1
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Alderman C, Anderson R, Zhang L, Hughes CJ, Li X, Ebmeier C, Wagley ME, Ahn NG, Ford HL, Zhao R. Biochemical characterization of the Eya and PP2A-B55α interaction. J Biol Chem 2024; 300:107408. [PMID: 38796066 DOI: 10.1016/j.jbc.2024.107408] [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: 12/15/2023] [Revised: 04/22/2024] [Accepted: 05/09/2024] [Indexed: 05/28/2024] Open
Abstract
The eyes absent (Eya) proteins were first identified as co-activators of the six homeobox family of transcription factors and are critical in embryonic development. These proteins are also re-expressed in cancers after development is complete, where they drive tumor progression. We have previously shown that the Eya3 N-terminal domain (NTD) contains Ser/Thr phosphatase activity through an interaction with the protein phosphatase 2A (PP2A)-B55α holoenzyme and that this interaction increases the half-life of Myc through pT58 dephosphorylation. Here, we showed that Eya3 directly interacted with the NTD of Myc, recruiting PP2A-B55α to Myc. We also showed that Eya3 increased the Ser/Thr phosphatase activity of PP2A-B55α but not PP2A-B56α. Furthermore, we demonstrated that the NTD (∼250 amino acids) of Eya3 was completely disordered, and it used a 38-residue segment to interact with B55α. In addition, knockdown and phosphoproteomic analyses demonstrated that Eya3 and B55α affected highly similar phosphosite motifs with a preference for Ser/Thr followed by Pro, consistent with Eya3's apparent Ser/Thr phosphatase activity being mediated through its interaction with PP2A-B55α. Intriguingly, mutating this Pro to other amino acids in a Myc peptide dramatically increased dephosphorylation by PP2A. Not surprisingly, MycP59A, a naturally occurring mutation hotspot in several cancers, enhanced Eya3-PP2A-B55α-mediated dephosphorylation of pT58 on Myc, leading to increased Myc stability and cell proliferation, underscoring the critical role of this phosphosite in regulating Myc stability.
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Affiliation(s)
- Christopher Alderman
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA; Medical Scientist Training Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA; Molecular Biology Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Ryan Anderson
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Lingdi Zhang
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Connor J Hughes
- Medical Scientist Training Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA; Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Xueni Li
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Chris Ebmeier
- Department of Biochemistry, University of Colorado-Boulder, Boulder, Colorado, USA
| | - Marisa E Wagley
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Natalie G Ahn
- Department of Biochemistry, University of Colorado-Boulder, Boulder, Colorado, USA
| | - Heide L Ford
- Molecular Biology Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA; Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Rui Zhao
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA; Molecular Biology Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA.
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2
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Freie B, Carroll PA, Varnum-Finney BJ, Ramsey EL, Ramani V, Bernstein I, Eisenman RN. A germline point mutation in the MYC-FBW7 phosphodegron initiates hematopoietic malignancies. Genes Dev 2024; 38:253-272. [PMID: 38565249 PMCID: PMC11065175 DOI: 10.1101/gad.351292.123] [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: 10/23/2023] [Accepted: 03/19/2024] [Indexed: 04/04/2024]
Abstract
Oncogenic activation of MYC in cancers predominantly involves increased transcription rather than coding region mutations. However, MYC-dependent lymphomas frequently acquire point mutations in the MYC phosphodegron, including at threonine 58 (T58), where phosphorylation permits binding via the FBW7 ubiquitin ligase triggering MYC degradation. To understand how T58 phosphorylation functions in normal cell physiology, we introduced an alanine mutation at T58 (T58A) into the endogenous c-Myc locus in the mouse germline. While MYC-T58A mice develop normally, lymphomas and myeloid leukemias emerge in ∼60% of adult homozygous T58A mice. We found that primitive hematopoietic progenitor cells from MYC-T58A mice exhibit aberrant self-renewal normally associated with hematopoietic stem cells (HSCs) and up-regulate a subset of MYC target genes important in maintaining stem/progenitor cell balance. In lymphocytes, genomic occupancy by MYC-T58A was increased at all promoters compared with WT MYC, while genes differentially expressed in a T58A-dependent manner were significantly more proximal to MYC-bound enhancers. MYC-T58A lymphocyte progenitors exhibited metabolic alterations and decreased activation of inflammatory and apoptotic pathways. Our data demonstrate that a single point mutation stabilizing MYC is sufficient to skew target gene expression, producing a profound gain of function in multipotential hematopoietic progenitors associated with self-renewal and initiation of lymphomas and leukemias.
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Affiliation(s)
- Brian Freie
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, Washington 98109, USA;
| | - Patrick A Carroll
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, Washington 98109, USA
| | | | - Erin L Ramsey
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, Washington 98109, USA
| | - Vijay Ramani
- Gladstone Institute for Data Science and Biotechnology, University of California, San Francisco, San Francisco, California 94158, USA
| | - Irwin Bernstein
- Clinical Research Division, Fred Hutchinson Cancer Center, Seattle, Washington 98109, USA
| | - Robert N Eisenman
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, Washington 98109, USA;
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3
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Molina E, García-Gutiérrez L, Junco V, Perez-Olivares M, de Yébenes VG, Blanco R, Quevedo L, Acosta JC, Marín AV, Ulgiati D, Merino R, Delgado MD, Varela I, Regueiro JR, Moreno de Alborán I, Ramiro AR, León J. MYC directly transactivates CR2/CD21, the receptor of the Epstein-Barr virus, enhancing the viral infection of Burkitt lymphoma cells. Oncogene 2023; 42:3358-3370. [PMID: 37773203 DOI: 10.1038/s41388-023-02846-9] [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] [Received: 02/01/2023] [Revised: 09/12/2023] [Accepted: 09/18/2023] [Indexed: 10/01/2023]
Abstract
MYC is an oncogenic transcription factor dysregulated in about half of total human tumors. While transcriptomic studies reveal more than 1000 genes regulated by MYC, a much smaller fraction of genes is directly transactivated by MYC. Virtually all Burkitt lymphoma (BL) carry chromosomal translocations involving MYC oncogene. Most endemic BL and a fraction of sporadic BL are associated with Epstein-Barr virus (EBV) infection. The currently accepted mechanism is that EBV is the BL-causing agent inducing MYC translocation. Herein we show that the EBV receptor, CR2 (also called CD21), is a direct MYC target gene. This is based on several pieces of evidence: MYC induces CR2 expression in both proliferating and arrested cells and in the absence of protein synthesis, binds the CR2 promoter and transactivates CR2 in an E-box-dependent manner. Moreover, using mice with conditional MYC ablation we show that MYC induces CR2 in primary B cells. Importantly, modulation of MYC levels directly correlates with EBV's ability of infection in BL cells. Altogether, in contrast to the widely accepted hypothesis for the correlation between EBV and BL, we propose an alternative hypothesis in which MYC dysregulation could be the first event leading to the subsequent EBV infection.
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Affiliation(s)
- Ester Molina
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-CSIC, Santander, Spain
- Departamento de Biología Molecular, Universidad de Cantabria, Santander, Spain
- The Hormel Institute, University of Minnesota, Austin, MN, USA
| | - Lucía García-Gutiérrez
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-CSIC, Santander, Spain
- Departamento de Biología Molecular, Universidad de Cantabria, Santander, Spain
| | - Vanessa Junco
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-CSIC, Santander, Spain
- Departamento de Biología Molecular, Universidad de Cantabria, Santander, Spain
| | - Mercedes Perez-Olivares
- Department of Immunology and Oncology, Centro Nacional de Biotecnología (CNB)-CSIC, Madrid, Spain
| | - Virginia G de Yébenes
- Centro Nacional de Investigaciones Cardiovasculares-CNIC Carlos III, Madrid, Spain
- Department of Immunology, Ophthalmology and ENT, Universidad Complutense, School of Medicine and 12 de Octubre Health Research Institute (imas12), Madrid, Spain
| | - Rosa Blanco
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-CSIC, Santander, Spain
- Departamento de Biología Molecular, Universidad de Cantabria, Santander, Spain
| | - Laura Quevedo
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-CSIC, Santander, Spain
- Departamento de Biología Molecular, Universidad de Cantabria, Santander, Spain
| | - Juan C Acosta
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-CSIC, Santander, Spain
- Departamento de Biología Molecular, Universidad de Cantabria, Santander, Spain
| | - Ana V Marín
- Department of Immunology, Ophthalmology and ENT, Universidad Complutense, School of Medicine and 12 de Octubre Health Research Institute (imas12), Madrid, Spain
| | - Daniela Ulgiati
- School of Biomedical Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Ramon Merino
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-CSIC, Santander, Spain
- Departamento de Biología Molecular, Universidad de Cantabria, Santander, Spain
| | - M Dolores Delgado
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-CSIC, Santander, Spain
- Departamento de Biología Molecular, Universidad de Cantabria, Santander, Spain
| | - Ignacio Varela
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-CSIC, Santander, Spain
- Departamento de Biología Molecular, Universidad de Cantabria, Santander, Spain
| | - José R Regueiro
- Department of Immunology, Ophthalmology and ENT, Universidad Complutense, School of Medicine and 12 de Octubre Health Research Institute (imas12), Madrid, Spain
| | | | - Almudena R Ramiro
- Centro Nacional de Investigaciones Cardiovasculares-CNIC Carlos III, Madrid, Spain
| | - Javier León
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-CSIC, Santander, Spain.
- Departamento de Biología Molecular, Universidad de Cantabria, Santander, Spain.
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Freie B, Carroll PA, Varnum-Finney BJ, Ramani V, Bernstein I, Eisenman RN. A Germline Point Mutation in the MYC-FBW7 Phosphodegron Initiates Hematopoietic Malignancies. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.23.563660. [PMID: 37961183 PMCID: PMC10634767 DOI: 10.1101/2023.10.23.563660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Oncogenic activation of MYC in cancers predominantly involves increased transcription rather than coding region mutations. However, MYC-dependent lymphomas frequently contain point mutations in the MYC phospho-degron, including at threonine-58 (T58), where phosphorylation permits binding by the FBW7 ubiquitin ligase triggering MYC degradation. To understand how T58 phosphorylation functions in normal cell physiology, we introduced an alanine mutation at T58 (T58A) into the endogenous c-Myc locus in the mouse germline. While MYC-T58A mice develop normally, lymphomas and myeloid leukemias emerge in ~60% of adult homozygous T58A mice. We find that primitive hematopoietic progenitor cells from MYC-T58A mice exhibit aberrant self-renewal normally associated with hematopoietic stem cells (HSCs) and upregulate a subset of Myc target genes important in maintaining stem/progenitor cell balance. Genomic occupancy by MYC-T58A was increased at all promoters, compared to WT MYC, while genes differentially expressed in a T58A-dependent manner were significantly more proximal to MYC-bound enhancers. MYC-T58A lymphocyte progenitors exhibited metabolic alterations and decreased activation of inflammatory and apoptotic pathways. Our data demonstrate that a single point mutation in Myc is sufficient to produce a profound gain of function in multipotential hematopoietic progenitors associated with self-renewal and initiation of lymphomas and leukemias.
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Affiliation(s)
- Brian Freie
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle WA, USA
| | - Patrick A Carroll
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle WA, USA
| | | | - Vijay Ramani
- Gladstone Institute for Data Science and Biotechnology, University of California, San Francisco, San Francisco CA, USA
| | - Irwin Bernstein
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle WA, USA
| | - Robert N Eisenman
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle WA, USA
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Arthur NB, Christensen KA, Mannino K, Ruzinova MB, Kumar A, Gruszczynska A, Day RB, Erdmann-Gilmore P, Mi Y, Sprung R, York CR, Reid Townsend R, Spencer DH, Sykes SM, Ferraro F. Missense mutations in Myc Box I influence MYC cellular localization, mRNA partitioning and turnover to promote leukemogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.22.563493. [PMID: 37961226 PMCID: PMC10634725 DOI: 10.1101/2023.10.22.563493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Somatic missense mutations in the phosphodegron domain of the MYC gene ( M YC Box I) are detected in the dominant clones of a subset of acute myeloid leukemia (AML) patients, but the mechanisms by which they contribute to AML are unknown. To unveil unique proprieties of MBI MYC mutant proteins, we systematically compared the cellular and molecular consequences of expressing similar oncogenic levels of wild type and MBI mutant MYC. We found that MBI MYC mutants can accelerate leukemia by driving unique transcriptional signatures in highly selected, myeloid progenitor subpopulations. Although these mutations increase MYC stability, they overall dampen MYC chromatin localization and lead to a cytoplasmic accumulation of the mutant proteins. This phenotype is coupled with increased translation of RNA binding proteins and nuclear export machinery, which results in altered RNA partitioning and accelerated decay of select transcripts encoding proapoptotic and proinflammatory genes. Heterozygous knockin mice harboring the germline MBI mutation Myc p.T73N exhibit cytoplasmic MYC localization, myeloid progenitors' expansion with similar transcriptional signatures to the overexpression model, and eventually develop hematological malignancies. This study uncovers that MBI MYC mutations alter MYC localization and disrupt mRNA subcellular distribution and turnover of select transcripts to accelerate tumor initiation and growth.
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6
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Vízkeleti L, Spisák S. Rewired Metabolism Caused by the Oncogenic Deregulation of MYC as an Attractive Therapeutic Target in Cancers. Cells 2023; 12:1745. [PMID: 37443779 PMCID: PMC10341379 DOI: 10.3390/cells12131745] [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: 04/10/2023] [Revised: 06/20/2023] [Accepted: 06/20/2023] [Indexed: 07/15/2023] Open
Abstract
MYC is one of the most deregulated oncogenes on multiple levels in cancer. As a node transcription factor, MYC plays a diverse regulatory role in many cellular processes, including cell cycle and metabolism, both in physiological and pathological conditions. The relentless growth and proliferation of tumor cells lead to an insatiable demand for energy and nutrients, which requires the rewiring of cellular metabolism. As MYC can orchestrate all aspects of cellular metabolism, its altered regulation plays a central role in these processes, such as the Warburg effect, and is a well-established hallmark of cancer development. However, our current knowledge of MYC suggests that its spatial- and concentration-dependent contribution to tumorigenesis depends more on changes in the global or relative expression of target genes. As the direct targeting of MYC is proven to be challenging due to its relatively high toxicity, understanding its underlying regulatory mechanisms is essential for the development of tumor-selective targeted therapies. The aim of this review is to comprehensively summarize the diverse forms of MYC oncogenic deregulation, including DNA-, transcriptional- and post-translational level alterations, and their consequences for cellular metabolism. Furthermore, we also review the currently available and potentially attractive therapeutic options that exploit the vulnerability arising from the metabolic rearrangement of MYC-driven tumors.
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Affiliation(s)
- Laura Vízkeleti
- Department of Bioinformatics, Faculty of Medicine, Semmelweis University, 1094 Budapest, Hungary;
| | - Sándor Spisák
- Institute of Enzymology, Research Centre for Natural Sciences, Eötvös Loránd Research Network, 1117 Budapest, Hungary
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7
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Abstract
Deregulation of transcription factors is critical to hallmarks of cancer. Genetic mutations, gene fusions, amplifications or deletions, epigenetic alternations, and aberrant post-transcriptional modification of transcription factors are involved in the regulation of various stages of carcinogenesis, including cancer initiation, progression, and metastasis. Thus, targeting the dysfunctional transcription factors may lead to new cancer therapeutic strategies. However, transcription factors are conventionally considered as "undruggable." Here, we summarize the recent progresses in understanding the regulation of transcription factors in cancers and strategies to target transcription factors and co-factors for preclinical and clinical drug development, particularly focusing on c-Myc, YAP/TAZ, and β-catenin due to their significance and interplays in cancer.
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8
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Fioresi R, Demurtas P, Perini G. Deep learning for MYC binding site recognition. FRONTIERS IN BIOINFORMATICS 2022; 2:1015993. [PMID: 36544623 PMCID: PMC9760990 DOI: 10.3389/fbinf.2022.1015993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 11/24/2022] [Indexed: 12/07/2022] Open
Abstract
Motivation: The definition of the genome distribution of the Myc transcription factor is extremely important since it may help predict its transcriptional activity particularly in the context of cancer. Myc is among the most powerful oncogenes involved in the occurrence and development of more than 80% of different types of pediatric and adult cancers. Myc regulates thousands of genes which can be in part different, depending on the type of tissues and tumours. Myc distribution along the genome has been determined experimentally through chromatin immunoprecipitation This approach, although powerful, is very time consuming and cannot be routinely applied to tumours of individual patients. Thus, it becomes of paramount importance to develop in silico tools that can effectively and rapidly predict its distribution on a given cell genome. New advanced computational tools (DeeperBind) can then be successfully employed to determine the function of Myc in a specific tumour, and may help to devise new directions and approaches to experiments first and personalized and more effective therapeutic treatments for a single patient later on. Results: The use of DeeperBind with DeepRAM on Colab platform (Google) can effectively predict the binding sites for the MYC factor with an accuracy above 0.96 AUC, when trained with multiple cell lines. The analysis of the filters in DeeperBind trained models shows, besides the consensus sequence CACGTG classically associated to the MYC factor, also the other consensus sequences G/C box or TGGGA, respectively bound by the SP1 and MIZ-1 transcription factors, which are known to mediate the MYC repressive response. Overall, our findings suggest a stronger synergy between the machine learning tools as DeeperBind and biological experiments, which may reduce the time consuming experiments by providing a direction to guide them.
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Vitsios D, Dhindsa RS, Matelska D, Mitchell J, Zou X, Armenia J, Hu F, Wang Q, Sidders B, Harper AR, Petrovski S. Cancer-driving mutations are enriched in genic regions intolerant to germline variation. SCIENCE ADVANCES 2022; 8:eabo6371. [PMID: 36026442 PMCID: PMC9417173 DOI: 10.1126/sciadv.abo6371] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Large reference datasets of protein-coding variation in human populations have allowed us to determine which genes and genic subregions are intolerant to germline genetic variation. There is also a growing number of genes implicated in severe Mendelian diseases that overlap with genes implicated in cancer. We hypothesized that cancer-driving mutations might be enriched in genic subregions that are depleted of germline variation relative to somatic variation. We introduce a new metric, OncMTR (oncology missense tolerance ratio), which uses 125,748 exomes in the Genome Aggregation Database (gnomAD) to identify these genic subregions. We demonstrate that OncMTR can significantly predict driver mutations implicated in hematologic malignancies. Divergent OncMTR regions were enriched for cancer-relevant protein domains, and overlaying OncMTR scores on protein structures identified functionally important protein residues. Last, we performed a rare variant, gene-based collapsing analysis on an independent set of 394,694 exomes from the UK Biobank and find that OncMTR markedly improves genetic signals for hematologic malignancies.
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Affiliation(s)
- Dimitrios Vitsios
- Centre for Genomics Research, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
- Corresponding author. (D.V.), (R.S.D.), (S.P.)
| | - Ryan S. Dhindsa
- Centre for Genomics Research, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Waltham, MA, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, Houston, TX, USA
- Corresponding author. (D.V.), (R.S.D.), (S.P.)
| | - Dorota Matelska
- Centre for Genomics Research, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Jonathan Mitchell
- Centre for Genomics Research, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Xuequing Zou
- Centre for Genomics Research, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Joshua Armenia
- Bioinformatics and Data Science, Research, and Early Development, Oncology R&D, AstraZeneca, Cambridge, UK
| | - Fengyuan Hu
- Centre for Genomics Research, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Quanli Wang
- Centre for Genomics Research, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Waltham, MA, USA
| | - Ben Sidders
- Bioinformatics and Data Science, Research, and Early Development, Oncology R&D, AstraZeneca, Cambridge, UK
| | - Andrew R. Harper
- Centre for Genomics Research, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Slavé Petrovski
- Centre for Genomics Research, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
- Department of Medicine, University of Melbourne, Austin Health, Melbourne, Victoria, Australia
- Corresponding author. (D.V.), (R.S.D.), (S.P.)
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10
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Welcker M, Wang B, Rusnac DV, Hussaini Y, Swanger J, Zheng N, Clurman BE. Two diphosphorylated degrons control c-Myc degradation by the Fbw7 tumor suppressor. SCIENCE ADVANCES 2022; 8:eabl7872. [PMID: 35089787 PMCID: PMC8797792 DOI: 10.1126/sciadv.abl7872] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 12/08/2021] [Indexed: 05/13/2023]
Abstract
c-Myc (hereafter, Myc) is a cancer driver whose abundance is regulated by the SCFFbw7 ubiquitin ligase and proteasomal degradation. Fbw7 binds to a phosphorylated Myc degron centered at threonine 58 (T58), and mutations of Fbw7 or T58 impair Myc degradation in cancers. Here, we identify a second Fbw7 phosphodegron at Myc T244 that is required for Myc ubiquitylation and acts in concert with T58 to engage Fbw7. While Ras-dependent Myc serine 62 phosphorylation (pS62) is thought to stabilize Myc by preventing Fbw7 binding, we find instead that pS62 greatly enhances Fbw7 binding and is an integral part of a high-affinity degron. Crystallographic studies revealed that both degrons bind Fbw7 in their diphosphorylated forms and that the T244 degron is recognized via a unique mode involving Fbw7 arginine 689 (R689), a mutational hotspot in cancers. These insights have important implications for Myc-associated tumorigenesis and therapeutic strategies targeting Myc stability.
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Affiliation(s)
- Markus Welcker
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
- Human Biology Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Baiyun Wang
- Department of Pharmacology, University of Washington, Seattle, WA 98195, USA
- Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA
| | - Domniţa-Valeria Rusnac
- Department of Pharmacology, University of Washington, Seattle, WA 98195, USA
- Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA
| | - Yasser Hussaini
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
- Human Biology Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Jherek Swanger
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
- Human Biology Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Ning Zheng
- Department of Pharmacology, University of Washington, Seattle, WA 98195, USA
- Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA
| | - Bruce E. Clurman
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
- Human Biology Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
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11
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Llombart V, Mansour MR. Therapeutic targeting of "undruggable" MYC. EBioMedicine 2022; 75:103756. [PMID: 34942444 PMCID: PMC8713111 DOI: 10.1016/j.ebiom.2021.103756] [Citation(s) in RCA: 150] [Impact Index Per Article: 75.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 11/23/2021] [Accepted: 12/01/2021] [Indexed: 12/13/2022] Open
Abstract
c-MYC controls global gene expression and regulates cell proliferation, cell differentiation, cell cycle, metabolism and apoptosis. According to some estimates, MYC is dysregulated in ≈70% of human cancers and strong evidence implicates aberrantly expressed MYC in both tumor initiation and maintenance. In vivo studies show that MYC inhibition elicits a prominent anti-proliferative effect and sustained tumor regression while any alteration on healthy tissue remains reversible. This opens an exploitable window for treatment that makes MYC one of the most appealing therapeutic targets for cancer drug development. This review describes the main functional and structural features of the protein structure of MYC and provides a general overview of the most relevant or recently identified interactors that modulate MYC oncogenic activity. This review also summarizes the different approaches aiming to abrogate MYC oncogenic function, with a particular focus on the prototype inhibitors designed for the direct and indirect targeting of MYC.
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Affiliation(s)
- Victor Llombart
- UCL Cancer Institute, University College London, Department of Haematology, London WC1E 6DD, UK
| | - Marc R Mansour
- UCL Cancer Institute, University College London, Department of Haematology, London WC1E 6DD, UK; UCL Great Ormond Street Institute of Child Health, Developmental Biology and Cancer, London, UK.
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12
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Luminescence complementation technology for the identification of MYC:TRRAP inhibitors. Oncotarget 2021; 12:2147-2157. [PMID: 34676047 PMCID: PMC8522838 DOI: 10.18632/oncotarget.28078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Accepted: 09/04/2021] [Indexed: 11/25/2022] Open
Abstract
Mechanism-based targeted therapies have exhibited remarkable success in treating otherwise untreatable or unresectable cancers. Novel targeted therapies that correct dysregulated transcriptional programs in cancer are an unmet medical need. The transcription factor MYC is the most frequently amplified gene in human cancer and is overexpressed because of mutations in an array of oncogenic signaling pathways. The fact that many cancer cells cannot survive without MYC – a phenomenon termed “MYC addiction” – provides a compelling case for the development of MYC-specific targeted therapies. We propose a new strategy to inhibit MYC function by disrupting its essential interaction with TRRAP using small molecules. To achieve our goal, we developed a platform using luminescence complementation for identifying small molecules as inhibitors of the MYC:TRRAP interaction. Here we present validation of this assay by measuring the disruption of TRRAP binding caused by substitutions to the invariant and essential MYC homology 2 region of MYC.
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Gene Transactivation and Transrepression in MYC-Driven Cancers. Int J Mol Sci 2021; 22:ijms22073458. [PMID: 33801599 PMCID: PMC8037706 DOI: 10.3390/ijms22073458] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 03/24/2021] [Accepted: 03/25/2021] [Indexed: 12/11/2022] Open
Abstract
MYC is a proto-oncogene regulating a large number of genes involved in a plethora of cellular functions. Its deregulation results in activation of MYC gene expression and/or an increase in MYC protein stability. MYC overexpression is a hallmark of malignant growth, inducing self-renewal of stem cells and blocking senescence and cell differentiation. This review summarizes the latest advances in our understanding of MYC-mediated molecular mechanisms responsible for its oncogenic activity. Several recent findings indicate that MYC is a regulator of cancer genome and epigenome: MYC modulates expression of target genes in a site-specific manner, by recruiting chromatin remodeling co-factors at promoter regions, and at genome-wide level, by regulating the expression of several epigenetic modifiers that alter the entire chromatin structure. We also discuss novel emerging therapeutic strategies based on both direct modulation of MYC and its epigenetic cofactors.
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14
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Guerra B, Recio C, Aranda-Tavío H, Guerra-Rodríguez M, García-Castellano JM, Fernández-Pérez L. The Mevalonate Pathway, a Metabolic Target in Cancer Therapy. Front Oncol 2021; 11:626971. [PMID: 33718197 PMCID: PMC7947625 DOI: 10.3389/fonc.2021.626971] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Accepted: 01/18/2021] [Indexed: 12/12/2022] Open
Abstract
A hallmark of cancer cells includes a metabolic reprograming that provides energy, the essential building blocks, and signaling required to maintain survival, rapid growth, metastasis, and drug resistance of many cancers. The influence of tumor microenviroment on cancer cells also results an essential driving force for cancer progression and drug resistance. Lipid-related enzymes, lipid-derived metabolites and/or signaling pathways linked to critical regulators of lipid metabolism can influence gene expression and chromatin remodeling, cellular differentiation, stress response pathways, or tumor microenviroment, and, collectively, drive tumor development. Reprograming of lipid metabolism includes a deregulated activity of mevalonate (MVA)/cholesterol biosynthetic pathway in specific cancer cells which, in comparison with normal cell counterparts, are dependent of the continuous availability of MVA/cholesterol-derived metabolites (i.e., sterols and non-sterol intermediates) for tumor development. Accordingly, there are increasing amount of data, from preclinical and epidemiological studies, that support an inverse association between the use of statins, potent inhibitors of MVA biosynthetic pathway, and mortality rate in specific cancers (e.g., colon, prostate, liver, breast, hematological malignances). In contrast, despite the tolerance and therapeutic efficacy shown by statins in cardiovascular disease, cancer treatment demands the use of relatively high doses of single statins for a prolonged period, thereby limiting this therapeutic strategy due to adverse effects. Clinically relevant, synergistic effects of tolerable doses of statins with conventional chemotherapy might enhance efficacy with lower doses of each drug and, probably, reduce adverse effects and resistance. In spite of that, clinical trials to identify combinatory therapies that improve therapeutic window are still a challenge. In the present review, we revisit molecular evidences showing that deregulated activity of MVA biosynthetic pathway has an essential role in oncogenesis and drug resistance, and the potential use of MVA pathway inhibitors to improve therapeutic window in cancer.
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Affiliation(s)
- Borja Guerra
- Molecular and Translational Pharmacology Lab, Institute for Biomedical and Health Research (IUIBS), University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - Carlota Recio
- Molecular and Translational Pharmacology Lab, Institute for Biomedical and Health Research (IUIBS), University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - Haidée Aranda-Tavío
- Molecular and Translational Pharmacology Lab, Institute for Biomedical and Health Research (IUIBS), University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - Miguel Guerra-Rodríguez
- Molecular and Translational Pharmacology Lab, Institute for Biomedical and Health Research (IUIBS), University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - José M García-Castellano
- Molecular and Translational Pharmacology Lab, Institute for Biomedical and Health Research (IUIBS), University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - Leandro Fernández-Pérez
- Molecular and Translational Pharmacology Lab, Institute for Biomedical and Health Research (IUIBS), University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
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Liu Y, Zhu C, Tang L, Chen Q, Guan N, Xu K, Guan X. MYC dysfunction modulates stemness and tumorigenesis in breast cancer. Int J Biol Sci 2021; 17:178-187. [PMID: 33390842 PMCID: PMC7757029 DOI: 10.7150/ijbs.51458] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 09/12/2020] [Indexed: 12/28/2022] Open
Abstract
As a transcription factor and proto-oncogene, MYC is known to be deregulated in a variety of tumors, including breast cancer. However, no consistent conclusion on the role and mechanism of MYC deregulation during breast cancer carcinogenesis has been formed. Here, we used the UALCAN, bc-GenExMiner, TCGA, cBioportal, STRING and Kaplan-Meier Plotter databases to explore the mRNA expression, prognosis, transcriptional profile changes, signal pathway rewiring and interaction with the cancer stem cells of MYC in breast cancer. We found that the expression of MYC varies in different subtypes of breast cancer, with relatively high frequency in TNBC. As a transcription factor, MYC not only participates in the rewiring of cancer signaling pathways, such as estrogen, WNT, NOTCH and other pathways, but also interacts with cancer stem cells. MYC is significantly positively correlated with breast cancer stem cell markers such as CD44, CD24, and ALDH1. Collectively, our results highlight that MYC plays an important regulatory role in the occurrence of breast cancer, and its amplification can be used as a predictor of diagnosis and prognosis. The interaction between MYC and cancer stem cells may play a crucial role in regulating the initiation and metastasis of breast cancer.
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Affiliation(s)
- Yiqiu Liu
- Department of Oncology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing 210029, China
| | - Chengjun Zhu
- Department of Oncology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing 210029, China
| | - Lin Tang
- Department of Medical Oncology, Medical School of Nanjing University, Nanjing, 210002, China
| | - Qin Chen
- Department of Oncology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing 210029, China
| | - Nan Guan
- College of Letters and Science, University of California, Los Angeles, 405 Hilgard Avenue, California, 90095, USA
| | - Kun Xu
- Department of Oncology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing 210029, China
| | - Xiaoxiang Guan
- Department of Oncology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing 210029, China
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Tandon V, de la Vega L, Banerjee S. Emerging roles of DYRK2 in cancer. J Biol Chem 2021; 296:100233. [PMID: 33376136 PMCID: PMC7948649 DOI: 10.1074/jbc.rev120.015217] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 12/28/2020] [Accepted: 12/29/2020] [Indexed: 12/14/2022] Open
Abstract
Over the last decade, the CMGC kinase DYRK2 has been reported as a tumor suppressor across various cancers triggering major antitumor and proapoptotic signals in breast, colon, liver, ovary, brain, and lung cancers, with lower DYRK2 expression correlated with poorer prognosis in patients. Contrary to this, various medicinal chemistry studies reported robust antiproliferative properties of DYRK2 inhibitors, whereas unbiased 'omics' and genome-wide association study-based studies identified DYRK2 as a highly overexpressed kinase in various patient tumor samples. A major paradigm shift occurred in the last 4 years when DYRK2 was found to regulate proteostasis in cancer via a two-pronged mechanism. DYRK2 phosphorylated and activated the 26S proteasome to enhance degradation of misfolded/tumor-suppressor proteins while also promoting the nuclear stability and transcriptional activity of its substrate, heat-shock factor 1 triggering protein folding. Together, DYRK2 regulates proteostasis and promotes protumorigenic survival for specific cancers. Indeed, potent and selective small-molecule inhibitors of DYRK2 exhibit in vitro and in vivo anti-tumor activity in triple-negative breast cancer and myeloma models. However, with conflicting and contradictory reports across different cancers, the overarching role of DYRK2 remains enigmatic. Specific cancer (sub)types coupled to spatiotemporal interactions with substrates could decide the procancer or anticancer role of DYRK2. The current review aims to provide a balanced and critical appreciation of the literature to date, highlighting top substrates such as p53, c-Myc, c-Jun, heat-shock factor 1, proteasome, or NOTCH1, to discuss DYRK2 inhibitors available to the scientific community and to shed light on this duality of protumorigenic and antitumorigenic roles of DYRK2.
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Affiliation(s)
- Vasudha Tandon
- Division of Cellular Medicine, School of Medicine, University of Dundee, Dundee, United Kingdom
| | - Laureano de la Vega
- Division of Cellular Medicine, School of Medicine, University of Dundee, Dundee, United Kingdom
| | - Sourav Banerjee
- Division of Cellular Medicine, School of Medicine, University of Dundee, Dundee, United Kingdom.
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17
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Schaafsma E, Zhao Y, Zhang L, Li Y, Cheng C. MYC Activity Inference Captures Diverse Mechanisms of Aberrant MYC Pathway Activation in Human Cancers. Mol Cancer Res 2020; 19:414-428. [PMID: 33234576 DOI: 10.1158/1541-7786.mcr-20-0526] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 08/21/2020] [Accepted: 11/20/2020] [Indexed: 11/16/2022]
Abstract
c-MYC (MYC) is deregulated in more than 50% of all cancers. While MYC amplification is the most common MYC-deregulating event, many other alterations can increase MYC activity. We thus systematically investigated MYC pathway activity across different tumor types. Using a logistic regression framework, we established tumor type-specific, transcriptomic-based MYC activity scores that can accurately capture MYC activity. We show that MYC activity scores reflect a variety of MYC-regulating mechanisms, including MYCL and/or MYCN amplification, MYC promoter methylation, MYC mRNA expression, lncRNA PVT1 expression, MYC mutations, and viral integrations near the MYC locus. Our MYC activity score incorporates all of these mechanisms, resulting in better prognostic predictions compared with MYC amplification status, MYC promoter methylation, and MYC mRNA expression in several cancer types. In addition, we show that tumor proliferation and immune evasion are likely contributors to this reduction in survival. Finally, we developed a MYC activity signature for liquid tumors in which MYC translocation is commonly observed, suggesting that our approach can be applied to different types of genomic alterations. In conclusion, we developed a MYC activity score that captures MYC pathway activity and is clinically relevant. IMPLICATIONS: By using cancer type-specific MYC activity profiles, we were able to assess MYC activity across many more tumor types than previously investigated. The range of different MYC-related alterations captured by our MYC activity score can be used to facilitate the application of future MYC inhibitors and aid physicians to preselect patients for targeted therapy.
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Affiliation(s)
- Evelien Schaafsma
- Department of Molecular and Systems Biology, Dartmouth College, Hanover, New Hampshire
| | - Yanding Zhao
- Department of Medicine, Baylor College of Medicine, Houston, Texas
| | - Lanjing Zhang
- Department of Biological Sciences, Rutgers University, Newark, New Jersey.,Department of Pathology, Princeton Medical Center, Plainsboro, New Jersey
| | - Yong Li
- Department of Medicine, Section of Epidemiology and Population Sciences, Baylor College of Medicine, Houston, Texas
| | - Chao Cheng
- Department of Medicine, Baylor College of Medicine, Houston, Texas. .,Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas.,Department of Biomedical Data Science, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire.,The Institute for Clinical and Translational Research, Baylor College of Medicine, Houston, Texas
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18
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Peroxynitrite promotes serine-62 phosphorylation-dependent stabilization of the oncoprotein c-Myc. Redox Biol 2020; 34:101587. [PMID: 32512497 PMCID: PMC7280771 DOI: 10.1016/j.redox.2020.101587] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 04/22/2020] [Accepted: 05/14/2020] [Indexed: 12/13/2022] Open
Abstract
Stabilization of c-Myc oncoprotein is dependent on post-translational modifications, especially its phosphorylation at serine-62 (S62), which enhances its tumorigenic potential. Herein we report that increase in intracellular superoxide induces phospho-stabilization and activation of c-Myc in cancer cells. Importantly, sustained phospho-S62 c-Myc was necessary for promoting superoxide dependent chemoresistance as non-phosphorylatable S62A c-Myc was insensitive to the redox impact when subjected to chemotherapeutic insults. This redox-dependent sustained S62 phosphorylation occurs through nitrative inhibition of phosphatase, PP2A, brought about by peroxynitrite, a reaction product of superoxide and nitric oxide. We identified a conserved tyrosine residue (Y238) in the c-Myc targeting subunit B56α of PP2A, which is selectively amenable to nitrative inhibition, further preventing holoenzyme assembly. In summary, we have established a novel mechanism wherein the pro-oxidant microenvironment stimulates a pro-survival milieu and reinforces tumor maintenance as a functional consequence of c-Myc activation through its sustained S62 phosphorylation via inhibition of phosphatase PP2A. Significance statement Increased peroxynitrite signaling in tumors causes sustained S62 c-Myc phosphorylation by PP2A inhibition. This is critical to promoting c-Myc stabilization and activation which promotes chemoresistance and provides significant proliferative and growth advantages to osteosarcomas.
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19
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Bisso A, Sabò A, Amati B. MYC in Germinal Center-derived lymphomas: Mechanisms and therapeutic opportunities. Immunol Rev 2019; 288:178-197. [PMID: 30874346 DOI: 10.1111/imr.12734] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 12/11/2018] [Indexed: 12/13/2022]
Abstract
The rearrangement of immunoglobulin loci during the germinal center reaction is associated with an increased risk of chromosomal translocations that activate oncogenes such as MYC, BCL2 or BCL6, thus contributing to the development of B-cell lymphomas. MYC and BCL2 activation are initiating events in Burkitt's (BL) and Follicular Lymphoma (FL), respectively, but can occur at later stages in other subtypes such as Diffuse Large-B Cell Lymphoma (DLBCL). MYC can also be activated during the progression of FL to the transformed stage. Thus, either DLBCL or FL can give rise to aggressive double-hit lymphomas (DHL) with concurrent activation of MYC and BCL2. Research over the last three decades has improved our understanding of the functions of these oncogenes and the basis for their cooperative action in lymphomagenesis. MYC, in particular, is a transcription factor that contributes to cell activation, growth and proliferation, while concomitantly sensitizing cells to apoptosis, the latter being blocked by BCL2. Here, we review our current knowledge about the role of MYC in germinal center B-cells and lymphomas, discuss MYC-induced dependencies that can sensitize cancer cells to select pharmacological inhibitors, and illustrate their therapeutic potential in aggressive lymphomas-and in particular in DHL, in combination with BCL2 inhibitors.
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Affiliation(s)
- Andrea Bisso
- Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, Milan, Italy
| | - Arianna Sabò
- Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, Milan, Italy
| | - Bruno Amati
- Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, Milan, Italy
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20
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Pasqualucci L. Molecular pathogenesis of germinal center-derived B cell lymphomas. Immunol Rev 2019; 288:240-261. [PMID: 30874347 DOI: 10.1111/imr.12745] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 01/21/2019] [Accepted: 01/25/2019] [Indexed: 12/14/2022]
Abstract
B cell lymphomas comprise a heterogeneous group of genetically, biologically, and clinically distinct neoplasms that, in most cases, originate from the clonal expansion of B cells in the germinal center (GC). In recent years, the advent of novel genomics technologies has revolutionized our understanding of the molecular pathogenesis of lymphoid malignancies as a multistep process that requires the progressive accumulation of multiple genetic and epigenetic alterations. A common theme that emerged from these studies is the ability of lymphoma cells to co-opt the same biological programs and signal transduction networks that operate during the normal GC reaction, and misuse them for their own survival advantage. This review summarizes recent progress in the understanding of the genetic and epigenetic mechanisms that drive the malignant transformation of GC B cells. These insights provide a conceptual framework for the identification of cellular pathways that may be explored for precision medicine approaches.
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Affiliation(s)
- Laura Pasqualucci
- Pathology and Cell Biology, Institute for Cancer Genetics, Columbia University, New York City, New York
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21
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Mudgapalli N, Nallasamy P, Chava H, Chava S, Pathania AS, Gunda V, Gorantla S, Pandey MK, Gupta SC, Challagundla KB. The role of exosomes and MYC in therapy resistance of acute myeloid leukemia: Challenges and opportunities. Mol Aspects Med 2019; 70:21-32. [PMID: 31623866 DOI: 10.1016/j.mam.2019.10.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 09/27/2019] [Accepted: 10/06/2019] [Indexed: 12/12/2022]
Abstract
Acute myeloid leukemia (AML) is caused by abnormal production of white blood cells, red blood cells or platelets. The leukemia cells communicate with their microenvironment through nano-vesicle exosomes that are 30-100 nm in diameter. These nano-vesicles are released from body fluids upon fusion of an endocytic compartment with the cell membrane. Exosomes function as cargo to deliver signaling molecules to distant cells. This allows cross-talk between hematopoietic cells and other distant target cell environments. Exosomes support leukemia growth by acting as messengers between tumor cells and the microenvironment as well as inducing oncogenic factors such as c-Myc. Exosomes have also been used as biomarkers in the clinical diagnosis of leukemia. Glycogen synthase kinase-3 (GSK-3) and protein phosphatase 2A (PP2A) are two crucial signaling molecules involved in the AML pathogenesis and MYC stability. GSK-3 is a serine/threonine protein kinase that coordinates with over 40 different proteins during physiological/pathological conditions in blood cells. The dysregulation in GSK-3 has been reported during hematological malignancies. GSK-3 acts as a tumor suppressor by targeting c-MYC, MCL-1 and β-catenin. Conversely, GSK-3 can also act as tumor promoter in some instances. The pharmacological modulators of GSK-3 such as ABT-869, 6-Bromoindirubin-3'-oxime (BIO), GS-87 and LY2090314 have shown promise in the treatment of hematological malignancy. PP2A is a heterotrimeric serine/threonine phosphatase involved in the regulation of hematological malignancy. PP2A-activating drugs (PADs) can effectively antagonize leukemogenesis. The discovery of exosomes, kinase inhibitors and phosphatase activators have provided new hope to the leukemia patients. This review discusses the role of exosomes, GSK-3 and PP2A in the pathogenesis of leukemia. We provide evidence from both preclinical and clinical studies.
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Affiliation(s)
- Nithya Mudgapalli
- Department of Biochemistry and Molecular Biology, The Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE, USA
; UNMC Summer Undergraduate Research Program, University of Nebraska Medical Center, Omaha, NE, USA
| | - Palanisamy Nallasamy
- Department of Biochemistry and Molecular Biology, The Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE, USA
| | - Haritha Chava
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, USA
| | - Srinivas Chava
- Department of Biochemistry and Molecular Biology, The Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE, USA
| | - Anup S Pathania
- Department of Biochemistry and Molecular Biology, The Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE, USA
| | - Venugopal Gunda
- Pediatric Oncology Laboratory, Child Health Research Institute, University of Nebraska Medical Center, Omaha, NE, USA
| | - Santhi Gorantla
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, USA
| | - Manoj K Pandey
- Department of Biomedical Sciences, Cooper Medical School of Rowan University, Camden, NJ, USA
| | - Subash C Gupta
- Laboratory for Translational Cancer Research, Department of Biochemistry, Institute of Science, Banaras Hindu University, Varanasi, 221 005, India
| | - Kishore B Challagundla
- Department of Biochemistry and Molecular Biology, The Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE, USA
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Mistletoe extract Fraxini inhibits the proliferation of liver cancer by down-regulating c-Myc expression. Sci Rep 2019; 9:6428. [PMID: 31015523 PMCID: PMC6478697 DOI: 10.1038/s41598-019-41444-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 08/09/2018] [Indexed: 01/25/2023] Open
Abstract
Mistletoe (Viscum album) is a type of parasitic plant reported to have anticancer activity including in hepatocellular carcinoma (HCC). However, the mechanism of mistletoe’s anticancer activity, and its effectiveness in treating HCC are not fully understood. We report here that mistletoe extracts, including Fraxini (grown on ash trees) and Iscador Q and M (grown on oak and maple trees), exert strong antiproliferative activity in Hep3B cells, with median inhibitory concentrations (IC50) of 0.5 µg/mL, 7.49 µg/mL, and 7.51 µg/mL, respectively. Results of Reversed Phase Proteomic Array analysis (RPPA) suggests that Fraxini substantially down-regulates c-Myc expression in Hep3B cells. Fraxini-induced growth inhibition (at a concentration of 1.25 μg/ml) was less pronounced in c-Myc knockdown Hep3B cells than in control cells. Furthermore, in the Hep3B xenograft model, Fraxini-treated (8 mg/kg body weight) mice had significantly smaller tumors (34.6 ± 11.9 mm3) than control mice (161.6 ± 79.4 mm3, p < 0.036). Similarly, c-Myc protein expression was reduced in Fraxini treated Hep3B cell xenografts compared to that of control mice. The reduction of c-Myc protein levels in vitro Hep3B cells appears to be mediated by the ubiquitin-proteasome system. Our results suggest the importance of c-Myc in Fraxini’s antiproliferative activity, which warrants further investigation.
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23
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Maik-Rachline G, Hacohen-Lev-Ran A, Seger R. Nuclear ERK: Mechanism of Translocation, Substrates, and Role in Cancer. Int J Mol Sci 2019; 20:ijms20051194. [PMID: 30857244 PMCID: PMC6429060 DOI: 10.3390/ijms20051194] [Citation(s) in RCA: 119] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 03/03/2019] [Accepted: 03/04/2019] [Indexed: 12/15/2022] Open
Abstract
The extracellular signal-regulated kinases 1/2 (ERK) are central signaling components that regulate stimulated cellular processes such as proliferation and differentiation. When dysregulated, these kinases participate in the induction and maintenance of various pathologies, primarily cancer. While ERK is localized in the cytoplasm of resting cells, many of its substrates are nuclear, and indeed, extracellular stimulation induces a rapid and robust nuclear translocation of ERK. Similarly to other signaling components that shuttle to the nucleus upon stimulation, ERK does not use the canonical importinα/β mechanism of nuclear translocation. Rather, it has its own unique nuclear translocation signal (NTS) that interacts with importin7 to allow stimulated shuttling via the nuclear pores. Prevention of the nuclear translocation inhibits proliferation of B-Raf- and N/K-Ras-transformed cancers. This effect is distinct from the one achieved by catalytic Raf and MEK inhibitors used clinically, as cells treated with the translocation inhibitors develop resistance much more slowly. In this review, we describe the mechanism of ERK translocation, present all its nuclear substrates, discuss its role in cancer and compare its translocation to the translocation of other signaling components. We also present proof of principle data for the use of nuclear ERK translocation as an anti-cancer target. It is likely that the prevention of nuclear ERK translocation will eventually serve as a way to combat Ras and Raf transformed cancers with less side-effects than the currently used drugs.
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Affiliation(s)
- Galia Maik-Rachline
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot 7610001, Israel.
| | - Avital Hacohen-Lev-Ran
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot 7610001, Israel.
| | - Rony Seger
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot 7610001, Israel.
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Chisholm KM, Krishnan C, Heerema-McKenney A, Natkunam Y. Immunohistochemical Profile of MYC Protein in Pediatric Small Round Blue Cell Tumors. Pediatr Dev Pathol 2017; 20:213-223. [PMID: 28521631 DOI: 10.1177/1093526616689642] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Deregulation of MYC oncoprotein in cancers can result from multiple oncogenic mechanisms. Although MYC translocations define Burkitt lymphoma and MYC protein expression is a poor prognostic factor in undifferentiated neuroblastomas, the distribution of MYC protein (c-MYC) across other pediatric small round blue cell tumors (SRBCT) has not been well characterized. We undertook this study to assess MYC protein expression in a large cohort of pediatric lymphomas, sarcomas, and other SRBCT. Tissue microarrays containing 302 SRBCT were successfully evaluated by immunohistochemistry using anti-MYC clone Y69, with nuclear positivity scored as 0%, 1%-25%, 26%-50%, 51%-75%, or 76%-100%. MYC protein staining of >50% of lesional cells was identified in 60% of Burkitt lymphomas, 50% of B lymphoblastic lymphomas, 33% of T lymphoblastic lymphomas, 31% of rhabdomyosarcomas, 33% of Ewing sarcomas, and 25% of soft tissue sarcomas, not otherwise specified. Only 14% of neuroblastomas showed >50% staining, and of these, if known, MYCN was not amplified. No cases of Wilms tumor, synovial sarcoma, or desmoplastic small round cell tumor had >50% staining. Recurrences and metastases often had the same percentage of MYC staining (15/30). In conclusion, MYC protein exhibited variable expression across and within pediatric SRBCT subtypes. Overall, these findings provide a baseline for MYC expression in pediatric SRBCT and suggest that there may be multiple mechanisms of MYC upregulation in these different neoplasms.
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Affiliation(s)
- Karen M Chisholm
- 1 Department of Pathology, Stanford University School of Medicine, Stanford, California, USA.,2 Now at Seattle Children's Hospital, Department of Laboratories, Seattle, Washington, USA
| | - Chandra Krishnan
- 3 Dell Children's Medical Center, Department of Pathology, Austin, Texas, USA
| | - Amy Heerema-McKenney
- 4 Pathology and Laboratory Medicine Institute, Cleveland Clinic Cleveland, Ohio, USA
| | - Yasodha Natkunam
- 1 Department of Pathology, Stanford University School of Medicine, Stanford, California, USA
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Kalkat M, De Melo J, Hickman KA, Lourenco C, Redel C, Resetca D, Tamachi A, Tu WB, Penn LZ. MYC Deregulation in Primary Human Cancers. Genes (Basel) 2017; 8:genes8060151. [PMID: 28587062 PMCID: PMC5485515 DOI: 10.3390/genes8060151] [Citation(s) in RCA: 242] [Impact Index Per Article: 34.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 05/19/2017] [Accepted: 05/19/2017] [Indexed: 12/12/2022] Open
Abstract
MYC regulates a complex biological program by transcriptionally activating and repressing its numerous target genes. As such, MYC is a master regulator of many processes, including cell cycle entry, ribosome biogenesis, and metabolism. In cancer, the activity of the MYC transcriptional network is frequently deregulated, contributing to the initiation and maintenance of disease. Deregulation often leads to constitutive overexpression of MYC, which can be achieved through gross genetic abnormalities, including copy number alterations, chromosomal translocations, increased enhancer activity, or through aberrant signal transduction leading to increased MYC transcription or increased MYC mRNA and protein stability. Herein, we summarize the frequency and modes of MYC deregulation and describe both well-established and more recent findings in a variety of cancer types. Notably, these studies have highlighted that with an increased appreciation for the basic mechanisms deregulating MYC in cancer, new therapeutic vulnerabilities can be discovered and potentially exploited for the inhibition of this potent oncogene in cancer.
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Affiliation(s)
- Manpreet Kalkat
- Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 1L7, Canada.
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON M5G 2M9, Canada.
| | - Jason De Melo
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON M5G 2M9, Canada.
| | - Katherine Ashley Hickman
- Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 1L7, Canada.
- Sunnybrook Research Institute, Toronto, ON M4N 3M5, Canada.
| | - Corey Lourenco
- Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 1L7, Canada.
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON M5G 2M9, Canada.
| | - Cornelia Redel
- Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 1L7, Canada.
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON M5G 2M9, Canada.
| | - Diana Resetca
- Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 1L7, Canada.
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON M5G 2M9, Canada.
| | - Aaliya Tamachi
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON M5G 2M9, Canada.
| | - William B Tu
- Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 1L7, Canada.
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON M5G 2M9, Canada.
| | - Linda Z Penn
- Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 1L7, Canada.
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON M5G 2M9, Canada.
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Chakravorty D, Jana T, Das Mandal S, Seth A, Bhattacharya A, Saha S. MYCbase: a database of functional sites and biochemical properties of Myc in both normal and cancer cells. BMC Bioinformatics 2017; 18:224. [PMID: 28454513 PMCID: PMC5410051 DOI: 10.1186/s12859-017-1652-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2016] [Accepted: 04/26/2017] [Indexed: 12/22/2022] Open
Abstract
Background Myc is an essential gene having multiple functions such as in cell growth, differentiation, apoptosis, genomic stability, angiogenesis, and disease biology. A large number of researchers dedicated to Myc biology are generating a substantial amount of data in normal and cancer cells/tissues including Burkitt’s lymphoma and ovarian cancer. Results MYCbase (http://bicresources.jcbose.ac.in/ssaha4/mycbase) is a collection of experimentally supported functional sites in Myc that can influence the biological cellular processes. The functional sites were compiled according to their role which includes mutation, methylation pattern, post-translational modifications, protein-protein interactions (PPIs), and DNA interactions. In addition, biochemical properties of Myc are also compiled, which includes metabolism/pathway, protein abundance, and modulators of protein-protein interactions. The OMICS data related to Myc- like gene expression, proteomics expression using mass-spectrometry and miRNAs targeting Myc were also compiled in MYCbase. The mutation and pathway data from the MYCbase were analyzed to look at the patterns and distributions across different diseases. There were few proteins/genes found common in Myc-protein interactions and Myc-DNA binding, and these can play a significant role in transcriptional feedback loops. Conclusion In this report, we present a comprehensive integration of relevant information regarding Myc in the form of MYCbase. The data compiled in MYCbase provides a reliable data resource for functional sites at the residue level and biochemical properties of Myc in various cancers.
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Affiliation(s)
- Debangana Chakravorty
- Bioinformatics Centre, Bose Institute, P 1/12, C.I.T. Road, Scheme-VII (M), Kolkata, 700054, India
| | - Tanmoy Jana
- Bioinformatics Centre, Bose Institute, P 1/12, C.I.T. Road, Scheme-VII (M), Kolkata, 700054, India
| | - Sukhen Das Mandal
- Bioinformatics Centre, Bose Institute, P 1/12, C.I.T. Road, Scheme-VII (M), Kolkata, 700054, India.,Current Address: Department of Biological sciences, Indian Institute of Science Education and Research, Kolkata, India
| | | | | | - Sudipto Saha
- Bioinformatics Centre, Bose Institute, P 1/12, C.I.T. Road, Scheme-VII (M), Kolkata, 700054, India.
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Fang X, Zhou W, Wu Q, Huang Z, Shi Y, Yang K, Chen C, Xie Q, Mack SC, Wang X, Carcaboso AM, Sloan AE, Ouyang G, McLendon RE, Bian XW, Rich JN, Bao S. Deubiquitinase USP13 maintains glioblastoma stem cells by antagonizing FBXL14-mediated Myc ubiquitination. J Exp Med 2016; 214:245-267. [PMID: 27923907 PMCID: PMC5206492 DOI: 10.1084/jem.20151673] [Citation(s) in RCA: 108] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Revised: 07/20/2016] [Accepted: 11/08/2016] [Indexed: 12/14/2022] Open
Abstract
Fang et al. show that the deubiquitinase USP13 stabilizes c-Myc in glioblastoma stem cells (GSCs) by counteracting FBXL14-mediated Myc ubiquitination. c-Myc stabilization maintains GSC self-renewal and tumorigenic potential. Glioblastoma is the most lethal brain tumor and harbors glioma stem cells (GSCs) with potent tumorigenic capacity. The function of GSCs in tumor propagation is maintained by several core transcriptional regulators including c-Myc. c-Myc protein is tightly regulated by posttranslational modification. However, the posttranslational regulatory mechanisms for c-Myc in GSCs have not been defined. In this study, we demonstrate that the deubiquitinase USP13 stabilizes c-Myc by antagonizing FBXL14-mediated ubiquitination to maintain GSC self-renewal and tumorigenic potential. USP13 was preferentially expressed in GSCs, and its depletion potently inhibited GSC proliferation and tumor growth by promoting c-Myc ubiquitination and degradation. In contrast, overexpression of the ubiquitin E3 ligase FBXL14 induced c-Myc degradation, promoted GSC differentiation, and inhibited tumor growth. Ectopic expression of the ubiquitin-insensitive mutant T58A–c-Myc rescued the effects caused by FBXL14 overexpression or USP13 disruption. These data suggest that USP13 and FBXL14 play opposing roles in the regulation of GSCs through reversible ubiquitination of c-Myc.
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Affiliation(s)
- Xiaoguang Fang
- Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195
| | - Wenchao Zhou
- Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195
| | - Qiulian Wu
- Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195
| | - Zhi Huang
- Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195
| | - Yu Shi
- Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195.,Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Key Laboratory of Tumor Immunopathology, Ministry of Education of China, Chongqing 400038, China
| | - Kailin Yang
- Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195
| | - Cong Chen
- Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195.,Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Key Laboratory of Tumor Immunopathology, Ministry of Education of China, Chongqing 400038, China
| | - Qi Xie
- Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195
| | - Stephen C Mack
- Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195
| | - Xiuxing Wang
- Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195
| | - Angel M Carcaboso
- Preclinical Therapeutics and Drug Delivery Research Program, Fundacio Sant Joan de Deu, 08950 Barcelona, Spain
| | - Andrew E Sloan
- Department of Neurological Surgery, University Hospitals, Case Western Reserve University School of Medicine, Cleveland, OH 44106.,Case Comprehensive Cancer Center, Case Western Reserve University School of Medicine, Cleveland, OH 44106
| | - Gaoliang Ouyang
- The State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361102, China
| | - Roger E McLendon
- Department of Pathology, Duke University Medical Center, Durham, NC 27710
| | - Xiu-Wu Bian
- Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Key Laboratory of Tumor Immunopathology, Ministry of Education of China, Chongqing 400038, China
| | - Jeremy N Rich
- Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195 .,Case Comprehensive Cancer Center, Case Western Reserve University School of Medicine, Cleveland, OH 44106
| | - Shideng Bao
- Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195 .,Case Comprehensive Cancer Center, Case Western Reserve University School of Medicine, Cleveland, OH 44106
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CRY2 and FBXL3 Cooperatively Degrade c-MYC. Mol Cell 2016; 64:774-789. [PMID: 27840026 DOI: 10.1016/j.molcel.2016.10.012] [Citation(s) in RCA: 128] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 08/31/2016] [Accepted: 10/06/2016] [Indexed: 11/22/2022]
Abstract
For many years, a connection between circadian clocks and cancer has been postulated. Here we describe an unexpected function for the circadian repressor CRY2 as a component of an FBXL3-containing E3 ligase that recruits T58-phosphorylated c-MYC for ubiquitylation. c-MYC is a critical regulator of cell proliferation; T58 is central in a phosphodegron long recognized as a hotspot for mutation in cancer. This site is also targeted by FBXW7, although the full machinery responsible for its turnover has remained obscure. CRY1 cannot substitute for CRY2 in promoting c-MYC degradation. Their unique functions may explain prior conflicting reports that have fueled uncertainty about the relationship between clocks and cancer. We demonstrate that c-MYC is a target of CRY2-dependent protein turnover, suggesting a molecular mechanism for circadian control of cell growth and a new paradigm for circadian protein degradation.
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Approach to the diagnosis and treatment of high-grade B-cell lymphomas with MYC and BCL2 and/or BCL6 rearrangements. Blood 2016; 129:280-288. [PMID: 27821509 DOI: 10.1182/blood-2016-02-636316] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 10/25/2016] [Indexed: 12/19/2022] Open
Abstract
High-grade B-cell lymphomas (HGBLs) with MYC and BCL2 and/or BCL6 rearrangements, so-called "double-hit" lymphomas (HGBL-DH), are aggressive lymphomas that form a separate provisional entity in the 2016 revised World Health Organization Classification of Lymphoid Tumors. Fluorescence in situ hybridization (FISH) will be required to identify HGBL-DH and will reclassify a subset of diffuse large B-cell lymphomas (DLBCLs) and HGBLs with features intermediate between DLBCL and Burkitt lymphoma into this new category. Identifying patients with HGBL-DH is important because it may change clinical management. This poses a challenge for centers that may not be ready to handle the additional workload and financial burden associated with the increase in requests for FISH testing. Herein, we review the mechanisms of deregulation of these oncogenes. We identify the factors associated with a poor prognosis and those that can guide diagnostic testing. Restricting FISH analysis to the 10% of DLBCL patients who have a germinal center B-cell phenotype and coexpress MYC and BCL2 proteins would be cost-effective and would identify the subset of patients who are at highest risk of experiencing a relapse following conventional therapy. These patients may benefit from intensified chemotherapy regimens or, ideally, should enroll in clinical trials investigating novel regimens.
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Zhang P, Cao L, Fan P, Mei Y, Wu M. LncRNA-MIF, a c-Myc-activated long non-coding RNA, suppresses glycolysis by promoting Fbxw7-mediated c-Myc degradation. EMBO Rep 2016; 17:1204-20. [PMID: 27317567 PMCID: PMC4967955 DOI: 10.15252/embr.201642067] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 05/17/2016] [Accepted: 05/23/2016] [Indexed: 01/26/2023] Open
Abstract
The c-Myc proto-oncogene is activated in more than half of all human cancers. However, the precise regulation of c-Myc protein stability is unknown. Here, we show that the lncRNA-MIF (c-Myc inhibitory factor), a c-Myc-induced long non-coding RNA, is a competing endogenous RNA for miR-586 and attenuates the inhibitory effect of miR-586 on Fbxw7, an E3 ligase for c-Myc, leading to increased Fbxw7 expression and subsequent c-Myc degradation. Our data reveal the existence of a feedback loop between c-Myc and lncRNA-MIF, through which c-Myc protein stability is finely controlled. Additionally, we show that the lncRNA-MIF inhibits aerobic glycolysis and tumorigenesis by suppressing c-Myc and miR-586.
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Affiliation(s)
- Pengfei Zhang
- CAS Key Laboratory of Innate Immunity and Chronic Disease, CAS Center for Excellence in Molecular Cell Science, Innovation Center for Cell Signaling Network, School of Life Sciences, University of Science & Technology of China, Hefei, Anhui, China
| | - Limian Cao
- CAS Key Laboratory of Innate Immunity and Chronic Disease, CAS Center for Excellence in Molecular Cell Science, Innovation Center for Cell Signaling Network, School of Life Sciences, University of Science & Technology of China, Hefei, Anhui, China
| | - Pingsheng Fan
- Affiliated Provincial Hospital of Anhui Medical University, Hefei, Anhui, China
| | - Yide Mei
- CAS Key Laboratory of Innate Immunity and Chronic Disease, CAS Center for Excellence in Molecular Cell Science, Innovation Center for Cell Signaling Network, School of Life Sciences, University of Science & Technology of China, Hefei, Anhui, China
| | - Mian Wu
- CAS Key Laboratory of Innate Immunity and Chronic Disease, CAS Center for Excellence in Molecular Cell Science, Innovation Center for Cell Signaling Network, School of Life Sciences, University of Science & Technology of China, Hefei, Anhui, China
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31
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Xu-Monette ZY, Deng Q, Manyam GC, Tzankov A, Li L, Xia Y, Wang XX, Zou D, Visco C, Dybkær K, Li J, Zhang L, Liang H, Montes-Moreno S, Chiu A, Orazi A, Zu Y, Bhagat G, Richards KL, Hsi ED, Choi WWL, van Krieken JH, Huh J, Ponzoni M, Ferreri AJM, Parsons BM, Møller MB, Wang SA, Miranda RN, Piris MA, Winter JN, Medeiros LJ, Li Y, Young KH. Clinical and Biologic Significance of MYC Genetic Mutations in De Novo Diffuse Large B-cell Lymphoma. Clin Cancer Res 2016; 22:3593-605. [PMID: 26927665 DOI: 10.1158/1078-0432.ccr-15-2296] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 02/09/2016] [Indexed: 12/21/2022]
Abstract
PURPOSE MYC is a critical driver oncogene in many cancers, and its deregulation in the forms of translocation and overexpression has been implicated in lymphomagenesis and progression of diffuse large B-cell lymphoma (DLBCL). The MYC mutational profile and its roles in DLBCL are unknown. This study aims to determine the spectrum of MYC mutations in a large group of patients with DLBCL, and to evaluate the clinical significance of MYC mutations in patients with DLBCL treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) immunochemotherapy. EXPERIMENTAL DESIGN We identified MYC mutations in 750 patients with DLBCL using Sanger sequencing and evaluated the prognostic significance in 602 R-CHOP-treated patients. RESULTS The frequency of MYC mutations was 33.3% at the DNA level (mutations in either the coding sequence or the untranslated regions) and 16.1% at the protein level (nonsynonymous mutations). Most of the nonsynonymous mutations correlated with better survival outcomes; in contrast, T58 and F138 mutations (which were associated with MYC rearrangements), as well as several mutations occurred at the 3' untranslated region, correlated with significantly worse survival outcomes. However, these mutations occurred infrequently (only in approximately 2% of DLBCL). A germline SNP encoding the Myc-N11S variant (observed in 6.5% of the study cohort) was associated with significantly better patient survival, and resulted in reduced tumorigenecity in mouse xenografts. CONCLUSIONS Various types of MYC gene mutations are present in DLBCL and show different impact on Myc function and clinical outcomes. Unlike MYC gene translocations and overexpression, most MYC gene mutations may not have a role in driving lymphomagenesis. Clin Cancer Res; 22(14); 3593-605. ©2016 AACR.
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Affiliation(s)
- Zijun Y Xu-Monette
- Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Qipan Deng
- Department of Cancer Biology, Cleveland Clinic, Cleveland, Ohio
| | - Ganiraju C Manyam
- Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | | | - Ling Li
- Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Yi Xia
- Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Xiao-Xiao Wang
- Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Dehui Zou
- Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | | | | | - Jun Li
- Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Li Zhang
- Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Han Liang
- Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | | | - April Chiu
- Memorial Sloan-Kettering Cancer Center, New York, New York
| | - Attilio Orazi
- Weill Medical College of Cornell University, New York, New York
| | - Youli Zu
- The Methodist Hospital, Houston, Texas
| | - Govind Bhagat
- Columbia University Medical Center and New York Presbyterian Hospital, New York, New York
| | - Kristy L Richards
- University of North Carolina School of Medicine, Chapel Hill, North Carolina
| | | | - William W L Choi
- University of Hong Kong Li Ka Shing Faculty of Medicine, Hong Kong, China
| | - J Han van Krieken
- Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands
| | - Jooryung Huh
- Asan Medical Center, Ulsan University College of Medicine, Seoul, Korea
| | | | | | - Ben M Parsons
- Gundersen Lutheran Health System, La Crosse, Wisconsin
| | | | - Sa A Wang
- Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Roberto N Miranda
- Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Miguel A Piris
- Hospital Universitario Marqués de Valdecilla, Santander, Spain
| | - Jane N Winter
- Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - L Jeffrey Medeiros
- Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Yong Li
- Department of Cancer Biology, Cleveland Clinic, Cleveland, Ohio.
| | - Ken H Young
- Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, Texas. The University of Texas School of Medicine, Graduate School of Biomedical Sciences, Houston, Texas.
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Lavallée VP, Lemieux S, Boucher G, Gendron P, Boivin I, Girard S, Hébert J, Sauvageau G. Identification of MYC mutations in acute myeloid leukemias with NUP98–NSD1 translocations. Leukemia 2016; 30:1621-4. [DOI: 10.1038/leu.2016.19] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Heo J, Eki R, Abbas T. Deregulation of F-box proteins and its consequence on cancer development, progression and metastasis. Semin Cancer Biol 2015; 36:33-51. [PMID: 26432751 DOI: 10.1016/j.semcancer.2015.09.015] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 09/25/2015] [Accepted: 09/25/2015] [Indexed: 01/28/2023]
Abstract
F-box proteins are substrate receptors of the SCF (SKP1-Cullin 1-F-box protein) E3 ubiquitin ligase that play important roles in a number of physiological processes and activities. Through their ability to assemble distinct E3 ubiquitin ligases and target key regulators of cellular activities for ubiquitylation and degradation, this versatile group of proteins is able to regulate the abundance of cellular proteins whose deregulated expression or activity contributes to disease. In this review, we describe the important roles of select F-box proteins in regulating cellular activities, the perturbation of which contributes to the initiation and progression of a number of human malignancies.
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Affiliation(s)
- Jinho Heo
- Department of Radiation Oncology, University of Virginia, Charlottesville, VA, USA
| | - Rebeka Eki
- Department of Radiation Oncology, University of Virginia, Charlottesville, VA, USA; Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, USA
| | - Tarek Abbas
- Department of Radiation Oncology, University of Virginia, Charlottesville, VA, USA; Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, USA; Center for Cell Signaling, University of Virginia, Charlottesville, VA, USA.
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Abstract
PURPOSE OF REVIEW Since the discovery of Epstein-Barr virus in Burkitt's lymphoma 50 years ago, only one other virus, namely Kaposi's sarcoma-associated herpesvirus/human herpesvirus-8, has been confirmed to be a direct cause of B-cell lymphoma. Here we will review the evidence for Epstein-Barr virus and Kaposi's sarcoma-associated herpesvirus as causal lymphoma agents. RECENT FINDINGS A deeper understanding of specific mechanisms by which Epstein-Barr virus and Kaposi's sarcoma-associated herpesvirus cause B-cell lymphomas has been acquired over the past years, in particular with respect to viral protein interactions with host cell pathways, and microRNA functions. Specific therapies based on knowledge of viral functions are beginning to be evaluated, mostly in preclinical models. SUMMARY Understanding the causal associations of specific infectious agents with certain B-cell lymphomas has allowed more accurate diagnosis and classification. A deeper knowledge of the specific mechanisms of transformation is essential to begin assessing whether virus-targeted treatment modalities may be used in the future.
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Affiliation(s)
- Ethel Cesarman
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, New York, USA
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McCloy RA, Parker BL, Rogers S, Chaudhuri R, Gayevskiy V, Hoffman NJ, Ali N, Watkins DN, Daly RJ, James DE, Lorca T, Castro A, Burgess A. Global Phosphoproteomic Mapping of Early Mitotic Exit in Human Cells Identifies Novel Substrate Dephosphorylation Motifs. Mol Cell Proteomics 2015; 14:2194-212. [PMID: 26055452 DOI: 10.1074/mcp.m114.046938] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Indexed: 12/27/2022] Open
Abstract
Entry into mitosis is driven by the coordinated phosphorylation of thousands of proteins. For the cell to complete mitosis and divide into two identical daughter cells it must regulate dephosphorylation of these proteins in a highly ordered, temporal manner. There is currently a lack of a complete understanding of the phosphorylation changes that occur during the initial stages of mitotic exit in human cells. Therefore, we performed a large unbiased, global analysis to map the very first dephosphorylation events that occur as cells exit mitosis. We identified and quantified the modification of >16,000 phosphosites on >3300 unique proteins during early mitotic exit, providing up to eightfold greater resolution than previous studies. The data have been deposited to the ProteomeXchange with identifier PXD001559. Only a small fraction (∼ 10%) of phosphorylation sites were dephosphorylated during early mitotic exit and these occurred on proteins involved in critical early exit events, including organization of the mitotic spindle, the spindle assembly checkpoint, and reformation of the nuclear envelope. Surprisingly this enrichment was observed across all kinase consensus motifs, indicating that it is independent of the upstream phosphorylating kinase. Therefore, dephosphorylation of these sites is likely determined by the specificity of phosphatase/s rather than the activity of kinase/s. Dephosphorylation was significantly affected by the amino acids at and surrounding the phosphorylation site, with several unique evolutionarily conserved amino acids correlating strongly with phosphorylation status. These data provide a potential mechanism for the specificity of phosphatases, and how they co-ordinate the ordered events of mitotic exit. In summary, our results provide a global overview of the phosphorylation changes that occur during the very first stages of mitotic exit, providing novel mechanistic insight into how phosphatase/s specifically regulate this critical transition.
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Affiliation(s)
- Rachael A McCloy
- From the ‡The Kinghorn Cancer Center, Garvan Institute of Medical Research, Darlinghurst, NSW, 2010, Australia
| | - Benjamin L Parker
- §The Charles Perkins Center, School of Molecular Bioscience and Sydney Medical School, The University of Sydney, NSW 2006, Australia
| | - Samuel Rogers
- From the ‡The Kinghorn Cancer Center, Garvan Institute of Medical Research, Darlinghurst, NSW, 2010, Australia
| | - Rima Chaudhuri
- §The Charles Perkins Center, School of Molecular Bioscience and Sydney Medical School, The University of Sydney, NSW 2006, Australia
| | - Velimir Gayevskiy
- From the ‡The Kinghorn Cancer Center, Garvan Institute of Medical Research, Darlinghurst, NSW, 2010, Australia
| | - Nolan J Hoffman
- §The Charles Perkins Center, School of Molecular Bioscience and Sydney Medical School, The University of Sydney, NSW 2006, Australia
| | - Naveid Ali
- From the ‡The Kinghorn Cancer Center, Garvan Institute of Medical Research, Darlinghurst, NSW, 2010, Australia
| | - D Neil Watkins
- From the ‡The Kinghorn Cancer Center, Garvan Institute of Medical Research, Darlinghurst, NSW, 2010, Australia; ¶St. Vincent's Clinical School, Faculty of Medicine, UNSW, Darlinghurst, NSW, Australia; ‖Department of Thoracic Medicine, St Vincent's Hospital, Darlinghurst, NSW, 2010, Australia
| | - Roger J Daly
- **Department of Biochemistry and Molecular Biology, School of Biomedical Sciences Monash University, Clatyon, VIC, 3800, Australia
| | - David E James
- §The Charles Perkins Center, School of Molecular Bioscience and Sydney Medical School, The University of Sydney, NSW 2006, Australia
| | - Thierry Lorca
- ‡‡Equipe Labellisée Ligue Nationale Contre le Cancer, Universités Montpellier 2 et 1, Centre de Recherche de Biochimie Macromoléculaire, CNRS UMR 5237, 1919 Route de Mende, 34293 Montpellier cedex 5, France
| | - Anna Castro
- ‡‡Equipe Labellisée Ligue Nationale Contre le Cancer, Universités Montpellier 2 et 1, Centre de Recherche de Biochimie Macromoléculaire, CNRS UMR 5237, 1919 Route de Mende, 34293 Montpellier cedex 5, France
| | - Andrew Burgess
- ¶St. Vincent's Clinical School, Faculty of Medicine, UNSW, Darlinghurst, NSW, Australia; From the ‡The Kinghorn Cancer Center, Garvan Institute of Medical Research, Darlinghurst, NSW, 2010, Australia;
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Chakraborty AA, Scuoppo C, Dey S, Thomas LR, Lorey SL, Lowe SW, Tansey WP. A common functional consequence of tumor-derived mutations within c-MYC. Oncogene 2015; 34:2406-9. [PMID: 24998853 PMCID: PMC4286529 DOI: 10.1038/onc.2014.186] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Accepted: 05/06/2014] [Indexed: 11/09/2022]
Abstract
The relevance of changes to the coding sequence of the c-MYC oncogene to malignancy is controversial. Overexpression of a pristine form of MYC is observed in many cancers and is sufficient to drive tumorigenesis in most contexts. Yet missense changes to MYC are found in ~50% of Burkitt's lymphomas, aggregate within an amino-terminal degron important for proteasomal destruction of MYC, and where examined profoundly enhance the tumorigenic properties of MYC in vitro and in vivo. Much of the controversy surrounding these mutants stems from the limited number of mutations that have been evaluated and their clustering within a single region of the MYC protein; the highly-conserved Myc box I (MbI) element. Here, by analysis of extant genomic data sets, we identify a previously unrecognized hotspot for tumor-associated MYC mutations, located in a conserved central portion of the protein. We show that, despite their distal location in MYC, mutations in this region precisely phenocopy those in MbI in terms of stability, in vitro transformation, growth-promoting properties, in vivo tumorigenesis and ability to escape p53-dependent tumor surveillance mechanisms. The striking parallels between the behavior of tumor-derived mutations in disparate regions of the MYC protein reveals that a common molecular process is disrupted by these mutations, implying an active role for these mutations in tumorigenesis and suggesting that different therapeutic strategies may be needed for treatment of lymphomas expressing wild type versus mutant forms of MYC protein.
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Affiliation(s)
- A A Chakraborty
- 1] Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, NY, USA [2] Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - C Scuoppo
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, NY, USA
| | - S Dey
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - L R Thomas
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - S L Lorey
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - S W Lowe
- 1] Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, NY, USA [2] Howard Hughes Medical Institute, New York, NY, USA
| | - W P Tansey
- 1] Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, NY, USA [2] Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
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Reversible linkage of two distinct small molecule inhibitors of Myc generates a dimeric inhibitor with improved potency that is active in myc over-expressing cancer cell lines. PLoS One 2015; 10:e0121793. [PMID: 25875098 PMCID: PMC4398458 DOI: 10.1371/journal.pone.0121793] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 01/19/2015] [Indexed: 12/13/2022] Open
Abstract
We describe the successful application of a novel approach for generating dimeric Myc inhibitors by modifying and reversibly linking two previously described small molecules. We synthesized two directed libraries of monomers, each comprised of a ligand, a connector, and a bioorthogonal linker element, to identify the optimal dimer configuration required to inhibit Myc. We identified combinations of monomers, termed self-assembling dimeric inhibitors, which displayed synergistic inhibition of Myc-dependent cell growth. We confirmed that these dimeric inhibitors directly bind to Myc blocking its interaction with Max and affect transcription of MYC dependent genes. Control combinations that are unable to form a dimer do not show any synergistic effects in these assays. Collectively, these data validate our new approach to generate more potent and selective inhibitors of Myc by self-assembly from smaller, lower affinity components. This approach provides an opportunity for developing novel therapeutics against Myc and other challenging protein:protein interaction (PPI) target classes.
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Chakraborty AA, Tansey WP. Do changes in the c-MYC coding sequence contribute to tumorigenesis? Mol Cell Oncol 2015; 2:e965631. [PMID: 27308414 PMCID: PMC4904990 DOI: 10.4161/23723548.2014.965631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 08/12/2014] [Accepted: 08/13/2014] [Indexed: 11/19/2022]
Abstract
The role of changes in the c-MYC coding sequence in cancer is controversial. Overexpression of wild-type protein is sufficient to drive tumorigenesis, yet point mutations in c-MYC are common in Burkitt's lymphoma. Our discovery that disparate tumor-associated mutations in c-MYC have similar protumorigenic effects suggests that these mutations contribute directly to malignancy.
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Affiliation(s)
- Abhishek A Chakraborty
- Department of Cell and Developmental Biology; Vanderbilt University School of Medicine; Nashville, TN USA; Present address: Department of Medical Oncology; Dana-Farber Cancer Institute and Brigham and Women's Hospital; Boston, MA USA
| | - William P Tansey
- Department of Cell and Developmental Biology; Vanderbilt University School of Medicine ; Nashville, TN USA
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Palma P, Cano C, Conde-Muiño R, Comino A, Bueno P, Ferrón JA, Cuadros M. Expression profiling of rectal tumors defines response to neoadjuvant treatment related genes. PLoS One 2014; 9:e112189. [PMID: 25380052 PMCID: PMC4224421 DOI: 10.1371/journal.pone.0112189] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 10/13/2014] [Indexed: 01/23/2023] Open
Abstract
To date, no effective method exists that predicts the response to preoperative chemoradiation (CRT) in locally advanced rectal cancer (LARC). Nevertheless, identification of patients who have a higher likelihood of responding to preoperative CRT could be crucial in decreasing treatment morbidity and avoiding expensive and time-consuming treatments. The aim of this study was to identify signatures or molecular markers related to response to pre-operative CRT in LARC. We analyzed the gene expression profiles of 26 pre-treatment biopsies of LARC (10 responders and 16 non-responders) without metastasis using Human WG CodeLink microarray platform. Two hundred and fifty seven genes were differentially over-expressed in the responder patient subgroup. Ingenuity Pathway Analysis revealed a significant ratio of differentially expressed genes related to cancer, cellular growth and proliferation pathways, and c-Myc network. We demonstrated that high Gng4, c-Myc, Pola1, and Rrm1 mRNA expression levels was a significant prognostic factor for response to treatment in LARC patients (p<0.05). Using this gene set, we were able to establish a new model for predicting the response to CRT in rectal cancer with a sensitivity of 60% and 100% specificity. Our results reflect the value of gene expression profiling to gain insight about the molecular pathways involved in the response to treatment of LARC patients. These findings could be clinically relevant and support the use of mRNA levels when aiming to identify patients who respond to CRT therapy.
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Affiliation(s)
- Pablo Palma
- Division of Colon & Rectal Surgery, Virgen de las Nieves Hospital (HUVN), Granada, Spain
| | - Carlos Cano
- Department of Computer Science and Artificial Intelligence, University of Granada, Granada, Spain
| | - Raquel Conde-Muiño
- Division of Colon & Rectal Surgery, Virgen de las Nieves Hospital (HUVN), Granada, Spain
| | - Ana Comino
- Department of Surgical Research, Virgen de las Nieves Hospital (HUVN), Granada, Spain
| | - Pablo Bueno
- Department of Surgical Research, Virgen de las Nieves Hospital (HUVN), Granada, Spain
| | - J. Antonio Ferrón
- Division of Colon & Rectal Surgery, Virgen de las Nieves Hospital (HUVN), Granada, Spain
- Department of Surgical Research, Virgen de las Nieves Hospital (HUVN), Granada, Spain
| | - Marta Cuadros
- Department of Biochemistry and Molecular Biology III e Immunology, University of Granada, Granada, Spain
- GENYO, Centre for Genomics and Oncological Research: Pfizer/University of de Granada/Junta de Andalucía, Granada, Spain
- * E-mail:
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Davis RJ, Welcker M, Clurman BE. Tumor suppression by the Fbw7 ubiquitin ligase: mechanisms and opportunities. Cancer Cell 2014; 26:455-64. [PMID: 25314076 PMCID: PMC4227608 DOI: 10.1016/j.ccell.2014.09.013] [Citation(s) in RCA: 267] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Revised: 09/23/2014] [Accepted: 09/26/2014] [Indexed: 12/13/2022]
Abstract
Tumor suppressors with widespread impact on carcinogenesis control broad spectra of oncogenic pathways. Protein degradation is an emerging mechanism by which tumor suppressors regulate a diversity of pathways and is exemplified by the SCF(Fbw7) ubiquitin ligase. Rapidly accumulating data indicate that SCF(Fbw7) regulates a network of crucial oncoproteins. Importantly, the FBXW7 gene, which encodes Fbw7, is one of the most frequently mutated genes in human cancers. These studies are yielding important new insights into tumorigenesis and may soon enable therapies targeting the Fbw7 pathway. Here, we focus on the mechanisms and consequences of Fbw7 deregulation in cancers and discuss possible therapeutic approaches.
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Affiliation(s)
- Ryan J Davis
- Clinical Research and Human Biology Divisions, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA; Molecular and Cellular Biology Program, University of Washington, Seattle, WA 98195, USA
| | - Markus Welcker
- Clinical Research and Human Biology Divisions, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Bruce E Clurman
- Clinical Research and Human Biology Divisions, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.
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Oduor CI, Chelimo K, Ouma C, Mulama DH, Foley J, Vulule J, Bailey JA, Moormann AM. Interleukin-6 and interleukin-10 gene promoter polymorphisms and risk of endemic Burkitt lymphoma. Am J Trop Med Hyg 2014; 91:649-54. [PMID: 25071000 DOI: 10.4269/ajtmh.13-0616] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Overexpression of interleukin-6 (IL-6) and IL-10 in endemic Burkitt lymphoma (eBL) may facilitate tumorigenesis by providing a permissive cytokine milieu. Promoter polymorphisms influence interindividual differences in cytokine production. We hypothesized that children genetically predisposed for elevated cytokine levels may be more susceptible to eBL. Using case-control samples from western Kenya consisting of 117 eBL cases and 88 ethnically matched healthy controls, we tested for the association between eBL risk and IL-10 (rs1800896, rs1800871, and rs1800872) and IL-6 (rs1800795) promoter single nucleotide polymorphisms (SNPs) as well as IL-10 promoter haplotypes. In addition, the association between these variants and Epstein Barr Virus (EBV) load was examined. Results showed that selected IL-10 and IL-6 promoter SNPs and IL-10 promoter haplotypes were not associated with risk eBL or EBV levels in EBV-seropositive children. Findings from this study reveal that common variants within the IL-10 and IL-6 promoters do not independently increase eBL risk in this vulnerable population.
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Affiliation(s)
- Cliff I Oduor
- Department of Biomedical Sciences and Technology, Maseno University, Maseno, Kenya; Center for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya; Department of Pediatrics, University of Massachusetts Medical School, Worcester, Massachusetts; Department of Medicine, Division of Transfusion, and Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, Massachusetts; Department of Quantitative Health Sciences, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Kiprotich Chelimo
- Department of Biomedical Sciences and Technology, Maseno University, Maseno, Kenya; Center for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya; Department of Pediatrics, University of Massachusetts Medical School, Worcester, Massachusetts; Department of Medicine, Division of Transfusion, and Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, Massachusetts; Department of Quantitative Health Sciences, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Collins Ouma
- Department of Biomedical Sciences and Technology, Maseno University, Maseno, Kenya; Center for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya; Department of Pediatrics, University of Massachusetts Medical School, Worcester, Massachusetts; Department of Medicine, Division of Transfusion, and Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, Massachusetts; Department of Quantitative Health Sciences, University of Massachusetts Medical School, Worcester, Massachusetts
| | - David H Mulama
- Department of Biomedical Sciences and Technology, Maseno University, Maseno, Kenya; Center for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya; Department of Pediatrics, University of Massachusetts Medical School, Worcester, Massachusetts; Department of Medicine, Division of Transfusion, and Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, Massachusetts; Department of Quantitative Health Sciences, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Joslyn Foley
- Department of Biomedical Sciences and Technology, Maseno University, Maseno, Kenya; Center for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya; Department of Pediatrics, University of Massachusetts Medical School, Worcester, Massachusetts; Department of Medicine, Division of Transfusion, and Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, Massachusetts; Department of Quantitative Health Sciences, University of Massachusetts Medical School, Worcester, Massachusetts
| | - John Vulule
- Department of Biomedical Sciences and Technology, Maseno University, Maseno, Kenya; Center for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya; Department of Pediatrics, University of Massachusetts Medical School, Worcester, Massachusetts; Department of Medicine, Division of Transfusion, and Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, Massachusetts; Department of Quantitative Health Sciences, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Jeffrey A Bailey
- Department of Biomedical Sciences and Technology, Maseno University, Maseno, Kenya; Center for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya; Department of Pediatrics, University of Massachusetts Medical School, Worcester, Massachusetts; Department of Medicine, Division of Transfusion, and Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, Massachusetts; Department of Quantitative Health Sciences, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Ann M Moormann
- Department of Biomedical Sciences and Technology, Maseno University, Maseno, Kenya; Center for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya; Department of Pediatrics, University of Massachusetts Medical School, Worcester, Massachusetts; Department of Medicine, Division of Transfusion, and Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, Massachusetts; Department of Quantitative Health Sciences, University of Massachusetts Medical School, Worcester, Massachusetts
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Abstract
MYC expression is tightly correlated with cell-cycle progression in normal tissues, whereas unchecked MYC expression is among the most prominent hallmarks of the hyperproliferation associated with most forms of cancer. At first glance it might seem counterintuitive that MYC is also among the most robust agents of programmed cell death (apoptosis) in mammalian cells. However it is clearly beneficial for a multicellular organism to have a mechanism for triggering death in cells that express potentially oncogenic levels of MYC. Decades of intense study have begun to provide an understanding of the mechanisms that regulate MYC's seemingly split personality. Key features of MYC-induced apoptosis will be discussed here along with examples of how our understanding of this pathway might be exploited for the therapeutic benefit of cancer patients.
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Affiliation(s)
- Steven B McMahon
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
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Liu PW, Lin Y, Chen XY. Expression of B-cell-specific Moloney murine leukemia virus integration site 1 mRNA and protein in gastric cancer. J Dig Dis 2014; 15:166-73. [PMID: 24393364 DOI: 10.1111/1751-2980.12129] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE To investigate the role of B-cell-specific Moloney murine leukemia virus integration site 1 (Bmi-1) in gastric cancer (GC) and its relationship with the clinicopathological features of GC. METHODS Laser capture microdissection combined with real-time polymerase chain reaction and Western blot were used to determine the expressions of Bmi-1, the cellular homologue of avian myelocytomatosis virus (c-Myc), enhancer of Zeste homolog 2 (EZH2), phosphatase and tensin homologue (PTEN) and epithelial cadherin (E-cadherin) in 20 GC specimens and the adjacent non-cancerous gastric tissues. RESULTS The mRNA and protein expressions of Bmi-1 in GC were increased compared with those of the non-cancerous gastric tissues (P = 0.012 and P = 0.000, respectively). Bmi-1 mRNA expression was positively correlated with tumor size, degree of tumor differentiation, invasion and lymph node metastasis. At both mRNA and protein levels, Bmi-1 was positively correlated with c-Myc and EZH2, but negatively correlated with PTEN and E-cadherin. CONCLUSION Bmi-1 might be involved in GC at both transcription and translation levels.
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Affiliation(s)
- Peng Wei Liu
- Department of Gastroenterology and Hepatology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Division of Gastrointestinal Pathology, Shanghai Institute of Digestive Disease, Shanghai, China
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Fletcher S, Prochownik EV. Small-molecule inhibitors of the Myc oncoprotein. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1849:525-43. [PMID: 24657798 DOI: 10.1016/j.bbagrm.2014.03.005] [Citation(s) in RCA: 113] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2013] [Revised: 03/09/2014] [Accepted: 03/12/2014] [Indexed: 01/23/2023]
Abstract
The c-Myc (Myc) oncoprotein is among the most attractive of cancer targets given that it is de-regulated in the majority of tumors and that its inhibition profoundly affects their growth and/or survival. However, its role as a seldom-mutated transcription factor, its lack of enzymatic activity for which suitable pharmaceutical inhibitors could be crafted and its expression by normal cells have largely been responsible for its being viewed as "undruggable". Work over the past several years, however, has begun to reverse this idea by allowing us to view Myc within the larger context of global gene regulatory control. Thus, Myc and its obligate heterodimeric partner, Max, are integral to the coordinated recruitment and post-translational modification of components of the core transcriptional machinery. Moreover, Myc over-expression re-programs numerous critical cellular functions and alters the cell's susceptibility to their inhibition. This new knowledge has therefore served as a framework upon which to develop new pharmaceutical approaches. These include the continuing development of small molecules which act directly to inhibit the critical Myc-Max interaction, those which act indirectly to prevent Myc-directed post-translational modifications necessary to initiate productive transcription and those which inhibit vital pathways upon which the Myc-transformed cell is particularly reliant. This article is part of a Special Issue entitled: Myc proteins in cell biology and pathology.
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Affiliation(s)
- Steven Fletcher
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, USA; University of Maryland Greenebaum Cancer Center, Baltimore, USA
| | - Edward V Prochownik
- Section of Hematology/Oncology, Children's Hospital of Pittsburgh of UPMC, USA; Department of Microbiology and Molecular Genetics, The University of Pittsburgh School of Medicine, USA; The University of Pittsburgh Cancer Institute, Pittsburgh, PA, USA.
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Abstract
PURPOSE OF REVIEW HIV-infected individuals have a greatly increased risk of developing malignancies, even when HIV infection is successfully controlled with antiretrovirals. Non-Hodgkin's lymphoma is considered an AIDS-defining entity, and this disease is currently the most common type of cancer in HIV-infected individuals in the USA and Europe. Here, we describe the different types of lymphomas occurring in individuals with AIDS, and the most relevant pathologic features helpful for histologic and immunohistochemical diagnosis. RECENT FINDINGS The incidence of some AIDS-related lymphoma subtypes has changed since the introduction of combined antiretroviral therapy, and some of the diagnostic methodologies have evolved. New biomarkers of disease have been identified, which may be useful for diagnosis. SUMMARY Better pathological classification strategies and deeper molecular understanding of the different lymphoma subtypes that occur in people with AIDS will begin to allow the transition to more precise diagnosis and targeted treatments.
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Abstract
Myc-family proteins are key controllers of the metabolic and proliferative status of the cell, and are subjected to a complex network of regulatory events that guarantee their efficient and fast modulation by extracellular stimuli. Hence, unbalances in regulatory mechanisms leading to altered Myc levels or activities are often reported in cancer cells. Here we show that c- and N-Myc are conjugated to SUMO proteins at conserved lysines in their C-terminal domain. No obvious effects of SUMOylation were detected on bulk N-Myc stability or activities, including the regulation of transcription, proliferation or apoptosis. N-Myc SUMOylation could be induced by cellular stresses, such as heat shock and proteasome inhibition, and in all instances concerned a small fraction of the N-Myc protein. We surmise that, as shown for other substrates, SUMOylation may be part of a quality-control mechanism acting on misfolded Myc proteins.
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Affiliation(s)
- Arianna Sabò
- Center for Genomic Science of IIT@SEMM, Fondazione Istituto Italiano di Tecnologia (IIT), Milan, Italy
- Department of Experimental Oncology, European Institute of Oncology (IEO), Milan, Italy
| | - Mirko Doni
- Department of Experimental Oncology, European Institute of Oncology (IEO), Milan, Italy
| | - Bruno Amati
- Center for Genomic Science of IIT@SEMM, Fondazione Istituto Italiano di Tecnologia (IIT), Milan, Italy
- Department of Experimental Oncology, European Institute of Oncology (IEO), Milan, Italy
- * E-mail:
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48
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Abstract
The MYC oncoprotein is an essential transcription factor that regulates the expression of many genes involved in cell growth, proliferation, and metabolic pathways. Thus, it is important to keep MYC activity in check in normal cells in order to avoid unwanted oncogenic changes. Normal cells have adapted several ways to control MYC levels, and these mechanisms can be disrupted in cancer cells. One of the major ways in which MYC levels are controlled in cells is through targeted degradation by the ubiquitin-proteasome system (UPS). Here, we discuss the role of the UPS in the regulation of MYC protein levels and review some of the many proteins that have been shown to regulate MYC protein stability. In addition, we discuss how this relates to MYC transcriptional activity, human cancers, and therapeutic targeting.
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Affiliation(s)
- Amy S Farrell
- Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, Oregon 97239
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49
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Abstract
The MYC family of proteins is a group of basic-helix-loop-helix-leucine zipper transcription factors that feature prominently in cancer. Overexpression of MYC is observed in the vast majority of human malignancies and promotes an extraordinary set of changes that impact cell proliferation, growth, metabolism, DNA replication, cell cycle progression, cell adhesion, differentiation, and metastasis. The purpose of this review is to introduce the reader to the mammalian family of MYC proteins, highlight important functional properties that endow them with their potent oncogenic potential, describe their mechanisms of action and of deregulation in cancer cells, and discuss efforts to target the unique properties of MYC, and of MYC-driven tumors, to treat cancer.
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50
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The MYC oncogene family in human cancer. Mol Oncol 2013. [DOI: 10.1017/cbo9781139046947.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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