51
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Cho Y, Kim YK. Cancer Stem Cells as a Potential Target to Overcome Multidrug Resistance. Front Oncol 2020; 10:764. [PMID: 32582535 PMCID: PMC7280434 DOI: 10.3389/fonc.2020.00764] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 04/21/2020] [Indexed: 12/21/2022] Open
Abstract
Multidrug resistance (MDR), which is a significant impediment to the success of cancer chemotherapy, is attributable to various defensive mechanisms in cancer. Initially, overexpression of ATP-binding cassette (ABC) transporters such as P-glycoprotein (P-gp) was considered the most important mechanism for drug resistance; hence, many investigators for a long time focused on the development of specific ABC transporter inhibitors. However, to date their efforts have failed to develop a clinically applicable drug, leaving only a number of problems. The concept of cancer stem cells (CSCs) has provided new directions for both cancer and MDR research. MDR is known to be one of the most important features of CSCs and thus plays a crucial role in cancer recurrence and exacerbation. Therefore, in recent years, research targeting CSCs has been increasing rapidly in search of an effective cancer treatment. Here, we review the drugs that have been studied and developed to overcome MDR and CSCs, and discuss the limitations and future perspectives.
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Affiliation(s)
| | - Yong Kee Kim
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Sookmyung Women's University, Seoul, South Korea
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52
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Abstract
Epigenetic mechanisms involve the placing (writing) or removal (erasing) of histone modifications that allow heterochromatin to transition to the open, activated euchromatin state necessary for transcription. A third, less studied epigenetic pathway involves the reading of these specific histone marks once placed. The BETs (bromodomain and extraterminal-containing protein family), which includes BRD2, BRD3, and BRD4 and the testis-restricted BRDT, are epigenetic reader proteins that bind to specific acetylated lysine residues on histone tails where they facilitate the assembly of transcription complexes including transcription factors and transcriptional machinery like RNA Polymerase II. As reviewed here, considerable recent data establishes BETs as novel determinants of induced transcriptional programs in vascular cells, like endothelial cells and vascular smooth muscle cells, cardiac myocytes and inflammatory cells, like monocyte/macrophages, cellular settings where these epigenetic reader proteins couple proximal stimuli to chromatin, acting at super-enhancer regulatory regions to direct gene expression. BET inhibition, including the use of specific chemical BET inhibitors like JQ-1, has many reported effects in vivo in the cardiovascular setting, like decreasing atherosclerosis, angiogenesis, intimal hyperplasia, pulmonary arterial hypertension, and cardiac hypertrophy. At the same time, data in endothelial cells, adipocytes, and elsewhere suggest BETs also help regulate gene expression under basal conditions. Studies in the cardiovascular setting have highlighted BET action as a means of controlling gene expression in differentiation, cell identity, and cell state transitions, whether physiological or pathological, adaptive, or maladaptive. While distinct BET inhibitors are being pursued as therapies in oncology, a large prospective clinical cardiovascular outcome study investigating the BET inhibitor RVX-208 (now called apabetalone) has already been completed. Independent of this specific agent and this one trial or the numerous unanswered questions that remain, BETs have emerged as novel epigenetic players involved in the execution of coordinated transcriptional programs in cardiovascular health and disease.
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Affiliation(s)
- Patricia Cristine Borck
- From the Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA (P.C.B., J.P.)
| | - Lian-Wang Guo
- Davis Heart and Lung Institute, Wexner Medical Center, Ohio State University, Columbus (L.-W.G.)
| | - Jorge Plutzky
- From the Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA (P.C.B., J.P.)
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53
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Laham-Karam N, Pinto GP, Poso A, Kokkonen P. Transcription and Translation Inhibitors in Cancer Treatment. Front Chem 2020; 8:276. [PMID: 32373584 PMCID: PMC7186406 DOI: 10.3389/fchem.2020.00276] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Accepted: 03/20/2020] [Indexed: 12/12/2022] Open
Abstract
Transcription and translation are fundamental cellular processes that govern the protein production of cells. These processes are generally up regulated in cancer cells, to maintain the enhanced metabolism and proliferative state of these cells. As such cancerous cells can be susceptible to transcription and translation inhibitors. There are numerous druggable proteins involved in transcription and translation which make lucrative targets for cancer drug development. In addition to proteins, recent years have shown that the "undruggable" transcription factors and RNA molecules can also be targeted to hamper the transcription or translation in cancer. In this review, we summarize the properties and function of the transcription and translation inhibitors that have been tested and developed, focusing on the advances of the last 5 years. To complement this, we also discuss some of the recent advances in targeting oncogenes tightly controlling transcription including transcription factors and KRAS. In addition to natural and synthetic compounds, we review DNA and RNA based approaches to develop cancer drugs. Finally, we conclude with the outlook to the future of the development of transcription and translation inhibitors.
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Affiliation(s)
- Nihay Laham-Karam
- A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Gaspar P. Pinto
- International Clinical Research Center, St. Anne University Hospital, Brno, Czechia
- Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Faculty of Science, Masaryk University, Brno, Czechia
| | - Antti Poso
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, Kuopio, Finland
- University Hospital Tübingen, Department of Internal Medicine VIII, University of Tübingen, Tübingen, Germany
| | - Piia Kokkonen
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, Kuopio, Finland
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54
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Trivedi A, Mehrotra A, Baum CE, Lewis B, Basuroy T, Blomquist T, Trumbly R, Filipp FV, Setaluri V, de la Serna IL. Bromodomain and extra-terminal domain (BET) proteins regulate melanocyte differentiation. Epigenetics Chromatin 2020; 13:14. [PMID: 32151278 PMCID: PMC7063807 DOI: 10.1186/s13072-020-00333-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 02/19/2020] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND Pharmacologic inhibition of bromodomain and extra-terminal (BET) proteins is currently being explored as a new therapeutic approach in cancer. Some studies have also implicated BET proteins as regulators of cell identity and differentiation through their interactions with lineage-specific factors. However, the role of BET proteins has not yet been investigated in melanocyte differentiation. Melanocyte inducing transcription factor (MITF) is the master regulator of melanocyte differentiation, essential for pigmentation and melanocyte survival. In this study, we tested the hypothesis that BET proteins regulate melanocyte differentiation through interactions with MITF. RESULTS Here we show that chemical inhibition of BET proteins prevents differentiation of unpigmented melanoblasts into pigmented melanocytes and results in de-pigmentation of differentiated melanocytes. BET inhibition also slowed cell growth, without causing cell death, increasing the number of cells in G1. Transcriptional profiling revealed that BET inhibition resulted in decreased expression of pigment-specific genes, including many MITF targets. The expression of pigment-specific genes was also down-regulated in melanoma cells, but to a lesser extent. We found that RNAi depletion of the BET family members, bromodomain-containing protein 4 (BRD4) and bromodomain-containing protein 2 (BRD2) inhibited expression of two melanin synthesis enzymes, TYR and TYRP1. Both BRD4 and BRD2 were detected on melanocyte promoters surrounding MITF-binding sites, were associated with open chromatin structure, and promoted MITF binding to these sites. Furthermore, BRD4 and BRD2 physically interacted with MITF. CONCLUSION These findings indicate a requirement for BET proteins in the regulation of pigmentation and melanocyte differentiation. We identified changes in pigmentation specific gene expression that occur upon BET inhibition in melanoblasts, melanocytes, and melanoma cells.
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Affiliation(s)
- Archit Trivedi
- Department of Cancer Biology, University of Toledo College of Medicine and Life Sciences, 3035 Arlington Ave, Toledo, OH 43614 USA
| | - Aanchal Mehrotra
- Department of Cancer Biology, University of Toledo College of Medicine and Life Sciences, 3035 Arlington Ave, Toledo, OH 43614 USA
- Present Address: Department of Genome Sciences, University of Washington School of Medicine, 1959 NE Pacific St, Seattle, WA 98195 USA
| | - Caitlin E. Baum
- Department of Pathology, University of Toledo College of Medicine and Life Sciences, 3035 Arlington Ave, Toledo, OH 43614 USA
| | - Brandon Lewis
- Department of Cancer Biology, University of Toledo College of Medicine and Life Sciences, 3035 Arlington Ave, Toledo, OH 43614 USA
| | - Tupa Basuroy
- Department of Cancer Biology, University of Toledo College of Medicine and Life Sciences, 3035 Arlington Ave, Toledo, OH 43614 USA
- Present Address: Cancer Center Division, Massachusetts General Hospital Harvard Medical School, 149 Thirteenth Street, 7th Floor, Charlestown, MA 02129 USA
| | - Thomas Blomquist
- Department of Pathology, University of Toledo College of Medicine and Life Sciences, 3035 Arlington Ave, Toledo, OH 43614 USA
| | - Robert Trumbly
- Department of Cancer Biology, University of Toledo College of Medicine and Life Sciences, 3035 Arlington Ave, Toledo, OH 43614 USA
| | - Fabian V. Filipp
- Cancer Systems Biology, Institute of Computational Biology, Helmholtz Zentrum München, Ingolstädter Landstraße 1, München, 85764 Germany
- School of Life Sciences Weihenstephan, Technical University München, Maximus-von-Imhof-Forum 3, Freising, 85354 Germany
| | - Vijayasaradhi Setaluri
- Department of Dermatology, University of Wisconsin-Madison, The School of Medicine and Public Health, 1 S. Park Street, Madison, WI 53715 USA
| | - Ivana L. de la Serna
- Department of Cancer Biology, University of Toledo College of Medicine and Life Sciences, 3035 Arlington Ave, Toledo, OH 43614 USA
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55
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Katavolos P, Cain G, Farman C, Romero FA, Magnuson S, Ly JQ, Choo EF, Katakam AK, Andaya R, Maher J. Preclinical Safety Assessment of a Highly Selective and Potent Dual Small-Molecule Inhibitor of CBP/P300 in Rats and Dogs. Toxicol Pathol 2020; 48:465-480. [PMID: 32124659 DOI: 10.1177/0192623319898469] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Cyclic adenosine monophosphate-response element (CREB)-binding protein (CBP) and EP300E1A-binding protein (p300) are members of the bromodomain and extraterminal motif (BET) family. These highly homologous proteins have a key role in modulating transcription, including altering the status of chromatin or through interactions with or posttranslational modifications of transcription factors. As CBP and p300 have known roles for stimulating c-Myc oncogenic activity, a small-molecule inhibitor, GNE-781, was developed to selectively and potently inhibit the CBP/p300 bromodomains (BRDs). Genetic models have been challenging to develop due to embryonic lethality arising from germline homozygous mutations in either CBP or P300. Hence, the purpose of this study was to characterize the role of dual inhibition of these proteins in adult rats and dogs. Repeat dose toxicity studies were conducted, and toxicologic and pathologic end points were assessed. GNE-781 was generally tolerated; however, marked effects on thrombopoiesis occurred in both species. Evidence of inhibition of erythroid, granulocytic, and lymphoid cell differentiation was also present, as well as deleterious changes in gastrointestinal and reproductive tissues. These findings are consistent with many preclinical (and clinical) effects reported with BET inhibitors targeting BRD proteins; thus, the current study findings indicate a likely important role for CBP/p300 in stem cell differentiation.
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Affiliation(s)
- Paula Katavolos
- Safety Assessment, Genentech, Inc, South San Francisco, CA, USA
| | - Gary Cain
- Safety Assessment, Genentech, Inc, South San Francisco, CA, USA
| | - Cindy Farman
- Safety Assessment, Genentech, Inc, South San Francisco, CA, USA.,Vet Path Services, Inc, Mason, OH, USA
| | - F Anthony Romero
- Medicinal Chemistry, Genentech, Inc, South San Francisco, CA, USA.,Terns Pharmaceuticals, San Mateo, CA, USA
| | - Steven Magnuson
- Medicinal Chemistry, Genentech, Inc, South San Francisco, CA, USA
| | - Justin Q Ly
- Department of Drug Metabolism and Pharmacology, Genentech, Inc, South San Francisco, CA, USA
| | - Edna F Choo
- Department of Drug Metabolism and Pharmacology, Genentech, Inc, South San Francisco, CA, USA
| | | | - Roxanne Andaya
- Safety Assessment, Genentech, Inc, South San Francisco, CA, USA
| | - Jonathan Maher
- Safety Assessment, Genentech, Inc, South San Francisco, CA, USA
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56
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Call SG, Duren RP, Panigrahi AK, Nguyen L, Freire PR, Grimm SL, Coarfa C, Conneely OM. Targeting Oncogenic Super Enhancers in MYC-Dependent AML Using a Small Molecule Activator of NR4A Nuclear Receptors. Sci Rep 2020; 10:2851. [PMID: 32071334 PMCID: PMC7029036 DOI: 10.1038/s41598-020-59469-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 01/29/2020] [Indexed: 12/11/2022] Open
Abstract
Epigenetic reprogramming in Acute Myeloid Leukemia (AML) leads to the aberrant activation of super enhancer (SE) landscapes that drive the expression of key oncogenes, including the oncogenic MYC pathway. These SEs have been identified as promising therapeutic targets, and have given rise to a new class of drugs, including BET protein inhibitors, which center on targeting SE activity. NR4A nuclear receptors are tumor suppressors of AML that function in part through transcriptional repression of the MYC-driven oncogenic program via mechanisms that remain unclear. Here we show that NR4A1, and the NR4A inducing drug dihydroergotamine (DHE), regulate overlapping gene expression programs in AML and repress transcription of a subset of SE-associated leukemic oncogenes, including MYC. NR4As interact with an AML-selective SE cluster that governs MYC transcription and decommissions its activation status by dismissing essential SE-bound coactivators including BRD4, Mediator and p300, leading to loss of p300-dependent H3K27 acetylation and Pol 2-dependent eRNA transcription. DHE shows similar efficacy to the BET inhibitor JQ1 at repressing SE-dependent MYC expression and AML growth in mouse xenografts. Thus, DHE induction of NR4As provides an alternative strategy to BET inhibitors to target MYC dependencies via suppression of the AML-selective SE governing MYC expression.
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Affiliation(s)
- S Greg Call
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, 77030, USA.,Molecular and Cellular Biology PhD Program, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Ryan P Duren
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, 77030, USA.,Integrative Molecular and Biomedical Sciences PhD Program, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Anil K Panigrahi
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Loc Nguyen
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Pablo R Freire
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, 77030, USA.,Molecular and Cellular Biology PhD Program, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Sandra L Grimm
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, 77030, USA.,Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, 77030, USA.,Center for Precision Environmental Health, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Cristian Coarfa
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, 77030, USA.,Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, 77030, USA.,Center for Precision Environmental Health, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Orla M Conneely
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, 77030, USA. .,Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, 77030, USA.
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57
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Mu X, Bai L, Xu Y, Wang J, Lu H. Protein targeting chimeric molecules specific for dual bromodomain 4 (BRD4) and Polo-like kinase 1 (PLK1) proteins in acute myeloid leukemia cells. Biochem Biophys Res Commun 2020; 521:833-839. [PMID: 31708096 DOI: 10.1016/j.bbrc.2019.11.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 11/02/2019] [Indexed: 12/18/2022]
Abstract
Proteolysis targeting chimeras (PROTACs) are hetero-bifunctional molecules that could simultaneously bind to the target protein and the E3 ubiquitin ligase, thereby leading to selective degradation of the target protein. Polo-like kinase 1 (PLK1) and bromodomain 4 (BRD4) are both attractive therapeutic targets in acute myeloid leukemia (AML). Here, we developed a small-molecule BRD4 and PLK1 degrader HBL-4 based on PROTAC technology, which leads to fast, efficient, and prolonged degradation of BRD4 and PLK1 in MV4-11 cells tested in vitro and vivo, and potent anti-proliferation and BRD4 and PLK1 degradation ability in human acute leukemia MOLM-13 and KG1 cells. Meanwhile, HBL-4 more effectively suppresses c-Myc levels than inhibitor BI2536, resulting in more effective inducing apoptosis activity in MV4-11 cells. At the same time, HBL-4 induced dramatically improved efficacy in the MV4-11 tumor xenograft model as compared with BI2536. This study is, to our knowledge, the first reports about dual PLK1 and BRD4 degraders, which potentially represents an important therapeutic advance in the treatment of cancer.
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MESH Headings
- Animals
- Antineoplastic Agents/chemistry
- Antineoplastic Agents/pharmacology
- Apoptosis/drug effects
- Cell Cycle Proteins/metabolism
- Cell Line, Tumor
- Cell Movement/drug effects
- Cell Survival/drug effects
- Gene Expression Regulation, Leukemic/drug effects
- Genes, myc
- Humans
- Leukemia, Myeloid, Acute/drug therapy
- Leukemia, Myeloid, Acute/genetics
- Leukemia, Myeloid, Acute/metabolism
- Leukemia, Myeloid, Acute/pathology
- Mice, SCID
- Molecular Targeted Therapy
- Protein Serine-Threonine Kinases/metabolism
- Proteolysis/drug effects
- Proto-Oncogene Proteins/metabolism
- Pteridines/chemistry
- Small Molecule Libraries/chemistry
- Small Molecule Libraries/pharmacology
- Transcription Factors/metabolism
- Xenograft Model Antitumor Assays
- Polo-Like Kinase 1
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Affiliation(s)
- Xupeng Mu
- Department of Central Laboratory, China-Japan Union Hospital, Jilin University, Changchun, China
| | - Liting Bai
- College of Pharmacy, Jilin University, Changchun, China
| | - Yingju Xu
- College of Pharmacy, Jilin University, Changchun, China
| | - Jingyao Wang
- School of Science, China Pharmaceutical University, Nanjing, China
| | - Haibin Lu
- College of Pharmacy, Jilin University, Changchun, China.
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58
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Selective inhibition of the BD2 bromodomain of BET proteins in prostate cancer. Nature 2020; 578:306-310. [PMID: 31969702 DOI: 10.1038/s41586-020-1930-8] [Citation(s) in RCA: 235] [Impact Index Per Article: 58.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 11/25/2019] [Indexed: 12/24/2022]
Abstract
Proteins of the bromodomain and extra-terminal (BET) domain family are epigenetic readers that bind acetylated histones through their bromodomains to regulate gene transcription. Dual-bromodomain BET inhibitors (DbBi) that bind with similar affinities to the first (BD1) and second (BD2) bromodomains of BRD2, BRD3, BRD4 and BRDt have displayed modest clinical activity in monotherapy cancer trials. A reduced number of thrombocytes in the blood (thrombocytopenia) as well as symptoms of gastrointestinal toxicity are dose-limiting adverse events for some types of DbBi1-5. Given that similar haematological and gastrointestinal defects were observed after genetic silencing of Brd4 in mice6, the platelet and gastrointestinal toxicities may represent on-target activities associated with BET inhibition. The two individual bromodomains in BET family proteins may have distinct functions7-9 and different cellular phenotypes after pharmacological inhibition of one or both bromodomains have been reported10,11, suggesting that selectively targeting one of the bromodomains may result in a different efficacy and tolerability profile compared with DbBi. Available compounds that are selective to individual domains lack sufficient potency and the pharmacokinetics properties that are required for in vivo efficacy and tolerability assessment10-13. Here we carried out a medicinal chemistry campaign that led to the discovery of ABBV-744, a highly potent and selective inhibitor of the BD2 domain of BET family proteins with drug-like properties. In contrast to the broad range of cell growth inhibition induced by DbBi, the antiproliferative activity of ABBV-744 was largely, but not exclusively, restricted to cell lines of acute myeloid leukaemia and prostate cancer that expressed the full-length androgen receptor (AR). ABBV-744 retained robust activity in prostate cancer xenografts, and showed fewer platelet and gastrointestinal toxicities than the DbBi ABBV-07514. Analyses of RNA expression and chromatin immunoprecipitation followed by sequencing revealed that ABBV-744 displaced BRD4 from AR-containing super-enhancers and inhibited AR-dependent transcription, with less impact on global transcription compared with ABBV-075. These results underscore the potential value of selectively targeting the BD2 domain of BET family proteins for cancer therapy.
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59
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Gegonne A, Chen QR, Dey A, Etzensperger R, Tai X, Singer A, Meerzaman D, Ozato K, Singer DS. Immature CD8 Single-Positive Thymocytes Are a Molecularly Distinct Subpopulation, Selectively Dependent on BRD4 for Their Differentiation. Cell Rep 2019; 24:117-129. [PMID: 29972774 PMCID: PMC6298745 DOI: 10.1016/j.celrep.2018.06.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 03/09/2018] [Accepted: 06/01/2018] [Indexed: 01/27/2023] Open
Abstract
T cell differentiation in the thymus proceeds in an ordered sequence of developmental events characterized by variable expression of CD4 and CD8 coreceptors. Here, we report that immature single-positive (ISP) thymocytes are molecularly distinct from all other T cell populations in the thymus in their expression of a gene profile that is dependent on the transcription factor BRD4. Conditional deletion of BRD4 at various stages of thymic differentiation reveals that BRD4 selectively regulates the further differentiation of ISPs by targeting cell cycle and metabolic pathways, but it does not affect the extensive proliferation that results in the generation of ISPs. These studies lead to the conclusion that the ISP subpopulation is not a hybrid transitional state but a molecularly distinct subpopulation that is selectively dependent on BRD4.
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Affiliation(s)
- Anne Gegonne
- Experimental Immunology Branch, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Qing-Rong Chen
- Center for Biomedical Informatics and Information Technology, National Cancer Institute, NIH, Rockville, MD 20892, USA
| | - Anup Dey
- Division of Developmental Biology, National Institute of Child Health and Human Development, NIH, Bethesda, MD 20892, USA
| | - Ruth Etzensperger
- Experimental Immunology Branch, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Xuguang Tai
- Experimental Immunology Branch, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Alfred Singer
- Experimental Immunology Branch, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Daoud Meerzaman
- Center for Biomedical Informatics and Information Technology, National Cancer Institute, NIH, Rockville, MD 20892, USA
| | - Keiko Ozato
- Division of Developmental Biology, National Institute of Child Health and Human Development, NIH, Bethesda, MD 20892, USA
| | - Dinah S Singer
- Experimental Immunology Branch, National Cancer Institute, NIH, Bethesda, MD 20892, USA.
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60
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Morgado-Pascual JL, Rayego-Mateos S, Tejedor L, Suarez-Alvarez B, Ruiz-Ortega M. Bromodomain and Extraterminal Proteins as Novel Epigenetic Targets for Renal Diseases. Front Pharmacol 2019; 10:1315. [PMID: 31780938 PMCID: PMC6857099 DOI: 10.3389/fphar.2019.01315] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 10/15/2019] [Indexed: 12/11/2022] Open
Abstract
Epigenetic mechanisms, especially DNA methylation and histone modifications, are dynamic processes that regulate the gene expression transcriptional program in normal and diseased states. The bromodomain and extraterminal (BET) protein family (BRD2, BRD3, BRD4, and BRDT) are epigenetic readers that, via bromodomains, regulate gene transcription by binding to acetylated lysine residues on histones and master transcriptional factors. Experimental data have demonstrated the involvement of some BET proteins in many pathological conditions, including tumor development, infections, autoimmunity, and inflammation. Selective bromodomain inhibitors are epigenetic drugs that block the interaction between BET proteins and acetylated proteins, thus exerting beneficial effects. Recent data have described the beneficial effect of BET inhibition on experimental renal diseases. Emerging evidence underscores the importance of environmental modifications in the origin of pathological features in chronic kidney diseases (CKD). Several cellular processes such as oxidation, metabolic disorders, cytokines, inflammation, or accumulated uremic toxins may induce epigenetic modifications that regulate key processes involved in renal damage and in other pathological conditions observed in CKD patients. Here, we review how targeting bromodomains in BET proteins may regulate essential processes involved in renal diseases and in associated complications found in CKD patients, such as cardiovascular damage, highlighting the potential of epigenetic therapeutic strategies against BET proteins for CKD treatment and associated risks.
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Affiliation(s)
- Jose Luis Morgado-Pascual
- Cellular Biology in Renal Diseases Laboratory, IIS-Fundación Jiménez Díaz, Universidad Autónoma Madrid, Madrid, Spain.,Red de Investigación Renal (REDinREN), Madrid, Spain
| | - Sandra Rayego-Mateos
- Red de Investigación Renal (REDinREN), Madrid, Spain.,Vascular and Renal Translational Research Group, Institut de Recerca Biomèdica de Lleida (IRBLleida), Lleida, Spain
| | - Lucia Tejedor
- Cellular Biology in Renal Diseases Laboratory, IIS-Fundación Jiménez Díaz, Universidad Autónoma Madrid, Madrid, Spain.,Red de Investigación Renal (REDinREN), Madrid, Spain
| | - Beatriz Suarez-Alvarez
- Red de Investigación Renal (REDinREN), Madrid, Spain.,Translational Immunology Laboratory, Health Research Institute of the Principality of Asturias (ISPA), Hospital Universitario Central de Asturias, Oviedo, Spain
| | - Marta Ruiz-Ortega
- Cellular Biology in Renal Diseases Laboratory, IIS-Fundación Jiménez Díaz, Universidad Autónoma Madrid, Madrid, Spain.,Red de Investigación Renal (REDinREN), Madrid, Spain
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61
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Letson C, Padron E. Non-canonical transcriptional consequences of BET inhibition in cancer. Pharmacol Res 2019; 150:104508. [PMID: 31698067 DOI: 10.1016/j.phrs.2019.104508] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 09/12/2019] [Accepted: 10/21/2019] [Indexed: 01/01/2023]
Abstract
Inhibition of the bromo and extra-terminal domain (BET) protein family in preclinical studies has demonstrated that BET proteins are critical for cancer progression and important therapeutic targets. Downregulation of the MYC oncogene, CDK6, BCL2 and FOSL1 are just a few examples of the effects of BET inhibitors that can lead to cell cycle arrest and apoptosis in cancer cells. However, BET inhibitors have had little success in the clinic as a single agent, and there are an increasing number of reports of resistance to BET inhibition emerging after sustained treatment of cancer cells in vitro. Here we summarize the non-canonical consequences of BET inhibition in cancer, and discuss how these may both lead to resistance and inform rational combinations that could greatly enhance the clinical application of these inhibitors.
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Affiliation(s)
- Christopher Letson
- Moffitt Cancer Center: 12902 USF Magnolia Drive, Tampa, FL 33612, United States.
| | - Eric Padron
- Moffitt Cancer Center: 12902 USF Magnolia Drive, Tampa, FL 33612, United States.
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62
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Gambacorta V, Gnani D, Vago L, Di Micco R. Epigenetic Therapies for Acute Myeloid Leukemia and Their Immune-Related Effects. Front Cell Dev Biol 2019; 7:207. [PMID: 31681756 PMCID: PMC6797914 DOI: 10.3389/fcell.2019.00207] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 09/11/2019] [Indexed: 12/19/2022] Open
Abstract
Over the past decades, our molecular understanding of acute myeloid leukemia (AML) pathogenesis dramatically increased, thanks also to the advent of next-generation sequencing (NGS) technologies. Many of these findings, however, have not yet translated into new prognostic markers or rationales for treatments. We now know that AML is a highly heterogeneous disease characterized by a very low mutational burden. Interestingly, the few mutations identified mainly reside in epigenetic regulators, which shape and define leukemic cell identity. In the light of these discoveries and given the increasing number of drugs targeting epigenetic regulators in clinical development and testing, great interest is emerging for the use of small molecules targeting leukemia epigenome. Together with their effects on leukemia cell-intrinsic properties, such as proliferation and survival, epigenetic drugs may affect the way leukemic cells communicate with the surrounding components of the tumor and immune microenvironment. Here, we review current knowledge on alterations in the AML epigenetic landscape and discuss the promises of epigenetic therapies for AML treatment. Finally, we summarize emerging molecular studies elucidating how epigenetic rewiring in cancer cells may as well exert immune-modulatory functions, boost the immune system, and potentially contribute to better patient outcomes.
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Affiliation(s)
- Valentina Gambacorta
- Unit of Senescence in Stem Cell Aging, Differentiation and Cancer, San Raffaele Telethon Institute for Gene Therapy (SR-TIGET), IRCCS San Raffaele Scientific Institute, Milan, Italy.,Unit of Immunogenetics, Leukemia Genomics and Immunobiology, IRCCS San Raffaele Scientific Institute, Milan, Italy.,Milano-Bicocca University, Milan, Italy
| | - Daniela Gnani
- Unit of Senescence in Stem Cell Aging, Differentiation and Cancer, San Raffaele Telethon Institute for Gene Therapy (SR-TIGET), IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Luca Vago
- Unit of Immunogenetics, Leukemia Genomics and Immunobiology, IRCCS San Raffaele Scientific Institute, Milan, Italy.,Unit of Hematology and Bone Marrow Transplantation, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Raffaella Di Micco
- Unit of Senescence in Stem Cell Aging, Differentiation and Cancer, San Raffaele Telethon Institute for Gene Therapy (SR-TIGET), IRCCS San Raffaele Scientific Institute, Milan, Italy
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63
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Morel D, Jeffery D, Aspeslagh S, Almouzni G, Postel-Vinay S. Combining epigenetic drugs with other therapies for solid tumours - past lessons and future promise. Nat Rev Clin Oncol 2019; 17:91-107. [PMID: 31570827 DOI: 10.1038/s41571-019-0267-4] [Citation(s) in RCA: 247] [Impact Index Per Article: 49.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/13/2019] [Indexed: 12/16/2022]
Abstract
Epigenetic dysregulation has long been recognized as a key factor contributing to tumorigenesis and tumour maintenance that can influence all of the recognized hallmarks of cancer. Despite regulatory approvals for the treatment of certain haematological malignancies, the efficacy of the first generation of epigenetic drugs (epi-drugs) in patients with solid tumours has been disappointing; however, successes have now been achieved in selected solid tumour subtypes, thanks to the development of novel compounds and a better understanding of cancer biology that have enabled precision medicine approaches. Several lines of evidence support that, beyond their potential as monotherapies, epigenetic drugs could have important roles in synergy with other anticancer therapies or in reversing acquired therapy resistance. Herein, we review the mechanisms by which epi-drugs can modulate the sensitivity of cancer cells to other forms of anticancer therapy, including chemotherapy, radiation therapy, hormone therapy, molecularly targeted therapy and immunotherapy. We provide a critical appraisal of the preclinical rationale, completed clinical studies and ongoing clinical trials relating to combination therapies incorporating epi-drugs. Finally, we propose and discuss rational clinical trial designs and drug development strategies, considering key factors including patient selection, tumour biomarker evaluation, drug scheduling and response assessment and study end points, with the aim of optimizing the development of such combinations.
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Affiliation(s)
- Daphné Morel
- ATIP-Avenir Group, UMR981, INSERM (French National Institute of Health and Medical Research), Gustave Roussy Cancer Campus, Villejuif, France
| | - Daniel Jeffery
- Nuclear Dynamics Unit - UMR3664, National Centre for Scientific Research, Institut Curie, Paris, France
| | | | - Geneviève Almouzni
- Nuclear Dynamics Unit - UMR3664, National Centre for Scientific Research, Institut Curie, Paris, France.
| | - Sophie Postel-Vinay
- ATIP-Avenir Group, UMR981, INSERM (French National Institute of Health and Medical Research), Gustave Roussy Cancer Campus, Villejuif, France. .,Drug Development Department (DITEP), Gustave Roussy Cancer Campus, Paris-Saclay University, Villejuif, France.
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64
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Ovarian Cancer Stem Cells: Role in Metastasis and Opportunity for Therapeutic Targeting. Cancers (Basel) 2019; 11:cancers11070934. [PMID: 31277278 PMCID: PMC6678643 DOI: 10.3390/cancers11070934] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 06/29/2019] [Accepted: 06/30/2019] [Indexed: 02/08/2023] Open
Abstract
Ovarian cancer (OC) is a heterogeneous disease usually diagnosed at a late stage. Cancer stem cells (CSCs) that exist within the bulk tumor survive first-line chemotherapy and contribute to resistant disease with metastasis. Understanding the key features of CSC biology provides valuable opportunities to develop OCSC-directed therapeutics, which will eventually improve the clinical outcomes of patients. Although significant developments have occurred since OCSCs were first described, the involvement of CSCs in ovarian tumor metastasis is not fully understood. Here, we discuss putative CSC markers and the fundamental role of CSCs in facilitating tumor dissemination in OC. Additionally, we focus on promising CSC-targeting strategies in preclinical and clinical studies of OC and discuss potential challenges in CSC research.
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65
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Affiliation(s)
- Michael F Clarke
- From the Stanford Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, CA
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66
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Yamamoto A, Hester J, Macklin PS, Kawai K, Uchiyama M, Biggs D, Bishop T, Bull K, Cheng X, Cawthorne E, Coleman ML, Crockford TL, Davies B, Dow LE, Goldin R, Kranc K, Kudo H, Lawson H, McAuliffe J, Milward K, Scudamore CL, Soilleux E, Issa F, Ratcliffe PJ, Pugh CW. Systemic silencing of PHD2 causes reversible immune regulatory dysfunction. J Clin Invest 2019; 129:3640-3656. [PMID: 31162141 PMCID: PMC6715380 DOI: 10.1172/jci124099] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 05/29/2019] [Indexed: 12/28/2022] Open
Abstract
Physiological effects of cellular hypoxia are sensed by prolyl hydroxylase (PHD) enzymes which regulate HIFs. Genetic interventions on HIF/PHD pathways reveal multiple phenotypes that extend the known biology of hypoxia. Recent studies unexpectedly implicate HIF in aspects of multiple immune and inflammatory pathways. However such studies are often limited by systemic lethal effects and/or use tissue-specific recombination systems, which are inherently irreversible, un-physiologically restricted and difficult to time. To study these processes better we developed recombinant mice which express tetracycline-regulated shRNAs broadly targeting the main components of the HIF/PHD pathway, permitting timed bi-directional intervention. We have shown that stabilization of HIF levels in adult mice through PHD2 enzyme silencing by RNA interference, or inducible recombination of floxed alleles, results in multi-lineage leukocytosis and features of autoimmunity. This phenotype was rapidly normalized on re-establishment of the hypoxia-sensing machinery when shRNA expression was discontinued. In both situations these effects were mediated principally through the Hif2a isoform. Assessment of cells bearing regulatory T cell markers from these mice revealed defective function and pro-inflammatory effects in vivo. We believe our findings have shown a new role for the PHD2/Hif2a couple in the reversible regulation of T cell and immune activity.
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Affiliation(s)
- Atsushi Yamamoto
- Nuffield Department of Medicine Research Building, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Joanna Hester
- Transplantation Research Immunology Group, Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom
| | - Philip S. Macklin
- Nuffield Department of Medicine Research Building, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Kento Kawai
- Transplantation Research Immunology Group, Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom
| | - Masateru Uchiyama
- Transplantation Research Immunology Group, Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom
| | - Daniel Biggs
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Tammie Bishop
- Nuffield Department of Medicine Research Building, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Katherine Bull
- Henry Wellcome Building for Molecular Physiology, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Xiaotong Cheng
- Nuffield Department of Medicine Research Building, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Eleanor Cawthorne
- Henry Wellcome Building for Molecular Physiology, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Mathew L. Coleman
- Henry Wellcome Building for Molecular Physiology, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Tanya L. Crockford
- Henry Wellcome Building for Molecular Physiology, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Ben Davies
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Lukas E. Dow
- Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, New York, New York, USA
| | - Rob Goldin
- Department of Cellular Pathology, Imperial College London, London, United Kingdom
| | - Kamil Kranc
- MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Hiromi Kudo
- Department of Cellular Pathology, Imperial College London, London, United Kingdom
| | - Hannah Lawson
- MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - James McAuliffe
- Ludwig Institute for Cancer Research, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Kate Milward
- Transplantation Research Immunology Group, Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom
| | - Cheryl L. Scudamore
- Veterinary Pathology, MRC Harwell, Mary Lyon Centre, Harwell Campus, Oxford, United Kingdom
| | - Elizabeth Soilleux
- Department of Pathology, School of Biological Sciences, University of Cambridge, Cambridge, United Kingdom
| | - Fadi Issa
- Transplantation Research Immunology Group, Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom
| | - Peter J. Ratcliffe
- Nuffield Department of Medicine Research Building, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Ludwig Institute for Cancer Research, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- The Francis Crick Institute, London, United Kingdom
| | - Chris W. Pugh
- Nuffield Department of Medicine Research Building, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
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67
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Padmanabhan A, Haldar SM. Drugging transcription in heart failure. J Physiol 2019; 598:3005-3014. [PMID: 30927446 DOI: 10.1113/jp276745] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 03/01/2019] [Indexed: 12/20/2022] Open
Abstract
Advances in our understanding of the basic biology and biochemistry of chromatin structure and function at genome scales has led to tremendous growth in the fields of epigenomics and transcriptional biology. While it has long been appreciated that transcriptional pathways are dysregulated in failing hearts, only recently has the idea of disrupting altered transcription by targeting chromatin-associated proteins been explored. Here, we provide a brief overview of efforts to drug transcription in the context of heart failure, focusing on the bromo- and extra-terminal domain (BET) family of chromatin co-activator proteins.
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Affiliation(s)
- Arun Padmanabhan
- Division of Cardiology, Department of Medicine, University of California San Francisco School of Medicine, San Francisco, CA, USA.,Gladstone Institutes, San Francisco, CA, USA
| | - Saptarsi M Haldar
- Division of Cardiology, Department of Medicine, University of California San Francisco School of Medicine, San Francisco, CA, USA.,Gladstone Institutes, San Francisco, CA, USA.,Cardiometabolic Disorders, Amgen, South San Francisco, CA, USA
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68
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Epigenetic therapies in heart failure. J Mol Cell Cardiol 2019; 130:197-204. [PMID: 30991033 DOI: 10.1016/j.yjmcc.2019.04.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 04/10/2019] [Accepted: 04/12/2019] [Indexed: 12/20/2022]
Abstract
Heart failure (HF) is a dominant cause of morbidity and mortality in the developed world, with available pharmacotherapies limited by high rates of residual mortality and a failure to directly target the changes in cell state that drive adverse cardiac remodeling. Pathologic cardiac remodeling is driven by stress-activated cardiac signaling cascades that converge on defined components of the chromatin regulatory apparatus in the nucleus, triggering broad shifts in transcription and cell state. Thus, studies focusing on how cytosolic signaling pathways couple to the nuclear gene control machinery has been an area of therapeutic interest in HF. In this review, we discuss current concepts pertaining to the role of chromatin regulators in HF pathogenesis, with a focus on specific proteins and RNA-containing macromolecular complexes that have shown promise as druggable targets in the experimental setting.
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69
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Sharrock J, Estacio-Gomez A, Jacobson J, Kierdorf K, Southall TD, Dionne MS. fs(1)h controls metabolic and immune function and enhances survival via AKT and FOXO in Drosophila. Dis Model Mech 2019; 12:dmm.037259. [PMID: 30910908 PMCID: PMC6505478 DOI: 10.1242/dmm.037259] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2018] [Accepted: 03/15/2019] [Indexed: 12/14/2022] Open
Abstract
The Drosophila fat body is the primary organ of energy storage as well as being responsible for the humoral response to infection. Its physiological function is of critical importance to the survival of the organism; however, many molecular regulators of its function remain ill-defined. Here, we show that the Drosophila melanogaster bromodomain-containing protein FS(1)H is required in the fat body for normal lifespan as well as metabolic and immune homeostasis. Flies lacking fat body fs(1)h exhibit short lifespan, increased expression of immune target genes, an inability to metabolize triglyceride, and low basal AKT activity, mostly resulting from systemic defects in insulin signalling. Removal of a single copy of the AKT-responsive transcription factor foxo normalises lifespan, metabolic function, uninduced immune gene expression and AKT activity. We suggest that the promotion of systemic insulin signalling activity is a key in vivo function of fat body fs(1)h. This article has an associated First Person interview with the first author of the paper. Summary: The bromodomain-containing protein FS(1)H is required in the Drosophila fat body for normal lifespan and metabolic and immune function, largely via the insulin pathway.
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Affiliation(s)
- Jessica Sharrock
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, UK.,Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
| | | | - Jake Jacobson
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, UK.,Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
| | - Katrin Kierdorf
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, UK.,Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
| | - Tony D Southall
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
| | - Marc S Dionne
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London SW7 2AZ, UK .,Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
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70
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Hinterndorfer M, Zuber J. Functional-genetic approaches to understanding drug response and resistance. Curr Opin Genet Dev 2019; 54:41-47. [PMID: 30951975 DOI: 10.1016/j.gde.2019.03.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 03/03/2019] [Indexed: 12/13/2022]
Abstract
Drug development remains a slow and expensive process, while the effective use of established therapeutics is widely hampered by our limited understanding of response and resistance mechanisms. Functional-genetic tools such as CRISPR/Cas9, advanced RNAi methods, and targeted protein degradation, together with other emerging technologies such as time-resolved and single-cell transcriptomics, fundamentally change the way we can search for candidate therapeutic targets and evaluate them before drug development. In addition, for already available therapeutics these tools open vast opportunities for probing response mechanisms and predictive biomarkers, and thereby guide the development of personalized therapies. Here, we review promising applications and remaining limitations of recently established functional-genetic tools for high-throughput screening and the in-depth analysis of candidate targets and established drugs.
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Affiliation(s)
- Matthias Hinterndorfer
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), 1030 Vienna, Austria
| | - Johannes Zuber
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), 1030 Vienna, Austria; Medical University of Vienna, Vienna BioCenter (VBC), 1030 Vienna, Austria.
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71
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Yang CY, Qin C, Bai L, Wang S. Small-molecule PROTAC degraders of the Bromodomain and Extra Terminal (BET) proteins - A review. DRUG DISCOVERY TODAY. TECHNOLOGIES 2019; 31:43-51. [PMID: 31200858 DOI: 10.1016/j.ddtec.2019.04.001] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 04/08/2019] [Accepted: 04/08/2019] [Indexed: 05/22/2023]
Abstract
The PROteolysis TArgeting Chimeric (PROTAC) concept has provided an opportunity for the discovery and development of a completely new type of therapy involving induction of protein degradation. The BET proteins, comprised of BRD2, BRD3, BRD4 and the testis-specific BRDT protein, are epigenetic readers and master transcription coactivators. Extremely potent and efficacious small-molecule PROTAC degraders of the BET proteins, based on available, potent and selective BET inhibitors, have been reported. BET degraders differ from BET inhibitors in their cellular potency, phenotypic effects, pharmacokinetic properties and toxicity profiles. Herein, we provide a review of BET degraders and the differential outcome observed in the cellular and animal models for BET degraders in comparison to BET inhibitors.
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Affiliation(s)
- Chao-Yie Yang
- The Rogel Cancer Center, Departments of Internal Medicine, Pharmacology, and Medicinal Chemistry, University of Michigan, Ann Arbor, MI 48109, United States
| | - Chong Qin
- The Rogel Cancer Center, Departments of Internal Medicine, Pharmacology, and Medicinal Chemistry, University of Michigan, Ann Arbor, MI 48109, United States
| | - Longchuan Bai
- The Rogel Cancer Center, Departments of Internal Medicine, Pharmacology, and Medicinal Chemistry, University of Michigan, Ann Arbor, MI 48109, United States
| | - Shaomeng Wang
- The Rogel Cancer Center, Departments of Internal Medicine, Pharmacology, and Medicinal Chemistry, University of Michigan, Ann Arbor, MI 48109, United States.
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72
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The BET Bromodomain Inhibitor I-BET-151 Induces Structural and Functional Alterations of the Heart Mitochondria in Healthy Male Mice and Rats. Int J Mol Sci 2019; 20:ijms20071527. [PMID: 30934680 PMCID: PMC6480532 DOI: 10.3390/ijms20071527] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 03/20/2019] [Accepted: 03/23/2019] [Indexed: 12/14/2022] Open
Abstract
The bromodomain and extra-terminal domain family inhibitors (BETi) are a promising new class of anticancer agents. Since numerous anticancer drugs have been correlated to cardiomyopathy, and since BETi can affect non-cancerous tissues, we aimed to investigate in healthy animals any ultrastructural BETi-induced alterations of the heart as compared to skeletal muscle. Male Wistar rats were either treated during 3 weeks with I-BET-151 (2 or 10 mg/kg/day) (W3) or treated for 3 weeks then allowed to recover for another 3 weeks (W6) (3-weeks drug washout). Male C57Bl/6J mice were only treated during 5 days (50 mg/kg/day). We demonstrated the occurrence of ultrastructural alterations and progressive destruction of cardiomyocyte mitochondria after I-BET-151 exposure. Those mitochondrial alterations were cardiac muscle-specific, since the skeletal muscles of exposed animals were similar in ultrastructure presentation to the non-exposed animals. I-BET-151 decreased the respiration rate of heart mitochondria in a dose-dependent manner. At the higher dose, it also decreased mitochondrial mass, as evidenced by reduced right ventricular citrate synthase content. I-BET-151 reduced the right and left ventricular fractional shortening. The concomitant decrease in the velocity-time-integral in both the aorta and the pulmonary artery is also suggestive of an impaired heart function. The possible context-dependent cardiac side effects of these drugs have to be appreciated. Future studies should focus on the basic mechanisms of potential cardiovascular toxicities induced by BETi and strategies to minimize these unexpected complications.
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73
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Alqahtani A, Choucair K, Ashraf M, Hammouda DM, Alloghbi A, Khan T, Senzer N, Nemunaitis J. Bromodomain and extra-terminal motif inhibitors: a review of preclinical and clinical advances in cancer therapy. Future Sci OA 2019; 5:FSO372. [PMID: 30906568 PMCID: PMC6426170 DOI: 10.4155/fsoa-2018-0115] [Citation(s) in RCA: 188] [Impact Index Per Article: 37.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 01/04/2019] [Indexed: 01/18/2023] Open
Abstract
Histone lysine acetylation is critical in regulating transcription. Dysregulation of this process results in aberrant gene expression in various diseases, including cancer. The bromodomain, present in several proteins, recognizes promotor lysine acetylation and recruits other transcription factors. The bromodomain extra-terminal (BET) family of proteins consists of four conserved mammalian members that regulate transcription of oncogenes such as MYC and the NUT fusion oncoprotein. Targeting the acetyl-lysine-binding property of BET proteins is a potential therapeutic approach of cancer. Consequently, following the demonstration that thienotriazolodiazepine small molecules effectively inhibit BET, clinical trials were initiated. We thus discuss the mechanisms of action of various BET inhibitors and the prospects for their clinical use as cancer therapeutics.
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Affiliation(s)
- Ali Alqahtani
- Department of Internal Medicine, University of Toledo College of Medicine & Life Sciences, Toledo, OH, 43614, USA
| | - Khalil Choucair
- Division of Hematology & Medical Oncology, Department of Medicine, University of Toledo College of Medicine & Life Sciences, Toledo, OH, 43614, USA
| | - Mushtaq Ashraf
- Division of Hematology & Medical Oncology, Department of Medicine, University of Toledo College of Medicine & Life Sciences, Toledo, OH, 43614, USA
| | - Danae M Hammouda
- Division of Hematology & Medical Oncology, Department of Medicine, University of Toledo College of Medicine & Life Sciences, Toledo, OH, 43614, USA
| | - Abduraham Alloghbi
- Department of Internal Medicine, University of Toledo College of Medicine & Life Sciences, Toledo, OH, 43614, USA
| | - Talal Khan
- Division of Hematology & Medical Oncology, Department of Medicine, University of Toledo College of Medicine & Life Sciences, Toledo, OH, 43614, USA
| | - Neil Senzer
- Division of Hematology & Medical Oncology, Department of Medicine, University of Toledo College of Medicine & Life Sciences, Toledo, OH, 43614, USA
| | - John Nemunaitis
- Division of Hematology & Medical Oncology, Department of Medicine, University of Toledo College of Medicine & Life Sciences, Toledo, OH, 43614, USA
- ProMedica Health System, Toledo, OH, 43606, USA
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74
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Piya S, Mu H, Bhattacharya S, Lorenzi PL, Davis RE, McQueen T, Ruvolo V, Baran N, Wang Z, Qian Y, Crews CM, Konopleva M, Ishizawa J, You MJ, Kantarjian H, Andreeff M, Borthakur G. BETP degradation simultaneously targets acute myelogenous leukemia stem cells and the microenvironment. J Clin Invest 2019; 129:1878-1894. [PMID: 30829648 DOI: 10.1172/jci120654] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Anti-leukemic effect of BET/BRD4 (BETP) protein inhibition has been largely attributed to transcriptional downregulation of cellular anabolic/anti-apoptotic processes but its effect on bone marrow microenvironment, a sanctuary favoring persistence of leukemia stem/progenitor cells, is unexplored. Sustained degradation of BETP with small-molecule BET proteolysis-targeting chimera (PROTAC), ARV-825, resulted in marked downregulation of surface CXCR4 and CD44, key proteins in leukemia-microenvironment interaction, in AML cells. Abrogation of surface CXCR4 expression impaired SDF-1α directed migration and was mediated through transcriptional down-regulation of PIM1 kinase that in turn phosphorylates CXCR4 and facilitates its surface localization. Down-regulation of CD44/CD44v8-10 impaired cystine uptake, lowered intracellular reduced glutathione and increased oxidative stress. More importantly, BETP degradation markedly decreased CD34+CD38-CD90-CD45RA+ leukemic stem cell population and alone or in combination with Cytarabine, prolonged survival in mouse model of human leukemia including AML-PDX. Gene expression profiling and single cell proteomics confirmed down regulation of the gene signatures associated with 'stemness' in AML and Wnt/β-catenin, Myc pathways. Hence, BETP degradation by ARV-825 simultaneously targets cell intrinsic signaling, stromal interactions and metabolism in AML.
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Affiliation(s)
- Sujan Piya
- Section of Molecular Hematology and Therapy.,Department of Leukemia
| | - Hong Mu
- Section of Molecular Hematology and Therapy.,Department of Leukemia
| | | | | | - R Eric Davis
- Department of Lymphoma and Myeloma, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Teresa McQueen
- Section of Molecular Hematology and Therapy.,Department of Leukemia
| | - Vivian Ruvolo
- Section of Molecular Hematology and Therapy.,Department of Leukemia
| | - Natalia Baran
- Section of Molecular Hematology and Therapy.,Department of Leukemia
| | - Zhiqiang Wang
- Department of Lymphoma and Myeloma, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Yimin Qian
- Arvinas Inc., New Haven, Connecticut, USA
| | - Craig M Crews
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut, USA
| | | | | | - M James You
- Department of Hematopathology, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | | | - Michael Andreeff
- Section of Molecular Hematology and Therapy.,Department of Leukemia
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75
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Tan X, Tong J, Wang YJ, Fletcher R, Schoen RE, Yu J, Shen L, Zhang L. BET Inhibitors Potentiate Chemotherapy and Killing of SPOP-Mutant Colon Cancer Cells via Induction of DR5. Cancer Res 2019; 79:1191-1203. [PMID: 30674532 DOI: 10.1158/0008-5472.can-18-3223] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 12/22/2018] [Accepted: 01/16/2019] [Indexed: 12/27/2022]
Abstract
Bromodomain and extraterminal domain (BET) family proteins such as BRD4 are epigenetic readers that control expression of a number of oncogenic proteins. Targeting this family of proteins has recently emerged as a promising anticancer approach. BET inhibitors (BETi), either alone or in combination with other anticancer agents, have exhibited efficacy in a variety of tumors. However, the molecular mechanisms underlying differential response to BETi are not well understood. In this study, we report that death receptor 5 (DR5), a key component of the extrinsic apoptotic pathway, is markedly induced in response to BRD4 depletion and BETi treatment in colorectal cancer cells. Induction of DR5, following BET inhibition, was mediated by endoplasmic reticulum stress and CHOP-dependent transcriptional activation. Enhanced DR5 induction was necessary for the chemosensitization and apoptotic effects of BETi and was responsible for increased BETi sensitivity in colorectal cancer cells containing a mutation in speckle-type POZ protein (SPOP), a subunit of BRD4 E3 ubiquitin ligase. In a colorectal cancer xenograft model, BETi combined with chemotherapy suppressed the tumor growth in a DR5-dependent manner and potently inhibited patient-derived xenograft tumor growth with enhanced DR5 induction and apoptosis. These findings suggest that BETi alone or in combination with chemotherapy is effective against colorectal cancer due to enhanced DR5 induction and apoptosis. DR5 induction may also serve as a useful marker for designing personalized treatment and improved colorectal cancer combination therapies.Significance: These findings reveal how BET inhibition sensitizes chemotherapy and kills a subset of colon cancer cells with specific genetic alterations and may provide a new molecular marker for improving colon cancer therapies.
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Affiliation(s)
- Xiao Tan
- Department of Oncology, Xiangya Hospital, Central South University, Changsha, Hunan Province, P.R. China
- UPMC Hillman Cancer Center, Pittsburgh, Pennsylvania
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Jingshan Tong
- UPMC Hillman Cancer Center, Pittsburgh, Pennsylvania
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Yi-Jun Wang
- UPMC Hillman Cancer Center, Pittsburgh, Pennsylvania
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Rochelle Fletcher
- UPMC Hillman Cancer Center, Pittsburgh, Pennsylvania
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Robert E Schoen
- UPMC Hillman Cancer Center, Pittsburgh, Pennsylvania
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Jian Yu
- UPMC Hillman Cancer Center, Pittsburgh, Pennsylvania
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Liangfang Shen
- Department of Oncology, Xiangya Hospital, Central South University, Changsha, Hunan Province, P.R. China.
| | - Lin Zhang
- UPMC Hillman Cancer Center, Pittsburgh, Pennsylvania.
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
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76
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Han Y, Lindner S, Bei Y, Garcia HD, Timme N, Althoff K, Odersky A, Schramm A, Lissat A, Künkele A, Deubzer HE, Eggert A, Schulte JH, Henssen AG. Synergistic activity of BET inhibitor MK-8628 and PLK inhibitor Volasertib in preclinical models of medulloblastoma. Cancer Lett 2019; 445:24-33. [PMID: 30611741 DOI: 10.1016/j.canlet.2018.12.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 12/05/2018] [Accepted: 12/11/2018] [Indexed: 11/20/2022]
Abstract
Medulloblastoma is the most prevalent central nervous system tumor in children. Targeted treatment approaches for patients with high-risk medulloblastoma are needed as current treatment regimens are not curative in many cases and cause significant therapy-related morbidity. Medulloblastoma harboring MYC amplification have the most aggressive clinical course and worst outcome. Targeting the BET protein BRD4 has significant anti-tumor effects in preclinical models of MYC-amplified medulloblastoma, however, in most cases these are not curative. We here assessed the therapeutic efficacy of the orally bioavailable BRD4 inhibitor, MK-8628, in preclinical models of medulloblastoma. MK-8628 showed therapeutic efficacy against in vitro and in vivo models of MYC-amplified medulloblastoma by inducing apoptotic cell death and cell cycle arrest. Gene expression analysis of cells treated with MK-8628 showed that anti-tumor effects were accompanied by significant repression of MYC transcription as well as disruption of MYC-regulated transcriptional programs. Additionally, we found that targeting of MYC protein stability through pharmacological PLK1 inhibition showed synergistic anti-medulloblastoma effects when combined with MK-8628 treatment. Thus, MK-8628 is effective against preclinical high-risk medulloblastoma models and its effects can be enhanced through simultaneous targeting of PLK1.
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Affiliation(s)
- Youjia Han
- Department of Pediatric Oncology/Hematology, Charité-Universitätsmedizin Berlin, Germany
| | - Sven Lindner
- Department of Pediatric Oncology and Hematology, University Children's Hospital Essen, Essen, Germany
| | - Yi Bei
- Department of Pediatric Oncology/Hematology, Charité-Universitätsmedizin Berlin, Germany
| | | | - Natalie Timme
- Department of Pediatric Oncology/Hematology, Charité-Universitätsmedizin Berlin, Germany
| | - Kristina Althoff
- Department of Pediatric Oncology and Hematology, University Children's Hospital Essen, Essen, Germany
| | - Andrea Odersky
- Department of Pediatric Oncology and Hematology, University Children's Hospital Essen, Essen, Germany
| | - Alexander Schramm
- Department of Pediatric Oncology and Hematology, University Children's Hospital Essen, Essen, Germany
| | - Andrej Lissat
- Department of Pediatric Oncology/Hematology, Charité-Universitätsmedizin Berlin, Germany
| | - Annette Künkele
- Department of Pediatric Oncology/Hematology, Charité-Universitätsmedizin Berlin, Germany; German Consortium for Translational Cancer Research (DKTK), Berlin, Germany; Berlin Institute of Health (BIH), Berlin, Germany
| | - Hedwig E Deubzer
- Department of Pediatric Oncology/Hematology, Charité-Universitätsmedizin Berlin, Germany; German Consortium for Translational Cancer Research (DKTK), Berlin, Germany; Berlin Institute of Health (BIH), Berlin, Germany; Experimental and Clinical Research Center (ECRC) of the Charité and the Max-Delbrück-Center for Molecular Medicine (MDC) in the Helmholtz Association, Berlin, Germany
| | - Angelika Eggert
- Department of Pediatric Oncology/Hematology, Charité-Universitätsmedizin Berlin, Germany; German Consortium for Translational Cancer Research (DKTK), Berlin, Germany
| | - Johannes H Schulte
- Department of Pediatric Oncology/Hematology, Charité-Universitätsmedizin Berlin, Germany; German Consortium for Translational Cancer Research (DKTK), Berlin, Germany
| | - Anton G Henssen
- Department of Pediatric Oncology/Hematology, Charité-Universitätsmedizin Berlin, Germany; German Consortium for Translational Cancer Research (DKTK), Berlin, Germany; Berlin Institute of Health (BIH), Berlin, Germany.
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77
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Klein K. Bromodomain protein inhibition: a novel therapeutic strategy in rheumatic diseases. RMD Open 2018; 4:e000744. [PMID: 30564450 PMCID: PMC6269638 DOI: 10.1136/rmdopen-2018-000744] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 09/28/2018] [Accepted: 10/17/2018] [Indexed: 12/18/2022] Open
Abstract
The reading of acetylation marks on histones by bromodomain (BRD) proteins is a key event in transcriptional activation. Small molecule inhibitors targeting bromodomain and extra-terminal (BET) proteins compete for binding to acetylated histones. They have strong anti-inflammatory properties and exhibit encouraging effects in different cell types in vitro and in animal models resembling rheumatic diseases in vivo. Furthermore, recent studies that focus on BRD proteins beyond BET family members are discussed.
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Affiliation(s)
- Kerstin Klein
- Center of Experimental Rheumatology, Department of Rheumatology, University Hospital Zurich, Zurich, Switzerland
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78
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Furlan A, Agbazahou F, Henry M, Gonzalez-Pisfil M, Le Nézet C, Champelovier D, Fournier M, Vandenbunder B, Bidaux G, Héliot L. P-TEFb et Brd4. Med Sci (Paris) 2018; 34:685-692. [DOI: 10.1051/medsci/20183408015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
La physiologie d’une cellule est dictée par l’intégration des signaux qu’elle reçoit et la mise en place de réponses adaptées par le biais, entre autres, de programmes transcriptionnels adéquats. Pour assurer un contrôle optimal de ces réponses, des mécanismes de régulation ont été sélectionnés, dont un processus de pause transcriptionnelle et de levée de cette pause par P-TEFb (positive transcription elongation factor) et Brd4 (bromodomain-containing protein 4). Le dérèglement de ce processus peut conduire à l’apparition de pathologies. P-TEFb et Brd4 ont ainsi émergé au cours des dernières années comme des cibles thérapeutiques potentielles dans le cadre des cancers et du syndrome d‘immunodéficience acquise (sida) notamment.
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79
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Livshits G, Alonso-Curbelo D, Morris JP, Koche R, Saborowski M, Wilkinson JE, Lowe SW. Arid1a restrains Kras-dependent changes in acinar cell identity. eLife 2018; 7:35216. [PMID: 30014851 PMCID: PMC6050044 DOI: 10.7554/elife.35216] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Accepted: 05/28/2018] [Indexed: 12/21/2022] Open
Abstract
Mutations in members of the SWI/SNF chromatin remodeling family are common events in cancer, but the mechanisms whereby disruption of SWI/SNF components alters tumorigenesis remain poorly understood. To model the effect of loss of function mutations in the SWI/SNF subunit Arid1a in pancreatic ductal adenocarcinoma (PDAC) initiation, we directed shRNA triggered, inducible and reversible suppression of Arid1a to the mouse pancreas in the setting of oncogenic KrasG12D. Arid1a cooperates with Kras in the adult pancreas as postnatal silencing of Arid1a following sustained KrasG12D expression induces rapid and irreversible reprogramming of acinar cells into mucinous PDAC precursor lesions. In contrast, Arid1a silencing during embryogenesis, concurrent with KrasG12D activation, leads to retention of acinar cell fate. Together, our results demonstrate Arid1a as a critical modulator of Kras-dependent changes in acinar cell identity, and underscore an unanticipated influence of timing and genetic context on the effects of SWI/SNF complex alterations in epithelial tumorigenesis. The pancreas produces many different hormones, as well as several substances important for digestion. To perform these roles, the pancreas contains different types of cells; for example, acinar cells make digestive enzymes that help to break down food. But, like other cells in the body, pancreatic cells can accumulate mutations in their DNA that cause them to divide, acquire an altered identity and form a cancerous tumor. The DNA of cells is packed into a structure called chromatin. While the DNA sequence is essentially the same across all normal cells of a given individual, chromatin can be more or less compacted in the different cell types that comprise our body tissues. A collection of proteins called the SWI/SNF complex can reorganize the chromatin to change how tightly the DNA is packed. This determines which genes in the DNA are accessible and can be activated, and which ones cannot. Around 25% of pancreatic cancers contain mutations in genes that produce proteins of the SWI/SNF complex. These mutations normally occur with an additional mutation that over-activates the gene that produces a potentially cancer-causing protein called Kras. Livshits et al. have now genetically engineered mice to investigate how one such SWI/SNF complex protein, called Arid1a, affects how pancreatic cancer develops using a genetic approach that made possible to temporarily halt the production of Arid1a in acinar cells by feeding these mice an antibiotic. The gene that produces Kras was also over-activated in the pancreases of the mice, making them more likely to develop cancer. Within just two weeks of stopping the production of Arid1a, the acinar cells stopped producing digestive enzymes and started making other proteins that are typically found in cancerous cells, indicating that Arid1a is involved in maintaining the normal identity and activity of these cells. Restoring the ability of altered acinar cells to produce normal levels of Arid1a (by removing the mice from the antibiotic diet) did not reverse these changes. Biochemical experiments showed that acinar cells with reduced levels of Arid1a have altered chromatin. In particular, the genes that produce digestive enzymes, which are normally active in healthy pancreases, were less accessible in mice who had over-active Kras and reduced levels of Arid1a. The results presented by Livshits et al. provide the first evidence of how alterations to Arid1a can lead to irreversible changes in the identity and activity of pancreatic acinar cells. These results will need to be carefully considered by researchers who are developing treatments for cancer patients with mutations in Arid1a and other SWI/SNF proteins. In particular, methods that attempt to restore the functions of absent SWI/SNF proteins to cancer cells are unlikely to treat the cancer successfully.
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Affiliation(s)
- Geulah Livshits
- Department of Cancer Biology and Genetics, Memorial Sloan Kettering Cancer Center, New York, United States
| | - Direna Alonso-Curbelo
- Department of Cancer Biology and Genetics, Memorial Sloan Kettering Cancer Center, New York, United States
| | - John P Morris
- Department of Cancer Biology and Genetics, Memorial Sloan Kettering Cancer Center, New York, United States
| | - Richard Koche
- Center of Epigenetics Research, Memorial Sloan Kettering Cancer Center, New York, United States
| | - Michael Saborowski
- Department of Gastroenterology, Hepatology, and Endocrinology, Hannover Medical School, Hannover, Germany
| | - John Erby Wilkinson
- Department of Pathology, University of Michigan School of Medicine, Ann Arbor, United States
| | - Scott W Lowe
- Department of Cancer Biology and Genetics, Memorial Sloan Kettering Cancer Center, New York, United States.,Howard Hughes Medical Institute, New York, United States
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80
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Moggs J, Terranova R. Chromatin dynamics underlying latent responses to xenobiotics. Toxicol Res (Camb) 2018; 7:606-617. [PMID: 30090610 PMCID: PMC6062062 DOI: 10.1039/c7tx00317j] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 02/26/2018] [Indexed: 11/21/2022] Open
Abstract
Pleiotropic xenobiotics can trigger dynamic alterations in mammalian chromatin structure and function but many of these are likely non-adverse and simply reflect short-term changes in DNA transactions underlying normal homeostatic, adaptive and protective cellular responses. However, it is plausible that a subset of xenobiotic-induced perturbations of somatic tissue or germline epigenomes result in delayed-onset and long-lasting adverse effects, in particular if they occur during critical stages of growth and development. These could include reprogramming, dedifferentiation, uncontrolled growth, and cumulative toxicity effects through molecular memory of prior xenobiotic exposures or altered susceptibility to subsequent xenobiotic exposures. Here we discuss the current evidence for epigenetic mechanisms underlying latent responses to xenobiotics, and the potential for identifying molecular epigenetic changes that are prodromal to overt morphologic or functional toxicity phenotypes.
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Affiliation(s)
- Jonathan Moggs
- Preclinical Safety , Translational Medicine , Novartis Institutes for BioMedical Research , Basel , Switzerland
| | - Rémi Terranova
- Preclinical Safety , Translational Medicine , Novartis Institutes for BioMedical Research , Basel , Switzerland
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81
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Marando L, Huntly BJP. Hematopoietic stem cells made BETter by inhibition. Haematologica 2018; 103:919-921. [PMID: 29866885 PMCID: PMC6058785 DOI: 10.3324/haematol.2018.193706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Ludovica Marando
- Wellcome Trust-MRC Cambridge Stem Cell Institute, UK
- Department of Haematology, University of Cambridge, UK
- Cambridge Institute for Medical Research, Cambridge Biomedical Campus, UK
| | - Brian J P Huntly
- Wellcome Trust-MRC Cambridge Stem Cell Institute, UK
- Department of Haematology, University of Cambridge, UK
- Cambridge Institute for Medical Research, Cambridge Biomedical Campus, UK
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82
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Enhanced efficacy of combined temozolomide and bromodomain inhibitor therapy for gliomas using targeted nanoparticles. Nat Commun 2018; 9:1991. [PMID: 29777137 PMCID: PMC5959860 DOI: 10.1038/s41467-018-04315-4] [Citation(s) in RCA: 203] [Impact Index Per Article: 33.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2017] [Accepted: 04/11/2018] [Indexed: 12/15/2022] Open
Abstract
Effective treatment for glioblastoma (GBM) is limited by the presence of the blood–brain barrier (BBB) and rapid resistance to single agent therapies. To address these issues, we developed a transferrin-functionalized nanoparticle (Tf-NP) that can deliver dual combination therapies. Using intravital imaging, we show the ability of Tf-NPs to traverse intact BBB in mice as well as achieve direct tumor binding in two intracranial orthotopic models of GBM. Treatment of tumor-bearing mice with Tf-NPs loaded with temozolomide and the bromodomain inhibitor JQ1 leads to increased DNA damage and apoptosis that correlates with a 1.5- to 2-fold decrease in tumor burden and corresponding increase in survival compared to equivalent free-drug dosing. Immunocompetent mice treated with Tf-NP-loaded drugs also show protection from the effects of systemic drug toxicity, demonstrating the preclinical potential of this nanoscale platform to deliver novel combination therapies to gliomas and other central nervous system tumors. The blood-brain barrier often limits effective delivery of treatments for glioblastoma . In this study, the authors develop transferrin-functionalized nanoparticles able to traverse the intact blood-brain barrier and deliver combination temozolomide and bromodomain inhibitor therapy to glioma-bearing mice.
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83
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Ozer HG, El-Gamal D, Powell B, Hing ZA, Blachly JS, Harrington B, Mitchell S, Grieselhuber NR, Williams K, Lai TH, Alinari L, Baiocchi RA, Brinton L, Baskin E, Cannon M, Beaver L, Goettl VM, Lucas DM, Woyach JA, Sampath D, Lehman AM, Yu L, Zhang J, Ma Y, Zhang Y, Spevak W, Shi S, Severson P, Shellooe R, Carias H, Tsang G, Dong K, Ewing T, Marimuthu A, Tantoy C, Walters J, Sanftner L, Rezaei H, Nespi M, Matusow B, Habets G, Ibrahim P, Zhang C, Mathé EA, Bollag G, Byrd JC, Lapalombella R. BRD4 Profiling Identifies Critical Chronic Lymphocytic Leukemia Oncogenic Circuits and Reveals Sensitivity to PLX51107, a Novel Structurally Distinct BET Inhibitor. Cancer Discov 2018; 8:458-477. [PMID: 29386193 PMCID: PMC5882533 DOI: 10.1158/2159-8290.cd-17-0902] [Citation(s) in RCA: 93] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 12/12/2017] [Accepted: 01/26/2018] [Indexed: 11/16/2022]
Abstract
Bromodomain and extra-terminal (BET) family proteins are key regulators of gene expression in cancer. Herein, we utilize BRD4 profiling to identify critical pathways involved in pathogenesis of chronic lymphocytic leukemia (CLL). BRD4 is overexpressed in CLL and is enriched proximal to genes upregulated or de novo expressed in CLL with known functions in disease pathogenesis and progression. These genes, including key members of the B-cell receptor (BCR) signaling pathway, provide a rationale for this therapeutic approach to identify new targets in alternative types of cancer. Additionally, we describe PLX51107, a structurally distinct BET inhibitor with novel in vitro and in vivo pharmacologic properties that emulates or exceeds the efficacy of BCR signaling agents in preclinical models of CLL. Herein, the discovery of the involvement of BRD4 in the core CLL transcriptional program provides a compelling rationale for clinical investigation of PLX51107 as epigenetic therapy in CLL and application of BRD4 profiling in other cancers.Significance: To date, functional studies of BRD4 in CLL are lacking. Through integrated genomic, functional, and pharmacologic analyses, we uncover the existence of BRD4-regulated core CLL transcriptional programs and present preclinical proof-of-concept studies validating BET inhibition as an epigenetic approach to target BCR signaling in CLL. Cancer Discov; 8(4); 458-77. ©2018 AACR.This article is highlighted in the In This Issue feature, p. 371.
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MESH Headings
- Animals
- Antineoplastic Agents/pharmacology
- Antineoplastic Agents/therapeutic use
- Cell Cycle Proteins
- Cell Line, Tumor
- Cell Proliferation
- Gene Expression Profiling
- Gene Expression Regulation, Leukemic
- Humans
- Isoxazoles/pharmacology
- Isoxazoles/therapeutic use
- Leukemia, Lymphocytic, Chronic, B-Cell/drug therapy
- Leukemia, Lymphocytic, Chronic, B-Cell/genetics
- Leukemia, Lymphocytic, Chronic, B-Cell/metabolism
- Leukemia, Lymphocytic, Chronic, B-Cell/physiopathology
- Mice
- Mice, SCID
- Nuclear Proteins/genetics
- Nuclear Proteins/metabolism
- Pyridines/pharmacology
- Pyridines/therapeutic use
- Pyrroles/pharmacology
- Pyrroles/therapeutic use
- Signal Transduction
- Transcription Factors/genetics
- Transcription Factors/metabolism
- Xenograft Model Antitumor Assays
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Affiliation(s)
- Hatice Gulcin Ozer
- Department of Biomedical Informatics, The Ohio State University, Columbus, Ohio
| | - Dalia El-Gamal
- Division of Hematology, Department of Medicine, The Ohio State University, Columbus, Ohio
| | | | - Zachary A Hing
- Division of Hematology, Department of Medicine, The Ohio State University, Columbus, Ohio
| | - James S Blachly
- Department of Biomedical Informatics, The Ohio State University, Columbus, Ohio
- Division of Hematology, Department of Medicine, The Ohio State University, Columbus, Ohio
| | - Bonnie Harrington
- College of Veterinary Medicine, The Ohio State University, Columbus, Ohio
| | - Shaneice Mitchell
- Division of Hematology, Department of Medicine, The Ohio State University, Columbus, Ohio
| | - Nicole R Grieselhuber
- Division of Hematology, Department of Medicine, The Ohio State University, Columbus, Ohio
| | - Katie Williams
- Division of Hematology, Department of Medicine, The Ohio State University, Columbus, Ohio
| | - Tzung-Huei Lai
- Division of Hematology, Department of Medicine, The Ohio State University, Columbus, Ohio
| | - Lapo Alinari
- Division of Hematology, Department of Medicine, The Ohio State University, Columbus, Ohio
| | - Robert A Baiocchi
- Division of Hematology, Department of Medicine, The Ohio State University, Columbus, Ohio
| | - Lindsey Brinton
- Division of Hematology, Department of Medicine, The Ohio State University, Columbus, Ohio
| | - Elizabeth Baskin
- Division of Hematology, Department of Medicine, The Ohio State University, Columbus, Ohio
| | - Matthew Cannon
- Division of Hematology, Department of Medicine, The Ohio State University, Columbus, Ohio
| | - Larry Beaver
- Division of Hematology, Department of Medicine, The Ohio State University, Columbus, Ohio
| | - Virginia M Goettl
- Division of Hematology, Department of Medicine, The Ohio State University, Columbus, Ohio
| | - David M Lucas
- Division of Hematology, Department of Medicine, The Ohio State University, Columbus, Ohio
| | - Jennifer A Woyach
- Division of Hematology, Department of Medicine, The Ohio State University, Columbus, Ohio
| | - Deepa Sampath
- Division of Hematology, Department of Medicine, The Ohio State University, Columbus, Ohio
| | - Amy M Lehman
- Center for Biostatistics, The Ohio State University, Columbus, Ohio
| | - Lianbo Yu
- Center for Biostatistics, The Ohio State University, Columbus, Ohio
| | | | - Yan Ma
- Plexxikon Inc., Berkeley, California
| | | | | | | | | | | | | | | | - Ken Dong
- Plexxikon Inc., Berkeley, California
| | | | | | | | | | | | | | | | | | | | | | | | - Ewy A Mathé
- Department of Biomedical Informatics, The Ohio State University, Columbus, Ohio
| | | | - John C Byrd
- Division of Hematology, Department of Medicine, The Ohio State University, Columbus, Ohio.
| | - Rosa Lapalombella
- Division of Hematology, Department of Medicine, The Ohio State University, Columbus, Ohio.
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84
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Wroblewski M, Scheller-Wendorff M, Udonta F, Bauer R, Schlichting J, Zhao L, Ben Batalla I, Gensch V, Päsler S, Wu L, Wanior M, Taipaleenmäki H, Bolamperti S, Najafova Z, Pantel K, Bokemeyer C, Qi J, Hesse E, Knapp S, Johnsen S, Loges S. BET-inhibition by JQ1 promotes proliferation and self-renewal capacity of hematopoietic stem cells. Haematologica 2018; 103:939-948. [PMID: 29567778 PMCID: PMC6058788 DOI: 10.3324/haematol.2017.181354] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 03/15/2018] [Indexed: 12/25/2022] Open
Abstract
Although inhibitors of bromodomain and extra terminal domain (BET) proteins show promising clinical activity in different hematologic malignancies, a systematic analysis of the consequences of pharmacological BET inhibition on healthy hematopoietic (stem) cells is urgently needed. We found that JQ1 treatment decreases the numbers of pre-, immature and mature B cells while numbers of early pro-B cells remain constant. In addition, JQ1 treatment increases apoptosis in T cells, all together leading to reduced cellularity in thymus, bone marrow and spleen. Furthermore, JQ1 induces proliferation of long-term hematopoietic stem cells, thereby increasing stem cell numbers. Due to increased numbers, JQ1-treated hematopoietic stem cells engrafted better after stem cell transplantation and repopulated the hematopoietic system significantly faster after sublethal myeloablation. As quantity and functionality of hematopoietic stem cells determine the duration of life-threatening myelosuppression, BET inhibition might benefit patients in myelosuppressive conditions.
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Affiliation(s)
- Mark Wroblewski
- Department of Hematology and Oncology with Sections BMT and Pneumology, Hubertus Wald Tumorzentrum, University Comprehensive Cancer Center Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Institute of Tumor Biology, Center of Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Marina Scheller-Wendorff
- Department of Hematology and Oncology with Sections BMT and Pneumology, Hubertus Wald Tumorzentrum, University Comprehensive Cancer Center Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Institute of Tumor Biology, Center of Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Department of Medicine V, Hematology, Oncology and Rheumatology, University of Heidelberg, Germany
| | - Florian Udonta
- Department of Hematology and Oncology with Sections BMT and Pneumology, Hubertus Wald Tumorzentrum, University Comprehensive Cancer Center Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Institute of Tumor Biology, Center of Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Raimund Bauer
- Department of Hematology and Oncology with Sections BMT and Pneumology, Hubertus Wald Tumorzentrum, University Comprehensive Cancer Center Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Institute of Tumor Biology, Center of Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Jara Schlichting
- Department of Hematology and Oncology with Sections BMT and Pneumology, Hubertus Wald Tumorzentrum, University Comprehensive Cancer Center Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Institute of Tumor Biology, Center of Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Lin Zhao
- Department of Hematology and Oncology with Sections BMT and Pneumology, Hubertus Wald Tumorzentrum, University Comprehensive Cancer Center Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Institute of Tumor Biology, Center of Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Department of Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Isabel Ben Batalla
- Department of Hematology and Oncology with Sections BMT and Pneumology, Hubertus Wald Tumorzentrum, University Comprehensive Cancer Center Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Institute of Tumor Biology, Center of Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Victoria Gensch
- Department of Hematology and Oncology with Sections BMT and Pneumology, Hubertus Wald Tumorzentrum, University Comprehensive Cancer Center Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Institute of Tumor Biology, Center of Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Sarina Päsler
- Department of Hematology and Oncology with Sections BMT and Pneumology, Hubertus Wald Tumorzentrum, University Comprehensive Cancer Center Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Institute of Tumor Biology, Center of Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Lei Wu
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Marek Wanior
- Institute for Pharmaceutical Chemistry, Johann Wolfgang Goethe-University and Buchmann Institute for Molecular Life Sciences, Frankfurt am Main, Germany
| | - Hanna Taipaleenmäki
- Heisenberg-Group for Molecular Skeletal Biology, Department of Trauma, Hand & Reconstructive Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Simona Bolamperti
- Heisenberg-Group for Molecular Skeletal Biology, Department of Trauma, Hand & Reconstructive Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Zeynab Najafova
- Department of General, Visceral and Pediatric Surgery, University Medical Center Göttingen, Germany
| | - Klaus Pantel
- Institute of Tumor Biology, Center of Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Carsten Bokemeyer
- Department of Hematology and Oncology with Sections BMT and Pneumology, Hubertus Wald Tumorzentrum, University Comprehensive Cancer Center Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Jun Qi
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Eric Hesse
- Heisenberg-Group for Molecular Skeletal Biology, Department of Trauma, Hand & Reconstructive Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Stefan Knapp
- Institute for Pharmaceutical Chemistry, Johann Wolfgang Goethe-University and Buchmann Institute for Molecular Life Sciences, Frankfurt am Main, Germany.,Nuffield Department of Clinical Medicine, Structural Genomics Consortium and Target Discovery Institute, University of Oxford, Old Road Campus Research Building, UK.,German Cancer Consortium (DKTK) Frankfurt am Main, Germany
| | - Steven Johnsen
- Institute of Tumor Biology, Center of Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Department of General, Visceral and Pediatric Surgery, University Medical Center Göttingen, Germany
| | - Sonja Loges
- Department of Hematology and Oncology with Sections BMT and Pneumology, Hubertus Wald Tumorzentrum, University Comprehensive Cancer Center Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany .,Institute of Tumor Biology, Center of Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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85
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Sahni JM, Keri RA. Targeting bromodomain and extraterminal proteins in breast cancer. Pharmacol Res 2018; 129:156-176. [PMID: 29154989 PMCID: PMC5828951 DOI: 10.1016/j.phrs.2017.11.015] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 11/10/2017] [Accepted: 11/13/2017] [Indexed: 12/13/2022]
Abstract
Breast cancer is a collection of distinct tumor subtypes that are driven by unique gene expression profiles. These transcriptomes are controlled by various epigenetic marks that dictate which genes are expressed and suppressed. During carcinogenesis, extensive restructuring of the epigenome occurs, including aberrant acetylation, alteration of methylation patterns, and accumulation of epigenetic readers at oncogenes. As epigenetic alterations are reversible, epigenome-modulating drugs could provide a mechanism to silence numerous oncogenes simultaneously. Here, we review the impact of inhibitors of the Bromodomain and Extraterminal (BET) family of epigenetic readers in breast cancer. These agents, including the prototypical BET inhibitor JQ1, have been shown to suppress a variety of oncogenic pathways while inducing minimal, if any, toxicity in models of several subtypes of breast cancer. BET inhibitors also synergize with multiple approved anti-cancer drugs, providing a greater response in breast cancer cell lines and mouse models than either single agent. The combined findings of the studies discussed here provide an excellent rationale for the continued investigation of the utility of BET inhibitors in breast cancer.
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Affiliation(s)
- Jennifer M Sahni
- Department of Pharmacology, Case Western Reserve University, Cleveland, OH 44106, United States
| | - Ruth A Keri
- Department of Pharmacology, Case Western Reserve University, Cleveland, OH 44106, United States; Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, OH 44106, United States; Department of General Medical Sciences-Oncology, Case Western Reserve University, Cleveland, OH 44106, United States.
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86
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Shao Z, Yao C, Khodadadi-Jamayran A, Xu W, Townes TM, Crowley MR, Hu K. Reprogramming by De-bookmarking the Somatic Transcriptional Program through Targeting of BET Bromodomains. Cell Rep 2018; 16:3138-3145. [PMID: 27653680 DOI: 10.1016/j.celrep.2016.08.060] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Revised: 04/19/2016] [Accepted: 08/18/2016] [Indexed: 01/11/2023] Open
Abstract
One critical event in reprogramming to pluripotency is erasure of the somatic transcriptional program of starting cells. Here, we present the proof of principle of a strategy for reprogramming to pluripotency facilitated by small molecules that interfere with the somatic transcriptional memory. We show that mild chemical targeting of the acetyllysine-binding pockets of the BET bromodomains, the transcriptional bookmarking domains, robustly enhances reprogramming. Furthermore, we show that chemical targeting of the transcriptional bookmarking BET bromodomains downregulates or turns off the expression of somatic genes in both naive and reprogramming fibroblasts. Chemical blocking of the BET bromodomains also results in loss of fibroblast morphology early in reprogramming. We therefore experimentally demonstrate that cell fate conversion can be achieved by chemically targeting the transcriptional bookmarking BET bromodomains responsible for transcriptional memory.
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Affiliation(s)
- Zhicheng Shao
- Stem Cell Institute, Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294-0024, USA
| | - Chunping Yao
- Stem Cell Institute, Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294-0024, USA; Department of Radiation Oncology, Shandong Cancer Hospital, Shandong University, Jinan, Shandong 250117, China
| | - Alireza Khodadadi-Jamayran
- Stem Cell Institute, Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294-0024, USA
| | - Weihua Xu
- Longyan University, Fujian 364012, China
| | - Tim M Townes
- Stem Cell Institute, Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294-0024, USA
| | - Michael R Crowley
- Howell and Elizabeth Heflin Center for Genomic Science, Department of Genetics, University of Alabama at Birmingham, Birmingham, AL 35294-0024, USA
| | - Kejin Hu
- Stem Cell Institute, Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294-0024, USA.
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87
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Runcie AC, Zengerle M, Chan KH, Testa A, van Beurden L, Baud MGJ, Epemolu O, Ellis LCJ, Read KD, Coulthard V, Brien A, Ciulli A. Optimization of a "bump-and-hole" approach to allele-selective BET bromodomain inhibition. Chem Sci 2018; 9:2452-2468. [PMID: 29732121 PMCID: PMC5909127 DOI: 10.1039/c7sc02536j] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 01/23/2018] [Indexed: 12/27/2022] Open
Abstract
Allele-specific chemical genetics enables selective inhibition within families of highly-conserved proteins.
Allele-specific chemical genetics enables selective inhibition within families of highly-conserved proteins. The four BET (bromodomain & extra-terminal domain) proteins – BRD2, BRD3, BRD4 and BRDT bind acetylated chromatin via their bromodomains and regulate processes such as cell proliferation and inflammation. BET bromodomains are of particular interest, as they are attractive therapeutic targets but existing inhibitors are pan-selective. We previously established a bump-&-hole system for the BET bromodomains, pairing a leucine/alanine mutation with an ethyl-derived analogue of an established benzodiazepine scaffold. Here we optimize upon this system with the introduction of a more conservative and less disruptive leucine/valine mutation. Extensive structure–activity-relationships of diverse benzodiazepine analogues guided the development of potent, mutant-selective inhibitors with desirable physiochemical properties. The active enantiomer of our best compound – 9-ME-1 – shows ∼200 nM potency, >100-fold selectivity for the L/V mutant over wild-type and excellent DMPK properties. Through a variety of in vitro and cellular assays we validate the capabilities of our optimized system, and then utilize it to compare the relative importance of the first and second bromodomains to chromatin binding. These experiments confirm the primacy of the first bromodomain in all BET proteins, but also significant variation in the importance of the second bromodomain. We also show that, despite having a minor role in chromatin recognition, BRD4 BD2 is still essential for gene expression, likely through the recruitment of non-histone proteins. The disclosed inhibitor:mutant pair provides a powerful tool for future cellular and in vivo target validation studies.
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Affiliation(s)
- A C Runcie
- Division of Biological Chemistry and Drug Discovery , School of Life Sciences , University of Dundee , Dundee , Scotland , UK .
| | - M Zengerle
- Division of Biological Chemistry and Drug Discovery , School of Life Sciences , University of Dundee , Dundee , Scotland , UK .
| | - K-H Chan
- Division of Biological Chemistry and Drug Discovery , School of Life Sciences , University of Dundee , Dundee , Scotland , UK .
| | - A Testa
- Division of Biological Chemistry and Drug Discovery , School of Life Sciences , University of Dundee , Dundee , Scotland , UK .
| | - L van Beurden
- Division of Biological Chemistry and Drug Discovery , School of Life Sciences , University of Dundee , Dundee , Scotland , UK .
| | - M G J Baud
- Division of Biological Chemistry and Drug Discovery , School of Life Sciences , University of Dundee , Dundee , Scotland , UK .
| | - O Epemolu
- Division of Biological Chemistry and Drug Discovery , School of Life Sciences , University of Dundee , Dundee , Scotland , UK .
| | - L C J Ellis
- Division of Biological Chemistry and Drug Discovery , School of Life Sciences , University of Dundee , Dundee , Scotland , UK .
| | - K D Read
- Division of Biological Chemistry and Drug Discovery , School of Life Sciences , University of Dundee , Dundee , Scotland , UK .
| | - V Coulthard
- Reach Separations Ltd , BioCity Nottingham , Nottingham , UK
| | - A Brien
- Reach Separations Ltd , BioCity Nottingham , Nottingham , UK
| | - A Ciulli
- Division of Biological Chemistry and Drug Discovery , School of Life Sciences , University of Dundee , Dundee , Scotland , UK .
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88
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Xu Y, Milazzo JP, Somerville TDD, Tarumoto Y, Huang YH, Ostrander EL, Wilkinson JE, Challen GA, Vakoc CR. A TFIID-SAGA Perturbation that Targets MYB and Suppresses Acute Myeloid Leukemia. Cancer Cell 2018; 33:13-28.e8. [PMID: 29316427 PMCID: PMC5764110 DOI: 10.1016/j.ccell.2017.12.002] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 09/22/2017] [Accepted: 12/05/2017] [Indexed: 01/08/2023]
Abstract
Targeting of general coactivators is an emerging strategy to interfere with oncogenic transcription factors (TFs). However, coactivator perturbations often lead to pleiotropic effects by influencing numerous TFs. Here we identify TAF12, a subunit of TFIID and SAGA coactivator complexes, as a selective requirement for acute myeloid leukemia (AML) progression. We trace this dependency to a direct interaction between the TAF12/TAF4 histone-fold heterodimer and the transactivation domain of MYB, a TF with established roles in leukemogenesis. Ectopic expression of the TAF4 histone-fold fragment can efficiently squelch TAF12 in cells, suppress MYB, and regress AML in mice. Our study reveals a strategy for potent MYB inhibition in AML and highlights how an oncogenic TF can be selectively neutralized by targeting a general coactivator complex.
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Affiliation(s)
- Yali Xu
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA; Molecular and Cellular Biology Program, Stony Brook University, New York, NY 11794, USA
| | - Joseph P Milazzo
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | | | - Yusuke Tarumoto
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Yu-Han Huang
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Elizabeth L Ostrander
- Division of Oncology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - John E Wilkinson
- ULAM/Department of Pathology, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA
| | - Grant A Challen
- Division of Oncology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
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89
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Lee JE, Park YK, Park S, Jang Y, Waring N, Dey A, Ozato K, Lai B, Peng W, Ge K. Brd4 binds to active enhancers to control cell identity gene induction in adipogenesis and myogenesis. Nat Commun 2017; 8:2217. [PMID: 29263365 PMCID: PMC5738375 DOI: 10.1038/s41467-017-02403-5] [Citation(s) in RCA: 135] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 11/28/2017] [Indexed: 01/13/2023] Open
Abstract
The epigenomic reader Brd4 is an important drug target for cancers. However, its role in cell differentiation and animal development remains largely unclear. Using two conditional knockout mouse strains and derived cells, we demonstrate that Brd4 controls cell identity gene induction and is essential for adipogenesis and myogenesis. Brd4 co-localizes with lineage-determining transcription factors (LDTFs) on active enhancers during differentiation. LDTFs coordinate with H3K4 mono-methyltransferases MLL3/MLL4 (KMT2C/KMT2D) and H3K27 acetyltransferases CBP/p300 to recruit Brd4 to enhancers activated during differentiation. Brd4 deletion prevents the enrichment of Mediator and RNA polymerase II transcription machinery, but not that of LDTFs, MLL3/MLL4-mediated H3K4me1, and CBP/p300-mediated H3K27ac, on enhancers. Consequently, Brd4 deletion prevents enhancer RNA production, cell identity gene induction and cell differentiation. Interestingly, Brd4 is dispensable for maintaining cell identity genes in differentiated cells. These findings identify Brd4 as an enhancer epigenomic reader that links active enhancers with cell identity gene induction in differentiation. Despite being an important cancer drug target, the role of epigenetic reader Brd4 in cell differentiation and development remains unclear. Here, the authors provide evidence that Brd4 plays an important role in adipogenesis and myogenesis by binding to active enhancers to regulate gene expression.
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Affiliation(s)
- Ji-Eun Lee
- Adipocyte Biology and Gene Regulation Section, Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Young-Kwon Park
- Adipocyte Biology and Gene Regulation Section, Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Sarah Park
- Adipocyte Biology and Gene Regulation Section, Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Younghoon Jang
- Adipocyte Biology and Gene Regulation Section, Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Nicholas Waring
- Adipocyte Biology and Gene Regulation Section, Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA.,Departments of Physics and Anatomy and Regenerative Biology, The George Washington University, Washington, DC, 20052, USA
| | - Anup Dey
- Program in Genomics of Differentiation, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Keiko Ozato
- Program in Genomics of Differentiation, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Binbin Lai
- Adipocyte Biology and Gene Regulation Section, Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA.,Departments of Physics and Anatomy and Regenerative Biology, The George Washington University, Washington, DC, 20052, USA
| | - Weiqun Peng
- Departments of Physics and Anatomy and Regenerative Biology, The George Washington University, Washington, DC, 20052, USA
| | - Kai Ge
- Adipocyte Biology and Gene Regulation Section, Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA.
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90
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Stathis A, Bertoni F. BET Proteins as Targets for Anticancer Treatment. Cancer Discov 2017; 8:24-36. [PMID: 29263030 DOI: 10.1158/2159-8290.cd-17-0605] [Citation(s) in RCA: 315] [Impact Index Per Article: 45.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 09/14/2017] [Accepted: 10/11/2017] [Indexed: 11/16/2022]
Affiliation(s)
| | - Francesco Bertoni
- Oncology Institute of Southern Switzerland, Bellinzona, Switzerland
- Università della Svizzera italiana, Istituto Oncologico di Ricerca, Bellinzona, Switzerland
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91
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BRD4 has dual effects on the HMGB1 and NF-κB signalling pathways and is a potential therapeutic target for osteoarthritis. Biochim Biophys Acta Mol Basis Dis 2017; 1863:3001-3015. [DOI: 10.1016/j.bbadis.2017.08.009] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 07/28/2017] [Accepted: 08/16/2017] [Indexed: 01/11/2023]
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92
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Korb E, Herre M, Zucker-Scharff I, Gresack J, Allis CD, Darnell RB. Excess Translation of Epigenetic Regulators Contributes to Fragile X Syndrome and Is Alleviated by Brd4 Inhibition. Cell 2017; 170:1209-1223.e20. [PMID: 28823556 DOI: 10.1016/j.cell.2017.07.033] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Revised: 05/17/2017] [Accepted: 07/21/2017] [Indexed: 11/28/2022]
Abstract
Fragile X syndrome (FXS) is a leading genetic cause of intellectual disability and autism. FXS results from the loss of function of fragile X mental retardation protein (FMRP), which represses translation of target transcripts. Most of the well-characterized target transcripts of FMRP are synaptic proteins, yet targeting these proteins has not provided effective treatments. We examined a group of FMRP targets that encode transcriptional regulators, particularly chromatin-associated proteins. Loss of FMRP in mice results in widespread changes in chromatin regulation and aberrant gene expression. To determine if targeting epigenetic factors could reverse phenotypes associated with the disorder, we focused on Brd4, a BET protein and chromatin reader targeted by FMRP. Inhibition of Brd4 function alleviated many of the phenotypes associated with FXS. We conclude that loss of FMRP results in significant epigenetic misregulation and that targeting transcription via epigenetic regulators like Brd4 may provide new treatments for FXS.
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Affiliation(s)
- Erica Korb
- Laboratory of Chromatin Biology and Epigenetics, The Rockefeller University, New York, NY 10065, USA
| | - Margaret Herre
- Laboratory of Molecular Neuro-oncology and Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA
| | - Ilana Zucker-Scharff
- Laboratory of Molecular Neuro-oncology and Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA
| | - Jodi Gresack
- Laboratory of Molecular and Cellular Neuroscience, The Rockefeller University, New York, NY 10065, USA
| | - C David Allis
- Laboratory of Chromatin Biology and Epigenetics, The Rockefeller University, New York, NY 10065, USA.
| | - Robert B Darnell
- Laboratory of Molecular Neuro-oncology and Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA.
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93
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RUNX1 is required for oncogenic Myb and Myc enhancer activity in T-cell acute lymphoblastic leukemia. Blood 2017; 130:1722-1733. [PMID: 28790107 DOI: 10.1182/blood-2017-03-775536] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2017] [Accepted: 07/24/2017] [Indexed: 12/14/2022] Open
Abstract
The gene encoding the RUNX1 transcription factor is mutated in a subset of T-cell acute lymphoblastic leukemia (T-ALL) patients, and RUNX1 mutations are associated with a poor prognosis. These mutations cluster in the DNA-binding Runt domain and are thought to represent loss-of-function mutations, indicating that RUNX1 suppresses T-cell transformation. RUNX1 has been proposed to have tumor suppressor roles in T-cell leukemia homeobox 1/3-transformed human T-ALL cell lines and NOTCH1 T-ALL mouse models. Yet, retroviral insertional mutagenesis screens identify RUNX genes as collaborating oncogenes in MYC-driven leukemia mouse models. To elucidate RUNX1 function(s) in leukemogenesis, we generated Tal1/Lmo2/Rosa26-CreERT2Runx1f/f mice and examined leukemia progression in the presence of vehicle or tamoxifen. We found that Runx1 deletion inhibits mouse leukemic growth in vivo and that RUNX silencing in human T-ALL cells triggers apoptosis. We demonstrate that a small molecule inhibitor, designed to interfere with CBFβ binding to RUNX proteins, impairs the growth of human T-ALL cell lines and primary patient samples. We demonstrate that a RUNX1 deficiency alters the expression of a crucial subset of TAL1- and NOTCH1-regulated genes, including the MYB and MYC oncogenes, respectively. These studies provide genetic and pharmacologic evidence that RUNX1 has oncogenic roles and reveal RUNX1 as a novel therapeutic target in T-ALL.
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94
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Pongas G, Kim MK, Min DJ, House CD, Jordan E, Caplen N, Chakka S, Ohiri J, Kruhlak MJ, Annunziata CM. BRD4 facilitates DNA damage response and represses CBX5/Heterochromatin protein 1 (HP1). Oncotarget 2017; 8:51402-51415. [PMID: 28881656 PMCID: PMC5584257 DOI: 10.18632/oncotarget.17572] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 04/10/2017] [Indexed: 11/25/2022] Open
Abstract
Ovarian cancer (OC) is a heterogeneous disease characterized by defective DNA repair. Very few targets are universally expressed in the high grade serous (HGS) subtype. We previously identified that CHK1 was overexpressed in most of HGSOC. Here, we sought to understand the DNA damage response (DDR) to CHK1 inhibition and increase the anti-tumor activity of this pathway. We found BRD4 suppression either by siRNA or BRD4 inhibitor JQ1 enhanced the cytotoxicity of CHK1 inhibition. Interestingly, BRD4 was amplified and/or upregulated in a subset of HGSOC with statistical correlation to overall survival. BRD4 inhibition increased CBX5 (HP1α) level. CHK1 inhibitor induced DDR marker, γ-H2AX, but BRD4 suppression did not. Furthermore, nuclear localization of CBX5 and γ-H2AX was mutually exclusive in BRD4-and CHK1-inhibited cells, suggesting BRD4 facilitates DDR by repressing CBX5. Our results provide a strong rationale for clinical investigation of CHK1 and BRD4 co-inhibition, especially for HGSOC patients with BRD4 overexpression.
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Affiliation(s)
- Georgios Pongas
- Women's Malignancies Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Marianne K. Kim
- Women's Malignancies Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Dong J. Min
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Carrie D. House
- Women's Malignancies Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Elizabeth Jordan
- Women's Malignancies Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Natasha Caplen
- Genetics Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Sirisha Chakka
- Genetics Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Joyce Ohiri
- Women's Malignancies Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Michael J. Kruhlak
- Experimental Immunology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Christina M. Annunziata
- Women's Malignancies Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
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95
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Xu Y, Vakoc CR. Targeting Cancer Cells with BET Bromodomain Inhibitors. Cold Spring Harb Perspect Med 2017; 7:cshperspect.a026674. [PMID: 28213432 DOI: 10.1101/cshperspect.a026674] [Citation(s) in RCA: 134] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Cancer cells are often hypersensitive to the targeting of transcriptional regulators, which may reflect the deregulated gene expression programs that underlie malignant transformation. One of the most prominent transcriptional vulnerabilities in human cancer to emerge in recent years is the bromodomain and extraterminal (BET) family of proteins, which are coactivators that link acetylated transcription factors and histones to the activation of RNA polymerase II. Despite unclear mechanisms underlying the gene specificity of BET protein function, small molecules targeting these regulators preferentially suppress the transcription of cancer-promoting genes. As a consequence, BET inhibitors elicit anticancer activity in numerous malignant contexts at doses that can be tolerated by normal tissues, a finding supported by animal studies and by phase I clinical trials in human cancer patients. In this review, we will discuss the remarkable, and often perplexing, therapeutic effects of BET bromodomain inhibition in cancer.
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Affiliation(s)
- Yali Xu
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724
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96
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Uncovering BRD4 hyperphosphorylation associated with cellular transformation in NUT midline carcinoma. Proc Natl Acad Sci U S A 2017. [PMID: 28630312 DOI: 10.1073/pnas.1703071114] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The epigenetic reader BRD4 plays a vital role in transcriptional regulation, cellular growth control, and cell-cycle progression. Dysregulation of BRD4 function has been implicated in the pathogenesis of a wide range of cancers. However, how BRD4 is regulated to maintain its normal function in healthy cells and how alteration of this process leads to cancer remain poorly understood. In this study, we discovered that BRD4 is hyperphosphorylated in NUT midline carcinoma and identified CDK9 as a potential kinase mediating BRD4 hyperphosphorylation. Disruption of BRD4 hyperphosphorylation using both chemical and molecular inhibitors led to the repression of BRD4 downstream oncogenes and abrogation of cellular transformation. BRD4 hyperphosphorylation is also observed in other cancers displaying enhanced BRD4 oncogenic activity. Our study revealed a mechanism that may regulate BRD4 biological function through phosphorylation, which, when dysregulated, could lead to oncogenesis. Our finding points to strategies to target the aberrant BRD4 signaling specifically for cancer intervention.
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97
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Kharenko OA, Hansen HC. Novel approaches to targeting BRD4. DRUG DISCOVERY TODAY. TECHNOLOGIES 2017; 24:19-24. [PMID: 29233295 DOI: 10.1016/j.ddtec.2017.10.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 02/15/2017] [Accepted: 10/11/2017] [Indexed: 06/07/2023]
Abstract
Inhibition of bromo and extra-terminal (BET) bromodomains, including BRD4, has emerged as a new exciting epigenetic target for oncology, in particular. Recently, novel alternatives to the traditional use of reversible small molecules have emerged, including proteolytic targeting BET agents and irreversible binding inhibitors. These alternatives to reversible inhibitors may offer some advantage and can be used as tools to further decipher the underlying biology. Supportive pre-clinical data have these novel approaches bound for clinical development in the near future.
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Affiliation(s)
- Olesya A Kharenko
- Zenith Epigenetics, Suite 300, 4820 Richard Road SW, Calgary, AB T3E 6L1, Canada
| | - Henrik C Hansen
- Zenith Epigenetics, Suite 300, 4820 Richard Road SW, Calgary, AB T3E 6L1, Canada.
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98
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Collins TA, Hattersley MM, Yates J, Clark E, Mondal M, Mettetal JT. Translational Modeling of Drug-Induced Myelosuppression and Effect of Pretreatment Myelosuppression for AZD5153, a Selective BRD4 Inhibitor. CPT-PHARMACOMETRICS & SYSTEMS PHARMACOLOGY 2017; 6:357-364. [PMID: 28378926 PMCID: PMC5488126 DOI: 10.1002/psp4.12194] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 03/03/2017] [Accepted: 03/22/2017] [Indexed: 01/04/2023]
Abstract
In this work, we evaluate the potential risk of thrombocytopenia in man for a BRD4 inhibitor, AZD5153, based on the platelet count decreases from a Han Wistar rat study. The effects in rat were modeled and used to make clinical predictions for human populations with healthy baseline blood counts. At doses >10 mg, a dose-dependent effect on circulating platelets is expected, with similar predicted changes for both q.d. and b.i.d. dose schedules. These results suggest that at predicted efficacious doses, AZD5153 is likely to have some reductions in the clinical platelet counts, but within the normal range at projected efficacious doses. The model was then extended to incorporate preexisting myelosuppression where bone marrow function is inhibited by acute myeloid leukemia. Under these conditions, duration of platelet count recovery has the potential to be prolonged due to drug-induced myelosuppression.
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Affiliation(s)
- T A Collins
- Drug Safety and Metabolism, AstraZeneca, Cambridge, UK
| | | | - Jwt Yates
- Oncology iMED, AstraZeneca, Cambridge, UK
| | - E Clark
- Oncology iMED, AstraZeneca, Waltham, Massachusetts, USA
| | - M Mondal
- Drug Safety and Metabolism, AstraZeneca, Waltham, Massachusetts, USA
| | - J T Mettetal
- Drug Safety and Metabolism, AstraZeneca, Waltham, Massachusetts, USA
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99
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Sakamaki JI, Wilkinson S, Hahn M, Tasdemir N, O'Prey J, Clark W, Hedley A, Nixon C, Long JS, New M, Van Acker T, Tooze SA, Lowe SW, Dikic I, Ryan KM. Bromodomain Protein BRD4 Is a Transcriptional Repressor of Autophagy and Lysosomal Function. Mol Cell 2017; 66:517-532.e9. [PMID: 28525743 PMCID: PMC5446411 DOI: 10.1016/j.molcel.2017.04.027] [Citation(s) in RCA: 171] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 03/15/2017] [Accepted: 04/28/2017] [Indexed: 12/12/2022]
Abstract
Autophagy is a membrane-trafficking process that directs degradation of cytoplasmic material in lysosomes. The process promotes cellular fidelity, and while the core machinery of autophagy is known, the mechanisms that promote and sustain autophagy are less well defined. Here we report that the epigenetic reader BRD4 and the methyltransferase G9a repress a TFEB/TFE3/MITF-independent transcriptional program that promotes autophagy and lysosome biogenesis. We show that BRD4 knockdown induces autophagy in vitro and in vivo in response to some, but not all, situations. In the case of starvation, a signaling cascade involving AMPK and histone deacetylase SIRT1 displaces chromatin-bound BRD4, instigating autophagy gene activation and cell survival. Importantly, this program is directed independently and also reciprocally to the growth-promoting properties of BRD4 and is potently repressed by BRD4-NUT, a driver of NUT midline carcinoma. These findings therefore identify a distinct and selective mechanism of autophagy regulation.
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MESH Headings
- AMP-Activated Protein Kinases/metabolism
- Animals
- Autophagy
- Carcinoma, Pancreatic Ductal/genetics
- Carcinoma, Pancreatic Ductal/metabolism
- Carcinoma, Pancreatic Ductal/pathology
- Cell Cycle Proteins
- Cell Line, Tumor
- Cell Proliferation
- Chromatin/genetics
- Chromatin/metabolism
- Down-Regulation
- Drosophila Proteins/genetics
- Drosophila Proteins/metabolism
- Drosophila melanogaster/genetics
- Drosophila melanogaster/metabolism
- Energy Metabolism
- Gene Expression Regulation, Neoplastic
- HEK293 Cells
- Histocompatibility Antigens/genetics
- Histocompatibility Antigens/metabolism
- Histone-Lysine N-Methyltransferase/genetics
- Histone-Lysine N-Methyltransferase/metabolism
- Humans
- Lysosomes/metabolism
- Lysosomes/pathology
- Mice, Inbred C57BL
- Mice, Transgenic
- Nuclear Proteins/genetics
- Nuclear Proteins/metabolism
- Oncogene Proteins, Fusion/genetics
- Oncogene Proteins, Fusion/metabolism
- Pancreatic Neoplasms/genetics
- Pancreatic Neoplasms/metabolism
- Pancreatic Neoplasms/pathology
- Protein Aggregates
- Protein Binding
- Proteolysis
- RNA Interference
- Signal Transduction
- Sirtuin 1/genetics
- Sirtuin 1/metabolism
- TOR Serine-Threonine Kinases/genetics
- TOR Serine-Threonine Kinases/metabolism
- Time Factors
- Transcription Factors/genetics
- Transcription Factors/metabolism
- Transcription, Genetic
- Transfection
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Affiliation(s)
- Jun-Ichi Sakamaki
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Simon Wilkinson
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Marcel Hahn
- Institute of Biochemistry II, Goethe University School of Medicine, 60590 Frankfurt, Germany
| | - Nilgun Tasdemir
- Department of Cancer Biology and Genetics, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Jim O'Prey
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - William Clark
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Ann Hedley
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Colin Nixon
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Jaclyn S Long
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Maria New
- Molecular Cell Biology of Autophagy, Francis Crick Institute, London NW1 1AT, UK
| | - Tim Van Acker
- Molecular Cell Biology of Autophagy, Francis Crick Institute, London NW1 1AT, UK
| | - Sharon A Tooze
- Molecular Cell Biology of Autophagy, Francis Crick Institute, London NW1 1AT, UK
| | - Scott W Lowe
- Department of Cancer Biology and Genetics, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA; Howard Hughes Medical Institute, New York, NY 10065, USA
| | - Ivan Dikic
- Institute of Biochemistry II, Goethe University School of Medicine, 60590 Frankfurt, Germany; Buchmann Institute for Molecular Life Sciences, Goethe University, 60438 Frankfurt, Germany; Institute of Immunology, School of Medicine, University of Split, 21 000 Split, Croatia
| | - Kevin M Ryan
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK.
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100
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Duan Q, McMahon S, Anand P, Shah H, Thomas S, Salunga HT, Huang Y, Zhang R, Sahadevan A, Lemieux ME, Brown JD, Srivastava D, Bradner JE, McKinsey TA, Haldar SM. BET bromodomain inhibition suppresses innate inflammatory and profibrotic transcriptional networks in heart failure. Sci Transl Med 2017; 9:eaah5084. [PMID: 28515341 PMCID: PMC5544253 DOI: 10.1126/scitranslmed.aah5084] [Citation(s) in RCA: 174] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 01/18/2017] [Accepted: 03/30/2017] [Indexed: 12/13/2022]
Abstract
Despite current standard of care, the average 5-year mortality after an initial diagnosis of heart failure (HF) is about 40%, reflecting an urgent need for new therapeutic approaches. Previous studies demonstrated that the epigenetic reader protein bromodomain-containing protein 4 (BRD4), an emerging therapeutic target in cancer, functions as a critical coactivator of pathologic gene transactivation during cardiomyocyte hypertrophy. However, the therapeutic relevance of these findings to human disease remained unknown. We demonstrate that treatment with the BET bromodomain inhibitor JQ1 has therapeutic effects during severe, preestablished HF from prolonged pressure overload, as well as after a massive anterior myocardial infarction in mice. Furthermore, JQ1 potently blocks agonist-induced hypertrophy in human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs). Integrated transcriptomic analyses across animal models and human iPSC-CMs reveal that BET inhibition preferentially blocks transactivation of a common pathologic gene regulatory program that is robustly enriched for NFκB and TGF-β signaling networks, typified by innate inflammatory and profibrotic myocardial genes. As predicted by these specific transcriptional mechanisms, we found that JQ1 does not suppress physiological cardiac hypertrophy in a mouse swimming model. These findings establish that pharmacologically targeting innate inflammatory and profibrotic myocardial signaling networks at the level of chromatin is effective in animal models and human cardiomyocytes, providing the critical rationale for further development of BET inhibitors and other epigenomic medicines for HF.
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Affiliation(s)
- Qiming Duan
- Gladstone Institute of Cardiovascular Disease, San Francisco, CA 94158, USA
| | - Sarah McMahon
- Gladstone Institute of Cardiovascular Disease, San Francisco, CA 94158, USA
| | - Priti Anand
- Gladstone Institute of Cardiovascular Disease, San Francisco, CA 94158, USA
| | - Hirsh Shah
- Institute for Transformative Molecular Medicine and Department of Medicine, Case Western Reserve University School of Medicine and University Hospitals Cleveland Medical Center, Cleveland, OH 44106, USA
| | - Sean Thomas
- Gladstone Institute of Cardiovascular Disease, San Francisco, CA 94158, USA
| | - Hazel T Salunga
- Gladstone Institute of Cardiovascular Disease, San Francisco, CA 94158, USA
| | - Yu Huang
- Gladstone Institute of Cardiovascular Disease, San Francisco, CA 94158, USA
| | - Rongli Zhang
- Institute for Transformative Molecular Medicine and Department of Medicine, Case Western Reserve University School of Medicine and University Hospitals Cleveland Medical Center, Cleveland, OH 44106, USA
| | - Aarathi Sahadevan
- Institute for Transformative Molecular Medicine and Department of Medicine, Case Western Reserve University School of Medicine and University Hospitals Cleveland Medical Center, Cleveland, OH 44106, USA
| | | | - Jonathan D Brown
- Division of Cardiovascular Medicine, Department of Medicine, and Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Deepak Srivastava
- Gladstone Institute of Cardiovascular Disease, San Francisco, CA 94158, USA
- Division of Cardiology, Department of Pediatrics, University of California San Francisco School of Medicine, San Francisco, CA 94158, USA
| | - James E Bradner
- Department of Medical Oncology, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA 02215, USA
| | - Timothy A McKinsey
- Division of Cardiology, Department of Medicine, Consortium for Fibrosis Research & Translation, University of Colorado, Anschutz Medical Campus, Denver, CO 80204, USA
| | - Saptarsi M Haldar
- Gladstone Institute of Cardiovascular Disease, San Francisco, CA 94158, USA.
- Division of Cardiology, Department of Medicine, and Cardiovascular Research Institute, University of California San Francisco School of Medicine, San Francisco, CA 94158, USA
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