotopic breast cancer, which is amenable to study of microvascular function and angiogenesis in this orthotopic site. The skin around the nipple of selected mammary glands of female Fischer 344 rats was removed and the nipple was cut at its base. R3230Ac tumor fragments or cells in Gelfoam were aseptically implanted into the nipple sinus. An acrylic disk was placed on top of the implant and was sutured in place. Histology showed that tumors were well established within 5 days. Similar techniques were also applied to BALB/c mice transplanted with 4T1 murine mammary carcinoma cells. With GFP-expressing tumor cells and serial observations, we demonstrated unique patterns of tumor cell proliferation and vascularization in both tumor models. The images obtained were comparable to those from the dorsal skinfold window chambers. This model will allow for study of tumor microcirculatory function, angiogenesis, tumor cell-host interactions, and evaluation of effects of various treatments.
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Affiliation(s)
- Siqing Shan
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, USA
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12
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Ferrara KW, Merritt CR, Burns PN, Foster FS, Mattrey RF, Wickline SA. Evaluation of tumor angiogenesis with US: imaging, Doppler, and contrast agents. Acad Radiol 2000; 7:824-39. [PMID: 11048880 DOI: 10.1016/s1076-6332(00)80631-5] [Citation(s) in RCA: 155] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- K W Ferrara
- Department of Biomedical Engineering, Univesity of California-Davis, USA
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13
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Dewhirst MW, Klitzman B, Braun RD, Brizel DM, Haroon ZA, Secomb TW. Review of methods used to study oxygen transport at the microcirculatory level. Int J Cancer 2000. [DOI: 10.1002/1097-0215(20001020)90:5<237::aid-ijc1>3.0.co;2-t] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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14
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Vajkoczy P, Ullrich A, Menger MD. Intravital fluorescence videomicroscopy to study tumor angiogenesis and microcirculation. Neoplasia 2000; 2:53-61. [PMID: 10933068 PMCID: PMC1531866 DOI: 10.1038/sj.neo.7900062] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Angiogenesis and microcirculation play a central role in growth and metastasis of human neoplasms, and, thus, represent a major target for novel treatment strategies. Mechanistic analysis of processes involved in tumor vascularization, however, requires sophisticated in vivo experimental models and techniques. Intravital microscopy allows direct assessment of tumor angiogenesis, microcirculation and overall perfusion. Its application to the study of tumor-induced neovascularization further provides information on molecular transport and delivery, intra- and extravascular cell-to-cell and cell-to-matrix interaction, as well as tumor oxygenation and metabolism. With the recent advances in the field of bioluminescence and fluorescent reporter genes, appropriate for in vivo imaging, the intravital fluorescent microscopic approach has to be considered a powerful tool to study microvascular, cellular and molecular mechanisms of tumor growth.
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Affiliation(s)
- P Vajkoczy
- Department of Neurosurgery, Klinikum Mannheim, University of Heidelberg, Mannheim, Germany.
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15
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Denekamp J, Daşu A. Inducible repair and the two forms of tumour hypoxia--time for a paradigm shift. Acta Oncol 1999; 38:903-18. [PMID: 10606420 DOI: 10.1080/028418699432590] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
Clinical experience shows that there is a therapeutic window between 60 and 70 Gy where many tumours are eradicated, but the function of the adjacent normal tissues is preserved. This implies much more cell kill in the tumour than is acceptable in the normal tissue. An SF2 of 0.5 or lower is needed to account for the eradication of all tumour cells, while an SF2 of 0.8 or higher is needed to explain why these doses are tolerated by normal tissues. No such systematic difference is known between the intrinsic sensitivity of well-oxygenated normal and tumour cells. The presence of radioresistant hypoxic cells in tumours makes it even more difficult to understand the clinical success. However, there is experimental evidence that starved cells lose their repair competence as a result of the depletion of cellular energy charge. MRS studies have shown that low ATP levels are a characteristic feature of solid tumours in rodents and man. In this paper we incorporate the concept of repair incompetence in starving, chronically hypoxic cells. The increased sensitivity of such cells has been derived from an analysis of mammalian cell lines showing inducible repair. It is proportional to the SF2 and highest in resistant cells. The distinction between acutely hypoxic radioresistant cells and chronically hypoxic radiosensitive cells provides the key to the realistic modelling of successful radiotherapy. It also opens new conceptual approaches to radiotherapy. We conclude that it is essential to distinguish between these two kinds of hypoxic cells in predictive assays and models.
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Affiliation(s)
- J Denekamp
- Oncology Department, University Hospital, Umeå, Sweden.
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16
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Gillies RJ, Schornack PA, Secomb TW, Raghunand N. Causes and effects of heterogeneous perfusion in tumors. Neoplasia 1999; 1:197-207. [PMID: 10935474 PMCID: PMC1508079 DOI: 10.1038/sj.neo.7900037] [Citation(s) in RCA: 192] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/1999] [Accepted: 05/27/1999] [Indexed: 12/11/2022]
Abstract
A characteristic of solid tumors is their heterogeneous distribution of blood flow, with significant hypoxia and acidity in low-flow regions. We review effects of heterogeneous tumor perfusion are reviewed and propose a conceptual model for its cause. Hypoxic-acidic regions are resistant to chemo- and radiotherapy and may stimulate progression to a more metastatic phenotype. In normal tissues, hypoxia and acidity induce angiogenesis, which is expected to improve perfusion. However, aggressive tumors can have high local microvessel density simultaneously with significant regions of hypoxia and acidosis. A possible explanation for this apparent contradiction is that the mechanisms regulating growth and adaptation of vascular networks are impaired. According to a recent theory for structural adaptation of vascular networks, four interrelated adaptive responses can work as a self-regulating system to produce a mature and efficient blood distribution system in normal tissues. It is proposed that heterogeneous perfusion in tumors may result from perturbation of this system. Angiogenesis may increase perfusion heterogeneity in tumors by increasing the disparity between parallel low- and high-resistance flow pathways. This conceptual model provides a basis for future rational therapies. For example, it indicates that selective destruction of tumor vasculature may increase perfusion efficiency and improve therapeutic efficacy.
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Affiliation(s)
- R J Gillies
- Arizona Cancer Center, University of Arizona, Tucson 85724-5024, USA.
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17
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Vajkoczy P, Goldbrunner R, Farhadi M, Vince G, Schilling L, Tonn JC, Schmiedek P, Menger MD. Glioma cell migration is associated with glioma-induced angiogenesis in vivo. Int J Dev Neurosci 1999; 17:557-63. [PMID: 10571417 DOI: 10.1016/s0736-5748(99)00021-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
To simultaneously assess glioma cell invasion and glioma angiogenesis in vivo by non-invasive and quantitative means, DiI-labeled C6 glioma spheroids were implanted into the dorsal skinfold chamber preparation of nude mice (n = 6). Heat-inactivated spheroids served as controls to distinguish between active and passive cell spread. Using multi-fluorescent intravital videomicroscopy, glioma cell migration was analyzed on days 1-4, 6, and 10 and spheroid vascularization was analyzed on days 3, 6, and 10 after implantation. Additionally, C6 glioma spheroids were implanted into the chronic cranial window of nude mice as an orthotopic implantation site (n = 4). In the dorsal skinfold chamber, spheroids were vascularized within 10 days and revealed a tumor-specific microvasculature. In parallel, individual glioma cells detached from the spheroid edge and migrated centrifugally demonstrating an affinity to tumor and host vessels. Glioma cells demonstrated a heterogeneous pattern of their regional migratory activity (0.2-9.6 microm/h) which correlated well with regional glioma angiogenesis (r = 0.733). Using the cranial window, glioma cells spread similarly demonstrating an affinity to the perivascular space of pial/subpial vessels with preference to the arteriolar segments. Intravital fluorescence microscopy represents a versatile technique to assess the complex relationship between glioma-driven angiogenesis and glioma cell invasion.
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Affiliation(s)
- P Vajkoczy
- Department of Neurosurgery, Klinikum Mannheim, University of Heidelberg, Mannheim, Germany.
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18
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Bernsen HJ, Rijken PF, Hagemeier NE, van der Kogel AJ. A quantitative analysis of vascularization and perfusion of human glioma xenografts at different implantation sites. Microvasc Res 1999; 57:244-57. [PMID: 10329251 DOI: 10.1006/mvre.1999.2143] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The effect of tissue site of implantation of four different human gliomas on tumor vascularity and perfusion was examined. Vascular parameters of gliomas implanted subcutaneously in the nude mouse and intracerebrally in the nude rat were analyzed. Tumor vessels were stained with an antibody to collagen type IV and perfusion was investigated with the perfusion marker Hoechst 33342. Characteristic vascular patterns were observed in both intracerebral and subcutaneous xenografts belonging to the same tumor line. Major differences in vascular architecture and in the degree of vascularization were noted in comparisons of the two implantation sites for the same tumor line. Tumor perfusion was highly variable for both locations of tumor growth. Distinct differences between the implantation sites of similar tumor lines in vascular perfusion, intervascular distance, and vascular density were present. Incomplete perfusion of vascular structures, as seen in this study, may result in reduced delivery of oxygen to tumor areas. Therefore, measurements of vascular density and intervascular distance alone, without knowledge of the perfusion status, may not be sufficient to estimate the degree of tumor oxygenation. Furthermore, differences in vascular parameters may have important consequences for treatment modalities such as radiotherapy and chemotherapy. Thus, the findings in our study suggest that care has to be taken in extrapolating therapy results obtained with subcutaneous glioma tumor models to the original growth location of gliomas, the brain, due to major differences in vasculature.
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Affiliation(s)
- H J Bernsen
- Institute of Radiotherapy, University of Nijmegen, Nijmegen, 6525 GA, The Netherlands
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19
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Vajkoczy P, Menger MD, Vollmar B, Schilling L, Schmiedek P, Hirth KP, Ullrich A, Fong TA. Inhibition of tumor growth, angiogenesis, and microcirculation by the novel Flk-1 inhibitor SU5416 as assessed by intravital multi-fluorescence videomicroscopy. Neoplasia 1999; 1:31-41. [PMID: 10935468 PMCID: PMC1716058 DOI: 10.1038/sj.neo.7900006] [Citation(s) in RCA: 116] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Vascular endothelial growth factor (VEGF) plays a fundamental role in mediating tumor angiogenesis and tumor growth. Here we investigate the direct effect of a novel small molecule inhibitor of the Flk-1-mediated signal transduction pathway of VEGF, SU5416, on tumor angiogenesis and microhemodynamics of an experimental glioblastoma by using intravital multifluorescence videomicroscopy. SU5416 treatment significantly suppressed tumor growth. In parallel, SU5416 demonstrated a potent antiangiogenic activity, resulting in a significant reduction of both the total and functional vascular density of the tumor microvasculature, which indicates an impaired vascularization as well as significant perfusion failure in treated tumors. This malperfusion was not compensated for by changes in vessel diameter or recruitment of nonperfused vessels. Analyses of the tumor microcirculation revealed significant microhemodynamic changes after angiogenesis blockage such as a higher red blood cell velocity and blood flow in remnant tumor vessels when compared with controls. Our results demonstrate that the novel antiangiogenic concept of targeting the tyrosine kinase of Flk-1/KDR by means of a small molecule inhibitor represents an efficient strategy to control growth and progression of angiogenesis-dependent tumors. This study provides insight into microvascular consequences of Flk-1/KDR targeting in vivo and may have important implications for the future treatment of angiogenesis-dependent neoplasms.
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Affiliation(s)
- P Vajkoczy
- Department of Neurosurgery, Klinikum Mannheim, University of Heidelberg, Germany.
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20
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Rainov NG, Sena-Esteves M, Fraefel C, Dobberstein KU, Chiocca EA, Breakefield XO. A chimeric fusion protein of cytochrome CYP4B1 and green fluorescent protein for detection of pro-drug activating gene delivery and for gene therapy in malignant glioma. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1999; 451:393-403. [PMID: 10026902 DOI: 10.1007/978-1-4615-5357-1_61] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Quantity and distribution of transgene-expressing tumor cells are central issues in cancer gene therapy. These are critical for the efficiency of tumor killing and for the bystander effect. In an attempt to combine the advantages of a potent bioactivating "suicide" gene with a marker gene for living cells, cDNA encoding cytochrome CYP4B1 was fused to the green fluorescent protein (GFP) cDNA. The resulting chimeric fusion protein, 4B1EGFP, was expressed in rodent and human glioma cell lines in culture. The ability of this recombinant enzyme to destroy tumor cells by converting the prodrug 4-ipomeanol (4-IM) into alkylating metabolites was evaluated in comparison with the cytotoxicity of the native CYP4B1 enzyme. The most sensitive 4B1EGFP-expressing glioma cell clone had a LD50 of 0.75 microgram/ml for 4-IM, as compared to a 4-IM LD50 of 0.5 microgram/ml in glioma cells expressing the native CYP4B1. A strong bystander effect mediated by cell-to-cell contact was present in the 4B1EGFP clones, allowing for more than 50% bystander kill at a ratio of expressing to non-expressing cells of 1:100. A herpes-simplex amplicon (pHSVPrPUC delta Hind) was constructed with the 4B1EGFP fusion protein, and recombinant helper-free HSV particles were packaged in Vero cells. Fisher 344 rats were inoculated with 4 x 10(5) 9L tumor cells to produce epidural tumor. Recombinant HSV particles were injected into the tumor at a dose of 1 x 10(7) pfu. Tumor was resected in living anesthetized animals 24, 48, and 72 hours after virus injection, and cryostat sections were evaluated by fluorescent microscopy. HSV-mediated delivery of the fusion protein to tumor cells was successfully demonstrated. In conclusion, the chimeric fusion protein 4B1EGFP retains essentially all features of the native CYP4B1 enzyme, and, moreover, offers advantages in terms of gene transfer visualization, which may lead to improvement of gene transfer strategies.
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Affiliation(s)
- N G Rainov
- Molecular Neurogenetics Unit, Massachusetts General Hospital, Boston, USA.
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21
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Zagar BG, Fornaris RJ, Ferrara KW. Ultrasonic mapping of the microvasculature: signal alignment. ULTRASOUND IN MEDICINE & BIOLOGY 1998; 24:809-824. [PMID: 9740383 DOI: 10.1016/s0301-5629(98)00042-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The ultimate goal of this work was the development of a system capable of estimating the low flow velocities in the microvasculature. Estimation of low velocity flow within these vessels is challenging due to the small signal levels and the effect of cardiac and respiratory motion. Realignment of the signal from a single line-of-sight to remove physiological tissue motion is a critical part of the process of small-vessel flow mapping, and our methods for this alignment are considered in this paper. Each method involves the correlation of pulses acquired from the same line-of-sight. The first method involves the correlation of adjacent pulses (nearest-neighbor), the second involves a single reference line and the third involves averaging the correlation over a set of reference lines. We find that a nearest-neighbor strategy is suboptimal, and that strategies involving a global reference line are superior. A bound on the variance of estimates of the location of the correlation peak is presented. This bound allows us to consider our results in comparison with an absolute limit. Finally, a new algorithm allowing for alignment between lines-of-sight is described, and initial results are presented. Such an algorithm does, in fact, reduce jitter, correct for tissue motion and enables us to better visualize vessel continuity. We find that vessels as small as 40 microm can be mapped in two dimensions using a 50-MHz transducer.
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Affiliation(s)
- B G Zagar
- Department of Electrical Engineering, Technical University Graz, Austria
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22
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Vajkoczy P, Schilling L, Ullrich A, Schmiedek P, Menger MD. Characterization of angiogenesis and microcirculation of high-grade glioma: an intravital multifluorescence microscopic approach in the athymic nude mouse. J Cereb Blood Flow Metab 1998; 18:510-20. [PMID: 9591843 DOI: 10.1097/00004647-199805000-00006] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The current study follows angiogenesis and microcirculatory changes associated with malignant glioma growth by means of an intravital fluorescence microscopic approach, which allows for the direct and continuous visualization of the glioma microvasculature and its quantitative analysis. Fluorescently labeled C6 rat glioma cells (5 x 10(5)) were implanted into dorsal skinfold chamber preparations of athymic nude mice. Glioma growth, vascularization, microhemodynamics, vascular permeability, and leukocyte-endothelial cell interactions were simultaneously followed over a 22-day observation period using intravital epiillumination microscopy and a multifluorescent labeling technique. Analysis of the process of glioma vascularization revealed three stages with distinct microvascular characteristics: avascular stage (days 0 to 6), lag of glioma growth but initial glioma-induced angiogenesis within the host tissue in peritumoral areas; early vascular stage (days 6 to 14), glioma cell proliferation associated with a spatially homogeneous development of a glioma microvasculature; and late vascular stage (days 14 to 22), exponential tumor growth and expansion (> 400 mm3) with high vascular densities in the peritumoral region and reduced vascularization (microvascular perfusion) in the glioma center. Within the center, the functional vessel length per area correlated inversely with glioma size (P < 0.01). In the peritumoral region, functional vessel length per area was independent of glioma size, indicating persistent, high angiogenic activity throughout the observation period. Thus, the microvasculature of mature gliomas revealed a microvascular zonal division with a progressive reduction of the functional vessel length per area within the tumor center. The perfusion failure of individual microvessels within the glioma center was partly compensated by an increase of diameters (P < 0.05), and thus by an increase of blood flow in these functional microvessels (P < 0.05) over time. Histologic analysis demonstrated both expanding and infiltrating growth patterns, as well as focal necroses on day 22. These are the first data from repeated in vivo analysis of glioma growth, vascularization, and microcirculation.
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Affiliation(s)
- P Vajkoczy
- Department of Neurosurgery, Klinikum Mannheim, University of Heidelberg, Germany
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23
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Kimura H, Wu NZ, Dodge R, Spencer DP, Klitzman BM, McIntyre TM, Dewhirst MW. Inhibition of radiation-induced up-regulation of leukocyte adhesion to endothelial cells with the platelet-activating factor inhibitor, BN52021. Int J Radiat Oncol Biol Phys 1995; 33:627-33. [PMID: 7558952 DOI: 10.1016/0360-3016(95)00205-d] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
PURPOSE The inflammatory process is likely involved in normal tissue damage after radiation exposure, yet few studies have directly evaluated the factors that might be involved in the regulation of inflammation after irradiation in vivo. We tested the hypothesis that platelet-activating factor, a neutrophil agonist synthesized by endothelial cells, is involved in the upregulation of radiation-induced leukocyte-endothelial cell interactions by using an inhibitor of its receptor, BN52021. METHODS AND MATERIALS Fischer-344 rats with dorsal skin-fold window chambers were randomized to three experimental groups: control (sham irradiation); 6 Gy radiation; and 6 Gy + BN52021. BN52021 (0.5 mg/kg) was administered 5 min prior to 6 Gy radiation. Leukocytes were stained in vivo with i.v. acridine orange for visualization with fluorescent microscopy. Venous vessel diameters were measured and number of rolling leukocytes were counted per 30-s period. The number of adhering leukocytes per unit surface area was also determined. Differences among the three experimental groups for rolling and adhering leukocytes were analyzed using a mixed-effects linear model with vessel shear rate used as a covariate. Results are reported as means +/- standard errors. RESULTS Irradiation caused upregulation of leukocyte rolling, as compared with sham-treated controls (p = 0.04): the BN compound in addition to radiation did not downregulate this effect. Irradiation also upregulated leukocyte adhesion (p < 0.001), but the addition of BN52021 prior to irradiation blocked this effect. The drug did not affect heart rate or blood pressure. CONCLUSIONS These results support the hypothesis that radiation-induced upregulation of leukocyte adhesion is mediated by platelet-activating factor. These results are consistent with prior reports that platelet-activating factor is not involved in leukocyte rolling, which involves separate families of adhesion molecules from those that regulate adhesion. BN52021, a ginkolide, or other related drugs might provide a useful pharmacological means to prevent or ameliorate inflammatory pathways that are invoked after radiation exposure.
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Affiliation(s)
- H Kimura
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, USA
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