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Shimakawa K, Doge S, Michishita M, Tanabe E, Tajima T, Kobayashi M, Bonkobara M, Watanabe M, Ochiai K, Tanaka Y. A Canine c-kit Novel Mutation Isolated from a Gastrointestinal Stromal Tumor (GIST) Retains the Ability to Form Dimers but Lacks Autophosphorylation. Animals (Basel) 2025; 15:1444. [PMID: 40427321 PMCID: PMC12108377 DOI: 10.3390/ani15101444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2025] [Revised: 05/13/2025] [Accepted: 05/15/2025] [Indexed: 05/29/2025] Open
Abstract
Gastrointestinal stromal tumors (GISTs) are mesenchymal tumors that develop in the gastrointestinal tract; KIT mutations are present in both canine and human GISTs. In this study, genomic DNA was extracted from formalin-fixed paraffin-embedded (FFPE) sections of 55 canine GIST cases, and mutation searches were performed for exons 8, 9, and 11. The results revealed novel mutations, A434T and F436S, in exon 8. In contrast to the A434T mutation without functional changes, the F436S mutant retained its dimerization ability, but lost its phosphorylation function and attenuated downstream Akt signaling, which is reflected in wound healing and migration activities. A comparison of the subcellular localization of WT KIT and the F436S mutant revealed no differences. In silico simulations indicated that the F436S mutation alters the structure of the near-membrane region and that its effects may extend to the transmembrane and intracellular domains compared to the WT. F436S is a point mutation that affects the entire molecule because co-mutation with the F436S mutation and the known autophosphorylation mutation reduces the autophosphorylation abilities.
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Affiliation(s)
- Kei Shimakawa
- Laboratory of Veterinary Hygiene, School of Veterinary Science, Nippon Veterinary and Life Science University, Tokyo 180-8602, Japan (Y.T.)
| | - So Doge
- Laboratory of Veterinary Pathology, School of Veterinary Science, Nippon Veterinary and Life Science University, Tokyo 180-8602, Japan (M.M.)
| | - Masaki Michishita
- Laboratory of Veterinary Pathology, School of Veterinary Science, Nippon Veterinary and Life Science University, Tokyo 180-8602, Japan (M.M.)
| | - Eri Tanabe
- Laboratory of Veterinary Hygiene, School of Veterinary Science, Nippon Veterinary and Life Science University, Tokyo 180-8602, Japan (Y.T.)
| | - Tsuyoshi Tajima
- Laboratory of Veterinary Pharmacology, School of Veterinary Science, Nippon Veterinary and Life Science University, Tokyo 180-8602, Japan;
| | - Masato Kobayashi
- Laboratory of Veterinary Reproduction, School of Veterinary Science, Nippon Veterinary and Life Science University, Tokyo 180-8602, Japan;
| | - Makoto Bonkobara
- Laboratory of Veterinary Clinical Pathology, School of Veterinary Science, Nippon Veterinary and Life Science University, Tokyo 180-8602, Japan;
| | - Masami Watanabe
- Laboratory of Urology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama 700-8558, Japan;
| | - Kazuhiko Ochiai
- Laboratory of Veterinary Hygiene, School of Veterinary Science, Nippon Veterinary and Life Science University, Tokyo 180-8602, Japan (Y.T.)
| | - Yoshikazu Tanaka
- Laboratory of Veterinary Hygiene, School of Veterinary Science, Nippon Veterinary and Life Science University, Tokyo 180-8602, Japan (Y.T.)
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Mayr L, Neyazi S, Schwark K, Trissal M, Beck A, Labelle J, Eder SK, Weiler-Wichtl L, Marques JG, de Biagi-Junior CAO, Lo Cascio C, Chapman O, Sridhar S, Kenkre R, Dutta A, Wang S, Wang J, Hack O, Nascimento A, Nguyen CM, Castellani S, Rozowsky JS, Groves A, Panditharatna E, Cruzeiro GAV, Haase RD, Tabatabai K, Madlener S, Wadden J, Adam T, Kong S, Miclea M, Patel T, Bruckner K, Senfter D, Lämmerer A, Supko J, Guntner AS, Palova H, Neradil J, Stepien N, Lötsch-Gojo D, Berger W, Leiss U, Rosenmayr V, Dorfer C, Dieckmann K, Peyrl A, Azizi AA, Baumgartner A, Slaby O, Pokorna P, Clark LM, Cameron A, Nguyen QD, Wakimoto H, Dubois F, Greenwald NF, Bandopadhayay P, Beroukhim R, Ligon K, Kramm C, Bronsema A, Bailey S, Stucklin AG, Mueller S, Skrypek M, Martinez N, Bowers DC, Jones DTW, Jones C, Jäger N, Sterba J, Müllauer L, Haberler C, Kumar-Sinha C, Chinnaiyan A, Mody R, Chavez L, Furtner J, Koschmann C, Gojo J, Filbin MG. Effective targeting of PDGFRA-altered high-grade glioma with avapritinib. Cancer Cell 2025; 43:740-756.e8. [PMID: 40086436 PMCID: PMC12121847 DOI: 10.1016/j.ccell.2025.02.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2024] [Revised: 11/27/2024] [Accepted: 02/12/2025] [Indexed: 03/16/2025]
Abstract
PDGFRA is crucial to tumorigenesis and frequently genomically altered in high-grade glioma (HGG). In a comprehensive dataset of pediatric HGG (n = 261), we detect PDGFRA mutations and/or amplifications in 15% of cases, suggesting PDGFRA as a therapeutic target. We reveal that the PDGFRA/KIT inhibitor avapritinib shows (1) selectivity for PDGFRA inhibition, (2) distinct patterns of subcellular effects, (3) in vitro and in vivo activity in patient-derived HGG models, and (4) effective blood-brain barrier penetration in mice and humans. Furthermore, we report preliminary clinical real-world experience using avapritinib in pediatric and young adult patients with predominantly recurrent/refractory PDGFRA-altered HGG (n = 8). Our early data demonstrate that avapritinib is well tolerated and results in radiographic response in 3/7 cases, suggesting a potential role for avapritinib in the treatment of HGG with specific PDGFRA alterations. Overall, these translational results underscore the therapeutic potential of PDGFRA inhibition with avapritinib in HGG.
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Affiliation(s)
- Lisa Mayr
- Department of Pediatric Oncology, Dana-Farber/Boston Children's Cancer and Blood Disorder Center and Harvard Medical School, Boston, MA 02215, USA; Department of Pediatrics and Adolescent Medicine, Comprehensive Center for Pediatrics and Comprehensive Cancer Center, Medical University of Vienna, 1090 Vienna, Austria
| | - Sina Neyazi
- Department of Pediatric Oncology, Dana-Farber/Boston Children's Cancer and Blood Disorder Center and Harvard Medical School, Boston, MA 02215, USA
| | - Kallen Schwark
- Department of Pediatrics, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Maria Trissal
- Department of Pediatric Oncology, Dana-Farber/Boston Children's Cancer and Blood Disorder Center and Harvard Medical School, Boston, MA 02215, USA
| | - Alexander Beck
- Center for Neuropathology and Prion Research, Ludwig Maximilians University Munich, Faculty of Medicine, Muenchen, 80539 Bayern, Germany
| | - Jenna Labelle
- Department of Pediatric Oncology, Dana-Farber/Boston Children's Cancer and Blood Disorder Center and Harvard Medical School, Boston, MA 02215, USA
| | - Sebastian K Eder
- Department of Pediatric Oncology, Dana-Farber/Boston Children's Cancer and Blood Disorder Center and Harvard Medical School, Boston, MA 02215, USA; St. Anna Children's Hospital, Department of Pediatrics and Adolescent Medicine, Medical University of Vienna and St. Anna Children's Cancer Research Institute (CCRI), 1090 Vienna, Austria
| | - Liesa Weiler-Wichtl
- Department of Pediatrics and Adolescent Medicine, Comprehensive Center for Pediatrics and Comprehensive Cancer Center, Medical University of Vienna, 1090 Vienna, Austria
| | - Joana G Marques
- Department of Pediatric Oncology, Dana-Farber/Boston Children's Cancer and Blood Disorder Center and Harvard Medical School, Boston, MA 02215, USA
| | - Carlos A O de Biagi-Junior
- Department of Pediatric Oncology, Dana-Farber/Boston Children's Cancer and Blood Disorder Center and Harvard Medical School, Boston, MA 02215, USA
| | - Costanza Lo Cascio
- Department of Pediatric Oncology, Dana-Farber/Boston Children's Cancer and Blood Disorder Center and Harvard Medical School, Boston, MA 02215, USA
| | - Owen Chapman
- Sanford Burnham Prebys Medical Discovery Institute, San Diego, CA 92037, USA
| | - Sunita Sridhar
- Sanford Burnham Prebys Medical Discovery Institute, San Diego, CA 92037, USA
| | - Rishaan Kenkre
- Sanford Burnham Prebys Medical Discovery Institute, San Diego, CA 92037, USA
| | - Aditi Dutta
- Sanford Burnham Prebys Medical Discovery Institute, San Diego, CA 92037, USA
| | - Shanqing Wang
- Sanford Burnham Prebys Medical Discovery Institute, San Diego, CA 92037, USA
| | - Jessica Wang
- Sanford Burnham Prebys Medical Discovery Institute, San Diego, CA 92037, USA
| | - Olivia Hack
- Department of Pediatric Oncology, Dana-Farber/Boston Children's Cancer and Blood Disorder Center and Harvard Medical School, Boston, MA 02215, USA
| | - Andrezza Nascimento
- Department of Pediatric Oncology, Dana-Farber/Boston Children's Cancer and Blood Disorder Center and Harvard Medical School, Boston, MA 02215, USA
| | - Cuong M Nguyen
- Department of Pediatric Oncology, Dana-Farber/Boston Children's Cancer and Blood Disorder Center and Harvard Medical School, Boston, MA 02215, USA
| | - Sophia Castellani
- Department of Pediatric Oncology, Dana-Farber/Boston Children's Cancer and Blood Disorder Center and Harvard Medical School, Boston, MA 02215, USA
| | - Jacob S Rozowsky
- Department of Pediatric Oncology, Dana-Farber/Boston Children's Cancer and Blood Disorder Center and Harvard Medical School, Boston, MA 02215, USA
| | - Andrew Groves
- Department of Pediatric Oncology, Dana-Farber/Boston Children's Cancer and Blood Disorder Center and Harvard Medical School, Boston, MA 02215, USA
| | - Eshini Panditharatna
- Department of Pediatric Oncology, Dana-Farber/Boston Children's Cancer and Blood Disorder Center and Harvard Medical School, Boston, MA 02215, USA
| | - Gustavo Alencastro Veiga Cruzeiro
- Department of Pediatric Oncology, Dana-Farber/Boston Children's Cancer and Blood Disorder Center and Harvard Medical School, Boston, MA 02215, USA
| | - Rebecca D Haase
- Department of Pediatric Oncology, Dana-Farber/Boston Children's Cancer and Blood Disorder Center and Harvard Medical School, Boston, MA 02215, USA
| | - Kuscha Tabatabai
- Department of Pediatric Oncology, Dana-Farber/Boston Children's Cancer and Blood Disorder Center and Harvard Medical School, Boston, MA 02215, USA
| | - Sibylle Madlener
- Department of Pediatrics and Adolescent Medicine, Comprehensive Center for Pediatrics and Comprehensive Cancer Center, Medical University of Vienna, 1090 Vienna, Austria
| | - Jack Wadden
- Department of Pediatrics, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Tiffany Adam
- Department of Pediatrics, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Seongbae Kong
- Department of Pediatrics, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Madeline Miclea
- Department of Pediatrics, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Tirth Patel
- Department of Pediatrics, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Katharina Bruckner
- Department of Pediatrics and Adolescent Medicine, Comprehensive Center for Pediatrics and Comprehensive Cancer Center, Medical University of Vienna, 1090 Vienna, Austria; Department of Neurosurgery, Comprehensive Center for Pediatrics and Comprehensive Cancer Center, Medical University of Vienna, 1090 Vienna, Austria
| | - Daniel Senfter
- Department of Pediatrics and Adolescent Medicine, Comprehensive Center for Pediatrics and Comprehensive Cancer Center, Medical University of Vienna, 1090 Vienna, Austria
| | - Anna Lämmerer
- Department of Pediatrics and Adolescent Medicine, Comprehensive Center for Pediatrics and Comprehensive Cancer Center, Medical University of Vienna, 1090 Vienna, Austria; Center for Cancer Research and Comprehensive Cancer Center, Medical University of Vienna, 1090 Vienna, Austria; Research Cluster "Translational Cancer Therapy Research", University of Vienna and Medical University of Vienna, 1090 Vienna, Austria
| | - Jeffrey Supko
- Department of Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Armin S Guntner
- Institute for Analytical and General Chemistry, Johannes Kepler University, 4040 Linz, Austria
| | - Hana Palova
- Central European Institute of Technology, Masaryk University, 60177 Brno, Czech Republic
| | - Jakub Neradil
- Department of Experimental Biology, Faculty of Science, Masaryk University, 61137 Brno, Czech Republic; International Clinical Research Center, St. Anne's University Hospital, Brno, Czech Republic
| | - Natalia Stepien
- Department of Pediatrics and Adolescent Medicine, Comprehensive Center for Pediatrics and Comprehensive Cancer Center, Medical University of Vienna, 1090 Vienna, Austria
| | - Daniela Lötsch-Gojo
- Department of Neurosurgery, Comprehensive Center for Pediatrics and Comprehensive Cancer Center, Medical University of Vienna, 1090 Vienna, Austria
| | - Walter Berger
- Center for Cancer Research and Comprehensive Cancer Center, Medical University of Vienna, 1090 Vienna, Austria; Research Cluster "Translational Cancer Therapy Research", University of Vienna and Medical University of Vienna, 1090 Vienna, Austria
| | - Ulrike Leiss
- Department of Pediatrics and Adolescent Medicine, Comprehensive Center for Pediatrics and Comprehensive Cancer Center, Medical University of Vienna, 1090 Vienna, Austria
| | - Verena Rosenmayr
- Department of Pediatrics and Adolescent Medicine, Comprehensive Center for Pediatrics and Comprehensive Cancer Center, Medical University of Vienna, 1090 Vienna, Austria
| | - Christian Dorfer
- Department of Neurosurgery, Comprehensive Center for Pediatrics and Comprehensive Cancer Center, Medical University of Vienna, 1090 Vienna, Austria
| | - Karin Dieckmann
- Department of Radiotherapy, Medical University of Vienna, 1090 Vienna, Austria
| | - Andreas Peyrl
- Department of Pediatrics and Adolescent Medicine, Comprehensive Center for Pediatrics and Comprehensive Cancer Center, Medical University of Vienna, 1090 Vienna, Austria
| | - Amedeo A Azizi
- Department of Pediatrics and Adolescent Medicine, Comprehensive Center for Pediatrics and Comprehensive Cancer Center, Medical University of Vienna, 1090 Vienna, Austria
| | - Alicia Baumgartner
- Department of Pediatric Oncology, Dana-Farber/Boston Children's Cancer and Blood Disorder Center and Harvard Medical School, Boston, MA 02215, USA; Department of Pediatrics and Adolescent Medicine, Comprehensive Center for Pediatrics and Comprehensive Cancer Center, Medical University of Vienna, 1090 Vienna, Austria
| | - Ondrej Slaby
- Central European Institute of Technology, Masaryk University, 60177 Brno, Czech Republic; Department of Biology, Faculty of Medicine, Masaryk University, 62500 Brno, Czech Republic
| | - Petra Pokorna
- Central European Institute of Technology, Masaryk University, 60177 Brno, Czech Republic
| | - Louise M Clark
- Lurie Family Imaging Center, Center for Biomedical Imaging in Oncology, Dana-Farber Cancer Institute, Boston, MA 02210, USA
| | - Amy Cameron
- Lurie Family Imaging Center, Center for Biomedical Imaging in Oncology, Dana-Farber Cancer Institute, Boston, MA 02210, USA
| | - Quang-De Nguyen
- Lurie Family Imaging Center, Center for Biomedical Imaging in Oncology, Dana-Farber Cancer Institute, Boston, MA 02210, USA
| | - Hiroaki Wakimoto
- Department of Neurosurgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Frank Dubois
- Department of Pediatric Oncology, Dana-Farber/Boston Children's Cancer and Blood Disorder Center and Harvard Medical School, Boston, MA 02215, USA
| | - Noah F Greenwald
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Department of Cancer Biology, Dana-Farber/Boston Children's Cancer and Blood Disorder Center and Harvard Medical School, Boston, MA 02115, USA
| | - Pratiti Bandopadhayay
- Department of Pediatric Oncology, Dana-Farber/Boston Children's Cancer and Blood Disorder Center and Harvard Medical School, Boston, MA 02215, USA
| | - Rameen Beroukhim
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Department of Cancer Biology and Medical Oncology, Dana-Farber Cancer Institute, and Harvard Medical School, Boston, MA 02115, USA
| | - Keith Ligon
- Department of Pediatric Oncology, Dana-Farber/Boston Children's Cancer and Blood Disorder Center and Harvard Medical School, Boston, MA 02215, USA
| | - Christof Kramm
- Division of Pediatric Hematology and Oncology, University Medical Center Göttingen, 37099 Göttingen, Germany
| | - Annika Bronsema
- Clinic of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Simon Bailey
- Great North Childrens Hospital and Newcastle University, Newcastle upon Tyne, UK; Newcastle Hospitals NHS Foundation Trust, NE1 4LP Newcastle, UK
| | - Ana Guerreiro Stucklin
- Department of Oncology and Children's Research Center, University Children's Hospital Zurich, 8008 Zurich, Switzerland
| | - Sabine Mueller
- Departments of Pediatrics, Neurology, and Neurological Surgery, University of California San Francisco, San Francisco, CA 94143, USA
| | - Mary Skrypek
- Department of Pediatric Hematology-Oncology, Children's Minnesota, Minneapolis, MN 55404, USA
| | - Nina Martinez
- Department of Neurology & Neurological Surgery, Jefferson University, Philadelphia, PA 19107, USA
| | - Daniel C Bowers
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - David T W Jones
- Hopp Children's Cancer Center Heidelberg (KiTZ), 69120 Heidelberg, Germany; Pediatric Glioma Research Group, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Chris Jones
- Division of Molecular Pathology, Institute of Cancer Research, SM2 5NG London, UK
| | - Natalie Jäger
- Hopp Children's Cancer Center Heidelberg (KiTZ) & Division of Pediatric Neurooncology, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Jaroslav Sterba
- Department of Pediatric Oncology, University Hospital Brno and Faculty of Medicine, Masaryk University, 662630 Brno, Czech Republic
| | - Leonhard Müllauer
- Department of Pathology, Medical University of Vienna, 1090 Vienna, Austria
| | - Christine Haberler
- Division of Neuropathology and Neurochemistry, Department of Neurology, Medical University of Vienna, 1090 Vienna, Austria
| | - Chandan Kumar-Sinha
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Arul Chinnaiyan
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Rajen Mody
- Department of Pediatrics, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Lukas Chavez
- Sanford Burnham Prebys Medical Discovery Institute, San Diego, CA 92037, USA
| | - Julia Furtner
- Division of Neuroradiology and Musculoskeletal Radiology, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, 1090 Vienna, Austria; Research Center of Medical Image Analysis and Artificial Intelligence, Danube Private University, 3500 Krems an der Donau, Austria
| | - Carl Koschmann
- Department of Pediatrics, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
| | - Johannes Gojo
- Department of Pediatrics and Adolescent Medicine, Comprehensive Center for Pediatrics and Comprehensive Cancer Center, Medical University of Vienna, 1090 Vienna, Austria.
| | - Mariella G Filbin
- Department of Pediatric Oncology, Dana-Farber/Boston Children's Cancer and Blood Disorder Center and Harvard Medical School, Boston, MA 02215, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
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Sagarika P, Yadav K, Sahi C. Volleying plasma membrane proteins from birth to death: Role of J-domain proteins. Front Mol Biosci 2022; 9:1072242. [PMID: 36589230 PMCID: PMC9798423 DOI: 10.3389/fmolb.2022.1072242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 12/02/2022] [Indexed: 12/23/2022] Open
Abstract
The function, stability, and turnover of plasma membrane (PM) proteins are crucial for cellular homeostasis. Compared to soluble proteins, quality control of plasma membrane proteins is extremely challenging. Failure to meet the high quality control standards is detrimental to cellular and organismal health. J-domain proteins (JDPs) are among the most diverse group of chaperones that collaborate with other chaperones and protein degradation machinery to oversee cellular protein quality control (PQC). Although fragmented, the available literature from different models, including yeast, mammals, and plants, suggests that JDPs assist PM proteins with their synthesis, folding, and trafficking to their destination as well as their degradation, either through endocytic or proteasomal degradation pathways. Moreover, some JDPs interact directly with the membrane to regulate the stability and/or functionality of proteins at the PM. The deconvoluted picture emerging is that PM proteins are relayed from one JDP to another throughout their life cycle, further underscoring the versatility of the Hsp70:JDP machinery in the cell.
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Activating Mutation in the Receptor Tyrosine Kinase FLT3 with Clinicopathological Relevance in Canine Mast Cell Tumors. Vet Med Int 2022; 2022:9509900. [PMID: 36072760 PMCID: PMC9441376 DOI: 10.1155/2022/9509900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 06/09/2022] [Accepted: 07/29/2022] [Indexed: 11/17/2022] Open
Abstract
Recent research has focused on the receptor tyrosine kinase (RTK) KIT which is involved in the pathogenesis of canine mast cell tumors (MCT). However, the role of other RTKs in this neoplasm remains unclear. The present study aimed to determine the frequency of FLT3 mutations and to evaluate the mutational status and clinicopathological relevance of canine MCT patients. There were a total of 20 cases that were cytologically and histopathological diagnosed as canine MCTs; genomic polymerase chain reaction (PCR) and Sanger sequencing were used to identify mutations. For the juxtamembrane (JM) domain, the FLT3 14/15 primer pair was used to investigate exon 14/15 loci. Based on genomic PCR amplification of exon 14/15 and 20 of the FLT3 gene and Sanger sequencing of 20 cases of canine MCTs, the overall frequency of FLT3 mutation in canine MCTs was 75%. The majority of FLT3 mutations (70%) were internal tandem duplications (ITD) of the JM domain, while one case arose from deletion mutations of the tyrosine kinase domain (TKD). However, double mutations were not observed in this study. Furthermore, there is also clinicopathological relevance to MCT dogs carrying FLT3-ITD mutations, showing a tendency toward leukocytosis due to neutrophilia, and resembling human acute myeloid leukemia (AML) with FLT3-ITD mutations. A subset of MCTs with FLT3-ITD mutations, showing an enhanced signal of phosphorylated ERK1/2 identified by immunoblotting, suggests that an activating mutation may be driven by a distinct signal of the ERK pathway. Our results indicate that FLT3-ITD mutation is an oncogenic driver of canine MCTs, and that it shares some clinicopathologic features with human AML. These findings may offer new opportunities for further studies on canine mast cell tumorigenesis and a novel therapeutic target for canine MCT cases harboring FLT3-ITD mutations.
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Noto CN, Hoft SG, DiPaolo RJ. Mast Cells as Important Regulators in Autoimmunity and Cancer Development. Front Cell Dev Biol 2021; 9:752350. [PMID: 34712668 PMCID: PMC8546116 DOI: 10.3389/fcell.2021.752350] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 09/17/2021] [Indexed: 01/04/2023] Open
Abstract
Mast cells are an essential part of the immune system and are best known as important modulators of allergic and anaphylactic immune responses. Upon activation, mast cells release a multitude of inflammatory mediators with various effector functions that can be both protective and damage-inducing. Mast cells can have an anti-inflammatory or pro-inflammatory immunological effect and play important roles in regulating autoimmune diseases including rheumatoid arthritis, type 1 diabetes, and multiple sclerosis. Importantly, chronic inflammation and autoimmunity are linked to the development of specific cancers including pancreatic cancer, prostate cancer, colorectal cancer, and gastric cancer. Inflammatory mediators released from activated mast cells regulate immune responses and promote vascular permeability and the recruitment of immune cells to the site of inflammation. Mast cells are present in increased numbers in tissues affected by autoimmune diseases as well as in tumor microenvironments where they co-localize with T regulatory cells and T effector cells. Mast cells can regulate immune responses by expressing immune checkpoint molecules on their surface, releasing anti-inflammatory cytokines, and promoting vascularization of solid tumor sites. As a result of these immune modulating activities, mast cells have disease-modifying roles in specific autoimmune diseases and cancers. Therefore, determining how to regulate the activities of mast cells in different inflammatory and tumor microenvironments may be critical to discovering potential therapeutic targets to treat autoimmune diseases and cancer.
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Affiliation(s)
- Christine N Noto
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis University, St. Louis, MO, United States
| | - Stella G Hoft
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis University, St. Louis, MO, United States
| | - Richard J DiPaolo
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Saint Louis University, St. Louis, MO, United States
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Canine mast cell tumour cells regulate tryptophan catabolism via the expression of indoleamine 2,3-dioxygenase. Res Vet Sci 2021; 137:159-162. [PMID: 33984619 DOI: 10.1016/j.rvsc.2021.04.030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 03/28/2021] [Accepted: 04/27/2021] [Indexed: 01/14/2023]
Abstract
Indoleamine 2,3-deoxygenase (IDO) produced by cancer cells catabolizes tryptophan (TRP) to kynurenine (KYN) in the environment, resulting induction of cancer immune escape through induction of T cell anergy and enhancement of regulatory T cells. Recently, inhibition of IDO has been recognized as one of therapeutic strategies for human neoplastic diseases. However, there have been few reports about IDO-expressing cancers in dogs. In this study, we attempted to examine whether canine mast cell tumour (MCT) cells express IDO and modulate the concentration of TRP and KYN in the environment. BR, MPT-1.2, and MPT-3 cells were used as canine MCT cells. Expression of IDO was examined with RT-PCR and western blotting. Concentrations of TRP and KYN in the culture medium after incubation with canine MCT cells were detected with liquid chromatography-tandem mass spectrometry. The expression of mRNA and protein of IDO were confirmed in all samples extracted from canine MCT cells. TRP concentration in the culture medium was decreased and that of KYN was increased on incubation with canine MCT cells. The ratio of KYN/TRP, widely considered to represent IDO activity, was also significantly elevated. Moreover, treatment with an IDO inhibitor L-1-methyl-tryptophan (L-1MT) clearly diminished the elevation of KYN/TRP ratio induced by the incubation with canine MCT cells. Our results indicate that canine MCT cells could directly regulate the concentrations of TRP and KYN through expressing IDO, suggesting that canine MCT have an immune escape ability. Therefore, inhibition of IDO might be a novel strategy for the treatment of dogs with MCT.
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Vanden Bempt I, Vander Borght S, Sciot R, Spans L, Claerhout S, Brems H, Lehnert S, Dehaspe L, Fransis S, Neuville B, Topal B, Schöffski P, Legius E, Debiec-Rychter M. Comprehensive targeted next-generation sequencing approach in the molecular diagnosis of gastrointestinal stromal tumor. Genes Chromosomes Cancer 2020; 60:239-249. [PMID: 33258138 DOI: 10.1002/gcc.22923] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 11/25/2020] [Accepted: 11/28/2020] [Indexed: 12/26/2022] Open
Abstract
Mutational analysis guides therapeutic decision making in patients with advanced-stage gastrointestinal stromal tumors (GISTs). We evaluated three targeted next-generation sequencing (NGS) assays, consecutively used over 4 years in our laboratory for mutational analysis of 162 primary GISTs: Agilent GIST MASTR, Illumina TruSight 26 and an in-house developed 96 gene panels. In addition, we investigated the feasibility of a more comprehensive approach by adding targeted RNA sequencing (Archer FusionPlex, 11 genes) in an attempt to reduce the number of Wild Type GISTs. We found KIT or PDGFRA mutations in 149 out of 162 GISTs (92.0%). Challenging KIT exon 11 alterations were initially missed by different assays in seven GISTs and typically represented deletions at the KIT intron 10-exon 11 boundary or large insertions/deletions (>24 base pairs). Comprehensive analysis led to the additional identification of driver alterations in 8/162 GISTs (4.9%): apart from BRAF and SDHA mutations (one case each), we found five GISTs harboring somatic neurofibromatosis type 1 (NF1) alterations (3.1%) and one case with an in-frame TRIM4-BRAF fusion not reported in GIST before. Eventually, no driver alteration was found in two out of 162 GISTs (1.2%) and three samples (1.9%) failed analysis. Our study shows that a comprehensive targeted NGS approach is feasible for routine mutational analysis of GIST, thereby substantially reducing the number of Wild Type GISTs, and highlights the need to optimize assays for challenging KIT exon 11 alterations.
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Affiliation(s)
- Isabelle Vanden Bempt
- Department for Human Genetics, University Hospitals Leuven, KU Leuven, Leuven, Belgium
| | - Sara Vander Borght
- Department for Human Genetics, University Hospitals Leuven, KU Leuven, Leuven, Belgium.,Department of Pathology, University Hospitals Leuven, KU Leuven, Leuven, Belgium
| | - Raf Sciot
- Department of Pathology, University Hospitals Leuven, KU Leuven, Leuven, Belgium
| | - Lien Spans
- Department for Human Genetics, University Hospitals Leuven, KU Leuven, Leuven, Belgium
| | - Sofie Claerhout
- Department for Human Genetics, University Hospitals Leuven, KU Leuven, Leuven, Belgium
| | - Hilde Brems
- Department for Human Genetics, University Hospitals Leuven, KU Leuven, Leuven, Belgium
| | - Stefan Lehnert
- Department for Human Genetics, University Hospitals Leuven, KU Leuven, Leuven, Belgium
| | - Luc Dehaspe
- Department for Human Genetics, University Hospitals Leuven, KU Leuven, Leuven, Belgium
| | - Sabine Fransis
- Department of Pathology, Ziekenhuis Oost Limburg, Genk, Belgium
| | - Bart Neuville
- Department of Gastroenterology and Hepatology, Ziekenhuis Oost-Limburg, Genk, Belgium
| | - Baki Topal
- Department of Abdominal Surgery, University Hospitals Leuven, KU Leuven, Leuven, Belgium
| | - Patrick Schöffski
- Department of General Medical Oncology, University Hospitals Leuven, Leuven Cancer Institute, and Department of Oncology, KU Leuven, Laboratory of Experimental Oncology, Leuven, Belgium.,Department of Oncology, KU Leuven, Laboratory of Experimental Oncology, Leuven, Belgium
| | - Eric Legius
- Department for Human Genetics, University Hospitals Leuven, KU Leuven, Leuven, Belgium
| | - Maria Debiec-Rychter
- Department for Human Genetics, University Hospitals Leuven, KU Leuven, Leuven, Belgium
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8
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Kato M, Yagami A, Tsukamoto T, Shinkai Y, Kato T, Kurahashi H. Novel mutation in the KITLG gene in familial progressive hyperpigmentation with or without hypopigmentation. J Dermatol 2020; 47:669-672. [PMID: 32189379 DOI: 10.1111/1346-8138.15313] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 02/18/2020] [Indexed: 11/27/2022]
Abstract
We herein report a novel mutation in familial progressive hyper- and hypopigmentation (FPHH). The KITLG gene encoding the KIT ligand protein is a disease-causing gene for FPHH. Various disease-causing gain-of-function mutations, which reside within or adjacent to the conserved VTNN motif of this gene, have been described to date. We have now identified a novel KITLG mutation, c.337G>A (p.Glu113Lys), in FPHH which is located within another ligand-receptor interaction site.
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Affiliation(s)
- Maki Kato
- Division of Molecular Genetics, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Japan
| | - Akiko Yagami
- Departments of, Department of, Dermatology, Fujita Health University School of Medicine, Toyoake, Japan
| | - Tetsuya Tsukamoto
- Department of, Diagnostic Pathology, Fujita Health University School of Medicine, Toyoake, Japan
| | - Yasuko Shinkai
- Division of Molecular Genetics, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Japan
| | - Takema Kato
- Division of Molecular Genetics, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Japan
| | - Hiroki Kurahashi
- Division of Molecular Genetics, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Japan
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9
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Arase N, Wataya-Kaneda M, Murota H, Nakagawa Y, Yamaoka T, Itoi-Ochi S, Hirayasu K, Arase H, Fujimoto M, Katayama I. Genotype and phenotype analysis of patients with pediatric cutaneous mastocytosis, especially wild-type KIT patients. J Dermatol 2020; 47:426-429. [PMID: 32077120 DOI: 10.1111/1346-8138.15266] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 01/20/2020] [Indexed: 11/26/2022]
Abstract
Pediatric cutaneous mastocytosis (CM) is mainly attributed to gain-of-function mutations in KIT in mast cells. On the other hand, growing evidence suggests that CM patients exist without KIT mutations. To date, the association between the KIT mutation status and clinical phenotype has not been elucidated in pediatric CM, especially in patients with wild-type KIT. Nevertheless, genetic analysis has yet to be performed with whole KIT sequence of mast cells in Japanese patients with pediatric CM. In the present study, 11 Japanese patients with pediatric CM were analyzed to determine whether they had KIT mutations in their skin, and their clinical phenotypes were observed. The approximate frequency of patients with KIT mutation and that of wild-type KIT was almost consistent with the European analysis. The distribution of overall macules was similar between the patients with and without KIT mutations.
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Affiliation(s)
- Noriko Arase
- Department of Dermatology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Mari Wataya-Kaneda
- Department of Dermatology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Hiroyuki Murota
- Department of Dermatology, Osaka University Graduate School of Medicine, Suita, Japan.,Department of Dermatology, Nagasaki University Graduate School of Biomedical Science, Nagasaki, Japan
| | - Yukinobu Nakagawa
- Department of Dermatology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Toshifumi Yamaoka
- Department of Dermatology, Osaka University Graduate School of Medicine, Suita, Japan.,Nakatsu Dermatology Clinic, Osaka, Japan
| | - Saori Itoi-Ochi
- Department of Dermatology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Kouyuki Hirayasu
- Laboratory of Immunochemistry, WPI Immunology Frontier Research Center, Osaka University, Suita, Japan.,Department of Immunology, Graduate School of Medicine, Kanazawa University, Kanazawa, Japan.,WPI Nano Life Science Institute, Kanazawa University, Kanazawa, Japan
| | - Hisashi Arase
- Laboratory of Immunochemistry, WPI Immunology Frontier Research Center, Osaka University, Suita, Japan.,Department of Immunochemistry, Research Institute for Microbial Diseases, Osaka University, Suita, Japan
| | - Manabu Fujimoto
- Department of Dermatology, Osaka University Graduate School of Medicine, Suita, Japan.,Laboratory of Cutaneous Immunology, WPI Immunology Frontier Research Center, Osaka University, Suita, Japan
| | - Ichiro Katayama
- Department of Dermatology, Osaka University Graduate School of Medicine, Suita, Japan.,Department of Pigmentation Research and Therapeutics, Osaka City University Graduate School of Medicine, Osaka, Japan
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10
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Derakhshani A, Vahidian F, Alihasanzadeh M, Mokhtarzadeh A, Lotfi Nezhad P, Baradaran B. Mast cells: A double-edged sword in cancer. Immunol Lett 2019; 209:28-35. [PMID: 30905824 DOI: 10.1016/j.imlet.2019.03.011] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2019] [Accepted: 03/20/2019] [Indexed: 12/14/2022]
Abstract
Mast cells (MCs), a type of innate immune cells, are derived from myeloid stem cells, sometimes known as mastocytes or labrocytes, and contain many granules rich in histamine and heparin. The mentioned cells are able to release various mediators such as cytokines, leukotrienes, and a large number of proteases into the environment. Many studies and experiments have established the infiltration of MCs into the tumor site. However, the findings are highly controversial to determine whether these immune cells contribute to the growth and development of the tumor or cause anti-tumor immune responses. Various studies have revealed that MCs have a pro-tumorigenic or anti-tumorigenic role depending on the type of cancer, the degree of tumor progression, and the location of these immune cells in the tumor bulk. Although these types of immune cells cause angiogenesis and tumor progression in some cancers, they have a significant anti-tumor role in some other types of cancers. In general, although a number of studies have specified the protective role of MCs in cancers, the increased number of MCs in the blood and microenvironment of tumors, as well as the increased level of angiogenesis and tumor progression, has been indicated in another array of studies. The function of MCs against or in favor of the cancers still requires further investigations to more accurately and specifically determine the role of MCs in the cancers. The function of MCs in tumors and their various roles in case of exposure to the cancer cells have been addressed in the present review. The concluding section of the present study recommends a number of methods for modification of MCs in cancer immunotherapy.
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Affiliation(s)
- Afshin Derakhshani
- Student Research Committee, Birjand University of Medical Sciences, Birjand, Iran; Cellular & Molecular Research Center, Birjand University of Medical Sciences, Birjand, Iran
| | - Fatemeh Vahidian
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Immunology, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mohammad Alihasanzadeh
- Department of Immunology, School of Medicine, Jiroft University of Medical Sciences, Jiroft, Iran
| | - Ahad Mokhtarzadeh
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Parisa Lotfi Nezhad
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Behzad Baradaran
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
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11
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Heyburn L, Hebron ML, Smith J, Winston C, Bechara J, Li Z, Lonskaya I, Burns MP, Harris BT, Moussa CEH. Tyrosine kinase inhibition reverses TDP-43 effects on synaptic protein expression, astrocytic function and amino acid dis-homeostasis. J Neurochem 2016; 139:610-623. [PMID: 27507246 DOI: 10.1111/jnc.13763] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Revised: 07/22/2016] [Accepted: 08/02/2016] [Indexed: 01/25/2023]
Abstract
The trans-activating response of DNA/RNA-binding protein (TDP)-43 pathology is associated with many neurodegenerative diseases via unknown mechanisms. Here, we use a transgenic mouse model over-expressing human wild-type neuronal TDP-43 to study the effects of TDP-43 pathology on glutamate metabolism and synaptic function. We found that neuronal TDP-43 over-expression affects synaptic protein expression, including Synapsin I, and alters surrounding astrocytic function. TDP-43 over-expression is associated with an increase in glutamate and γ-amino butyric acid and reduction of glutamine and aspartate levels, indicating impairment of presynaptic terminal. TDP-43 also decreases tricarboxylic acid cycle metabolism and induces oxidative stress via lactate accumulation. Neuronal TDP-43 does not alter microglia activity or significantly changes systemic and brain inflammatory markers compared to control. We previously demonstrated that brain-penetrant tyrosine kinase inhibitors (TKIs), nilotinib and bosutinib, reduce TDP-43-induced cell death in transgenic mice. Here, we show that TKIs reverse the effects of TDP-43 on synaptic proteins, increase astrocytic function and restore glutamate and neurotransmitter balance in TDP-43 mice. Nilotinib, but not bosutinib, reverses mitochondrial impairment and oxidative metabolism. Taken together, these data suggest that TKIs can attenuate TDP-43 toxicity and improve synaptic and astrocytic function, independent of microglial or other inflammatory effects. In conclusion, our data demonstrate novel mechanisms of the effects of neuronal TDP-43 over-expression on synaptic protein expression and alteration of astrocytic function.
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Affiliation(s)
- Lanier Heyburn
- Laboratory for Dementia and Parkinsonism, Department of Neurology, Georgetown University Medical Center, Washington, District of Columbia, USA.,Department of Pathology, Georgetown University Medical Center, Washington, District of Columbia, USA
| | - Michaeline L Hebron
- Laboratory for Dementia and Parkinsonism, Department of Neurology, Georgetown University Medical Center, Washington, District of Columbia, USA
| | - Jacqueline Smith
- Drug Discovery Center, Georgetown University Medical Center, Washington, District of Columbia, USA
| | - Charisse Winston
- Trauma and Dementia Laboratory, Department of Neuroscience, Georgetown University Medical Center, Washington, District of Columbia, USA
| | - John Bechara
- Laboratory for Dementia and Parkinsonism, Department of Neurology, Georgetown University Medical Center, Washington, District of Columbia, USA
| | - Zhaoxia Li
- Laboratory for Dementia and Parkinsonism, Department of Neurology, Georgetown University Medical Center, Washington, District of Columbia, USA.,School of Traditional Chinese Medicine, Capital Medical University, Fengtai District, Beijing, China
| | - Irina Lonskaya
- Laboratory for Dementia and Parkinsonism, Department of Neurology, Georgetown University Medical Center, Washington, District of Columbia, USA
| | - Mark P Burns
- Trauma and Dementia Laboratory, Department of Neuroscience, Georgetown University Medical Center, Washington, District of Columbia, USA
| | - Brent T Harris
- Laboratory for Dementia and Parkinsonism, Department of Neurology, Georgetown University Medical Center, Washington, District of Columbia, USA.,Department of Pathology, Georgetown University Medical Center, Washington, District of Columbia, USA
| | - Charbel E-H Moussa
- Laboratory for Dementia and Parkinsonism, Department of Neurology, Georgetown University Medical Center, Washington, District of Columbia, USA
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12
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Lonskaya I, Hebron ML, Selby ST, Turner RS, Moussa CEH. Nilotinib and bosutinib modulate pre-plaque alterations of blood immune markers and neuro-inflammation in Alzheimer's disease models. Neuroscience 2015; 304:316-27. [PMID: 26235435 DOI: 10.1016/j.neuroscience.2015.07.070] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 07/15/2015] [Accepted: 07/25/2015] [Indexed: 01/08/2023]
Abstract
Alzheimer's disease (AD) brains exhibit plaques and tangles in association with inflammation. The non-receptor tyrosine kinase Abl is linked to neuro-inflammation in AD. Abl inhibition by nilotinib or bosutinib facilitates amyloid clearance and may decrease inflammation. Transgenic mice that express Dutch, Iowa and Swedish APP mutations (TgAPP) and display progressive Aβ plaque deposition were treated with tyrosine kinase inhibitors (TKIs) to determine pre-plaque effects on systemic and CNS inflammation using milliplex® ELISA. Plaque Aβ was detected at 4months in TgAPP and pre-plaque intracellular Aβ accumulation (2.5months) was associated with changes of cytokines and chemokines prior to detection of glial changes. Plaque formation correlated with increased levels of pro-inflammatory cytokines (TNF-α, IL-6, IL-1α, IL-1β) and markers of immunosuppressive and adaptive immunity, including, IL-4, IL-10, IL-2, IL-3, Vascular Endothelial Growth Factor (VEGF) and IFN-γ. An inverse relationship of chemokines was observed as CCL2 and CCL5 were lower than WT mice at 2months and significantly increased after plaque appearance, while soluble CX3CL1 decreased. A change in glial profile was only robustly detected at 6months in Tg-APP mice and TKIs reduced astrocyte and dendritic cell number with no effects on microglia, suggesting alteration of brain immunity. Nilotinib decreased blood and brain cytokines and chemokines and increased CX3CL1. Bosutinib increased brain and blood IL-10 and CX3CL1, suggesting a protective role for soluble CX3CL1. Taken together these data suggest that TKIs regulate systemic and CNS immunity and may be useful treatments in early AD through dual effects on amyloid clearance and immune modulation.
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Affiliation(s)
- I Lonskaya
- Department of Neurology, Laboratory for Dementia and Parkinsonism, Georgetown University Medical Center, Washington D.C. 20007, USA
| | - M L Hebron
- Department of Neurology, Laboratory for Dementia and Parkinsonism, Georgetown University Medical Center, Washington D.C. 20007, USA
| | - S T Selby
- Department of Neurology, Laboratory for Dementia and Parkinsonism, Georgetown University Medical Center, Washington D.C. 20007, USA
| | - R S Turner
- Department of Neurology, Memory Disorders Program, Georgetown University Medical Center, Washington D.C. 20007, USA
| | - C E-H Moussa
- Department of Neurology, Laboratory for Dementia and Parkinsonism, Georgetown University Medical Center, Washington D.C. 20007, USA.
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