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Tanim K, Holtzhausen A, Thapa A, Huelse JM, Graham DK, Earp HS. MERTK Inhibition as a Targeted Novel Cancer Therapy. Int J Mol Sci 2024; 25:7660. [PMID: 39062902 PMCID: PMC11277220 DOI: 10.3390/ijms25147660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2024] [Revised: 07/06/2024] [Accepted: 07/07/2024] [Indexed: 07/28/2024] Open
Abstract
In this issue honoring the contributions of Greg Lemke, the Earp and Graham lab teams discuss several threads in the discovery, action, signaling, and translational/clinical potential of MERTK, originally called c-mer, a member of the TYRO3, AXL, and MERTK (TAM) family of receptor tyrosine kinases. The 30-year history of the TAM RTK family began slowly as all three members were orphan RTKs without known ligands and/or functions when discovered by three distinct alternate molecular cloning strategies in the pre-genome sequencing era. The pace of understanding their physiologic and pathophysiologic roles has accelerated over the last decade. The activation of ligands bridging externalized phosphatidylserine (PtdSer) has placed these RTKs in a myriad of processes including neurodevelopment, cancer, and autoimmunity. The field is ripe for further advancement and this article hopefully sets the stage for further understanding and therapeutic intervention. Our review will focus on progress made through the collaborations of the Earp and Graham labs over the past 30 years.
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Affiliation(s)
- K.M. Tanim
- Aflac Cancer and Blood Disorders Center, Children’s Healthcare of Atlanta, Atlanta, GA 30322, USA; (K.M.T.); (A.T.); (J.M.H.)
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Alisha Holtzhausen
- Lineburger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA;
| | - Aashis Thapa
- Aflac Cancer and Blood Disorders Center, Children’s Healthcare of Atlanta, Atlanta, GA 30322, USA; (K.M.T.); (A.T.); (J.M.H.)
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Justus M. Huelse
- Aflac Cancer and Blood Disorders Center, Children’s Healthcare of Atlanta, Atlanta, GA 30322, USA; (K.M.T.); (A.T.); (J.M.H.)
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Douglas K. Graham
- Aflac Cancer and Blood Disorders Center, Children’s Healthcare of Atlanta, Atlanta, GA 30322, USA; (K.M.T.); (A.T.); (J.M.H.)
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - H. Shelton Earp
- Lineburger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA;
- Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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Tutusaus A, Morales A, García de Frutos P, Marí M. GAS6/TAM Axis as Therapeutic Target in Liver Diseases. Semin Liver Dis 2024; 44:99-114. [PMID: 38395061 PMCID: PMC11027478 DOI: 10.1055/a-2275-0408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/25/2024]
Abstract
TAM (TYRO3, AXL, and MERTK) protein tyrosine kinase membrane receptors and their vitamin K-dependent ligands GAS6 and protein S (PROS) are well-known players in tumor biology and autoimmune diseases. In contrast, TAM regulation of fibrogenesis and the inflammation mechanisms underlying metabolic dysfunction-associated steatohepatitis (MASH), cirrhosis, and, ultimately, liver cancer has recently been revealed. GAS6 and PROS binding to phosphatidylserine exposed in outer membranes of apoptotic cells links TAMs, particularly MERTK, with hepatocellular damage. In addition, AXL and MERTK regulate the development of liver fibrosis and inflammation in chronic liver diseases. Acute hepatic injury is also mediated by the TAM system, as recent data regarding acetaminophen toxicity and acute-on-chronic liver failure have uncovered. Soluble TAM-related proteins, mainly released from activated macrophages and hepatic stellate cells after hepatic deterioration, are proposed as early serum markers for disease progression. In conclusion, the TAM system is becoming an interesting pharmacological target in liver pathology and a focus of future biomedical research in this field.
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Affiliation(s)
- Anna Tutusaus
- Department of Cell Death and Proliferation, IIBB-CSIC, IDIBAPS, Barcelona, Catalunya, Spain
- Barcelona Clinic Liver Cancer (BCLC) Group, Barcelona, Spain
| | - Albert Morales
- Department of Cell Death and Proliferation, IIBB-CSIC, IDIBAPS, Barcelona, Catalunya, Spain
- Barcelona Clinic Liver Cancer (BCLC) Group, Barcelona, Spain
| | - Pablo García de Frutos
- Department of Cell Death and Proliferation, IIBB-CSIC, IDIBAPS, Barcelona, Catalunya, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Cardiovasculares (CIBERCV), Barcelona, Comunidad de Madrid, Spain
| | - Montserrat Marí
- Department of Cell Death and Proliferation, IIBB-CSIC, IDIBAPS, Barcelona, Catalunya, Spain
- Barcelona Clinic Liver Cancer (BCLC) Group, Barcelona, Spain
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3
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DeRyckere D, Huelse JM, Earp HS, Graham DK. TAM family kinases as therapeutic targets at the interface of cancer and immunity. Nat Rev Clin Oncol 2023; 20:755-779. [PMID: 37667010 DOI: 10.1038/s41571-023-00813-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/07/2023] [Indexed: 09/06/2023]
Abstract
Novel treatment approaches are needed to overcome innate and acquired mechanisms of resistance to current anticancer therapies in cancer cells and the tumour immune microenvironment. The TAM (TYRO3, AXL and MERTK) family receptor tyrosine kinases (RTKs) are potential therapeutic targets in a wide range of cancers. In cancer cells, TAM RTKs activate signalling pathways that promote cell survival, metastasis and resistance to a variety of chemotherapeutic agents and targeted therapies. TAM RTKs also function in innate immune cells, contributing to various mechanisms that suppress antitumour immunity and promote resistance to immune-checkpoint inhibitors. Therefore, TAM antagonists provide an unprecedented opportunity for both direct and immune-mediated therapeutic activity provided by inhibition of a single target, and are likely to be particularly effective when used in combination with other cancer therapies. To exploit this potential, a variety of agents have been designed to selectively target TAM RTKs, many of which have now entered clinical testing. This Review provides an essential guide to the TAM RTKs for clinicians, including an overview of the rationale for therapeutic targeting of TAM RTKs in cancer cells and the tumour immune microenvironment, a description of the current preclinical and clinical experience with TAM inhibitors, and a perspective on strategies for continued development of TAM-targeted agents for oncology applications.
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Affiliation(s)
- Deborah DeRyckere
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Atlanta, GA, USA
- Department of Paediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Justus M Huelse
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Atlanta, GA, USA
- Department of Paediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - H Shelton Earp
- Department of Medicine, UNC Lineberger Comprehensive Cancer Center, Chapel Hill, NC, USA
- Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Douglas K Graham
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Atlanta, GA, USA.
- Department of Paediatrics, Emory University School of Medicine, Atlanta, GA, USA.
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Sha M, Li H, Guo B, Geng X. Myeloid-specific knockout of SHP2 regulates PI3K/PLCγ signaling pathway to protect against early myocardial infarction injury. Aging (Albany NY) 2023; 15:9877-9889. [PMID: 37768203 PMCID: PMC10564428 DOI: 10.18632/aging.205096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 08/29/2023] [Indexed: 09/29/2023]
Abstract
OBJECTIVES To study the effects of myeloid-specific knockout of SHP2 on early myocardial infarction and explore its molecular mechanism. METHODS The model of myocardial infarction was established by using SHP2 in myeloid-specific knockout mice, and the effect of SHP2MAC-KO on myocardial function was detected by echocardiography. The effects of SHP2 on myocardial infarct size in myeloid-specific knockout mice was examined by TTC assay and Masson staining. Then, the detection of apoptosis was performed using TUNEL staining and inflammatory cell infiltration was observed using immunohistochemical staining. Moreover, macrophages in mouse hearts were selected by Flow Cytometry and treated with PI3K inhibitors respectively. Western blotting was then used to detect protein expression of p-SHP2 and PI3K/PLCγ signaling pathway. The phagocytic ability of cells was detected by endocytosis test, and the expression of inflammatory cytokines was detected by ELISA. RESULTS Specific knockout of SHP2 in mice with myocardial infarction can improve the cardiac function, decrease infarct size, and reduce apoptosis as well as inflammatory cell infiltration. It also can mediate the PI3K/PLCγ signaling pathway in macrophages, which in turn enhances the endocytosis of macrophages and reduces the expression of inflammatory cytokines in macrophages. CONCLUSIONS Myeloid-specific knockout of SHP2 regulates PI3K/PLCγ signaling pathway to protect against early myocardial infarction injury.
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Affiliation(s)
- Menglin Sha
- Department of Cardiology, The Third Hospital of Hebei Medical University, Shijiazhuang, Hebei, China
| | - Hongxing Li
- Department of Cardiology, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, China
| | - Bingyan Guo
- Department of Cardiology, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, China
| | - Xiaoyong Geng
- Department of Cardiology, The Third Hospital of Hebei Medical University, Shijiazhuang, Hebei, China
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Kelvin JM, Jain J, Thapa A, Qui M, Birnbaum LA, Moore SG, Zecca H, Summers RJ, Switchenko JM, Costanza E, Uricoli B, Wang X, Jui NT, Fu H, Du Y, DeRyckere D, Graham DK, Dreaden EC. Constitutively Synergistic Multiagent Drug Formulations Targeting MERTK, FLT3, and BCL-2 for Treatment of AML. Pharm Res 2023; 40:2133-2146. [PMID: 37704893 DOI: 10.1007/s11095-023-03596-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 08/26/2023] [Indexed: 09/15/2023]
Abstract
PURPOSE Although high-dose, multiagent chemotherapy has improved leukemia survival rates, treatment outcomes remain poor in high-risk subsets, including acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) in infants. The development of new, more effective therapies for these patients is therefore an urgent, unmet clinical need. METHODS The dual MERTK/FLT3 inhibitor MRX-2843 and BCL-2 family protein inhibitors were screened in high-throughput against a panel of AML and MLL-rearranged precursor B-cell ALL (infant ALL) cell lines. A neural network model was built to correlate ratiometric drug synergy and target gene expression. Drugs were loaded into liposomal nanocarriers to assess primary AML cell responses. RESULTS MRX-2843 synergized with venetoclax to reduce AML cell density in vitro. A neural network classifier based on drug exposure and target gene expression predicted drug synergy and growth inhibition in AML with high accuracy. Combination monovalent liposomal drug formulations delivered defined drug ratios intracellularly and recapitulated synergistic drug activity. The magnitude and frequency of synergistic responses were both maintained and improved following drug formulation in a genotypically diverse set of primary AML bone marrow specimens. CONCLUSIONS We developed a nanoscale combination drug formulation that exploits ectopic expression of MERTK tyrosine kinase and dependency on BCL-2 family proteins for leukemia cell survival in pediatric AML and infant ALL cells. We demonstrate ratiometric drug delivery and synergistic cell killing in AML, a result achieved by a systematic, generalizable approach of combination drug screening and nanoscale formulation that may be extended to other drug pairs or diseases in the future.
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Affiliation(s)
- James M Kelvin
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, 30322, USA
| | - Juhi Jain
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, 30322, USA
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Atlanta, GA, 30322, USA
- Department of Pediatrics, University of Arizona College of Medicine, and Banner University Medical Center Tucson, Tucson, AZ, 85724, USA
| | - Aashis Thapa
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Min Qui
- Department of Pharmacology and Chemical Biology, Emory Chemical Biology Discovery Center, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Lacey A Birnbaum
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, 30322, USA
| | - Samuel G Moore
- Systems Mass Spectrometry Core Facility, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Henry Zecca
- Department of Chemistry, Emory University, Atlanta, GA, 30322, USA
| | - Ryan J Summers
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, 30322, USA
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Atlanta, GA, 30322, USA
| | - Jeffrey M Switchenko
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, GA, 30322, USA
- Winship Cancer Institute of Emory University, Atlanta, GA, 30322, USA
| | - Emma Costanza
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, 30322, USA
| | - Biaggio Uricoli
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, 30322, USA
| | - Xiaodong Wang
- Center for Integrative Chemical Biology and Drug Discovery, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Nathan T Jui
- Department of Chemistry, Emory University, Atlanta, GA, 30322, USA
- Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Haian Fu
- Department of Pharmacology and Chemical Biology, Emory Chemical Biology Discovery Center, Emory University School of Medicine, Atlanta, GA, 30322, USA
- Winship Cancer Institute of Emory University, Atlanta, GA, 30322, USA
| | - Yuhong Du
- Department of Pharmacology and Chemical Biology, Emory Chemical Biology Discovery Center, Emory University School of Medicine, Atlanta, GA, 30322, USA
- Winship Cancer Institute of Emory University, Atlanta, GA, 30322, USA
| | - Deborah DeRyckere
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, 30322, USA
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Atlanta, GA, 30322, USA
| | - Douglas K Graham
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, 30322, USA.
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Atlanta, GA, 30322, USA.
| | - Erik C Dreaden
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, 30322, USA.
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, 30322, USA.
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Atlanta, GA, 30322, USA.
- Winship Cancer Institute of Emory University, Atlanta, GA, 30322, USA.
- Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
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6
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Kelvin JM, Jain J, Thapa A, Qui M, Birnbaum LA, Moore SG, Zecca H, Summers RJ, Costanza E, Uricoli B, Wang X, Jui NT, Fu H, Du Y, DeRyckere D, Graham DK, Dreaden EC. Constitutively synergistic multiagent drug formulations targeting MERTK, FLT3, and BCL-2 for treatment of AML. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.13.531236. [PMID: 36993676 PMCID: PMC10054973 DOI: 10.1101/2023.03.13.531236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Although high-dose, multi-agent chemotherapy has improved leukemia survival rates in recent years, treatment outcomes remain poor in high-risk subsets, including acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) in infants. Development of new, more effective therapies for these patients is therefore an urgent, unmet clinical need. To address this challenge, we developed a nanoscale combination drug formulation that exploits ectopic expression of MERTK tyrosine kinase and dependency on BCL-2 family proteins for leukemia cell survival in pediatric AML and MLL- rearranged precursor B-cell ALL (infant ALL). In a novel, high-throughput combination drug screen, the MERTK/FLT3 inhibitor MRX-2843 synergized with venetoclax and other BCL-2 family protein inhibitors to reduce AML cell density in vitro . Neural network models based on drug exposure and target gene expression were used to identify a classifier predictive of drug synergy in AML. To maximize the therapeutic potential of these findings, we developed a combination monovalent liposomal drug formulation that maintains ratiometric drug synergy in cell-free assays and following intracellular delivery. The translational potential of these nanoscale drug formulations was confirmed in a genotypically diverse set of primary AML patient samples and both the magnitude and frequency of synergistic responses were not only maintained but were improved following drug formulation. Together, these findings demonstrate a systematic, generalizable approach to combination drug screening, formulation, and development that maximizes therapeutic potential, was effectively applied to develop a novel nanoscale combination therapy for treatment of AML, and could be extended to other drug combinations or diseases in the future.
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Geng K. Post-translational modifications of the ligands: Requirement for TAM receptor activation. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2021; 357:35-55. [PMID: 33234244 DOI: 10.1016/bs.ircmb.2020.09.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The Tyro3, Axl, and MerTK (TAM) receptors are three homologous Type I Receptor Tyrosine Kinases that have important homeostatic functions in multicellular organisms by regulating the clearance of apoptotic cells (efferocytosis). Pathologically, TAM receptors are overexpressed in a wide array of human cancers, and often associated with aggressive tumor grade and poor overall survival. In addition to their expression on tumor cells, TAMs are also expressed on infiltrating myeloid-derived cells in the tumor microenvironment, where they appear to act akin to negative immune checkpoints that impair host anti-tumor immunity. The ligands for TAMs are two endogenous proteins, Growth Arrest-Specific 6 (Gas6) and Protein S (Pros1), that function as bridging molecules between externalized phosphatidylserine (PtdSer) on apoptotic cells and the TAM ectodomains. One interesting feature of TAMs biology is that their ligand proteins require specific post-translational modifications to acquire activities. This chapter summarized these important modifications and explained the molecular mechanisms behind such phenomenon. Current evidences suggest that these modifications help Gas6/Pros1 to achieve optimal PtdSer-binding capacities. In addition, this chapter included recent discovery of regulating machineries of PtdSer dynamic across the plasma membrane, as well as their potential impacts in the tumor microenvironment. Taken together, this review highlights the importance of the upstream PtdSer and Gas6 in regulating TAMs' function and hope to provide researchers with new perspectives to inspire future studies of TAM receptors in human disease models.
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Affiliation(s)
- Ke Geng
- Public Health Research Institute, Rutgers Biomedical and Health Sciences, New Jersey Medical School, Newark, NJ, United States.
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Ricketts TD, Prieto-Dominguez N, Gowda PS, Ubil E. Mechanisms of Macrophage Plasticity in the Tumor Environment: Manipulating Activation State to Improve Outcomes. Front Immunol 2021; 12:642285. [PMID: 34025653 PMCID: PMC8139576 DOI: 10.3389/fimmu.2021.642285] [Citation(s) in RCA: 83] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 04/16/2021] [Indexed: 12/12/2022] Open
Abstract
Macrophages are a specialized class of innate immune cells with multifaceted roles in modulation of the inflammatory response, homeostasis, and wound healing. While developmentally derived or originating from circulating monocytes, naïve macrophages can adopt a spectrum of context-dependent activation states ranging from pro-inflammatory (classically activated, M1) to pro-wound healing (alternatively activated, M2). Tumors are known to exploit macrophage polarization states to foster a tumor-permissive milieu, particularly by skewing macrophages toward a pro-tumor (M2) phenotype. These pro-tumoral macrophages can support cancer progression by several mechanisms including immune suppression, growth factor production, promotion of angiogenesis and tissue remodeling. By preventing the adoption of this pro-tumor phenotype or reprogramming these macrophages to a more pro-inflammatory state, it may be possible to inhibit tumor growth. Here, we describe types of tumor-derived signaling that facilitate macrophage reprogramming, including paracrine signaling and activation of innate immune checkpoints. We also describe intervention strategies targeting macrophage plasticity to limit disease progression and address their implications in cancer chemo- and immunotherapy.
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Affiliation(s)
| | | | | | - Eric Ubil
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, United States
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Huelse J, Fridlyand D, Earp S, DeRyckere D, Graham DK. MERTK in cancer therapy: Targeting the receptor tyrosine kinase in tumor cells and the immune system. Pharmacol Ther 2020; 213:107577. [PMID: 32417270 PMCID: PMC9847360 DOI: 10.1016/j.pharmthera.2020.107577] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The receptor tyrosine kinase MERTK is aberrantly expressed in numerous human malignancies, and is a novel target in cancer therapeutics. Physiologic roles of MERTK include regulation of tissue homeostasis and repair, innate immune control, and platelet aggregation. However, aberrant expression in a wide range of liquid and solid malignancies promotes neoplasia via growth factor independence, cell cycle progression, proliferation and tumor growth, resistance to apoptosis, and promotion of tumor metastases. Additionally, MERTK signaling contributes to an immunosuppressive tumor microenvironment via induction of an anti-inflammatory cytokine profile and regulation of the PD-1 axis, as well as regulation of macrophage, myeloid-derived suppressor cell, natural killer cell and T cell functions. Various MERTK-directed therapies are in preclinical development, and clinical trials are underway. In this review we discuss MERTK inhibition as an emerging strategy for cancer therapy, focusing on MERTK expression and function in neoplasia and its role in mediating resistance to cytotoxic and targeted therapies as well as in suppressing anti-tumor immunity. Additionally, we review preclinical and clinical pharmacological strategies to target MERTK.
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Affiliation(s)
- Justus Huelse
- Aflac Cancer and Blood Disorders Center, Children’s Healthcare of Atlanta, Department of Pediatrics, Emory University, Atlanta, Georgia
| | - Diana Fridlyand
- Aflac Cancer and Blood Disorders Center, Children’s Healthcare of Atlanta, Department of Pediatrics, Emory University, Atlanta, Georgia
| | - Shelton Earp
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC
| | - Deborah DeRyckere
- Aflac Cancer and Blood Disorders Center, Children’s Healthcare of Atlanta, Department of Pediatrics, Emory University, Atlanta, Georgia
| | - Douglas K. Graham
- Aflac Cancer and Blood Disorders Center, Children’s Healthcare of Atlanta, Department of Pediatrics, Emory University, Atlanta, Georgia
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Novitskiy SV, Zaynagetdinov R, Vasiukov G, Gutor S, Han W, Serezani A, Matafonov A, Gleaves LA, Sherrill TP, Polosukhin VV, Blackwell TS. Gas6/MerTK signaling is negatively regulated by NF-κB and supports lung carcinogenesis. Oncotarget 2019; 10:7031-7042. [PMID: 31903163 PMCID: PMC6925028 DOI: 10.18632/oncotarget.27345] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 11/07/2019] [Indexed: 01/24/2023] Open
Abstract
Growth arrest-specific 6 (Gas6) has been implicated in carcinogenesis through activation of its receptors, particularly MerTK. To investigate whether Gas6 plays a role in resistance to NF-κB inhibitors, which have not proven to be effective agents for lung cancer therapy, we studied lung cancer models induced by urethane injection or expression of mutant Kras (KrasG12D). We found that Gas6 is primarily produced by macrophages during tumorigenesis and that Gas6 is negatively regulated by NF-κB. Since Gas6 is a vitamin K dependent protein, we used low-dose warfarin to block Gas6 production and showed that this treatment inhibited tumorigenesis in both the urethane and KrasG12D models, most prominently in mice with targeted deletion of IKKβ in myeloid cells (IKKβΔMye mice). In addition, MerTK deficient mice had reduced urethane-induced tumorigenesis. Inhibition of the Gas6-MerTK pathway in all these models reduced macrophages and neutrophils in the lungs of tumor-bearing mice. Analysis of mouse lung tumors revealed MerTK staining on tumor cells and in vitro studies showed that Gas6 increased proliferation of human lung cancer cell lines. To assess the therapeutic potential for combination treatment targeting NF-κB and Gas6-MerTK, we injected Lewis Lung Carcinoma cells subcutaneously and treated mice with Bay 11-70852 (NF-κB inhibitor) and/or Foretinib (MerTK inhibitor). While individual treatments were ineffective, combination therapy markedly reduced tumor growth, blocked tumor cell proliferation, reduced tumor-associated macrophages, and increased CD4+ T cells. Together, our studies unmask a role for Gas6-MerTK signaling in lung carcinogenesis and indicate that up-regulation of Gas6 production in macrophages could be a major mechanism of resistance to NF-κB inhibitors.
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Affiliation(s)
- Sergey V Novitskiy
- Division of Allergy, Pulmonary and Critical Care Medicine, Department of Medicine, Vanderbilt University, Nashville, TN 37212, USA
| | - Rinat Zaynagetdinov
- Division of Allergy, Pulmonary and Critical Care Medicine, Department of Medicine, Vanderbilt University, Nashville, TN 37212, USA
| | - Georgii Vasiukov
- Division of Allergy, Pulmonary and Critical Care Medicine, Department of Medicine, Vanderbilt University, Nashville, TN 37212, USA
| | - Sergey Gutor
- Division of Allergy, Pulmonary and Critical Care Medicine, Department of Medicine, Vanderbilt University, Nashville, TN 37212, USA
| | - Wei Han
- Division of Allergy, Pulmonary and Critical Care Medicine, Department of Medicine, Vanderbilt University, Nashville, TN 37212, USA
| | - Ana Serezani
- Division of Allergy, Pulmonary and Critical Care Medicine, Department of Medicine, Vanderbilt University, Nashville, TN 37212, USA
| | - Anton Matafonov
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University, Nashville, TN 37212, USA
| | - Linda A Gleaves
- Division of Allergy, Pulmonary and Critical Care Medicine, Department of Medicine, Vanderbilt University, Nashville, TN 37212, USA
| | - Taylor P Sherrill
- Division of Allergy, Pulmonary and Critical Care Medicine, Department of Medicine, Vanderbilt University, Nashville, TN 37212, USA
| | - Vasiliy V Polosukhin
- Division of Allergy, Pulmonary and Critical Care Medicine, Department of Medicine, Vanderbilt University, Nashville, TN 37212, USA
| | - Timothy S Blackwell
- Division of Allergy, Pulmonary and Critical Care Medicine, Department of Medicine, Vanderbilt University, Nashville, TN 37212, USA.,Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37212, USA.,Department of Veterans Affairs Medical Center, Nashville, TN 37212, USA
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11
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Li Y, Wittchen ES, Monaghan-Benson E, Hahn C, Earp HS, Doerschuk CM, Burridge K. The role of endothelial MERTK during the inflammatory response in lungs. PLoS One 2019; 14:e0225051. [PMID: 31805065 PMCID: PMC6894824 DOI: 10.1371/journal.pone.0225051] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 10/28/2019] [Indexed: 12/20/2022] Open
Abstract
As a key homeostasis regulator in mammals, the MERTK receptor tyrosine kinase is crucial for efferocytosis, a process that requires remodeling of the cell membrane and adjacent actin cytoskeleton. Membrane and cytoskeletal reorganization also occur in endothelial cells during inflammation, particularly during neutrophil transendothelial migration (TEM) and during changes in permeability. However, MERTK’s function in endothelial cells remains unclear. This study evaluated the contribution of endothelial MERTK to neutrophil TEM and endothelial barrier function. In vitro experiments using primary human pulmonary microvascular endothelial cells found that neutrophil TEM across the endothelial monolayers was enhanced when MERTK expression in endothelial cells was reduced by siRNA knockdown. Examination of endothelial barrier function revealed increased passage of dextran across the MERTK-depleted monolayers, suggesting that MERTK helps maintain endothelial barrier function. MERTK knockdown also altered adherens junction structure, decreased junction protein levels, and reduced basal Rac1 activity in endothelial cells, providing potential mechanisms of how MERTK regulates endothelial barrier function. To study MERTK’s function in vivo, inflammation in the lungs of global Mertk-/- mice was examined during acute pneumonia. In response to P. aeruginosa, more neutrophils were recruited to the lungs of Mertk-/- than wildtype mice. Vascular leakage of Evans blue dye into the lung tissue was also greater in Mertk-/- mice. To analyze endothelial MERTK’s involvement in these processes, we generated inducible endothelial cell-specific (iEC) Mertk-/- mice. When similarly challenged with P. aeruginosa, iEC Mertk-/- mice demonstrated no difference in neutrophil TEM into the inflamed lungs or in vascular permeability compared to control mice. These results suggest that deletion of MERTK in human pulmonary microvascular endothelial cells in vitro and in all cells in vivo aggravates the inflammatory response. However, selective MERTK deletion in endothelial cells in vivo failed to replicate this response.
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Affiliation(s)
- Yitong Li
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Erika S Wittchen
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Elizabeth Monaghan-Benson
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Cornelia Hahn
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America.,Division of Pulmonary Diseases and Critical Care Medicine, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - H Shelton Earp
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Claire M Doerschuk
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America.,Division of Pulmonary Diseases and Critical Care Medicine, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America.,Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Keith Burridge
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America.,Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
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12
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Tsai KYF, Hirschi Budge KM, Llavina S, Davis T, Long M, Bennett A, Sitton B, Arroyo JA, Reynolds PR. RAGE and AXL expression following secondhand smoke (SHS) exposure in mice. Exp Lung Res 2019; 45:297-309. [PMID: 31762322 DOI: 10.1080/01902148.2019.1684596] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 10/21/2019] [Indexed: 02/07/2023]
Abstract
Aim and Purpose: Tobacco exposure is one of the top three global health risks leading to the development of chronic obstructive pulmonary disease (COPD). Although there is extensive research into the effects of cigarette smoke, the effect of secondhand smoke (SHS) in the lung remains limited. SHS induces receptors for advanced glycation end-products (RAGE) and an inflammatory response that leads to COPD characteristics. Semi-synthetic glycosaminoglycan ethers (SAGEs) are sulfated polysaccharides derived from hyaluronic acid that inhibit RAGE signaling. The growth arrest-specific 6 (Gas6) protein is known to induce dynamic cellular responses and is correlated with cell function. Gas6 binds to the AXL tyrosine kinase receptor and AXL-mediated signaling is implicated in proliferation and inflammation. This project's purpose was to study the correlation between RAGE, AXL, and Gas6 during SHS exposure in the lung. Methods: C57Bl/6 mice were exposed to SHS alone or SHS + SAGEs for 4 weeks and compared to control animals exposed to room air (RA). Results: Compared to controls we observed: 1) increased RAGE mRNA and protein expression in SHS-exposed lungs which was decreased by SAGEs; 2) decreased expression of total AXL, but highly elevated pAXL expression following exposure; 3) highly elevated Gas6 expression when RAGE was targeted by SAGEs during SHS exposure; 4) SHS-mediated BALF cellularity and inflammatory molecule elaboration; and 5) the induction of both RAGE and AXL by Gas6 in cell culture models. Conclusions: Our results suggest that there is a possible correlation between RAGE and AXL during SHS exposure. Additional research is critically needed that dissects the molecular interplay between these two important signaling cascades. At this point, the current studies provide insight into tobacco-mediated effects in the lung and clarify possible avenues for alleviating complications that could arise during SHS exposure such as those observed during COPD exacerbations.
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Affiliation(s)
- Kary Y F Tsai
- Lung and Placenta Laboratory, Department of Physiology and Developmental Biology, Brigham Young University, Provo, Utah, USA
| | - Kelsey M Hirschi Budge
- Lung and Placenta Laboratory, Department of Physiology and Developmental Biology, Brigham Young University, Provo, Utah, USA
| | - Sam Llavina
- Lung and Placenta Laboratory, Department of Physiology and Developmental Biology, Brigham Young University, Provo, Utah, USA
| | - Taylor Davis
- Lung and Placenta Laboratory, Department of Physiology and Developmental Biology, Brigham Young University, Provo, Utah, USA
| | - Matt Long
- Lung and Placenta Laboratory, Department of Physiology and Developmental Biology, Brigham Young University, Provo, Utah, USA
| | - Abby Bennett
- Lung and Placenta Laboratory, Department of Physiology and Developmental Biology, Brigham Young University, Provo, Utah, USA
| | - Beau Sitton
- Lung and Placenta Laboratory, Department of Physiology and Developmental Biology, Brigham Young University, Provo, Utah, USA
| | - Juan A Arroyo
- Lung and Placenta Laboratory, Department of Physiology and Developmental Biology, Brigham Young University, Provo, Utah, USA
| | - Paul R Reynolds
- Lung and Placenta Laboratory, Department of Physiology and Developmental Biology, Brigham Young University, Provo, Utah, USA
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13
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TAM Receptor Pathways at the Crossroads of Neuroinflammation and Neurodegeneration. DISEASE MARKERS 2019; 2019:2387614. [PMID: 31636733 PMCID: PMC6766163 DOI: 10.1155/2019/2387614] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 06/04/2019] [Accepted: 08/12/2019] [Indexed: 02/07/2023]
Abstract
Increasing evidence suggests that pathogenic mechanisms underlying neurodegeneration are strongly linked with neuroinflammatory responses. Tyro3, Axl, and Mertk (TAM receptors) constitute a subgroup of the receptor tyrosine kinase family, cell surface receptors which transmit signals from the extracellular space to the cytoplasm and nucleus. TAM receptors and the corresponding ligands, Growth Arrest Specific 6 and Protein S, are expressed in different tissues, including the nervous system, playing complex roles in tissue repair, inflammation and cell survival, proliferation, and migration. In the nervous system, TAM receptor signalling modulates neurogenesis and neuronal migration, synaptic plasticity, microglial activation, phagocytosis, myelination, and peripheral nerve repair, resulting in potential interest in neuroinflammatory and neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and Multiple Sclerosis. In Alzheimer and Parkinson diseases, a role of TAM receptors in neuronal survival and pathological protein aggregate clearance has been suggested, while in Multiple Sclerosis TAM receptors are involved in myelination and demyelination processes. To better clarify roles and pathways involving TAM receptors may have important therapeutic implications, given the fine modulation of multiple molecular processes which could be reached. In this review, we summarise the roles of TAM receptors in the central nervous system, focusing on the regulation of immune responses and microglial activities and analysing in vitro and in vivo studies regarding TAM signalling involvement in neurodegeneration.
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14
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Arshad F, Khan MF, Akhtar W, Alam MM, Nainwal LM, Kaushik SK, Akhter M, Parvez S, Hasan SM, Shaquiquzzaman M. Revealing quinquennial anticancer journey of morpholine: A SAR based review. Eur J Med Chem 2019; 167:324-356. [PMID: 30776694 DOI: 10.1016/j.ejmech.2019.02.015] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 01/24/2019] [Accepted: 02/04/2019] [Indexed: 02/07/2023]
Abstract
Morpholine, a six-membered heterocycle containing one nitrogen and one oxygen atom, is a moiety of great significance. It forms an important intermediate in many industrial and organic syntheses. Morpholine containing drugs are of high therapeutic value. Its wide array of pharmacological activity includes anti-diabetic, anti-emetic, growth stimulant, anti-depressant, bronchodilator and anticancer. Multi-drug resistance in cancer cases have emerged in the last few years and have led to the failure of many chemotherapeutic drugs. Newer treatment methods and drugs are being developed to overcome this problem. Target based drug discovery is an effective method to develop novel anticancer drugs. To develop newer drugs, previously reported work needs to be studied. Keeping this in mind, last five year's literature on morpholine used as anticancer agents has been reviewed and summarized in the paper herein.
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Affiliation(s)
- Fatima Arshad
- Drug Design & Medicinal Chemistry Lab, Department of Pharmaceutical Chemistry, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi, 110062, India
| | - Mohemmed Faraz Khan
- Drug Design & Medicinal Chemistry Lab, Department of Pharmaceutical Chemistry, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi, 110062, India
| | - Wasim Akhtar
- Drug Design & Medicinal Chemistry Lab, Department of Pharmaceutical Chemistry, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi, 110062, India
| | - Mohammad Mumtaz Alam
- Drug Design & Medicinal Chemistry Lab, Department of Pharmaceutical Chemistry, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi, 110062, India
| | - Lalit Mohan Nainwal
- Drug Design & Medicinal Chemistry Lab, Department of Pharmaceutical Chemistry, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi, 110062, India
| | - Sumit Kumar Kaushik
- Drug Design & Medicinal Chemistry Lab, Department of Pharmaceutical Chemistry, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi, 110062, India
| | - Mymoona Akhter
- Drug Design & Medicinal Chemistry Lab, Department of Pharmaceutical Chemistry, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi, 110062, India
| | - Suhel Parvez
- Department of Toxicology, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi, 110062, India
| | | | - Mohammad Shaquiquzzaman
- Drug Design & Medicinal Chemistry Lab, Department of Pharmaceutical Chemistry, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi, 110062, India.
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15
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The Dual Role of TAM Receptors in Autoimmune Diseases and Cancer: An Overview. Cells 2018; 7:cells7100166. [PMID: 30322068 PMCID: PMC6210017 DOI: 10.3390/cells7100166] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 10/05/2018] [Accepted: 10/09/2018] [Indexed: 01/01/2023] Open
Abstract
Receptor tyrosine kinases (RTKs) regulate cellular processes by converting signals from the extracellular environment to the cytoplasm and nucleus. Tyro3, Axl, and Mer (TAM) receptors form an RTK family that plays an intricate role in tissue maintenance, phagocytosis, and inflammation as well as cell proliferation, survival, migration, and development. Defects in TAM signaling are associated with numerous autoimmune diseases and different types of cancers. Here, we review the structure of TAM receptors, their ligands, and their biological functions. We discuss the role of TAM receptors and soluble circulating TAM receptors in the autoimmune diseases systemic lupus erythematosus (SLE) and multiple sclerosis (MS). Lastly, we discuss the effect of TAM receptor deregulation in cancer and explore the therapeutic potential of TAM receptors in the treatment of diseases.
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16
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Zhen Y, Finkelman FD, Shao WH. Mechanism of Mer receptor tyrosine kinase inhibition of glomerular endothelial cell inflammation. J Leukoc Biol 2018; 103:709-717. [PMID: 29350876 DOI: 10.1002/jlb.3a0917-368r] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 11/28/2017] [Accepted: 12/12/2017] [Indexed: 12/14/2022] Open
Abstract
Endotoxin induces a variety of proinflammatory mediators and plays a crucial role in kidney inflammation. The receptor tyrosine kinase, Mer, diminishes renal inflammation by attenuating inflammatory responses. We previously reported that Mer is predominantly expressed on glomerular endothelial cells (GECs) and that Mer deficiency is associated with increased renal inflammation when mice are challenged with nephrotoxic serum. We consequently hypothesized that Mer signaling down-regulates LPS-driven inflammatory responses in GECs. To test this hypothesis, primary GECs were isolated from the kidneys of Mer-KO and wild-type (WT) control mice. LPS treatment induced Akt and STAT3 activation along with Bcl-xl up-regulation in WT GECs; these responses were all increased in Mer-deficient GECs. In addition, STAT1 and ERK1/2 up-regulation and activation were observed in Mer-KO GECs exposed to LPS. In contrast, expression of the inhibitory signaling molecule, suppressor of cytokine signaling-3 (SOCS-3), was much higher in LPS-stimulated WT than Mer-deficient GECs. Deficiency of Mer was also associated with significantly increased NF-κB expression and activation. These observations indicate that Mer functions as an intrinsic feedback inhibitor of inflammatory mediator-driven immune responses in GECs during kidney injury and suggest a new therapeutic strategy for glomerular diseases.
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Affiliation(s)
- Yuxuan Zhen
- Division of Immunology, Allergy and Rheumatology, Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, USA
| | - Fred D Finkelman
- Division of Immunology, Allergy and Rheumatology, Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, USA.,Division of Immunobiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Wen-Hai Shao
- Division of Immunology, Allergy and Rheumatology, Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, USA
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17
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von Mässenhausen A, Sanders C, Thewes B, Deng M, Queisser A, Vogel W, Kristiansen G, Duensing S, Schröck A, Bootz F, Brossart P, Kirfel J, Heasley L, Brägelmann J, Perner S. MERTK as a novel therapeutic target in head and neck cancer. Oncotarget 2017; 7:32678-94. [PMID: 27081701 PMCID: PMC5078043 DOI: 10.18632/oncotarget.8724] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 03/28/2016] [Indexed: 02/06/2023] Open
Abstract
Although head and neck cancer (HNSCC) is the sixth most common tumor entity worldwide therapy options remain limited leading to 5-year survival rates of only 50 %. MERTK is a promising therapeutic target in several tumor entities, however, its role in HNSCC has not been described yet. The aim of our study was to investigate the biological significance of MERTK and to evaluate its potential as a novel therapeutic target in this dismal tumor entity. In two large HNSCC cohorts (n=537 and n=520) we found that MERTK is overexpressed in one third of patients. In-vitro, MERTK overexpression led to increased proliferation, migration and invasion whereas MERTK inhibition with the small molecule inhibitor UNC1062 or MERTK knockdown reduced cell motility via the small GTPase RhoA. Taken together, we are the first to show that MERTK is frequently overexpressed in HNSCC and plays an important role in tumor cell motility. It might therefore be a potential target for selected patients suffering from this dismal tumor entity.
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Affiliation(s)
- Anne von Mässenhausen
- Section of Prostate Cancer Research, University Hospital of Bonn, Bonn, Germany.,Institute of Pathology, University Hospital of Bonn, Bonn, Germany.,Center for Integrated Oncology Cologne/Bonn, University Hospital of Bonn, Bonn, Germany
| | - Christine Sanders
- Section of Prostate Cancer Research, University Hospital of Bonn, Bonn, Germany.,Institute of Pathology, University Hospital of Bonn, Bonn, Germany.,Center for Integrated Oncology Cologne/Bonn, University Hospital of Bonn, Bonn, Germany
| | - Britta Thewes
- Section of Prostate Cancer Research, University Hospital of Bonn, Bonn, Germany.,Institute of Pathology, University Hospital of Bonn, Bonn, Germany.,Center for Integrated Oncology Cologne/Bonn, University Hospital of Bonn, Bonn, Germany
| | - Mario Deng
- Pathology of The University Hospital of Luebeck, Luebeck, Germany.,Leibniz Research Center Borstel, Borstel, Germany
| | - Angela Queisser
- Section of Prostate Cancer Research, University Hospital of Bonn, Bonn, Germany.,Institute of Pathology, University Hospital of Bonn, Bonn, Germany.,Center for Integrated Oncology Cologne/Bonn, University Hospital of Bonn, Bonn, Germany
| | - Wenzel Vogel
- Pathology of The University Hospital of Luebeck, Luebeck, Germany.,Leibniz Research Center Borstel, Borstel, Germany
| | - Glen Kristiansen
- Institute of Pathology, University Hospital of Bonn, Bonn, Germany.,Center for Integrated Oncology Cologne/Bonn, University Hospital of Bonn, Bonn, Germany
| | - Stefan Duensing
- Department of Urology, University of Heidelberg, Heidelberg, Germany
| | - Andreas Schröck
- Center for Integrated Oncology Cologne/Bonn, University Hospital of Bonn, Bonn, Germany.,Department of Otorhinolaryngology/Head and Neck Surgery, University Hospital of Bonn, Bonn, Germany
| | - Friedrich Bootz
- Center for Integrated Oncology Cologne/Bonn, University Hospital of Bonn, Bonn, Germany.,Department of Otorhinolaryngology/Head and Neck Surgery, University Hospital of Bonn, Bonn, Germany
| | - Peter Brossart
- Center for Integrated Oncology Cologne/Bonn, University Hospital of Bonn, Bonn, Germany.,Department of Hematology/Oncology, University Hospital of Bonn, Bonn, Germany
| | - Jutta Kirfel
- Institute of Pathology, University Hospital of Bonn, Bonn, Germany.,Center for Integrated Oncology Cologne/Bonn, University Hospital of Bonn, Bonn, Germany
| | - Lynn Heasley
- Department of Craniofacial Biology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Johannes Brägelmann
- Section of Prostate Cancer Research, University Hospital of Bonn, Bonn, Germany.,Center for Integrated Oncology Cologne/Bonn, University Hospital of Bonn, Bonn, Germany.,Department of Hematology/Oncology, University Hospital of Bonn, Bonn, Germany
| | - Sven Perner
- Pathology of The University Hospital of Luebeck, Luebeck, Germany.,Leibniz Research Center Borstel, Borstel, Germany
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18
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Jung Y, Decker AM, Wang J, Lee E, Kana LA, Yumoto K, Cackowski FC, Rhee J, Carmeliet P, Buttitta L, Morgan TM, Taichman RS. Endogenous GAS6 and Mer receptor signaling regulate prostate cancer stem cells in bone marrow. Oncotarget 2017; 7:25698-711. [PMID: 27028863 PMCID: PMC5041937 DOI: 10.18632/oncotarget.8365] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 03/07/2016] [Indexed: 12/29/2022] Open
Abstract
GAS6 and its receptors (Tryo 3, Axl, Mer or “TAM”) are known to play a role in regulating tumor progression in a number of settings. Previously we have demonstrated that GAS6 signaling regulates invasion, proliferation, chemotherapy-induced apoptosis of prostate cancer (PCa) cells. We have also demonstrated that GAS6 secreted from osteoblasts in the bone marrow environment plays a critical role in establishing prostate tumor cell dormancy. Here we investigated the role that endogenous GAS6 and Mer receptor signaling plays in establishing prostate cancer stem cells in the bone marrow microenvironment. We first observed that high levels of endogenous GAS6 are expressed by disseminated tumor cells (DTCs) in the bone marrow, whereas relatively low levels of endogenous GAS6 are expressed in PCa tumors grown in a s.c. setting. Interestingly, elevated levels of endogenous GAS6 were identified in putative cancer stem cells (CSCs, CD133+/CD44+) compared to non-CSCs (CD133–/CD44–) isolated from PCa/osteoblast cocultures in vitro and in DTCs isolated from the bone marrow 24 hours after intracardiac injection. Moreover, we found that endogenous GAS6 expression is associated with Mer receptor expression in growth arrested (G1) PCa cells, which correlates with the increase of the CSC populations. Importantly, we found that overexpression of GAS6 activates phosphorylation of Mer receptor signaling and subsequent induction of the CSC phenotype in vitro and in vivo. Together these data suggest that endogenous GAS6 and Mer receptor signaling contribute to the establishment of PCa CSCs in the bone marrow microenvironment, which may have important implications for targeting metastatic disease.
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Affiliation(s)
- Younghun Jung
- Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI, USA
| | - Ann M Decker
- Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI, USA
| | - Jingcheng Wang
- Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI, USA
| | - Eunsohl Lee
- Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI, USA
| | - Lulia A Kana
- Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI, USA
| | - Kenji Yumoto
- Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI, USA
| | - Frank C Cackowski
- Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI, USA.,Department of Internal Medicine, Division of Hematology and Oncology, University of Michigan School of Medicine, Ann Arbor, MI, USA
| | - James Rhee
- Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI, USA
| | - Peter Carmeliet
- Laboratory of Angiogenesis and Vascular Metabolism, Vesalius Research Center (VRC), VIB, K.U. Leuven, Belgium.,Laboratory of Angiogenesis and Vascular Metabolism, Department of Oncology, K.U. Leuven, Belgium
| | - Laura Buttitta
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Todd M Morgan
- Department of Urology, University of Michigan School of Medicine, Ann Arbor, MI, USA
| | - Russell S Taichman
- Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI, USA
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19
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Wu G, Ma Z, Hu W, Wang D, Gong B, Fan C, Jiang S, Li T, Gao J, Yang Y. Molecular insights of Gas6/TAM in cancer development and therapy. Cell Death Dis 2017; 8:e2700. [PMID: 28333143 PMCID: PMC5386520 DOI: 10.1038/cddis.2017.113] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 01/09/2017] [Accepted: 01/30/2017] [Indexed: 12/13/2022]
Abstract
Since growth arrest-specific gene 6 (Gas6) was discovered in 1988, numerous studies have highlighted the role of the Gas6 protein and its receptors Tyro3, Axl and Mer (collectively referred to as TAM), in proliferation, apoptosis, efferocytosis, leukocyte migration, sequestration and platelet aggregation. Gas6 has a critical role in the development of multiple types of cancers, including pancreatic, prostate, oral, ovarian and renal cancers. Acute myelocytic leukaemia (AML) is a Gas6-dependent cancer, and Gas6 expression predicts poor prognosis in AML. Interestingly, Gas6 also has a role in establishing tumour dormancy in the bone marrow microenvironment and in suppressing intestinal tumorigenesis. Numerous studies regarding cancer therapy have targeted Gas6 and TAM receptors with good results. However, some findings have suggested that Gas6 is associated with the development of resistance to cancer therapies. Concerning these significant effects of Gas6 in numerous cancers, we discuss the roles of Gas6 in cancer development in this review. First, we introduce basic knowledge on Gas6 and TAM receptors. Next, we describe and discuss the involvement of Gas6 and TAM receptors in cancers from different organ systems. Finally, we highlight the progress in therapies targeting Gas6 and TAM receptors. This review presents the significant roles of Gas6 in cancers from different systems and may contribute to the continued promotion of Gas6 as a therapeutic target.
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Affiliation(s)
- Guiling Wu
- Department of Thoracic and Cardiovascular Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu 210008, China.,Department of Geriatrics, Xijing Hospital, The Fourth Military Medical University, 127 Changle West Road, Xi'an 710032, China.,Department of Biomedical Engineering, The Fourth Military Medical University, 169 Changle West Road, Xi'an 710032, China
| | - Zhiqiang Ma
- Department of Thoracic Surgery, Tangdu Hospital, The Fourth Military Medical University, 1 Xinsi Road, Xi'an 710038, China
| | - Wei Hu
- Department of Biomedical Engineering, The Fourth Military Medical University, 169 Changle West Road, Xi'an 710032, China
| | - Dongjin Wang
- Department of Thoracic and Cardiovascular Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu 210008, China
| | - Bing Gong
- Department of Thoracic and Cardiovascular Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu 210008, China
| | - Chongxi Fan
- Department of Biomedical Engineering, The Fourth Military Medical University, 169 Changle West Road, Xi'an 710032, China
| | - Shuai Jiang
- Department of Aerospace Medicine, The Fourth Military Medical University, 169 Changle West Road, Xi'an 710032, China
| | - Tian Li
- Department of Biomedical Engineering, The Fourth Military Medical University, 169 Changle West Road, Xi'an 710032, China
| | - Jianyuan Gao
- Department of Geriatrics, Xijing Hospital, The Fourth Military Medical University, 127 Changle West Road, Xi'an 710032, China
| | - Yang Yang
- Department of Thoracic and Cardiovascular Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing, Jiangsu 210008, China.,Department of Biomedical Engineering, The Fourth Military Medical University, 169 Changle West Road, Xi'an 710032, China
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20
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Wang X, Liu J, Zhang W, Stashko MA, Nichols J, Miley M, Norris-Drouin J, Chen Z, Machius M, DeRyckere D, Wood E, Graham DK, Earp HS, Kireev D, Frye SV. Design and Synthesis of Novel Macrocyclic Mer Tyrosine Kinase Inhibitors. ACS Med Chem Lett 2016; 7:1044-1049. [PMID: 27994735 PMCID: PMC5151143 DOI: 10.1021/acsmedchemlett.6b00221] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 09/13/2016] [Indexed: 11/28/2022] Open
Abstract
Mer tyrosine kinase (MerTK) is aberrantly elevated in various tumor cells and has a normal anti-inflammatory role in the innate immune system. Inhibition of MerTK may provide dual effects against these MerTK-expressing tumors through reducing cancer cell survival and redirecting the innate immune response. Recently, we have designed novel and potent macrocyclic pyrrolopyrimidines as MerTK inhibitors using a structure-based approach. The most active macrocycles had an EC50 below 40 nM in a cell-based MerTK phosphor-protein ELISA assay. The X-ray structure of macrocyclic analogue 3 complexed with MerTK was also resolved and demonstrated macrocycles binding in the ATP binding pocket of the MerTK protein as anticipated. In addition, the lead compound 16 (UNC3133) had a 1.6 h half-life and 16% oral bioavailability in a mouse PK study.
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Affiliation(s)
- Xiaodong Wang
- Center
for Integrative Chemical Biology and Drug Discovery, Division of Chemical
Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Jing Liu
- Center
for Integrative Chemical Biology and Drug Discovery, Division of Chemical
Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Weihe Zhang
- Center
for Integrative Chemical Biology and Drug Discovery, Division of Chemical
Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Michael A. Stashko
- Center
for Integrative Chemical Biology and Drug Discovery, Division of Chemical
Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - James Nichols
- Meryx,
Inc., 450 West Dr., Chapel Hill, North Carolina 27599, United States
| | - Michael
J. Miley
- Department
of Pharmacology, University of North Carolina
at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Jacqueline Norris-Drouin
- Center
for Integrative Chemical Biology and Drug Discovery, Division of Chemical
Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Zhilong Chen
- Center
for Integrative Chemical Biology and Drug Discovery, Division of Chemical
Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Mischa Machius
- Department
of Pharmacology, University of North Carolina
at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Deborah DeRyckere
- Aflac
Cancer and Blood Disorders Center of Children’s Healthcare
of Atlanta, Department of Pediatrics, School of Medicine, Emory University, Atlanta, Georgia 30322, United States
| | - Edgar Wood
- Meryx,
Inc., 450 West Dr., Chapel Hill, North Carolina 27599, United States
| | - Douglas K. Graham
- Meryx,
Inc., 450 West Dr., Chapel Hill, North Carolina 27599, United States
- Aflac
Cancer and Blood Disorders Center of Children’s Healthcare
of Atlanta, Department of Pediatrics, School of Medicine, Emory University, Atlanta, Georgia 30322, United States
| | - H. Shelton Earp
- Center
for Integrative Chemical Biology and Drug Discovery, Division of Chemical
Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
- Meryx,
Inc., 450 West Dr., Chapel Hill, North Carolina 27599, United States
- Lineberger
Comprehensive Cancer Center, Department of Medicine, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Dmitri Kireev
- Center
for Integrative Chemical Biology and Drug Discovery, Division of Chemical
Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Stephen V. Frye
- Center
for Integrative Chemical Biology and Drug Discovery, Division of Chemical
Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
- Meryx,
Inc., 450 West Dr., Chapel Hill, North Carolina 27599, United States
- Lineberger
Comprehensive Cancer Center, Department of Medicine, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
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21
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Kimani SG, Kumar S, Davra V, Chang YJ, Kasikara C, Geng K, Tsou WI, Wang S, Hoque M, Boháč A, Lewis-Antes A, De Lorenzo MS, Kotenko SV, Birge RB. Normalization of TAM post-receptor signaling reveals a cell invasive signature for Axl tyrosine kinase. Cell Commun Signal 2016; 14:19. [PMID: 27595981 PMCID: PMC5011882 DOI: 10.1186/s12964-016-0142-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 08/26/2016] [Indexed: 12/11/2022] Open
Abstract
Background Tyro3, Axl, and Mertk (TAMs) are a family of three conserved receptor tyrosine kinases that have pleiotropic roles in innate immunity and homeostasis and when overexpressed in cancer cells can drive tumorigenesis. Methods In the present study, we engineered EGFR/TAM chimeric receptors (EGFR/Tyro3, EGFR/Axl, and EGF/Mertk) with the goals to interrogate post-receptor functions of TAMs, and query whether TAMs have unique or overlapping post-receptor activation profiles. Stable expression of EGFR/TAMs in EGFR-deficient CHO cells afforded robust EGF inducible TAM receptor phosphorylation and activation of downstream signaling. Results Using a series of unbiased screening approaches, that include kinome-view analysis, phosphor-arrays, RNAseq/GSEA analysis, as well as cell biological and in vivo readouts, we provide evidence that each TAM has unique post-receptor signaling platforms and identify an intrinsic role for Axl that impinges on cell motility and invasion compared to Tyro3 and Mertk. Conclusion These studies demonstrate that TAM show unique post-receptor signatures that impinge on distinct gene expression profiles and tumorigenic outcomes. Electronic supplementary material The online version of this article (doi:10.1186/s12964-016-0142-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Stanley G Kimani
- Rutgers, Department of Microbiology, Biochemistry and Molecular Genetics, Cancer Center, Rutgers- New Jersey Medical School, 205 South Orange Ave, Newark, NJ, 07103, USA
| | - Sushil Kumar
- Rutgers, Department of Microbiology, Biochemistry and Molecular Genetics, Cancer Center, Rutgers- New Jersey Medical School, 205 South Orange Ave, Newark, NJ, 07103, USA
| | - Viralkumar Davra
- Rutgers, Department of Microbiology, Biochemistry and Molecular Genetics, Cancer Center, Rutgers- New Jersey Medical School, 205 South Orange Ave, Newark, NJ, 07103, USA
| | - Yun-Juan Chang
- Rutgers, Biomedical and Health Sciences, OIT/High Performance and Research Computing, 185 South Orange Ave, Newark, NJ, 07103, USA
| | - Canan Kasikara
- Rutgers, Department of Microbiology, Biochemistry and Molecular Genetics, Cancer Center, Rutgers- New Jersey Medical School, 205 South Orange Ave, Newark, NJ, 07103, USA
| | - Ke Geng
- Rutgers, Department of Microbiology, Biochemistry and Molecular Genetics, Cancer Center, Rutgers- New Jersey Medical School, 205 South Orange Ave, Newark, NJ, 07103, USA
| | - Wen-I Tsou
- Rutgers, Department of Microbiology, Biochemistry and Molecular Genetics, Cancer Center, Rutgers- New Jersey Medical School, 205 South Orange Ave, Newark, NJ, 07103, USA
| | - Shenyan Wang
- Rutgers, Department of Microbiology, Biochemistry and Molecular Genetics, Cancer Center, Rutgers- New Jersey Medical School, 205 South Orange Ave, Newark, NJ, 07103, USA
| | - Mainul Hoque
- Rutgers, Department of Microbiology, Biochemistry and Molecular Genetics, Genomics Research Program, Rutgers- New Jersey Medical School, 185 South Orange Ave, Newark, NJ, 07103, USA
| | - Andrej Boháč
- Department of Organic Chemistry, Comenius University in Bratislava, Faculty of Natural Sciences, Mlynská dolina, Ilkovičova 6, 842 15, Bratislava, Slovakia.,Biomagi, Ltd, Mamateyova 26, 851 04, Bratislava, Slovakia
| | - Anita Lewis-Antes
- Rutgers, Department of Microbiology, Biochemistry and Molecular Genetics, Cancer Center, Rutgers- New Jersey Medical School, 205 South Orange Ave, Newark, NJ, 07103, USA
| | - Mariana S De Lorenzo
- Rutgers, Department of Microbiology, Biochemistry and Molecular Genetics, Cancer Center, Rutgers- New Jersey Medical School, 205 South Orange Ave, Newark, NJ, 07103, USA
| | - Sergei V Kotenko
- Rutgers, Department of Microbiology, Biochemistry and Molecular Genetics, Cancer Center, Rutgers- New Jersey Medical School, 205 South Orange Ave, Newark, NJ, 07103, USA
| | - Raymond B Birge
- Rutgers, Department of Microbiology, Biochemistry and Molecular Genetics, Cancer Center, Rutgers- New Jersey Medical School, 205 South Orange Ave, Newark, NJ, 07103, USA.
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22
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Zhen Y, Priest SO, Shao WH. Opposing Roles of Tyrosine Kinase Receptors Mer and Axl Determine Clinical Outcomes in Experimental Immune-Mediated Nephritis. THE JOURNAL OF IMMUNOLOGY 2016; 197:2187-94. [PMID: 27527599 DOI: 10.4049/jimmunol.1600793] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 07/18/2016] [Indexed: 12/16/2022]
Abstract
Glomerulonephritis is one of the most severe manifestations of systemic lupus erythematosus, with considerable morbidity and mortality. There remains a major unmet need for successful management of lupus nephritis. TAM family receptor tyrosine kinases (Mer and Axl) play an important role in the maintenance of immune homeostasis in the kidney. Mer is constitutively expressed in the glomeruli; Axl expression is inducible in glomeruli under inflammatory conditions. To investigate the distinct functions of Axl and Mer in lupus nephritis, we compared the severity of nephrotoxic serum glomerulonephritis in wild-type (WT), Axl-knockout (KO), Mer-KO, and Axl/Mer-KO mice. Mer-KO mice developed severe glomerulonephritis, with significantly decreased survival and increased blood urea nitrogen levels compared with WT mice given the same treatment. However, nephrotoxic serum-treated Axl-KO mice had significantly increased survival rates and improved renal function compared with similarly treated WT, Mer-KO, and Axl/Mer-KO mice. Interestingly, mice lacking both Axl and Mer developed kidney inflammation comparable to WT mice. Western blot analysis revealed significantly increased Stat3 phosphorylation and caspase-1 activation in the kidneys of nephritic Mer-KO mice. In contrast, Axl-deficient nephrotoxic serum-injected mice showed decreased Akt phosphorylation and Bcl-xL upregulation. Thus, the reciprocal activation of Axl and Mer receptor tyrosine kinases has a major impact on the outcome of renal inflammation.
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Affiliation(s)
- Yuxuan Zhen
- Section of Rheumatology, Department of Medicine, Temple University, Philadelphia, PA 19140
| | - Stephen O Priest
- Section of Rheumatology, Department of Medicine, Temple University, Philadelphia, PA 19140
| | - Wen-Hai Shao
- Section of Rheumatology, Department of Medicine, Temple University, Philadelphia, PA 19140
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23
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Wang SB, Cui MT, Wang XF, Ohkoshi E, Goto M, Yang DX, Li L, Yuan S, Morris-Natschke SL, Lee KH, Xie L. Synthesis, biological evaluation, and physicochemical property assessment of 4-substituted 2-phenylaminoquinazolines as Mer tyrosine kinase inhibitors. Bioorg Med Chem 2016; 24:3083-3092. [PMID: 27238842 PMCID: PMC4920374 DOI: 10.1016/j.bmc.2016.05.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 05/12/2016] [Accepted: 05/16/2016] [Indexed: 11/29/2022]
Abstract
Current results identified 4-substituted 2-phenylaminoquinazoline compounds as novel Mer tyrosine kinase (Mer TK) inhibitors with a new scaffold. Twenty-one 2,4-disubstituted quinazolines (series 4-7) were designed, synthesized, and evaluated against Mer TK and a panel of human tumor cell lines aimed at exploring new Mer TK inhibitors as novel potential antitumor agents. A new lead, 4b, was discovered with a good balance between high potency (IC50 0.68μM) in the Mer TK assay and antiproliferative activity against MV4-11 (GI50 8.54μM), as well as other human tumor cell lines (GI50<20μM), and a desirable druglike property profile with low logP value (2.54) and high aqueous solubility (95.6μg/mL). Molecular modeling elucidated an expected binding mode of 4b with Mer TK and necessary interactions between them, thus supporting the hypothesis that Mer TK might be a biologic target of this kind of new active compound.
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Affiliation(s)
- Sheng-Biao Wang
- Beijing Institute of Pharmacology & Toxicology, 27 Tai-Ping Road, Beijing 100850, China
| | - Mu-Tian Cui
- Beijing Institute of Pharmacology & Toxicology, 27 Tai-Ping Road, Beijing 100850, China
| | - Xiao-Feng Wang
- Beijing Institute of Pharmacology & Toxicology, 27 Tai-Ping Road, Beijing 100850, China; Pharmacy Department, Urumqi General Hospital, Lanzhou Military Region, Urumqi 830000, China
| | - Emika Ohkoshi
- Natural Products Research Laboratories, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, NC 27599, USA
| | - Masuo Goto
- Natural Products Research Laboratories, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, NC 27599, USA
| | - De-Xuan Yang
- Beijing Institute of Radiation Medicine, 27 Tai-Ping Road, Beijing 100850, China
| | - Linna Li
- Beijing Institute of Radiation Medicine, 27 Tai-Ping Road, Beijing 100850, China
| | - Shoujun Yuan
- Beijing Institute of Radiation Medicine, 27 Tai-Ping Road, Beijing 100850, China
| | - Susan L Morris-Natschke
- Natural Products Research Laboratories, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, NC 27599, USA
| | - Kuo-Hsiung Lee
- Natural Products Research Laboratories, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, NC 27599, USA; Chinese Medicine Research and Development Center, China Medical University & Hospital, Taichung, Taiwan.
| | - Lan Xie
- Beijing Institute of Pharmacology & Toxicology, 27 Tai-Ping Road, Beijing 100850, China; Natural Products Research Laboratories, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, NC 27599, USA.
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24
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Mukherjee SK, Wilhelm A, Antoniades CG. TAM receptor tyrosine kinase function and the immunopathology of liver disease. Am J Physiol Gastrointest Liver Physiol 2016; 310:G899-905. [PMID: 26867565 PMCID: PMC4935487 DOI: 10.1152/ajpgi.00382.2015] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 01/28/2016] [Indexed: 01/31/2023]
Abstract
Tyro3, Axl, MERTK (TAM) receptor tyrosine kinases are implicated in the regulation of the innate immune response through clearance of apoptotic cellular debris and control of cytokine signaling cascades. As a result they are pivotal in regulating the inflammatory response to tissue injury. Within the liver, immune regulatory signaling is employed to prevent the overactivation of innate immunity in response to continual antigenic challenge from the gastrointestinal tract. In this review we appraise current understanding of the role of TAM receptor function in the regulation of both innate and adaptive immunity, with a focus on its impact upon hepatic inflammatory pathology.
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Affiliation(s)
- S. K. Mukherjee
- 1Division of Digestive Diseases, Department of Medicine, Imperial College London, London, United Kingdom; and
| | - A. Wilhelm
- 1Division of Digestive Diseases, Department of Medicine, Imperial College London, London, United Kingdom; and
| | - C. G. Antoniades
- 1Division of Digestive Diseases, Department of Medicine, Imperial College London, London, United Kingdom; and ,2Division of Transplantation Immunology & Mucosal Biology, Institute of Liver Sciences, King's College London, London, United Kingdom
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25
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Mer tyrosine kinase promotes the survival of t(1;19)-positive acute lymphoblastic leukemia (ALL) in the central nervous system (CNS). Blood 2015; 125:820-30. [DOI: 10.1182/blood-2014-06-583062] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Key Points
Mer mediates quiescence and chemotherapy resistance in a CNS coculture model and causes CNS infiltration in immunodeficient mice. Mer expression correlates with CNS positivity upon initial diagnosis in t(1;19)-positive pediatric ALL patients.
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26
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Knubel KH, Pernu BM, Sufit A, Nelson S, Pierce AM, Keating AK. MerTK inhibition is a novel therapeutic approach for glioblastoma multiforme. Oncotarget 2015; 5:1338-51. [PMID: 24658326 PMCID: PMC4012720 DOI: 10.18632/oncotarget.1793] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Glioblastoma is an aggressive tumor that occurs in both adult and pediatric patients and is known for its invasive quality and high rate of recurrence. Current therapies for glioblastoma result in high morbidity and dismal outcomes. The TAM subfamily of receptor tyrosine kinases includes Tyro3, Axl, and MerTK. Axl and MerTK exhibit little to no expression in normal brain but are highly expressed in glioblastoma and contribute to the critical malignant phenotypes of survival, chemosensitivity and migration. We have found that Foretinib, a RTK inhibitor currently in clinical trial, inhibited phosphorylation of TAM receptors, with highest efficacy against MerTK, and blocked downstream activation of Akt and Erk in adult and pediatric glioblastoma cell lines, findings that are previously unreported. Survival, proliferation, migration, and collagen invasion were hindered in vitro. Foretinib treatment in vivo abolished MerTK phosphorylation and reduced tumor growth 3-4 fold in a subcutaneous mouse model. MerTK targeted shRNA completely prevented intracranial and subcutaneous glioma growth further delineating the impact of MerTK inhibition on glioblastoma. Our findings provide additional target validation for MerTK inhibition in glioblastoma and demonstrate that robust MerTK inhibition can be achieved with the multi-kinase inhibitor Foretinib as an innovative and translational therapeutic approach to glioblastoma.
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Affiliation(s)
- Kristina H Knubel
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA
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27
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Graham DK, DeRyckere D, Davies KD, Earp HS. The TAM family: phosphatidylserine sensing receptor tyrosine kinases gone awry in cancer. Nat Rev Cancer 2014; 14:769-85. [PMID: 25568918 DOI: 10.1038/nrc3847] [Citation(s) in RCA: 516] [Impact Index Per Article: 51.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The TYRO3, AXL (also known as UFO) and MERTK (TAM) family of receptor tyrosine kinases (RTKs) are aberrantly expressed in multiple haematological and epithelial malignancies. Rather than functioning as oncogenic drivers, their induction in tumour cells predominately promotes survival, chemoresistance and motility. The unique mode of maximal activation of this RTK family requires an extracellular lipid–protein complex. For example, the protein ligand, growth arrest-specific protein 6 (GAS6), binds to phosphatidylserine (PtdSer) that is externalized on apoptotic cell membranes, which activates MERTK on macrophages. This triggers engulfment of apoptotic material and subsequent anti-inflammatory macrophage polarization. In tumours, autocrine and paracrine ligands and apoptotic cells are abundant, which provide a survival signal to the tumour cell and favour an anti-inflammatory, immunosuppressive microenvironment. Thus, TAM kinase inhibition could stimulate antitumour immunity, reduce tumour cell survival, enhance chemosensitivity and diminish metastatic potential.
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28
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Nguyen KQN, Tsou WI, Calarese DA, Kimani SG, Singh S, Hsieh S, Liu Y, Lu B, Wu Y, Garforth SJ, Almo SC, Kotenko SV, Birge RB. Overexpression of MERTK receptor tyrosine kinase in epithelial cancer cells drives efferocytosis in a gain-of-function capacity. J Biol Chem 2014; 289:25737-49. [PMID: 25074939 DOI: 10.1074/jbc.m114.570838] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
MERTK, a member of the TAM (TYRO3, AXL, and MERTK) receptor tyrosine kinases, has complex and diverse roles in cell biology. On the one hand, knock-out of MERTK results in age-dependent autoimmunity characterized by failure of apoptotic cell clearance, while on the other, MERTK overexpression in cancer drives classical oncogene pathways leading to cell transformation. To better understand the interplay between cell transformation and efferocytosis, we stably expressed MERTK in human MCF10A cells, a non-tumorigenic breast epithelial cell line devoid of endogenous MERTK. While stable expression of MERTK in MCF10A resulted in enhanced motility and AKT-mediated chemoprotection, MERTK-10A cells did not form stable colonies in soft agar, or enhance proliferation compared with parental MCF10A cells. Concomitant to chemoresistance, MERTK also stimulated efferocytosis in a gain-of-function capacity. However, unlike AXL, MERTK activation was highly dependent on apoptotic cells, suggesting MERTK may preferentially interface with phosphatidylserine. Consistent with this idea, knockdown of MERTK in breast cancer cells MDA-MB 231 reduced efferocytosis, while transient or stable expression of MERTK stimulated apoptotic cell clearance in all cell lines tested. Moreover, human breast cancer cells with higher endogenous MERTK showed higher levels of efferocytosis that could be blocked by soluble TAM receptors. Finally, through MERTK, apoptotic cells induced PD-L1 expression, an immune checkpoint blockade, suggesting that cancer cells may adopt MERTK-driven efferocytosis as an immune suppression mechanism for their advantage. These data collectively identify MERTK as a significant link between cancer progression and efferocytosis, and a potentially unrealized tumor-promoting event when MERTK is overexpressed in epithelial cells.
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Affiliation(s)
- Khanh-Quynh N Nguyen
- From the Department of Biochemistry and Molecular Biology, University Hospital Cancer Center
| | - Wen-I Tsou
- From the Department of Biochemistry and Molecular Biology, University Hospital Cancer Center, Center for Immunity and Inflammation, New Jersey Medical School, and
| | - Daniel A Calarese
- Department of Biochemistry, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York 10461
| | - Stanley G Kimani
- From the Department of Biochemistry and Molecular Biology, University Hospital Cancer Center
| | - Sukhwinder Singh
- Department of Pathology and Laboratory Medicine, Flow Cytometry and Immunology Core Laboratory, Rutgers Biomedical and Health Sciences, Newark, New Jersey 07103
| | - Shelly Hsieh
- Rutgers, New Jersey Medical School of Yeshiva University, Newark, New Jersey 07103
| | - Yongzhang Liu
- Institute of Biophysics and Attardi Institute of Mitochondrial Biomedicine, School of Life Sciences, Wenzhou Medical University, Wenzhou 325035, China, and
| | - Bin Lu
- Institute of Biophysics and Attardi Institute of Mitochondrial Biomedicine, School of Life Sciences, Wenzhou Medical University, Wenzhou 325035, China, and
| | - Yi Wu
- Cyrus Tang Hematology Center, Soochow University, Suzhou, Jiangsu 215123, China
| | - Scott J Garforth
- Department of Biochemistry, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York 10461
| | - Steve C Almo
- Department of Biochemistry, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York 10461
| | - Sergei V Kotenko
- From the Department of Biochemistry and Molecular Biology, University Hospital Cancer Center, Center for Immunity and Inflammation, New Jersey Medical School, and
| | - Raymond B Birge
- From the Department of Biochemistry and Molecular Biology, University Hospital Cancer Center,
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29
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Wang B, Sun S, Liu Z. Analysis of dysregulation of immune system in pancreatic cancer based on gene expression profile. Mol Biol Rep 2014; 41:4361-7. [PMID: 24619357 DOI: 10.1007/s11033-014-3307-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Accepted: 02/14/2014] [Indexed: 01/08/2023]
Abstract
The aim of this study was to explore the dysregulated expression of the immune system in pancreatic cancer and clarify the pathogenesis of pancreatic cancer. The Dataset GSE15471 was downloaded from GEO database, Student's t test was used to screen differentially expressed genes (DEGs) between the pancreatic cancer group and the normal control group. Kyoto Encyclopedia of Genes and Genomes (KEGG) provides functional annotation was employed to explore the significant DEGs involved in biological functions. We got 988 significantly DEGs, including 832 up-regulated genes and 156 down-regulated genes. The ratio of up-regulated genes and down-regulated genes was 5.3. Total 13 biological pathways which were significant enriched with DEGs by KEGG pathway enrichment analysis. Finally, we constructed a overall network of the immune system in pancreatic cancer with these biological pathways information. Our study reveals that dysregulated pathways in pancreatic cancer associated with the immune system. Besides, we also identify some important molecular biomarkers of the pancreatic cancer, including CXCR4 and CD4. Dysfunctional pathways and important molecular biomarkers of pancreatic cancer will provide useful information for potential treatment of pancreatic cancer.
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Affiliation(s)
- Baosheng Wang
- Department of General Surgery, Shengjing Hospital of China Medical University, No. 36 Sanhao Street, Heping District, Shenyang, 110004, China,
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30
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Miyoshi H, Kato K, Iwama H, Maeda E, Sakamoto T, Fujita K, Toyota Y, Tani J, Nomura T, Mimura S, Kobayashi M, Morishita A, Kobara H, Mori H, Yoneyama H, Deguchi A, Himoto T, Kurokohchi K, Okano K, Suzuki Y, Murao K, Masaki T. Effect of the anti-diabetic drug metformin in hepatocellular carcinoma in vitro and in vivo. Int J Oncol 2014; 45:322-32. [PMID: 24806290 DOI: 10.3892/ijo.2014.2419] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2013] [Accepted: 04/07/2014] [Indexed: 01/09/2023] Open
Abstract
Metformin is a commonly used oral anti-hyperglycemic agent of the biguanide family. Recent studies suggest that metformin may reduce cancer risk and improve prognosis. However, the antitumor mechanism of metformin in several types of cancers, including hepatocellular carcinoma (HCC), has not been elucidated. The goal of the present study was to evaluate the effects of metformin on HCC cell proliferation in vitro and in vivo, and to study microRNAs (miRNAs) associated with the antitumor effect of metformin in vitro. We used the cell lines Alex, HLE and Huh7, and normal hepatocytes to study the effects of metformin on human HCC cells. In an in vivo study, athymic nude mice bearing xenograft tumors were treated with metformin or left untreated. Tumor growth was recorded after 4 weeks, and the expression of cell cycle-related proteins was determined. Metformin inhibited the proliferation of Alex, HLE and Huh7 cells in vitro and in vivo. Metformin blocked the cell cycle in G0/G1 in vitro and in vivo. This blockade was accompanied by a strong decrease of G1 cyclins, especially cyclin D1, cyclin E and cyclin-dependent kinase 4 (Cdk4). In addition, microRNA (miRNA) expression was markedly altered by the treatment with metformin in vitro and in vivo. In addition, various miRNAs induced by metformin also may contribute to the suppression of tumor growth. Our results demonstrate that metformin inhibits the growth of HCC, possibly by inducing G1 cell cycle arrest through the alteration of microRNAs.
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Affiliation(s)
- Hisaaki Miyoshi
- Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Kiyohito Kato
- Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Hisakazu Iwama
- Life Science Research Center, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Emiko Maeda
- Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Teppei Sakamoto
- Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Koji Fujita
- Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Yuka Toyota
- Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Joji Tani
- Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Takako Nomura
- Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Shima Mimura
- Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Mitsuyoshi Kobayashi
- Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Asahiro Morishita
- Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Hideki Kobara
- Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Hirohito Mori
- Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Hirohito Yoneyama
- Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Akihiro Deguchi
- Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Takashi Himoto
- Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Kazutaka Kurokohchi
- Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Keiichi Okano
- Department of Gastroenterological Surgery, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Yasuyuki Suzuki
- Department of Gastroenterological Surgery, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Koji Murao
- Department of Laboratory Medicine, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Tsutomu Masaki
- Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa, Japan
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31
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Pierce AM, Keating AK. TAM receptor tyrosine kinases: expression, disease and oncogenesis in the central nervous system. Brain Res 2013; 1542:206-20. [PMID: 24184575 DOI: 10.1016/j.brainres.2013.10.049] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Revised: 10/18/2013] [Accepted: 10/24/2013] [Indexed: 01/10/2023]
Abstract
Receptor tyrosine kinases (RTKs) are cell surface proteins that tightly regulate a variety of downstream intra-cellular processes; ligand-receptor interactions result in cascades of signaling events leading to growth, proliferation, differentiation and migration. There are 58 described RTKs, which are further categorized into 20 different RTK families. When dysregulated or overexpressed, these RTKs are implicated in disordered growth, development, and oncogenesis. The TAM family of RTKs, consisting of Tyro3, Axl, and MerTK, is prominently expressed during the development and function of the central nervous system (CNS). Aberrant expression and dysregulated activation of TAM family members has been demonstrated in a variety of CNS-related disorders and diseases, including the most common but least treatable brain cancer in children and adults: glioblastoma multiforme.
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Affiliation(s)
- Angela M Pierce
- University of Colorado School of Medicine, Department of Pediatrics, 12800 E. 19th Avenue, P18-4105, MS 8302 Aurora, CO 80045, USA.
| | - Amy K Keating
- University of Colorado School of Medicine, Department of Pediatrics, 12800 E. 19th Avenue, P18-4105, MS 8302 Aurora, CO 80045, USA.
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Abstract
MERTK is a receptor tyrosine kinase of the TAM (Tyro3, Axl, MERTK) family, with a defined spectrum of normal expression. However, MERTK is overexpressed or ectopically expressed in a wide variety of cancers, including leukemia, non-small cell lung cancer, glioblastoma, melanoma, prostate cancer, breast cancer, colon cancer, gastric cancer, pituitary adenomas, and rhabdomyosarcomas, potentially resulting in the activation of several canonical oncogenic signaling pathways. These include the mitogen-activated protein kinase and phosphoinositide 3-kinase pathways, as well as regulation of signal transducer and activator of transcription family members, migration-associated proteins including the focal adhesion kinase and myosin light chain 2, and prosurvival proteins such as survivin and Bcl-2. Each has been implicated in MERTK physiologic and oncogenic functions. In neoplastic cells, these signaling events result in functional phenotypes such as decreased apoptosis, increased migration, chemoresistance, increased colony formation, and increased tumor formation in murine models. Conversely, MERTK inhibition by genetic or pharmacologic means can reverse these pro-oncogenic phenotypes. Multiple therapeutic approaches to MERTK inhibition are currently in development, including ligand "traps", a monoclonal antibody, and small-molecule tyrosine kinase inhibitors.
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Affiliation(s)
- Christopher T. Cummings
- Department of Pediatrics, Section of Hematology, Oncology and Bone Marrow Transplantation, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Deborah DeRyckere
- Department of Pediatrics, Section of Hematology, Oncology and Bone Marrow Transplantation, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - H. Shelton Earp
- UNC Lineberger Comprehensive Cancer Center, Departments of Medicine and Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Douglas K. Graham
- Department of Pediatrics, Section of Hematology, Oncology and Bone Marrow Transplantation, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Corresponding Author: Douglas K. Graham, Department of Pediatrics, Section of Hematology, Oncology and Bone Marrow Transplantation, University of Colorado Anschutz Medical Campus, Mail Stop 8302, 12800 East 19th Avenue, P18-4400, Aurora, CO 80045 USA.
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Mer receptor tyrosine kinase is a therapeutic target in pre-B-cell acute lymphoblastic leukemia. Blood 2013; 122:1599-609. [PMID: 23861246 DOI: 10.1182/blood-2013-01-478156] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Acute lymphoblastic leukemia (ALL) is currently treated with an intense regimen of chemotherapy yielding cure rates near 85%. However, alterations to treatment strategies using available drugs are unlikely to provide significant improvement in survival or decrease therapy-associated toxicities. Here, we report ectopic expression of the Mer receptor tyrosine kinase in pre-B-cell ALL (B-ALL) cell lines and pediatric patient samples. Inhibition of Mer in B-ALL cell lines decreased activation of AKT and MAPKs and led to transcriptional changes, including decreased expression of antiapoptotic PRKCB gene and increase in proapoptotic BAX and BBC3 genes. Further, Mer inhibition promoted chemosensitization, decreased colony-forming potential in clonogenic assays, and delayed disease onset in a mouse xenograft model of leukemia. Our results identify Mer as a potential therapeutic target in B-ALL and suggest that inhibitors of Mer may potentiate lymphoblast killing when used in combination with chemotherapy. This strategy could reduce minimal residual disease and/or allow for chemotherapy dose reduction, thereby leading to improved event-free survival and reduced therapy-associated toxicity for patients with B-ALL. Additionally, Mer is aberrantly expressed in numerous other malignancies suggesting that this approach may have broad applications.
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Tworkoski KA, Platt JT, Bacchiocchi A, Bosenberg M, Boggon TJ, Stern DF. MERTK controls melanoma cell migration and survival and differentially regulates cell behavior relative to AXL. Pigment Cell Melanoma Res 2013; 26:527-41. [PMID: 23617806 DOI: 10.1111/pcmr.12110] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Accepted: 04/12/2013] [Indexed: 11/28/2022]
Abstract
The receptor tyrosine kinase AXL regulates melanoma cell proliferation and migration. We now demonstrate that AXL and the related kinase MERTK are alternately expressed in melanoma and are associated with different transcriptional signatures. MERTK-positive melanoma cells are more proliferative and less migratory than AXL-positive melanoma cells and overexpression of AXL increases cell motility relative to MERTK. MERTK is expressed in up to 50% of melanoma cells and shRNA-mediated knockdown of MERTK reduces colony formation and cell migration in a CDC42-dependent fashion. Targeting MERTK also decreases cell survival and proliferation in an AKT-dependent manner. Finally, we identify a novel mutation in the kinase domain of MERTK, MERTK(P) (802S) , that increases the motility of melanoma cells relative to wild-type MERTK. Together, these data demonstrate that MERTK is a possible therapeutic target in melanoma, that AXL and MERTK are associated with differential cell behaviors, and that mutations in MERTK may contribute to melanoma pathogenesis.
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Affiliation(s)
- Kathryn A Tworkoski
- Department of Pathology, Yale University School of Medicine, New Haven, CT, USA
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35
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Lee-Sherick AB, Eisenman KM, Sather S, McGranahan A, Armistead PM, McGary CS, Hunsucker SA, Schlegel J, Martinson H, Cannon C, Keating AK, Earp HS, Liang X, DeRyckere D, Graham DK. Aberrant Mer receptor tyrosine kinase expression contributes to leukemogenesis in acute myeloid leukemia. Oncogene 2013; 32:5359-68. [PMID: 23474756 PMCID: PMC3898106 DOI: 10.1038/onc.2013.40] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Revised: 12/14/2012] [Accepted: 12/30/2012] [Indexed: 01/13/2023]
Abstract
Acute myeloid leukemia (AML) continues to be extremely difficult to treat successfully, and the unacceptably low overall survival rates mandate that we assess new potential therapies to ameliorate poor clinical response to conventional therapy. Abnormal tyrosine kinase activation in AML has been associated with poor prognosis and provides strategic targets for novel therapy development. We found that Mer receptor tyrosine kinase was over-expressed in a majority of pediatric (29/36, 80%) and adult (10/10, 100%) primary AML patient blasts at the time of diagnosis, and 100% of patient samples at the time of relapse. Mer was also found to be expressed in 12 of 14 AML cell lines (86%). In contrast, normal bone marrow myeloid precursors expressed little to no Mer. Following AML cell line stimulation with Gas6, a Mer ligand, we observed activation of prosurvival and proliferative signaling pathways, including phosphorylation of ERK1/2, p38, MSK1, CREB, ATF1, AKT and STAT6. To assess the phenotypic role of Mer in AML, two independent short-hairpin RNA (shRNA) constructs were used to decrease Mer expression in the AML cell lines Nomo-1 and Kasumi-1. Reduction of Mer protein levels significantly increased rates of myeloblast apoptosis two to threefold in response to serum starvation. Furthermore, myeloblasts with knocked-down Mer demonstrated decreased colony formation by 67-87%, relative to control cell lines (P<0.01). NOD-SCID-gamma mice transplanted with Nomo-1 myeloblasts with reduced levels of Mer had a significant prolongation in survival compared with mice transplanted with the parental or control cell lines (median survival 17 days in parental and control cell lines, versus 32-36 days in Mer knockdown cell lines, P<0.0001). These data suggest a role for Mer in acute myeloid leukemogenesis and indicate that targeted inhibition of Mer may be an effective therapeutic strategy in pediatric and adult AML.
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Affiliation(s)
- A B Lee-Sherick
- Department of Pediatrics, Division of Hematology, Oncology, and Bone Marrow Transplantation, Aurora, CO, USA
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Wang XF, Tian XT, Ohkoshi E, Qin B, Liu YN, Wu PC, Hour MJ, Hung HY, Qian K, Huang R, Bastow KF, Janzen WP, Jin J, Morris-Natschke SL, Lee KH, Xie L. Design and synthesis of diarylamines and diarylethers as cytotoxic antitumor agents. Bioorg Med Chem Lett 2012; 22:6224-8. [DOI: 10.1016/j.bmcl.2012.08.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Revised: 07/26/2012] [Accepted: 08/01/2012] [Indexed: 10/28/2022]
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Mer or Axl receptor tyrosine kinase inhibition promotes apoptosis, blocks growth and enhances chemosensitivity of human non-small cell lung cancer. Oncogene 2012; 32:3420-31. [PMID: 22890323 PMCID: PMC3502700 DOI: 10.1038/onc.2012.355] [Citation(s) in RCA: 153] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Revised: 06/22/2012] [Accepted: 06/30/2012] [Indexed: 01/01/2023]
Abstract
Non-small cell lung cancer (NSCLC) is a prevalent and devastating disease that claims more lives than breast, prostate, colon, and pancreatic cancers combined. Current research suggests that standard chemotherapy regimens have been optimized to maximal efficiency. Promising new treatment strategies involve novel agents targeting molecular aberrations present in subsets of NSCLC. We evaluated 88 human NSCLC tumors of diverse histology and identified Mer and Axl as receptor tyrosine kinases (RTKs) overexpressed in 69% and 93%, respectively, of tumors relative to surrounding normal lung tissue. Mer and Axl were also frequently overexpressed and activated in NSCLC cell lines. Ligand-dependent Mer or Axl activation stimulated MAPK, AKT, and FAK signaling pathways indicating roles for these RTKs in multiple oncogenic processes. In addition, we identified a novel pro-survival pathway—involving AKT, CREB, Bcl-xL, survivin, and Bcl-2—downstream of Mer, which is differentially modulated by Axl signaling. We demonstrated that shRNA knockdown of Mer or Axl significantly reduced NSCLC colony formation and growth of subcutaneous xenografts in nude mice. Mer or Axl knockdown also improved in vitro NSCLC sensitivity to chemotherapeutic agents by promoting apoptosis. When comparing the effects of Mer and Axl knockdown, Mer inhibition exhibited more complete blockade of tumor growth while Axl knockdown more robustly improved chemosensitivity. These results indicate that Mer and Axl play complementary and overlapping roles in NSCLC and suggest that treatment strategies targeting both RTKs may be more effective than singly-targeted agents. Our findings validate Mer and Axl as potential therapeutic targets in NSCLC and provide justification for development of novel therapeutic compounds that selectively inhibit Mer and/or Axl.
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38
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Mer receptor tyrosine kinase promotes invasion and survival in glioblastoma multiforme. Oncogene 2012; 32:872-82. [PMID: 22469987 DOI: 10.1038/onc.2012.104] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The infiltration of glioma cells into adjacent tissue is one of the major obstacles in the therapeutic management of malignant brain tumours, in most cases precluding complete surgical resection. Consequently, malignant glioma patients almost invariably experience tumour recurrences. Within the brain, glioma cells migrate rapidly either amoeboidly or mesenchymally to invade surrounding structures, in dependence on the extracellular environment. In addition, radiotherapy, frequently applied as adjuvant therapeutic modality, may enhance tumour cell mobility. Here, we show that the receptor tyrosine kinase Mer (MerTK) is overexpressed in glioblastoma multiforme (GBM) and that this is accompanied with increased invasive potential. MerTK expression is maintained in primary GBM-derived tumour spheres under stem cell culture conditions but diminishes significantly in serum-containing cultures with concomitant downregulation of Nestin and Sox2. Depletion of MerTK disrupts the rounded morphology of glioma cells and decreases their invasive capacity. Furthermore, the expression and phosphorylation of myosin light chain 2 are strongly associated with MerTK activity, indicating that the effect of MerTK on glioma cell invasion is mediated by actomyosin contractility. Finally, DNA damage robustly triggers the upregulation and phosphorylation of MerTK, which protects cells from apoptosis. This effect is strongly impaired upon MerTK depletion or overexpression of an inactive MerTK mutant. Collectively, our data suggests that MerTK is a novel therapeutic target in the treatment of the malignant gliomas.
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Prolonged exposure to a Mer ligand in leukemia: Gas6 favors expression of a partial Mer glycoform and reveals a novel role for Mer in the nucleus. PLoS One 2012; 7:e31635. [PMID: 22363695 PMCID: PMC3282750 DOI: 10.1371/journal.pone.0031635] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Accepted: 01/10/2012] [Indexed: 12/28/2022] Open
Abstract
Mer tyrosine kinase is ectopically expressed in acute lymphoblastic leukemia and associated with enhanced chemoresistance and disease progression. While such effects are generally ascribed to increased engagement of oncogenic pathways downstream of Mer stimulation by its ligand, Gas6, Mer has not been characterized beyond the scope of its signaling activity. The present study explores Mer behavior following prolonged exposure to Gas6, a context similar to the Gas6-enriched microenvironment of the bone marrow, where a steady supply of ligand facilitates continuous engagement of Mer and likely sustains the presence of leukemic cells. Long-term Gas6 exposure induced production of a partially N-glycosylated form of Mer from newly synthesized stores of protein. Preferential expression of the partial Mer glycoform was associated with diminished levels of Mer on the cell surface and altered Mer localization within the nuclear-soluble and chromatin-bound fractions. The presence of Mer in the nucleus is a novel finding for this receptor, and the glycoform-specific preferences observed in each nuclear compartment suggest that glycosylation may influence Mer function within particular subcellular locales. Previous studies have established Mer as an attractive cancer biologic target, and understanding the complexity of its activity has important implications for potential strategies of Mer inhibition in leukemia therapy. Our results identify several novel features of Mer that expand the breadth of its functions and impact the development of therapeutic modalities designed to target Mer.
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40
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Verma A, Warner SL, Vankayalapati H, Bearss DJ, Sharma S. Targeting Axl and Mer kinases in cancer. Mol Cancer Ther 2011; 10:1763-73. [PMID: 21933973 DOI: 10.1158/1535-7163.mct-11-0116] [Citation(s) in RCA: 173] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Receptor tyrosine kinases (RTK) are cell-surface transmembrane receptors that contain regulated kinase activity within their cytoplasmic domain and play an important role in signal transduction in both normal and malignant cells. The mammalian TAM RTK family includes 3 closely related members: Tyro-3, Axl, and Mer. Overexpression or ectopic expression of the TAM receptors has been detected in a wide array of human cancers. Growth arrest-specific gene 6 has been identified as the major ligand for these TAM RTKs, and its binding to the receptors has been shown to promote proliferation and survival of cancer cells in vitro. Abnormal expression and activation of Axl or Mer can provide a survival advantage for certain cancer cells. Inhibition of Axl and Mer may enhance the sensitivity of cancer cells to cytotoxic agents and would potentially be a therapeutic strategy to target cancer cells. This review elucidates the role of Axl and Mer in normal cellular function and their role in oncogenesis. In addition, we review the potential to inhibit these RTKs for the development of therapeutic targets in treatment of cancer.
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Affiliation(s)
- Anupam Verma
- Pediatric Hematology/Oncology, Primary Children's Medical Center, Huntsman Cancer Institute, 2000 Circle of Hope, Salt Lake City, UT 84112, USA.
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41
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Lee-Sherick AB, Linger RMA, Gore L, Keating AK, Graham DK. Targeting paediatric acute lymphoblastic leukaemia: novel therapies currently in development. Br J Haematol 2010; 151:295-311. [PMID: 20813012 DOI: 10.1111/j.1365-2141.2010.08282.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Modifications to the treatment of acute lymphoblastic leukaemia (ALL) in children have led to a dramatic increase in survival in the past 40 years. Despite this success, a significant subset of paediatric leukaemia patients either relapse or fail to ever achieve a complete remission. Additionally, some patients necessitate treatment with intensified chemotherapy regimens due to clinical or laboratory findings which identify them as high risk. These patients are unlikely to respond to further minor adjustments to the dosing or timing of administration of the same chemotherapy medications. Many novel targeted therapies for the treatment of childhood ALL provide potential mechanisms to further improve cure rates, and provide the possibility of minimizing toxicity to non-malignant cells, given their specificity to malignant cell phenotypes. This article explores many of the potential targeted therapies in varying stages of development, from those currently in clinical trials to those still being refined in the research laboratory.
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Affiliation(s)
- Alisa B Lee-Sherick
- Department of Paediatrics, Section of Haematology, Oncology, and Bone Marrow Transplantation, University of Colorado Denver School of Medicine, Aurora, CO, USA
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Alciato F, Sainaghi PP, Sola D, Castello L, Avanzi GC. TNF-α, IL-6, and IL-1 expression is inhibited by GAS6 in monocytes/macrophages. J Leukoc Biol 2010; 87:869-75. [DOI: 10.1189/jlb.0909610] [Citation(s) in RCA: 142] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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A genomic screen identifies TYRO3 as a MITF regulator in melanoma. Proc Natl Acad Sci U S A 2009; 106:17025-30. [PMID: 19805117 DOI: 10.1073/pnas.0909292106] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Malignant melanoma is the most aggressive form of cutaneous carcinoma, accounting for 75% of all deaths caused by skin cancers. Microphthalmia-associated transcription factor (MITF) is a master gene regulating melanocyte development and functions as a "lineage addiction" oncogene in malignant melanoma. We have identified the receptor protein tyrosine kinase TYRO3 as an upstream regulator of MITF expression by a genome-wide gain-of-function cDNA screen and show that TYRO3 induces MITF-M expression in a SOX10-dependent manner in melanoma cells. Expression of TYRO3 is significantly elevated in human primary melanoma tissue samples and melanoma cell lines and correlates with MITF-M mRNA levels. TYRO3 overexpression bypasses BRAF(V600E)-induced senescence in primary melanocytes, inducing transformation of non-tumorigenic cell lines. Furthermore, TYRO3 knockdown represses cellular proliferation and colony formation in melanoma cells, and sensitizes them to chemotherapeutic agent-induced apoptosis; TYRO3 knockdown in melanoma cells also inhibits tumorigenesis in vivo. Taken together, these data indicate that TYRO3 may serve as a target for the development of therapeutic agents for melanoma.
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44
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Mer receptor tyrosine kinase is a novel therapeutic target in pediatric B-cell acute lymphoblastic leukemia. Blood 2009; 114:2678-87. [PMID: 19643988 DOI: 10.1182/blood-2009-03-209247] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Acute lymphoblastic leukemia (ALL) is currently treated with an intense regimen of chemotherapy yielding cure rates near 80%. However, additional changes using available drugs are unlikely to provide significant improvement in survival. New therapies are warranted given the risk of severe therapy-associated toxicities including infertility, organ damage, and secondary malignancy. Here, we report ectopic expression of the receptor tyrosine kinase Mer in pediatric B-cell ALL. Inhibition of Mer prevented Erk 1/2 activation, increased the sensitivity of B-ALL cells to cytotoxic agents in vitro by promoting apoptosis, and delayed disease onset in a mouse model of leukemia. In addition, we discovered cross-talk between the Mer and mammalian target of rapamycin (mTOR) signaling pathways. Our results identify Mer as a novel therapeutic target in ALL and suggest that inhibitors of Mer will interact synergistically with currently used therapies. This strategy may allow for dose reduction resulting in decreased toxicity and increased survival rates. Mer is aberrantly expressed in numerous other malignancies suggesting that this approach may have broad applications.
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45
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Anwar A, Keating AK, Joung D, Sather S, Kim GK, Sawczyn KK, Brandão L, Henson PM, Graham DK. Mer tyrosine kinase (MerTK) promotes macrophage survival following exposure to oxidative stress. J Leukoc Biol 2009; 86:73-9. [PMID: 19386698 DOI: 10.1189/jlb.0608334] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The MerTK plays several important roles in normal macrophage physiology, including regulation of cytokine secretion and clearance of apoptotic cells. Mer signaling in other cell types, including malignant cells that ectopically overexpress the RTK, leads to downstream prosurvival pathway activation. We explored the hypothesis that Mer has a prosurvival role in macrophages exposed to oxidative stress. H(2)O(2) treatment of peritoneal exudate murine macrophages and J774 cells rapidly stimulated Mer phosphorylation in a concentration-dependent manner. Mer phosphorylation was dependent on the ligand Gas6, as treatment with warfarin or MerFc (a fusion protein of the extracellular domain of Mer and the Fc portion of human Ig), inhibitors of Gas6 activity, blocked H(2)O(2)-mediated activation of Mer. Antiapoptotic signals including pAkt and pErk 1/2 were increased dramatically (threefold and 4.5-fold, respectively) in WT Mer-positive macrophages compared with Mer KO macrophages stimulated with H(2)O(2). In a consistent manner, Mer expression led to decreased cleavage of proapoptotic indicators PARP and Caspase-3. Furthermore, Mer provided up to twofold enhanced cellular survival to primary macrophages exposed to H(2)O(2). These data represent the first report of Mer activation in response to oxidative stress and demonstrate the ability of Mer RTK to promote macrophage survival in disease states that involve an oxidative stress environment.
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Affiliation(s)
- Adil Anwar
- Department of Pediatrics, University of Colorado Denver, Aurora, CO 80045, USA
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46
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Curtis JL, Todt JC, Hu B, Osterholzer JJ, Freeman CM. Tyro3 receptor tyrosine kinases in the heterogeneity of apoptotic cell uptake. Front Biosci (Landmark Ed) 2009; 14:2631-46. [PMID: 19273223 DOI: 10.2741/3401] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Mononuclear phagocytes comprise a mobile, broadly dispersed and highly adaptable system that lies at the very epicenter of host defense against pathogens and the interplay of the innate and adaptive arms of immunity. Understanding the molecular mechanisms that control the response of mononuclear phagocytes to apoptotic cells and the anti-inflammatory consequences of that response is an important goal with implications for multiple areas of biomedical sciences. This review details current understanding of the heterogeneity of apoptotic cell uptake by different members of the mononuclear phagocyte family in humans and mice. It also recounts the unique role of the Tyro3 family of receptor tyrosine kinases, best characterized for Mertk, in the signal transduction leading both to apoptotic cell ingestion and the anti-inflammatory effects that result.
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Affiliation(s)
- Jeffrey L Curtis
- Pulmonary and Critical Care Medicine, Department of Veterans Affairs Healthsystem and University of Michigan Health System, Ann Arbor, MI 48105, USA.
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47
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Johnson G, Swart C, Moore SW. Non-enzymatic developmental functions of acetylcholinesterase - the question of redundancy. FEBS J 2008; 275:5129-38. [DOI: 10.1111/j.1742-4658.2008.06644.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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48
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Linger RMA, Keating AK, Earp HS, Graham DK. TAM receptor tyrosine kinases: biologic functions, signaling, and potential therapeutic targeting in human cancer. Adv Cancer Res 2008; 100:35-83. [PMID: 18620092 DOI: 10.1016/s0065-230x(08)00002-x] [Citation(s) in RCA: 539] [Impact Index Per Article: 33.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Tyro-3, Axl, and Mer constitute the TAM family of receptor tyrosine kinases (RTKs) characterized by a conserved sequence within the kinase domain and adhesion molecule-like extracellular domains. This small family of RTKs regulates an intriguing mix of processes, including cell proliferation/survival, cell adhesion and migration, blood clot stabilization, and regulation of inflammatory cytokine release. Genetic or experimental alteration of TAM receptor function can contribute to a number of disease states, including coagulopathy, autoimmune disease, retinitis pigmentosa, and cancer. In this chapter, we first provide a comprehensive review of the structure, regulation, biologic functions, and downstream signaling pathways of these receptors. In addition, we discuss recent evidence which suggests a role for TAM receptors in oncogenic mechanisms as family members are overexpressed in a spectrum of human cancers and have prognostic significance in some. Possible strategies for targeted inhibition of the TAM family in the treatment of human cancer are described. Further research will be necessary to evaluate the full clinical implications of TAM family expression and activation in cancer.
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Affiliation(s)
- Rachel M A Linger
- Department of Pediatrics, University of Colorado at Denver and Health Sciences Center, Aurora, CO, USA
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49
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Kazeros A, Harvey BG, Carolan BJ, Vanni H, Krause A, Crystal RG. Overexpression of apoptotic cell removal receptor MERTK in alveolar macrophages of cigarette smokers. Am J Respir Cell Mol Biol 2008; 39:747-57. [PMID: 18587056 DOI: 10.1165/rcmb.2007-0306oc] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Mononuclear phagocytes play an important role in the removal of apoptotic cells by expressing cell surface receptors that recognize and remove apoptotic cells. Based on the knowledge that cigarette smoking is associated with increased lung cell turnover, we hypothesized that alveolar macrophages (AMs) of normal cigarette smokers may exhibit enhanced expression of apoptotic cell removal receptor genes. AMs obtained by bronchoalveolar lavage of normal nonsmokers (n = 11) and phenotypic normal smokers (n = 13; 36 +/- 6 pack-years) were screened for mRNA expression of all known apoptotic cell removal receptors using Affymetrix HG-U133 Plus 2.0 microarray chips with TaqMan RT-PCR confirmation. Of the 14 known apoptotic receptors expressed, only MER tyrosine kinase (MERTK), a transmembrane tyrosine kinase receptor, was significantly up-regulated in smokers. MERTK expression was then assessed in AMs of smokers versus nonsmokers by TaqMan RT-PCR, immunocytochemistry, Western analysis, and flow analysis. Smoker AMs had up-regulation of MERTK mRNA levels (smoker vs. nonsmoker: 3.6-fold by microarray, P < 0.003; 9.5-fold by TaqMan RT-PCR, P < 0.02). Immunocytochemistry demonstrated a qualitative increase in MERTK protein expression on AMs of smokers. Increased protein expression of MERTK on AMs of smokers was confirmed by Western and flow analyses (P < 0.007 and P < 0.0002, respectively). MERTK, a cell surface receptor that recognizes apoptotic cells, is expressed on human AMs, and its expression is up-regulated in AMs of cigarette smokers. This up-regulation of MERTK may reflect an increased demand for removal of apoptotic cells in smokers, an observation with implications for the development of chronic obstructive pulmonary disease, a disorder associated with dysregulated apoptosis of lung parenchymal cells.
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Affiliation(s)
- Angeliki Kazeros
- Division of Pulmonary and Critical Care, Weill Medical College of Cornell University, New York, New York 10065, USA
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50
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Bellido-Martín L, de Frutos PG. Vitamin K-dependent actions of Gas6. VITAMINS AND HORMONES 2008; 78:185-209. [PMID: 18374195 DOI: 10.1016/s0083-6729(07)00009-x] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Gas6 (growth arrest-specific gene 6) is the last addition to the family of plasma vitamin K-dependent proteins. Gas6 was cloned and characterized in 1993 and found to be similar to the plasma anticoagulant protein S. Soon after it was recognized as a growth factor-like molecule, as it interacted with receptor tyrosine kinases (RTKs) of the TAM family; Tyro3, Axl, and MerTK. Since then, the role of Gas6, protein S, and the TAM receptors has been found to be important in inflammation, hemostasis, and cancer, making this system an interesting target in biomedicine. Gas6 employs a unique mechanism of action, interacting through its vitamin K-dependent Gla module with phosphatidylserine-containing membranes and through its carboxy-terminal LG domains with the TAM membrane receptors. The fact that these proteins are affected by anti-vitamin K therapy is discussed in detail.
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Affiliation(s)
- Lola Bellido-Martín
- Department of Cell Death and Proliferation, Institute for Biomedical Research of Barcelona, IIBB-CSIC-IDIBAPS, Barcelona 08036, Spain
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