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Abstract
Despite MYC being among the most intensively studied oncogenes, its role in normal development has not been determined as Myc-/- mice do not survival beyond mid-gestation. Myc ± mice live longer than their wild-type counterparts and are slower to accumulate many age-related phenotypes. However, Myc haplo-insufficiency likely conceals other important phenotypes as many high-affinity Myc targets genes continue to be regulated normally. By delaying Myc inactivation until after birth it has recently been possible to study the consequences of its near-complete total body loss and thus to infer its normal function. Against expectation, these "MycKO" mice lived significantly longer than control wild-type mice but manifested a marked premature aging phenotype. This seemingly paradoxical behavior was potentially explained by a >3-fold lower lifetime incidence of cancer, normally the most common cause of death in mice and often Myc-driven. Myc loss accelerated the accumulation of numerous "Aging Hallmarks", including the loss of mitochondrial and ribosomal structural and functional integrity, the generation of reactive oxygen species, the acquisition of genotoxic damage, the detrimental rewiring of metabolism and the onset of senescence. In both mice and humans, normal aging in many tissues was accompaniued by the downregulation of Myc and the loss of Myc target gene regulation. Unlike most mouse models of premature aging, which are based on monogenic disorders of DNA damage recognition and repair, the MycKO mouse model directly impacts most Aging Hallmarks and may therefore more faithfully replicate the normal aging process of both mice and humans. It further establishes that the strong association between aging and cancer can be genetically separated and is maintained by a single gene.
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Affiliation(s)
- Edward V. Prochownik
- Division of Hematology/Oncology, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, PA, United States
- The Department of Microbiology and Molecular Genetics, UPMC, Pittsburgh, PA, United States
- The Hillman Cancer Center of UPMC, Pittsburgh, PA, United States
- The Pittsburgh Liver Research Center, UPMC, Pittsburgh, PA, United States
| | - Huabo Wang
- Division of Hematology/Oncology, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, PA, United States
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Cruz Cruz J, Allison KC, Page LS, Jenkins AJ, Wang X, Earp HS, Frye SV, Graham DK, Verneris MR, Lee-Sherick AB. Inhibiting efferocytosis reverses macrophage-mediated immunosuppression in the leukemia microenvironment. Front Immunol 2023; 14:1146721. [PMID: 36960055 PMCID: PMC10027704 DOI: 10.3389/fimmu.2023.1146721] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 02/20/2023] [Indexed: 03/09/2023] Open
Abstract
Background Previous studies show that the spleen and bone marrow can serve as leukemia microenvironments in which macrophages play a significant role in immune evasion and chemoresistance. We hypothesized that the macrophage driven tolerogenic process of efferocytosis is a major contributor to the immunosuppressive leukemia microenvironment and that this was driven by aberrant phosphatidylserine expression from cell turnover and cell membrane dysregulation. Methods Since MerTK is the prototypic efferocytosis receptor, we assessed whether the MerTK inhibitor MRX2843, which is currently in clinical trials, would reverse immune evasion and enhance immune-mediated clearance of leukemia cells. Results We found that inhibition of MerTK decreased leukemia-associated macrophage expression of M2 markers PD-L1, PD-L2, Tim-3, CD163 and Arginase-1 compared to vehicle-treated controls. Additionally, MerTK inhibition led to M1 macrophage repolarization including elevated CD86 and HLA-DR expression, and increased production of T cell activating cytokines, including IFN-β, IL-18, and IL-1β through activation of NF-κB. Collectively, this macrophage repolarization had downstream effects on T cells within the leukemia microenvironment, including decreased PD-1+Tim-3+ and LAG3+ checkpoint expression, and increased CD69+CD107a+ expression. Discussion These results demonstrate that MerTK inhibition using MRX2843 altered the leukemia microenvironment from tumor-permissive toward immune responsiveness to leukemia and culminated in improved immune-mediated clearance of AML.
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Affiliation(s)
- Joselyn Cruz Cruz
- Division of Pediatric Hematology, Oncology, and Bone Marrow Transplant, University of Colorado, Aurora, CO, United States
| | - Kristen C. Allison
- Division of Pediatric Hematology, Oncology, and Bone Marrow Transplant, University of Colorado, Aurora, CO, United States
| | - Lauren S. Page
- Division of Pediatric Hematology, Oncology, and Bone Marrow Transplant, University of Colorado, Aurora, CO, United States
| | - Alexis J. Jenkins
- Division of Pediatric Hematology, Oncology, and Bone Marrow Transplant, University of Colorado, Aurora, CO, United States
| | - Xiaodong Wang
- Center for Integrative Chemical Biology and Drug Discovery, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - H. Shelton Earp
- Lineberger Comprehensive Cancer Center, Departments of Medicine and Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Stephen V. Frye
- Center for Integrative Chemical Biology and Drug Discovery, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Douglas K. Graham
- Department of Pediatrics, Emory University, Atlanta, GA, United States
| | - Michael R. Verneris
- Division of Pediatric Hematology, Oncology, and Bone Marrow Transplant, University of Colorado, Aurora, CO, United States
| | - Alisa B. Lee-Sherick
- Division of Pediatric Hematology, Oncology, and Bone Marrow Transplant, University of Colorado, Aurora, CO, United States
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Vital T, Wali A, Butler KV, Xiong Y, Foster JP, Marcel SS, McFadden AW, Nguyen VU, Bailey BM, Lamb KN, James LI, Frye SV, Mosely AL, Jin J, Pattenden SG, Davis IJ. MS0621, a novel small-molecule modulator of Ewing sarcoma chromatin accessibility, interacts with an RNA-associated macromolecular complex and influences RNA splicing. Front Oncol 2023; 13:1099550. [PMID: 36793594 PMCID: PMC9924231 DOI: 10.3389/fonc.2023.1099550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 01/11/2023] [Indexed: 01/31/2023] Open
Abstract
Ewing sarcoma is a cancer of children and young adults characterized by the critical translocation-associated fusion oncoprotein EWSR1::FLI1. EWSR1::FLI1 targets characteristic genetic loci where it mediates aberrant chromatin and the establishment of de novo enhancers. Ewing sarcoma thus provides a model to interrogate mechanisms underlying chromatin dysregulation in tumorigenesis. Previously, we developed a high-throughput chromatin-based screening platform based on the de novo enhancers and demonstrated its utility in identifying small molecules capable of altering chromatin accessibility. Here, we report the identification of MS0621, a molecule with previously uncharacterized mechanism of action, as a small molecule modulator of chromatin state at sites of aberrant chromatin accessibility at EWSR1::FLI1-bound loci. MS0621 suppresses cellular proliferation of Ewing sarcoma cell lines by cell cycle arrest. Proteomic studies demonstrate that MS0621 associates with EWSR1::FLI1, RNA binding and splicing proteins, as well as chromatin regulatory proteins. Surprisingly, interactions with chromatin and many RNA-binding proteins, including EWSR1::FLI1 and its known interactors, were RNA-independent. Our findings suggest that MS0621 affects EWSR1::FLI1-mediated chromatin activity by interacting with and altering the activity of RNA splicing machinery and chromatin modulating factors. Genetic modulation of these proteins similarly inhibits proliferation and alters chromatin in Ewing sarcoma cells. The use of an oncogene-associated chromatin signature as a target allows for a direct approach to screen for unrecognized modulators of epigenetic machinery and provides a framework for using chromatin-based assays for future therapeutic discovery efforts.
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Affiliation(s)
- Tamara Vital
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Department of Genetics, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Aminah Wali
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Department of Genetics, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Kyle V. Butler
- Mount Sinai Center for Therapeutics Discovery, Department of Pharmacological Sciences, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States
- Mount Sinai Center for Therapeutics Discovery, Department of Oncological Sciences, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States
- Mount Sinai Center for Therapeutics Discovery, Department of Neuroscience, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Yan Xiong
- Mount Sinai Center for Therapeutics Discovery, Department of Pharmacological Sciences, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States
- Mount Sinai Center for Therapeutics Discovery, Department of Oncological Sciences, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States
- Mount Sinai Center for Therapeutics Discovery, Department of Neuroscience, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Joseph P. Foster
- Department of Genetics, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Curriculum in Bioinformatics and Computational Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Shelsa S. Marcel
- Department of Genetics, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Curriculum in Bioinformatics and Computational Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Andrew W. McFadden
- Lineberger Comprehensive Cancer Center, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Valerie U. Nguyen
- Lineberger Comprehensive Cancer Center, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Benton M. Bailey
- Lineberger Comprehensive Cancer Center, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Kelsey N. Lamb
- Center for Integrative Chemical Biology and Drug Discovery, Division of Chemical Biology and Medicinal Chemistry, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Lindsey I. James
- Lineberger Comprehensive Cancer Center, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Center for Integrative Chemical Biology and Drug Discovery, Division of Chemical Biology and Medicinal Chemistry, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Stephen V. Frye
- Lineberger Comprehensive Cancer Center, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Center for Integrative Chemical Biology and Drug Discovery, Division of Chemical Biology and Medicinal Chemistry, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Amber L. Mosely
- Indiana University Simon Comprehensive Cancer Center, Indiana University School of Medicine, Indianapolis, IN, United States
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Jian Jin
- Mount Sinai Center for Therapeutics Discovery, Department of Pharmacological Sciences, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States
- Mount Sinai Center for Therapeutics Discovery, Department of Oncological Sciences, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States
- Mount Sinai Center for Therapeutics Discovery, Department of Neuroscience, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Samantha G. Pattenden
- Lineberger Comprehensive Cancer Center, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Center for Integrative Chemical Biology and Drug Discovery, Division of Chemical Biology and Medicinal Chemistry, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Ian J. Davis
- Department of Genetics, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Lineberger Comprehensive Cancer Center, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Department of Pediatrics, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
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Paolini L, Hussain S, Galardy PJ. Chromosome instability in neuroblastoma: A pathway to aggressive disease. Front Oncol 2022; 12:988972. [PMID: 36338721 PMCID: PMC9633097 DOI: 10.3389/fonc.2022.988972] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 10/03/2022] [Indexed: 11/15/2023] Open
Abstract
For over 100-years, genomic instability has been investigated as a central player in the pathogenesis of human cancer. Conceptually, genomic instability includes an array of alterations from small deletions/insertions to whole chromosome alterations, referred to as chromosome instability. Chromosome instability has a paradoxical impact in cancer. In most instances, the introduction of chromosome instability has a negative impact on cellular fitness whereas in cancer it is usually associated with a worse prognosis. One exception is the case of neuroblastoma, the most common solid tumor outside of the brain in children. Neuroblastoma tumors have two distinct patterns of genome instability: whole-chromosome aneuploidy, which is associated with a better prognosis, or segmental chromosomal alterations, which is a potent negative prognostic factor. Through a computational screen, we found that low levels of the de- ubiquitinating enzyme USP24 have a highly significant negative impact on survival in neuroblastoma. At the molecular level, USP24 loss leads to destabilization of the microtubule assembly factor CRMP2 - producing mitotic errors and leading to chromosome missegregation and whole-chromosome aneuploidy. This apparent paradox may be reconciled through a model in which whole chromosome aneuploidy leads to the subsequent development of segmental chromosome alterations. Here we review the mechanisms behind chromosome instability and the evidence for the progressive development of segmental alterations from existing numerical aneuploidy in support of a multi-step model of neuroblastoma progression.
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Affiliation(s)
- Lucia Paolini
- Department of Pediatrics, University of Milano-Bicocca, San Gerardo Hospital, Monza, MI, Italy
- Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, MN, United States
| | - Sajjad Hussain
- Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, MN, United States
| | - Paul J. Galardy
- Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, MN, United States
- Division of Pediatric Hematology-Oncology, Mayo Clinic, Rochester, MN, United States
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