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de Groot AP, de Haan G. How CBX proteins regulate normal and leukemic blood cells. FEBS Lett 2024. [PMID: 38426219 DOI: 10.1002/1873-3468.14839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 01/26/2024] [Accepted: 02/09/2024] [Indexed: 03/02/2024]
Abstract
Hematopoietic stem cell (HSC) fate decisions are dictated by epigenetic landscapes. The Polycomb Repressive Complex 1 (PRC1) represses genes that induce differentiation, thereby maintaining HSC self-renewal. Depending on which chromobox (CBX) protein (CBX2, CBX4, CBX6, CBX7, or CBX8) is part of the PRC1 complex, HSC fate decisions differ. Here, we review how this occurs. We describe how CBX proteins dictate age-related changes in HSCs and stimulate oncogenic HSC fate decisions, either as canonical PRC1 members or by alternative interactions, including non-epigenetic regulation. CBX2, CBX7, and CBX8 enhance leukemia progression. To target, reprogram, and kill leukemic cells, we suggest and describe multiple therapeutic strategies to interfere with the epigenetic functions of oncogenic CBX proteins. Future studies should clarify to what extent the non-epigenetic function of cytoplasmic CBX proteins is important for normal, aged, and leukemic blood cells.
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Affiliation(s)
- Anne P de Groot
- European Research Institute for Biology of Ageing (ERIBA), University Medical Center Groningen (UMCG), The Netherlands
- Sanquin Research, Landsteiner Laboratory, Sanquin Blood Supply, Amsterdam, The Netherlands
| | - Gerald de Haan
- European Research Institute for Biology of Ageing (ERIBA), University Medical Center Groningen (UMCG), The Netherlands
- Sanquin Research, Landsteiner Laboratory, Sanquin Blood Supply, Amsterdam, The Netherlands
- Department of Hematology, Amsterdam UMC, University of Amsterdam, The Netherlands
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2
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Hu H, Muntean AG. The YEATS domain epigenetic reader proteins ENL and AF9 and their therapeutic value in leukemia. Exp Hematol 2023; 124:15-21. [PMID: 37295550 PMCID: PMC10527611 DOI: 10.1016/j.exphem.2023.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 05/30/2023] [Accepted: 06/01/2023] [Indexed: 06/12/2023]
Abstract
Recent studies have uncovered similarities and differences between 2 highly homologous epigenetic reading proteins, namely, ENL (MLLT1) and AF9 (MLLT3) with therapeutic implications. The importance of these proteins has traditionally been exemplified by their involvement in chromosomal translocations with the mixed-lineage leukemia gene (MLL; aka KMT2a). MLL rearrangements occur in a subset of acute leukemias and generate potent oncogenic MLL-fusion proteins that impact epigenetic and transcriptional regulation. Leukemic patients with MLL rearrangements display intermediate-to-poor prognoses, necessitating further mechanistic research. Several protein complexes involved in regulating RNA polymerase II transcription and the epigenetic landscape are hijacked in MLL-r leukemia, which include ENL and AF9. Recent biochemical studies have defined a highly homologous YEATS domain in ENL and AF9 that binds acylated histones, which aids in the localization and retention of these proteins to transcriptional targets. In addition, detailed characterization of the homologous ANC-1 homology domain (AHD) on ENL and AF9 revealed differential association with transcriptional activating and repressing complexes. Importantly, CRISPR knockout screens have demonstrated a unique role for wild-type ENL in leukemic stem cell function, whereas AF9 appears important for normal hematopoietic stem cells. In this perspective, we examine the ENL and AF9 proteins with attention to recent work characterizing the epigenetic reading YEATS domains and AHD on both wild-type proteins and when fused to MLL. We summarized the drug development efforts and their therapeutic potential and assess ongoing research that has refined our understanding of how these proteins function, which continues to reveal new therapeutic avenues.
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Affiliation(s)
- Hsiangyu Hu
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI
| | - Andrew G Muntean
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI.
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3
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Li X, Yao Y, Wu F, Song Y. A proteolysis-targeting chimera molecule selectively degrades ENL and inhibits malignant gene expression and tumor growth. J Hematol Oncol 2022; 15:41. [PMID: 35395864 PMCID: PMC8994274 DOI: 10.1186/s13045-022-01258-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 03/18/2022] [Indexed: 02/07/2023] Open
Abstract
Background Chromosome translocations involving mixed lineage leukemia 1 (MLL1) cause acute leukemia in most infants and 5–10% children/adults with dismal clinical outcomes. Most frequent MLL1-fusion partners AF4/AFF4, AF9/ENL and ELL, together with CDK9/cyclin-T1, constitute super elongation complexes (SEC), which promote aberrant gene transcription, oncogenesis and maintenance of MLL1-rearranged (MLL1-r) leukemia. Notably, ENL, but not its paralog AF9, is essential for MLL1-r leukemia (and several other cancers) and therefore a drug target. Moreover, recurrent ENL mutations are found in Wilms tumor, the most common pediatric kidney cancer, and play critical roles in oncogenesis. Methods Proteolysis-Targeting Chimera (PROTAC) molecules were designed and synthesized to degrade ENL. Biological activities of these compounds were characterized in cell and mouse models of MLL1-r leukemia and other cancers. Results Compound 1 efficiently degraded ENL with DC50 of 37 nM and almost depleted it at ~ 500 nM in blood and solid tumor cells. AF9 (as well as other proteins in SEC) was not significantly decreased. Compound 1-mediated ENL reduction significantly suppressed malignant gene signatures, selectively inhibited cell proliferation of MLL1-r leukemia and Myc-driven cancer cells with EC50s as low as 320 nM, and induced cell differentiation and apoptosis. It exhibited significant antitumor activity in a mouse model of MLL1-r leukemia. Compound 1 can also degrade a mutant ENL in Wilms tumor and suppress its mediated gene transcription. Conclusion Compound 1 is a novel chemical probe for cellular and in vivo studies of ENL (including its oncogenic mutants) and a lead compound for further anticancer drug development. Supplementary Information The online version contains supplementary material available at 10.1186/s13045-022-01258-8.
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Affiliation(s)
- Xin Li
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX, 77030, USA
| | - Yuan Yao
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX, 77030, USA
| | - Fangrui Wu
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX, 77030, USA
| | - Yongcheng Song
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX, 77030, USA. .,Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX, 77030, USA.
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4
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Yeewa R, Chaiya P, Jantrapirom S, Shotelersuk V, Lo Piccolo L. Multifaceted roles of YEATS domain-containing proteins and novel links to neurological diseases. Cell Mol Life Sci 2022; 79:183. [PMID: 35279775 PMCID: PMC11071958 DOI: 10.1007/s00018-022-04218-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 02/17/2022] [Accepted: 02/22/2022] [Indexed: 11/29/2022]
Abstract
The so-called Yaf9, ENL, AF9, Taf14, and Sas5 (YEATS) domain-containing proteins, hereafter referred to as YD proteins, take control over the transcription by multiple steps of regulation either involving epigenetic remodelling of chromatin or guiding the processivity of RNA polymerase II to facilitate elongation-coupled mRNA 3' processing. Interestingly, an increasing amount of evidence suggest a wider repertoire of YD protein's functions spanning from non-coding RNA regulation, RNA-binding proteins networking, post-translational regulation of a few signalling transduction proteins and the spindle pole formation. However, such a large set of non-canonical roles is still poorly characterized. Notably, four paralogous of human YEATS domain family members, namely eleven-nineteen-leukaemia (ENL), ALL1-fused gene from chromosome 9 protein (AF9), YEATS2 and glioma amplified sequence 41 (GAS41), have a strong link to cancer yet new findings also highlight a potential novel role in neurological diseases. Here, in an attempt to more comprehensively understand the complexity of four YD proteins and to gain more insight into the novel functions they may accomplish in the neurons, we summarized the YD protein's networks, systematically searched and reviewed the YD genetic variants associated with neurodevelopmental disorders and finally interrogated the model organism Drosophila melanogaster.
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Affiliation(s)
- Ranchana Yeewa
- Centre of Multidisciplinary Technology for Advanced Medicine (CMUTEAM), Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200, Thailand
| | - Pawita Chaiya
- Centre of Multidisciplinary Technology for Advanced Medicine (CMUTEAM), Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200, Thailand
| | - Salinee Jantrapirom
- Drosophila Centre for Human Diseases and Drug Discovery (DHD), Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200, Thailand
- Department of Pharmacology, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200, Thailand
| | - Vorasuk Shotelersuk
- Centre of Excellence for Medical Genomics, Medical Genomics Cluster, Department of Paediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, 10330, Thailand
- Excellence Centre for Genomics and Precision Medicine, The Thai Red Cross Society, King Chulalongkorn Memorial Hospital, Bangkok, 10330, Thailand
| | - Luca Lo Piccolo
- Centre of Multidisciplinary Technology for Advanced Medicine (CMUTEAM), Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200, Thailand.
- Musculoskeletal Science and Translational Research Centre (MSTR), Faculty of Medicine, Chiang Mai University, Muang, Chiang Mai, 50200, Thailand.
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5
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Wang S, C Ordonez-Rubiano S, Dhiman A, Jiao G, Strohmier BP, Krusemark CJ, Dykhuizen EC. Polycomb group proteins in cancer: multifaceted functions and strategies for modulation. NAR Cancer 2021; 3:zcab039. [PMID: 34617019 PMCID: PMC8489530 DOI: 10.1093/narcan/zcab039] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 08/24/2021] [Accepted: 09/10/2021] [Indexed: 12/12/2022] Open
Abstract
Polycomb repressive complexes (PRCs) are a heterogenous collection of dozens, if not hundreds, of protein complexes composed of various combinations of subunits. PRCs are transcriptional repressors important for cell-type specificity during development, and as such, are commonly mis-regulated in cancer. PRCs are broadly characterized as PRC1 with histone ubiquitin ligase activity, or PRC2 with histone methyltransferase activity; however, the mechanism by which individual PRCs, particularly the highly diverse set of PRC1s, alter gene expression has not always been clear. Here we review the current understanding of how PRCs act, both individually and together, to establish and maintain gene repression, the biochemical contribution of individual PRC subunits, the mis-regulation of PRC function in different cancers, and the current strategies for modulating PRC activity. Increased mechanistic understanding of PRC function, as well as cancer-specific roles for individual PRC subunits, will uncover better targets and strategies for cancer therapies.
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Affiliation(s)
- Sijie Wang
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University and Purdue University Center for Cancer Research, 201 S. University St., West Lafayette, IN 47907 USA
| | - Sandra C Ordonez-Rubiano
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University and Purdue University Center for Cancer Research, 201 S. University St., West Lafayette, IN 47907 USA
| | - Alisha Dhiman
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University and Purdue University Center for Cancer Research, 201 S. University St., West Lafayette, IN 47907 USA
| | - Guanming Jiao
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University and Purdue University Center for Cancer Research, 201 S. University St., West Lafayette, IN 47907 USA
| | - Brayden P Strohmier
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University and Purdue University Center for Cancer Research, 201 S. University St., West Lafayette, IN 47907 USA
| | - Casey J Krusemark
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University and Purdue University Center for Cancer Research, 201 S. University St., West Lafayette, IN 47907 USA
| | - Emily C Dykhuizen
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University and Purdue University Center for Cancer Research, 201 S. University St., West Lafayette, IN 47907 USA
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6
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Tip60 activates Hoxa9 and Meis1 expression through acetylation of H2A.Z, promoting MLL-AF10 and MLL-ENL acute myeloid leukemia. Leukemia 2021; 35:2840-2853. [PMID: 33967269 DOI: 10.1038/s41375-021-01244-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 02/15/2021] [Accepted: 03/26/2021] [Indexed: 02/06/2023]
Abstract
Chromosome translocations involving the MLL gene are common rearrangements in leukemia. Such translocations fuse the MLL 5'-region to partner genes in frame, producing MLL-fusions that cause MLL-related leukemia. MLL-fusions activate transcription of target genes such as HoxA cluster and Meis1, but the underlying mechanisms remain to be fully elucidated. In this study, we discovered that Tip60, a MYST-type histone acetyltransferase, was required for the expression of HoxA cluster and Meis1 genes and the development of MLL-fusion leukemia. Tip60 was recruited by MLL-AF10 and MLL-ENL fusions to the Hoxa9 locus, where it acetylated H2A.Z, thereby promoting Hoxa9 gene expression. Conditional deletion of Tip60 prevented the development of MLL-AF10 and MLL-ENL leukemia, indicating that Tip60 is indispensable for the leukemogenic activity of the MLL-AF10 and MLL-ENL-fusions. Our findings provide novel insight about epigenetic regulation in the development of MLL-AF10 and MLL-ENL-fusion leukemia.
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7
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Zeisig BB, So CWE. Therapeutic Opportunities of Targeting Canonical and Noncanonical PcG/TrxG Functions in Acute Myeloid Leukemia. Annu Rev Genomics Hum Genet 2021; 22:103-125. [PMID: 33929894 DOI: 10.1146/annurev-genom-111120-102443] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Transcriptional deregulation is a key driver of acute myeloid leukemia (AML), a heterogeneous blood cancer with poor survival rates. Polycomb group (PcG) and Trithorax group (TrxG) genes, originally identified in Drosophila melanogaster several decades ago as master regulators of cellular identity and epigenetic memory, not only are important in mammalian development but also play a key role in AML disease biology. In addition to their classical canonical antagonistic transcriptional functions, noncanonical synergistic and nontranscriptional functions of PcG and TrxG are emerging. Here, we review the biochemical properties of major mammalian PcG and TrxG complexes and their roles in AML disease biology, including disease maintenance as well as drug resistance. We summarize current efforts on targeting PcG and TrxG for treatment of AML and propose rational synthetic lethality and drug-induced antagonistic pleiotropy options involving PcG and TrxG as potential new therapeutic avenues for treatment of AML.
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Affiliation(s)
- Bernd B Zeisig
- Leukaemia and Stem Cell Biology Group, School of Cancer and Pharmaceutical Sciences, King's College London, London SE5 9NU, United Kingdom;
- Department of Haematological Medicine, King's College Hospital, London SE5 9RS, United Kingdom
| | - Chi Wai Eric So
- Leukaemia and Stem Cell Biology Group, School of Cancer and Pharmaceutical Sciences, King's College London, London SE5 9NU, United Kingdom;
- Department of Haematological Medicine, King's College Hospital, London SE5 9RS, United Kingdom
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8
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Wu F, Nie S, Yao Y, Huo T, Li X, Wu X, Zhao J, Lin YL, Zhang Y, Mo Q, Song Y. Small-molecule inhibitor of AF9/ENL-DOT1L/AF4/AFF4 interactions suppresses malignant gene expression and tumor growth. Theranostics 2021; 11:8172-8184. [PMID: 34373735 PMCID: PMC8344022 DOI: 10.7150/thno.56737] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 06/28/2021] [Indexed: 01/22/2023] Open
Abstract
Chromosome translocations involving mixed lineage leukemia (MLL) gene cause acute leukemia with a poor prognosis. MLL is frequently fused with transcription cofactors AF4 (~35%), AF9 (25%) or its paralog ENL (10%). The AHD domain of AF9/ENL binds to AF4, its paralog AFF4, or histone-H3 lysine-79 (H3K79) methyltransferase DOT1L. Formation of AF9/ENL/AF4/AFF4-containing super elongation complexes (SEC) and the catalytic activity of DOT1L are essential for MLL-rearranged leukemia. Protein-protein interactions (PPI) between AF9/ENL and DOT1L/AF4/AFF4 are therefore a potential drug target. Methods: Compound screening followed by medicinal chemistry was used to find inhibitors of such PPIs, which were examined for their biological activities against MLL-rearranged leukemia and other cancer cells. Results: Compound-1 was identified to be a novel small-molecule inhibitor of the AF9/ENL-DOT1L/AF4/AFF4 interaction with IC50s of 0.9-3.5 µM. Pharmacological inhibition of the PPIs significantly reduced SEC and DOT1L-mediated H3K79 methylation in the leukemia cells. Gene profiling shows compound-1 significantly suppressed the gene signatures related to onco-MLL, DOT1L, HoxA9 and Myc. It selectively inhibited proliferation of onco-MLL- or Myc-driven cancer cells and induced cell differentiation and apoptosis. Compound-1 exhibited strong antitumor activity in a mouse model of MLL-rearranged leukemia. Conclusions: The AF9/ENL-DOT1L/AF4/AFF4 interactions are validated to be an anticancer target and compound-1 is a useful in vivo probe for biological studies as well as a pharmacological lead for further drug development.
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9
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Anshabo AT, Milne R, Wang S, Albrecht H. CDK9: A Comprehensive Review of Its Biology, and Its Role as a Potential Target for Anti-Cancer Agents. Front Oncol 2021; 11:678559. [PMID: 34041038 PMCID: PMC8143439 DOI: 10.3389/fonc.2021.678559] [Citation(s) in RCA: 74] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 04/16/2021] [Indexed: 12/25/2022] Open
Abstract
Cyclin-dependent kinases (CDKs) are proteins pivotal to a wide range of cellular functions, most importantly cell division and transcription, and their dysregulations have been implicated as prominent drivers of tumorigenesis. Besides the well-established role of cell cycle CDKs in cancer, the involvement of transcriptional CDKs has been confirmed more recently. Most cancers overtly employ CDKs that serve as key regulators of transcription (e.g., CDK9) for a continuous production of short-lived gene products that maintain their survival. As such, dysregulation of the CDK9 pathway has been observed in various hematological and solid malignancies, making it a valuable anticancer target. This therapeutic potential has been utilized for the discovery of CDK9 inhibitors, some of which have entered human clinical trials. This review provides a comprehensive discussion on the structure and biology of CDK9, its role in solid and hematological cancers, and an updated review of the available inhibitors currently being investigated in preclinical and clinical settings.
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Affiliation(s)
- Abel Tesfaye Anshabo
- Drug Discovery and Development, Centre for Cancer Diagnostics and Therapeutics, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Robert Milne
- Drug Discovery and Development, Centre for Cancer Diagnostics and Therapeutics, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Shudong Wang
- Drug Discovery and Development, Centre for Cancer Diagnostics and Therapeutics, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Hugo Albrecht
- Drug Discovery and Development, Centre for Cancer Diagnostics and Therapeutics, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
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10
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Li X, Song Y. Structure, function and inhibition of critical protein-protein interactions involving mixed lineage leukemia 1 and its fusion oncoproteins. J Hematol Oncol 2021; 14:56. [PMID: 33823889 PMCID: PMC8022399 DOI: 10.1186/s13045-021-01057-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 03/05/2021] [Indexed: 12/13/2022] Open
Abstract
Mixed lineage leukemia 1 (MLL1, also known as MLL or KMT2A) is an important transcription factor and histone-H3 lysine-4 (H3K4) methyltransferase. It is a master regulator for transcription of important genes (e.g., Hox genes) for embryonic development and hematopoiesis. However, it is largely dispensable in matured cells. Dysregulation of MLL1 leads to overexpression of certain Hox genes and eventually leukemia initiation. Chromosome translocations involving MLL1 cause ~ 75% of acute leukemia in infants and 5–10% in children and adults with a poor prognosis. Targeted therapeutics against oncogenic fusion MLL1 (onco-MLL1) are therefore needed. Onco-MLL1 consists of the N-terminal DNA-interacting domains of MLL1 fused with one of > 70 fusion partners, among which transcription cofactors AF4, AF9 and its paralog ENL, and ELL are the most frequent. Wild-type (WT)- and onco-MLL1 involve numerous protein–protein interactions (PPI), which play critical roles in regulating gene expression in normal physiology and leukemia. Moreover, WT-MLL1 has been found to be essential for MLL1-rearranged (MLL1-r) leukemia. Rigorous studies of such PPIs have been performed and much progress has been achieved in understanding their structures, structure–function relationships and the mechanisms for activating gene transcription as well as leukemic transformation. Inhibition of several critical PPIs by peptides, peptidomimetic or small-molecule compounds has been explored as a therapeutic approach for MLL1-r leukemia. This review summarizes the biological functions, biochemistry, structure and inhibition of the critical PPIs involving MLL1 and its fusion partner proteins. In addition, challenges and perspectives of drug discovery targeting these PPIs for the treatment of MLL1-r leukemia are discussed.
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Affiliation(s)
- Xin Li
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX, 77030, USA
| | - Yongcheng Song
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX, 77030, USA. .,Dan L. Duncan Comprehensive Cancer Center, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX, 77030, USA.
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11
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Automated CUT&Tag profiling of chromatin heterogeneity in mixed-lineage leukemia. Nat Genet 2021; 53:1586-1596. [PMID: 34663924 PMCID: PMC8571097 DOI: 10.1038/s41588-021-00941-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 08/12/2021] [Indexed: 11/10/2022]
Abstract
Acute myeloid and lymphoid leukemias often harbor chromosomal translocations involving the KMT2A gene, encoding the KMT2A lysine methyltransferase (also known as mixed-lineage leukemia-1), and produce in-frame fusions of KMT2A to other chromatin-regulatory proteins. Here we map fusion-specific targets across the genome for diverse KMT2A oncofusion proteins in cell lines and patient samples. By modifying CUT&Tag chromatin profiling for full automation, we identify common and tumor-subtype-specific sites of aberrant chromatin regulation induced by KMT2A oncofusion proteins. A subset of KMT2A oncofusion-binding sites are marked by bivalent (H3K4me3 and H3K27me3) chromatin signatures, and single-cell CUT&Tag profiling reveals that these sites display cell-to-cell heterogeneity suggestive of lineage plasticity. In addition, we find that aberrant enrichment of H3K4me3 in gene bodies is sensitive to Menin inhibitors, demonstrating the utility of automated chromatin profiling for identifying therapeutic vulnerabilities. Thus, integration of automated and single-cell CUT&Tag can uncover epigenomic heterogeneity within patient samples and predict sensitivity to therapeutic agents.
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12
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Schmidt CR, Achille NJ, Kuntimaddi A, Boulton AM, Leach BI, Zhang S, Zeleznik-Le NJ, Bushweller JH. BCOR Binding to MLL-AF9 Is Essential for Leukemia via Altered EYA1, SIX, and MYC Activity. Blood Cancer Discov 2020; 1:162-177. [PMID: 32954361 DOI: 10.1158/2643-3230.bcd-20-0036] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
MLL is a target of chromosomal translocations in acute leukemias with poor prognosis. The common MLL fusion partner AF9 (MLLT3) can directly bind to AF4, DOT1L, BCOR, and CBX8. To delineate the relevance of BCOR and CBX8 binding to MLL-AF9 for leukemogenesis, here we determine protein structures of AF9 complexes with CBX8 and BCOR, and show that binding of all four partners to AF9 is mutually exclusive. Using the structural analyses, we identify point mutations that selectively disrupt AF9 interactions with BCOR and CBX8. In bone marrow stem/progenitor cells expressing point mutant CBX8 or point mutant MLL-AF9, we show that disruption of direct CBX8/MLL-AF9 binding does not impact in vitro cell proliferation, whereas loss of direct BCOR/MLL-AF9 binding causes partial differentiation and increased proliferation. Strikingly, loss of MLL-AF9/BCOR binding abrogated its leukemogenic potential in a mouse model. The MLL-AF9 mutant deficient for BCOR binding reduces the expression of the EYA1 phosphatase and the protein level of c-Myc. Reduction in BCOR binding to MLL-AF9 alters a MYC-driven gene expression program, as well as altering expression of SIX-regulated genes, likely contributing to the observed reduction in the leukemia-initiating cell population.
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Affiliation(s)
- Charles R Schmidt
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia
| | - Nicholas J Achille
- Department of Cancer Biology, Loyola University Chicago, Maywood, Illinois
| | - Aravinda Kuntimaddi
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia
| | - Adam M Boulton
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia
| | - Benjamin I Leach
- Department of Cancer Biology, Loyola University Chicago, Maywood, Illinois
| | - Shubin Zhang
- Department of Cancer Biology, Loyola University Chicago, Maywood, Illinois
| | - Nancy J Zeleznik-Le
- Department of Cancer Biology, Loyola University Chicago, Maywood, Illinois.
- Department of Medicine, Loyola University Chicago, Maywood, Illinois
| | - John H Bushweller
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia.
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13
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Takahashi S, Yokoyama A. The molecular functions of common and atypical MLL fusion protein complexes. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2020; 1863:194548. [PMID: 32320750 DOI: 10.1016/j.bbagrm.2020.194548] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 02/19/2020] [Accepted: 03/31/2020] [Indexed: 12/17/2022]
Abstract
Mixed-lineage leukemia (MLL) fuses with a variety of partners to produce a functionally altered MLL complex that is not expressed in normal cells, which transforms normal hematopoietic progenitors into leukemia cells. Because more than 80 fusion partners have been identified to date, the molecular functions of MLL fusion protein complexes appear diverse. However, over the past decade, the common functions utilized for leukemic transformation have begun to be elucidated. It appears that most (if not all) MLL fusion protein complexes utilize the AF4/ENL/P-TEFb and DOT1L complexes to some extent. Based on an understanding of the underlying molecular mechanisms, several molecular targeting drugs are being developed, opening paths to novel therapies. Here, we review the recent progress made in identifying the molecular functions of various MLL fusions and categorize the numerous fusion partners into several functionally-distinct groups to help discern commonalities and differences among various MLL fusion protein complexes.
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Affiliation(s)
- Satoshi Takahashi
- Tsuruoka Metabolomics Laboratory, National Cancer Center, Tsuruoka, Japan; Department of Hematology and Oncology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Akihiko Yokoyama
- Tsuruoka Metabolomics Laboratory, National Cancer Center, Tsuruoka, Japan; National Cancer Center Research Institute, Tokyo, Japan.
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14
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Slany RK. MLL fusion proteins and transcriptional control. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2020; 1863:194503. [PMID: 32061883 DOI: 10.1016/j.bbagrm.2020.194503] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 12/17/2019] [Accepted: 02/11/2020] [Indexed: 12/20/2022]
Abstract
The highly leukemogenic MLL fusion proteins have a unique mechanism of action. This review summarizes the current knowledge of how MLL fusions interact with the transcriptional machinery and it proposes a hypothesis how these proteins modify transcriptional control to act as transcriptional amplifiers causing runaway production of certain RNAs that transform hematopoietic cells.
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Affiliation(s)
- Robert K Slany
- Department of Genetics, Friedrich-Alexander-University Erlangen-Nürnberg, Germany.
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15
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Shokouhian M, Bagheri M, Poopak B, Chegeni R, Davari N, Saki N. Altering chromatin methylation patterns and the transcriptional network involved in regulation of hematopoietic stem cell fate. J Cell Physiol 2020; 235:6404-6423. [PMID: 32052445 DOI: 10.1002/jcp.29642] [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] [Received: 08/14/2019] [Accepted: 01/31/2020] [Indexed: 12/15/2022]
Abstract
Hematopoietic stem cells (HSCs) are quiescent cells with self-renewal capacity and potential multilineage development. Various molecular regulatory mechanisms such as epigenetic modifications and transcription factor (TF) networks play crucial roles in establishing a balance between self-renewal and differentiation of HSCs. Histone/DNA methylations are important epigenetic modifications involved in transcriptional regulation of specific lineage HSCs via controlling chromatin structure and accessibility of DNA. Also, TFs contribute to either facilitation or inhibition of gene expression through binding to enhancer or promoter regions of DNA. As a result, epigenetic factors and TFs regulate the activation or repression of HSCs genes, playing a central role in normal hematopoiesis. Given the importance of histone/DNA methylation and TFs in gene expression regulation, their aberrations, including changes in HSCs-related methylation of histone/DNA and TFs (e.g., CCAAT-enhancer-binding protein α, phosphatase and tensin homolog deleted on the chromosome 10, Runt-related transcription factor 1, signal transducers and activators of transcription, and RAS family proteins) could disrupt HSCs fate. Herewith, we summarize how dysregulations in the expression of genes related to self-renewal, proliferation, and differentiation of HSCs caused by changes in epigenetic modifications and transcriptional networks lead to clonal expansion and leukemic transformation.
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Affiliation(s)
- Mohammad Shokouhian
- Department of Hematology and Blood Transfusion, School of Allied Medical Sciences, Iran University of Medical Sciences, Tehran, Iran
| | - Marziye Bagheri
- Thalassemia and Hemoglobinopathy Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Behzad Poopak
- Department of Hematology, Faculty of Paramedical Sciences, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Rouzbeh Chegeni
- Michener Institute of Education at University Health Network, Toronto, Canada
| | - Nader Davari
- Thalassemia and Hemoglobinopathy Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Najmaldin Saki
- Thalassemia and Hemoglobinopathy Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
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16
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Wang S, Denton KE, Hobbs KF, Weaver T, McFarlane JMB, Connelly KE, Gignac MC, Milosevich N, Hof F, Paci I, Musselman CA, Dykhuizen EC, Krusemark CJ. Optimization of Ligands Using Focused DNA-Encoded Libraries To Develop a Selective, Cell-Permeable CBX8 Chromodomain Inhibitor. ACS Chem Biol 2020; 15:112-131. [PMID: 31755685 DOI: 10.1021/acschembio.9b00654] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Polycomb repressive complex 1 (PRC1) is critical for mediating gene expression during development. Five chromobox (CBX) homolog proteins, CBX2, CBX4, CBX6, CBX7, and CBX8, are incorporated into PRC1 complexes, where they mediate targeting to trimethylated lysine 27 of histone H3 (H3K27me3) via the N-terminal chromodomain (ChD). Individual CBX paralogs have been implicated as drug targets in cancer; however, high similarities in sequence and structure among the CBX ChDs provide a major obstacle in developing selective CBX ChD inhibitors. Here we report the selection of small, focused, DNA-encoded libraries (DELs) against multiple homologous ChDs to identify modifications to a parental ligand that confer both selectivity and potency for the ChD of CBX8. This on-DNA, medicinal chemistry approach enabled the development of SW2_110A, a selective, cell-permeable inhibitor of the CBX8 ChD. SW2_110A binds CBX8 ChD with a Kd of 800 nM, with minimal 5-fold selectivity for CBX8 ChD over all other CBX paralogs in vitro. SW2_110A specifically inhibits the association of CBX8 with chromatin in cells and inhibits the proliferation of THP1 leukemia cells driven by the MLL-AF9 translocation. In THP1 cells, SW2_110A treatment results in a significant decrease in the expression of MLL-AF9 target genes, including HOXA9, validating the previously established role for CBX8 in MLL-AF9 transcriptional activation, and defining the ChD as necessary for this function. The success of SW2_110A provides great promise for the development of highly selective and cell-permeable probes for the full CBX family. In addition, the approach taken provides a proof-of-principle demonstration of how DELs can be used iteratively for optimization of both ligand potency and selectivity.
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Affiliation(s)
- Sijie Wang
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University and Purdue University Center for Cancer Research, 575 Stadium Mall Drive, West Lafayette, Indiana 47906, United States
| | - Kyle E. Denton
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University and Purdue University Center for Cancer Research, 575 Stadium Mall Drive, West Lafayette, Indiana 47906, United States
| | - Kathryn F. Hobbs
- Department of Biochemistry, Carver College of Medicine, University of Iowa, 51 Newton Road, Iowa City, Iowa 52242, United States
| | - Tyler Weaver
- Department of Biochemistry, Carver College of Medicine, University of Iowa, 51 Newton Road, Iowa City, Iowa 52242, United States
| | | | - Katelyn E. Connelly
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University and Purdue University Center for Cancer Research, 575 Stadium Mall Drive, West Lafayette, Indiana 47906, United States
| | - Michael C. Gignac
- Department of Chemistry, University of Victoria, Victoria V8W 3V6, Canada
| | - Natalia Milosevich
- Department of Chemistry, University of Victoria, Victoria V8W 3V6, Canada
| | - Fraser Hof
- Department of Chemistry, University of Victoria, Victoria V8W 3V6, Canada
| | - Irina Paci
- Department of Chemistry, University of Victoria, Victoria V8W 3V6, Canada
| | - Catherine A. Musselman
- Department of Biochemistry, Carver College of Medicine, University of Iowa, 51 Newton Road, Iowa City, Iowa 52242, United States
| | - Emily C. Dykhuizen
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University and Purdue University Center for Cancer Research, 575 Stadium Mall Drive, West Lafayette, Indiana 47906, United States
| | - Casey J. Krusemark
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University and Purdue University Center for Cancer Research, 575 Stadium Mall Drive, West Lafayette, Indiana 47906, United States
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17
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Welte T, Tuck AC, Papasaikas P, Carl SH, Flemr M, Knuckles P, Rankova A, Bühler M, Großhans H. The RNA hairpin binder TRIM71 modulates alternative splicing by repressing MBNL1. Genes Dev 2019; 33:1221-1235. [PMID: 31371437 PMCID: PMC6719626 DOI: 10.1101/gad.328492.119] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 06/19/2019] [Indexed: 01/19/2023]
Abstract
In this study, Welte et al. investigated the dual roles of mammalian TRIM71, a phylogenetically conserved regulator of development, in the control of stem cell fate. They demonstrate that TRIM71 shapes the transcriptome of mESCs predominantly through its RNA-binding activity and identify a set of primary targets consistently regulated in various human and mouse cell lines, including MBNL1/Muscleblind. TRIM71/LIN-41, a phylogenetically conserved regulator of development, controls stem cell fates. Mammalian TRIM71 exhibits both RNA-binding and protein ubiquitylation activities, but the functional contribution of either activity and relevant primary targets remain poorly understood. Here, we demonstrate that TRIM71 shapes the transcriptome of mouse embryonic stem cells (mESCs) predominantly through its RNA-binding activity. We reveal that TRIM71 binds targets through 3′ untranslated region (UTR) hairpin motifs and that it acts predominantly by target degradation. TRIM71 mutations implicated in etiogenesis of human congenital hydrocephalus impair target silencing. We identify a set of primary targets consistently regulated in various human and mouse cell lines, including MBNL1 (Muscleblind-like protein 1). MBNL1 promotes cell differentiation through regulation of alternative splicing, and we demonstrate that TRIM71 promotes embryonic splicing patterns through MBNL1 repression. Hence, repression of MBNL1-dependent alternative splicing may contribute to TRIM71's function in regulating stem cell fates.
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Affiliation(s)
- Thomas Welte
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland
| | - Alex C Tuck
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland
| | - Panagiotis Papasaikas
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland.,Swiss Institute of Bioinformatics, 4058 Basel, Switzerland.,These authors contributed equally to this work
| | - Sarah H Carl
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland.,Swiss Institute of Bioinformatics, 4058 Basel, Switzerland.,These authors contributed equally to this work
| | - Matyas Flemr
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland
| | - Philip Knuckles
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland
| | - Aneliya Rankova
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland.,University of Basel, 4056 Basel, Switzerland
| | - Marc Bühler
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland.,University of Basel, 4056 Basel, Switzerland
| | - Helge Großhans
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland.,University of Basel, 4056 Basel, Switzerland
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18
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Xu X, Schneider B. Therapeutic targeting potential of chromatin-associated proteins in MLL-rearranged acute leukemia. Cell Oncol (Dordr) 2018; 42:117-130. [DOI: 10.1007/s13402-018-0414-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/08/2018] [Indexed: 02/07/2023] Open
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19
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Zhou J, Ng Y, Chng WJ. ENL: structure, function, and roles in hematopoiesis and acute myeloid leukemia. Cell Mol Life Sci 2018; 75:3931-3941. [PMID: 30066088 PMCID: PMC11105289 DOI: 10.1007/s00018-018-2895-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2018] [Revised: 07/16/2018] [Accepted: 07/27/2018] [Indexed: 01/09/2023]
Abstract
ENL/MLLT1 is a distinctive member of the KMT2 family based on its structural homology. ENL is a histone acetylation reader and a critical component of the super elongation complex. ENL plays pivotal roles in the regulation of chromatin remodelling and gene expression of many important proto-oncogenes, such as Myc, Hox genes, via histone acetylation. Novel insights of the key role of the YEATS domain of ENL in the transcriptional control of leukemogenic gene expression has emerged from whole genome Crisp-cas9 studies in acute myeloid leukemia (AML). In this review, we have summarized what is currently known about the structure and function of the ENL molecule. We described the ENL's role in normal hematopoiesis, and leukemogenesis. We have also outlined the detailed molecular mechanisms underlying the regulation of target gene expression by ENL, as well as its major interacting partners and complexes involved. Finally, we discuss the emerging knowledge of different approaches for the validation of ENL as a therapeutic target and the development of small-molecule inhibitors disrupting the YEATS reader pocket of ENL protein, which holds great promise for the treatment of AML. This review will not only provide a fundamental understanding of the structure and function of ENL and update on the roles of ENL in AML, but also the development of new therapeutic strategies.
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Affiliation(s)
- Jianbiao Zhou
- Cancer Science Institute of Singapore, Centre for Translational Medicine, National University of Singapore, 14 Medical Drive, Singapore, 117599, Republic of Singapore.
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Republic of Singapore.
| | - Yvonne Ng
- Cancer Science Institute of Singapore, Centre for Translational Medicine, National University of Singapore, 14 Medical Drive, Singapore, 117599, Republic of Singapore
| | - Wee-Joo Chng
- Cancer Science Institute of Singapore, Centre for Translational Medicine, National University of Singapore, 14 Medical Drive, Singapore, 117599, Republic of Singapore.
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Republic of Singapore.
- Department of Hematology-Oncology, National University Cancer Institute of Singapore (NCIS), The National University Health System (NUHS), 1E, Kent Ridge Road, Singapore, 119228, Republic of Singapore.
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20
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Skucha A, Ebner J, Schmöllerl J, Roth M, Eder T, César-Razquin A, Stukalov A, Vittori S, Muhar M, Lu B, Aichinger M, Jude J, Müller AC, Győrffy B, Vakoc CR, Valent P, Bennett KL, Zuber J, Superti-Furga G, Grebien F. MLL-fusion-driven leukemia requires SETD2 to safeguard genomic integrity. Nat Commun 2018; 9:1983. [PMID: 29777171 PMCID: PMC5959866 DOI: 10.1038/s41467-018-04329-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 04/23/2018] [Indexed: 12/21/2022] Open
Abstract
MLL-fusions represent a large group of leukemia drivers, whose diversity originates from the vast molecular heterogeneity of C-terminal fusion partners of MLL. While studies of selected MLL-fusions have revealed critical molecular pathways, unifying mechanisms across all MLL-fusions remain poorly understood. We present the first comprehensive survey of protein-protein interactions of seven distantly related MLL-fusion proteins. Functional investigation of 128 conserved MLL-fusion-interactors identifies a specific role for the lysine methyltransferase SETD2 in MLL-leukemia. SETD2 loss causes growth arrest and differentiation of AML cells, and leads to increased DNA damage. In addition to its role in H3K36 tri-methylation, SETD2 is required to maintain high H3K79 di-methylation and MLL-AF9-binding to critical target genes, such as Hoxa9. SETD2 loss synergizes with pharmacologic inhibition of the H3K79 methyltransferase DOT1L to induce DNA damage, growth arrest, differentiation, and apoptosis. These results uncover a dependency for SETD2 during MLL-leukemogenesis, revealing a novel actionable vulnerability in this disease.
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Affiliation(s)
- Anna Skucha
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, 1090, Austria
- Ludwig Boltzmann Institute for Cancer Research, Vienna, 1090, Austria
| | - Jessica Ebner
- Ludwig Boltzmann Institute for Cancer Research, Vienna, 1090, Austria
| | | | - Mareike Roth
- Research Institute of Molecular Pathology, Vienna, 1030, Austria
| | - Thomas Eder
- Ludwig Boltzmann Institute for Cancer Research, Vienna, 1090, Austria
| | - Adrián César-Razquin
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, 1090, Austria
| | - Alexey Stukalov
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, 1090, Austria
| | - Sarah Vittori
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, 1090, Austria
| | - Matthias Muhar
- Research Institute of Molecular Pathology, Vienna, 1030, Austria
| | - Bin Lu
- Cold Spring Harbor Larboratory, Cold Spring Harbor, 11724, NY, USA
| | - Martin Aichinger
- Research Institute of Molecular Pathology, Vienna, 1030, Austria
| | - Julian Jude
- Research Institute of Molecular Pathology, Vienna, 1030, Austria
| | - André C Müller
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, 1090, Austria
| | - Balázs Győrffy
- MTA TTK Lendület Cancer Biomarker Research Group, Institute of Enzymology, Second Department of Pediatrics, Semmelweis University, Budapest, 1094, Hungary
| | | | - Peter Valent
- Department of Internal Medicine I. Division of Hematology and Hemostaseology, Ludwig Boltzmann Cluster Oncology, Medical University of Vienna, Vienna, 1090, Austria
| | - Keiryn L Bennett
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, 1090, Austria
| | - Johannes Zuber
- Research Institute of Molecular Pathology, Vienna, 1030, Austria
| | - Giulio Superti-Furga
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, 1090, Austria
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, 1090, Austria
| | - Florian Grebien
- Ludwig Boltzmann Institute for Cancer Research, Vienna, 1090, Austria.
- Institute for Medical Biochemistry, University of Veterinary Medicine, Vienna, 1210, Austria.
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21
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Nakada D. ENLightening YEATS in antagonizing polycomb repression. Blood 2018; 131:591. [PMID: 29438969 PMCID: PMC5805493 DOI: 10.1182/blood-2017-12-821553] [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: 11/20/2022] Open
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22
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The interaction of ENL with PAF1 mitigates polycomb silencing and facilitates murine leukemogenesis. Blood 2017; 131:662-673. [PMID: 29217648 DOI: 10.1182/blood-2017-11-815035] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 12/01/2017] [Indexed: 12/21/2022] Open
Abstract
Eleven-nineteen leukemia (ENL) is a chromatin reader present in complexes stimulating transcriptional elongation. It is fused to mixed-lineage leukemia (MLL) in leukemia, and missense mutations have been identified in Wilms tumor and acute myeloid leukemia. Here we demonstrate that ENL overcomes polycomb silencing through recruitment of PAF1 via the conserved YEATS domain, which recognizes acetylated histone H3. PAF1 was responsible for antirepressive activities of ENL in vitro, and it determined the transforming potential of MLL-ENL. MLL-ENL target loci showed supraphysiological PAF1 binding, hyperubiquitination of histone H2B and hypomodification with H2AUb, resulting in accelerated transcription rates. YEATS mutations induced a gain of function, transforming primary hematopoietic cells in vitro and in transplantation assays through aberrant transcription and H2B ubiquitination of Hoxa9 and Meis1 Mechanistically, H3 and PAF1 competed for ENL interaction, with activating mutations favoring PAF1 binding, whereas the MLL moiety provided a constitutive PAF1 tether allowing MLL fusions to circumvent H3 competition.
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23
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Evolution of AF6-RAS association and its implications in mixed-lineage leukemia. Nat Commun 2017; 8:1099. [PMID: 29062045 PMCID: PMC5653649 DOI: 10.1038/s41467-017-01326-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 09/09/2017] [Indexed: 12/31/2022] Open
Abstract
Elucidation of activation mechanisms governing protein fusions is essential for therapeutic development. MLL undergoes rearrangement with numerous partners, including a recurrent translocation fusing the epigenetic regulator to a cytoplasmic RAS effector, AF6/afadin. We show here that AF6 employs a non-canonical, evolutionarily conserved α-helix to bind RAS, unique to AF6 and the classical RASSF effectors. Further, all patients with MLL-AF6 translocations express fusion proteins missing only this helix from AF6, resulting in exposure of hydrophobic residues that induce dimerization. We provide evidence that oligomerization is the dominant mechanism driving oncogenesis from rare MLL translocation partners and employ our mechanistic understanding of MLL-AF6 to examine how dimers induce leukemia. Proteomic data resolve association of dimerized MLL with gene expression modulators, and inhibiting dimerization disrupts formation of these complexes while completely abrogating leukemogenesis in mice. Oncogenic gene translocations are thus selected under pressure from protein structure/function, underscoring the complex nature of chromosomal rearrangements. Several rearrangements of the MLL gene are associated with acute leukemia, including the fusion of MLL with a RAS effector protein, AF6. Here the authors show that the truncated AF6 can induce AF6-MLL dimerization and drive its oncogenic activity.
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24
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Okuda H, Stanojevic B, Kanai A, Kawamura T, Takahashi S, Matsui H, Takaori-Kondo A, Yokoyama A. Cooperative gene activation by AF4 and DOT1L drives MLL-rearranged leukemia. J Clin Invest 2017; 127:1918-1931. [PMID: 28394257 DOI: 10.1172/jci91406] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 02/16/2017] [Indexed: 11/17/2022] Open
Abstract
The eleven-nineteen leukemia (ENL) protein family, composed of ENL and AF9, is a common component of 3 transcriptional modulators: AF4-ENL-P-TEFb complex (AEP), DOT1L-AF10-ENL complex (referred to as the DOT1L complex) and polycomb-repressive complex 1 (PRC1). Each complex associates with chromatin via distinct mechanisms, conferring different transcriptional properties including activation, maintenance, and repression. The mixed-lineage leukemia (MLL) gene often fuses with ENL and AF10 family genes in leukemia. However, the functional interrelationship among those 3 complexes in leukemic transformation remains largely elusive. Here, we have shown that MLL-ENL and MLL-AF10 constitutively activate transcription by aberrantly inducing both AEP-dependent transcriptional activation and DOT1L-dependent transcriptional maintenance, mostly in the absence of PRC1, to fully transform hematopoietic progenitors. These results reveal a cooperative transcriptional activation mechanism of AEP and DOT1L and suggest a molecular rationale for the simultaneous inhibition of the MLL fusion-AF4 complex and DOT1L for more effective treatment of MLL-rearranged leukemia.
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25
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Polycomb complexes PRC1 and their function in hematopoiesis. Exp Hematol 2017; 48:12-31. [PMID: 28087428 DOI: 10.1016/j.exphem.2016.12.006] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 12/19/2016] [Accepted: 12/20/2016] [Indexed: 12/31/2022]
Abstract
Hematopoiesis, the process by which blood cells are continuously produced, is one of the best studied differentiation pathways. Hematological diseases are associated with reiterated mutations in genes encoding important gene expression regulators, including chromatin regulators. Among them, the Polycomb group (PcG) of proteins is an essential system of gene silencing involved in the maintenance of cell identities during differentiation. PcG proteins assemble into two major types of Polycomb repressive complexes (PRCs) endowed with distinct histone-tail-modifying activities. PRC1 complexes are histone H2A E3 ubiquitin ligases and PRC2 trimethylates histone H3. Established conceptions about their activities, mostly derived from work in embryonic stem cells, are being modified by new findings in differentiated cells. Here, we focus on PRC1 complexes, reviewing recent evidence on their intricate architecture, the diverse mechanisms of their recruitment to targets, and the different ways in which they engage in transcriptional control. We also discuss hematopoietic PRC1 gain- and loss-of-function mouse strains, including those that model leukemic and lymphoma diseases, in the belief that these genetic analyses provide the ultimate test for molecular mechanisms driving normal hematopoiesis and hematological malignancies.
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26
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Winters AC, Bernt KM. MLL-Rearranged Leukemias-An Update on Science and Clinical Approaches. Front Pediatr 2017; 5:4. [PMID: 28232907 PMCID: PMC5299633 DOI: 10.3389/fped.2017.00004] [Citation(s) in RCA: 265] [Impact Index Per Article: 37.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 01/09/2017] [Indexed: 12/18/2022] Open
Abstract
The mixed-lineage leukemia 1 (MLL1) gene (now renamed Lysine [K]-specific MethylTransferase 2A or KMT2A) on chromosome 11q23 is disrupted in a unique group of acute leukemias. More than 80 different partner genes in these fusions have been described, although the majority of leukemias result from MLL1 fusions with one of about six common partner genes. Approximately 10% of all leukemias harbor MLL1 translocations. Of these, two patient populations comprise the majority of cases: patients younger than 1 year of age at diagnosis (primarily acute lymphoblastic leukemias) and young- to-middle-aged adults (primarily acute myeloid leukemias). A much rarer subgroup of patients with MLL1 rearrangements develop leukemia that is attributable to prior treatment with certain chemotherapeutic agents-so-called therapy-related leukemias. In general, outcomes for all of these patients remain poor when compared to patients with non-MLL1 rearranged leukemias. In this review, we will discuss the normal biological roles of MLL1 and its fusion partners, how these roles are hypothesized to be dysregulated in the context of MLL1 rearrangements, and the clinical manifestations of this group of leukemias. We will go on to discuss the progress in clinical management and promising new avenues of research, which may lead to more effective targeted therapies for affected patients.
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Affiliation(s)
- Amanda C Winters
- Division of Pediatric Hematology/Oncology/BMT, University of Colorado School of Medicine and Children's Hospital Colorado , Aurora, CO , USA
| | - Kathrin M Bernt
- Division of Pediatric Hematology/Oncology/BMT, University of Colorado School of Medicine and Children's Hospital Colorado , Aurora, CO , USA
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27
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Connelly KE, Dykhuizen EC. Compositional and functional diversity of canonical PRC1 complexes in mammals. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2016; 1860:233-245. [PMID: 28007606 DOI: 10.1016/j.bbagrm.2016.12.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 12/12/2016] [Accepted: 12/15/2016] [Indexed: 12/17/2022]
Abstract
The compositional complexity of Polycomb Repressive Complex 1 (PRC1) increased dramatically during vertebrate evolution. What is considered the "canonical" PRC1 complex consists of four subunits originally identified as regulators of body segmentation in Drosophila. In mammals, each of these four canonical subunits consists of two to six paralogs that associate in a combinatorial manner to produce over a hundred possible distinct PRC1 complexes with unknown function. Genetic studies have begun to define the phenotypic roles for different PRC1 paralogs; however, relating these phenotypes to unique biochemical and transcriptional function for the different paralogs has been challenging. In this review, we attempt to address how the compositional diversity of canonical PRC1 complexes relates to unique roles for individual PRC1 paralogs in transcriptional regulation. This review focuses primarily on PRC1 complex composition, genome targeting, and biochemical function.
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Affiliation(s)
- Katelyn E Connelly
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, 201 S. University St., West Lafayette, IN 47907, USA
| | - Emily C Dykhuizen
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, 201 S. University St., West Lafayette, IN 47907, USA; Purdue University Center for Cancer Research, 201 S. University St., West Lafayette, IN 47907, USA.
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28
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Godfrey L, Kerry J, Thorne R, Repapi E, Davies JOJ, Tapia M, Ballabio E, Hughes JR, Geng H, Konopleva M, Milne TA. MLL-AF4 binds directly to a BCL-2 specific enhancer and modulates H3K27 acetylation. Exp Hematol 2016; 47:64-75. [PMID: 27856324 PMCID: PMC5333536 DOI: 10.1016/j.exphem.2016.11.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 10/21/2016] [Accepted: 11/02/2016] [Indexed: 11/15/2022]
Abstract
Survival rates for children and adults carrying mutations in the Mixed Lineage Leukemia (MLL) gene continue to have a very poor prognosis. The most common MLL mutation in acute lymphoblastic leukemia is the t(4;11)(q21;q23) chromosome translocation that fuses MLL in-frame with the AF4 gene producing MLL-AF4 and AF4-MLL fusion proteins. Previously, we found that MLL-AF4 binds to the BCL-2 gene and directly activates it through DOT1L recruitment and increased H3K79me2/3 levels. In the study described here, we performed a detailed analysis of MLL-AF4 regulation of the entire BCL-2 family. By measuring nascent RNA production in MLL-AF4 knockdowns, we found that of all the BCL-2 family genes, MLL-AF4 directly controls the active transcription of both BCL-2 and MCL-1 and also represses BIM via binding of the polycomb group repressor 1 (PRC1) complex component CBX8. We further analyzed MLL-AF4 activation of the BCL-2 gene using Capture-C and identified a BCL-2-specific enhancer, consisting of two clusters of H3K27Ac at the 3' end of the gene. Loss of MLL-AF4 activity results in a reduction of H3K79me3 levels in the gene body and H3K27Ac levels at the 3' BCL-2 enhancer, revealing a novel regulatory link between these two histone marks and MLL-AF4-mediated activation of BCL-2.
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Affiliation(s)
- Laura Godfrey
- Weatherall Institute of Molecular Medicine, MRC Molecular Haematology Unit, University of Oxford, Headington, Oxford, UK
| | - Jon Kerry
- Weatherall Institute of Molecular Medicine, MRC Molecular Haematology Unit, University of Oxford, Headington, Oxford, UK
| | - Ross Thorne
- Weatherall Institute of Molecular Medicine, MRC Molecular Haematology Unit, University of Oxford, Headington, Oxford, UK
| | - Emmanouela Repapi
- Weatherall Institute of Molecular Medicine, Computational Biology Research Group, University of Oxford, Headington, Oxford, UK
| | - James O J Davies
- Weatherall Institute of Molecular Medicine, MRC Molecular Haematology Unit, University of Oxford, Headington, Oxford, UK
| | - Marta Tapia
- Weatherall Institute of Molecular Medicine, MRC Molecular Haematology Unit, University of Oxford, Headington, Oxford, UK
| | - Erica Ballabio
- Weatherall Institute of Molecular Medicine, MRC Molecular Haematology Unit, University of Oxford, Headington, Oxford, UK
| | - Jim R Hughes
- Weatherall Institute of Molecular Medicine, MRC Molecular Haematology Unit, University of Oxford, Headington, Oxford, UK
| | - Huimin Geng
- Department of Laboratory Medicine, University of California San Francisco, San Francisco, CA
| | - Marina Konopleva
- Department of Leukemia, University of Texas MD Anderson Cancer Center, Houston, TX
| | - Thomas A Milne
- Weatherall Institute of Molecular Medicine, MRC Molecular Haematology Unit, University of Oxford, Headington, Oxford, UK.
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Luo W, Tan SK. Correlation between CBX8 protein and tumors. Shijie Huaren Xiaohua Zazhi 2016; 24:3899-3904. [DOI: 10.11569/wcjd.v24.i27.3899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Chromobox protein homolog 8 (CBX8), the core component of the polycomb group (PcG) protein family PRC1 complex, plays an important role in cell proliferation, senescence, maintenance of stem cell self-renewal and/or relapse, and the occurrence of tumors. Recently, CBX8 was found to be overexpressed in a variety of malignant tumors and closely related to the progression and prognosis of tumors. This paper reviews the current progress in research of CBX8 in tumors.
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Abstract
Polycomb group (PcG) repress, whereas Trithorax group (TrxG) activate transcription for tissue development and cellular proliferation, and misregulation of these factors is often associated with cancer. ENL (MLLT1) and AF9 (MLLT3) are fusion partners of Mixed Lineage Leukemia (MLL), TrxG proteins, and are factors in Super Elongation Complex (SEC). SEC controls transcriptional elongation to release RNA polymerase II, paused around transcription start site. In MLL rearranged leukemia, several components of SEC have been found as MLL-fusion partners and the control of transcriptional elongation is misregulated leading to tumorigenesis in MLL-SEC fused Leukemia. It has been suggested that unexpected collaboration of ENL/AF9-MLL and PcG are involved in tumorigenesis in leukemia. Recently, we found that the collaboration of ENL/AF9 and PcG led to a novel mechanism of transcriptional switch from elongation to repression under ATM-signaling for genome integrity. Activated ATM phosphorylates ENL/AF9 in SEC, and the phosphorylated ENL/AF9 binds BMI1 and RING1B, a heterodimeric E3-ubiquitin-ligase complex in Polycomb Repressive complex 1 (PRC1), and recruits PRC1 at transcriptional elongation sites to rapidly repress transcription. The ENL/AF9 in SEC- and PcG-mediated transcriptional repression promotes DSB repair near transcription sites. The implication of this is that the collaboration of ENL/AF9 in SEC and PcG ensures a rapid response of transcriptional switching from elongation to repression to neighboring genotoxic stresses for DSB repair. Therefore, these results suggested that the collaboration of ENL/AF9 and PcG in transcriptional control is required to maintain genome integrity and may be link to the MLL-ENL/AF9 leukemia.
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Affiliation(s)
- Ayako Ui
- Department of Translational Oncology, St. Marianna University, School of Medicine, Miyamae-Ku, Kawasaki, Japan
- Division of Dynamic Proteome in Cancer and Aging, Institute of Development, Aging and Cancer, Tohoku University, Aoba-ku, Sendai, Japan
| | - Akira Yasui
- Division of Dynamic Proteome in Cancer and Aging, Institute of Development, Aging and Cancer, Tohoku University, Aoba-ku, Sendai, Japan
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31
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Garcia-Cuellar MP, Büttner C, Bartenhagen C, Dugas M, Slany RK. Leukemogenic MLL-ENL Fusions Induce Alternative Chromatin States to Drive a Functionally Dichotomous Group of Target Genes. Cell Rep 2016; 15:310-22. [PMID: 27050521 DOI: 10.1016/j.celrep.2016.03.018] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 02/23/2016] [Accepted: 03/02/2016] [Indexed: 12/20/2022] Open
Abstract
MLL fusions are leukemogenic transcription factors that enhance transcriptional elongation through modification of chromatin and RNA Pol II. Global transcription rates and chromatin changes accompanying the transformation process induced by MLL-ENL were monitored by nascent RNA-seq and ChIP-seq, revealing 165 direct target genes separated into two distinct clades. ME5 genes bound MLL-ENL at the promoter, relied on DOT1L-mediated histone methylation, and coded preferentially for transcription factors, including many homeobox genes. A distinct ME3 group accumulated MLL-ENL beyond the termination site, was dependent on P-TEFb-mediated phosphorylation of RNA Pol II for transcription, and translated mainly into proteins involved in RNA biology and ribosome assembly. This dichotomy was reflected by a differential sensitivity toward small molecule inhibitors, suggesting the possibility of a combinatorial strategy for treatment of MLL-induced leukemia.
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Affiliation(s)
- Maria-Paz Garcia-Cuellar
- Department of Genetics, Friedrich-Alexander-University Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - Christian Büttner
- Institute of Human Genetics, Friedrich-Alexander-University Erlangen-Nürnberg, 91058 Erlangen, Germany
| | | | - Martin Dugas
- Department of Medical Informatics, University Münster, 48149 Münster, Germany
| | - Robert K Slany
- Department of Genetics, Friedrich-Alexander-University Erlangen-Nürnberg, 91058 Erlangen, Germany.
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32
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The molecular mechanics of mixed lineage leukemia. Oncogene 2016; 35:5215-5223. [PMID: 26923329 DOI: 10.1038/onc.2016.30] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Revised: 01/14/2016] [Accepted: 01/21/2016] [Indexed: 12/14/2022]
Abstract
Mixed lineage leukemia caused by MLL fusion proteins is still a mostly incurable disease. Research on novel treatment strategies has gained momentum in the last years with the elucidation of the molecular mechanisms underlying the transforming potential of these powerful oncoproteins. This review summarizes the recent developments in this area including new attempts to treat MLL in a rational way by exploiting the biochemical vulnerabilities of the leukemogenic process.
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Benito JM, Godfrey L, Kojima K, Hogdal L, Wunderlich M, Geng H, Marzo I, Harutyunyan KG, Golfman L, North P, Kerry J, Ballabio E, Chonghaile TN, Gonzalo O, Qiu Y, Jeremias I, Debose L, O'Brien E, Ma H, Zhou P, Jacamo R, Park E, Coombes KR, Zhang N, Thomas DA, O'Brien S, Kantarjian HM, Leverson JD, Kornblau SM, Andreeff M, Müschen M, Zweidler-McKay PA, Mulloy JC, Letai A, Milne TA, Konopleva M. MLL-Rearranged Acute Lymphoblastic Leukemias Activate BCL-2 through H3K79 Methylation and Are Sensitive to the BCL-2-Specific Antagonist ABT-199. Cell Rep 2015; 13:2715-27. [PMID: 26711339 PMCID: PMC4700051 DOI: 10.1016/j.celrep.2015.12.003] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 10/21/2015] [Accepted: 11/19/2015] [Indexed: 12/25/2022] Open
Abstract
Targeted therapies designed to exploit specific molecular pathways in aggressive cancers are an exciting area of current research. Mixed Lineage Leukemia (MLL) mutations such as the t(4;11) translocation cause aggressive leukemias that are refractory to conventional treatment. The t(4;11) translocation produces an MLL/AF4 fusion protein that activates key target genes through both epigenetic and transcriptional elongation mechanisms. In this study, we show that t(4;11) patient cells express high levels of BCL-2 and are highly sensitive to treatment with the BCL-2-specific BH3 mimetic ABT-199. We demonstrate that MLL/AF4 specifically upregulates the BCL-2 gene but not other BCL-2 family members via DOT1L-mediated H3K79me2/3. We use this information to show that a t(4;11) cell line is sensitive to a combination of ABT-199 and DOT1L inhibitors. In addition, ABT-199 synergizes with standard induction-type therapy in a xenotransplant model, advocating for the introduction of ABT-199 into therapeutic regimens for MLL-rearranged leukemias.
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Affiliation(s)
- Juliana M Benito
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Laura Godfrey
- Weatherall Institute of Molecular Medicine, Molecular Haematology Unit, NIHR Oxford Biomedical Research Centre Programme, University of Oxford, Headington, Oxford OX3 9DS, UK
| | - Kensuke Kojima
- Division of Hematology, Respiratory Medicine and Oncology, Department of Internal Medicine, Faculty of Medicine, Saga University, Saga 840-8502, Japan
| | - Leah Hogdal
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - Mark Wunderlich
- Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Huimin Geng
- Department of Laboratory Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Isabel Marzo
- Department of Biochemistry, Molecular and Cell Biology, University of Zaragoza, 50018 Zaragoza, Spain
| | - Karine G Harutyunyan
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Leonard Golfman
- Division of Pediatrics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Phillip North
- Weatherall Institute of Molecular Medicine, Molecular Haematology Unit, NIHR Oxford Biomedical Research Centre Programme, University of Oxford, Headington, Oxford OX3 9DS, UK
| | - Jon Kerry
- Weatherall Institute of Molecular Medicine, Molecular Haematology Unit, NIHR Oxford Biomedical Research Centre Programme, University of Oxford, Headington, Oxford OX3 9DS, UK
| | - Erica Ballabio
- Weatherall Institute of Molecular Medicine, Molecular Haematology Unit, NIHR Oxford Biomedical Research Centre Programme, University of Oxford, Headington, Oxford OX3 9DS, UK
| | - Triona Ní Chonghaile
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, York House, Dublin 2, Ireland
| | - Oscar Gonzalo
- Department of Biochemistry, Molecular and Cell Biology, University of Zaragoza, 50018 Zaragoza, Spain
| | - Yihua Qiu
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Irmela Jeremias
- German Research Center for Environmental Health (GmbH), 85764 Neuherberg, Germany
| | - LaKiesha Debose
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Eric O'Brien
- Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Helen Ma
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Ping Zhou
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Rodrigo Jacamo
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Eugene Park
- Department of Laboratory Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Kevin R Coombes
- Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Nianxiang Zhang
- Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Deborah A Thomas
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Susan O'Brien
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Hagop M Kantarjian
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Joel D Leverson
- Department of Oncology Development, AbbVie Inc., North Chicago, IL 60064, USA
| | - Steven M Kornblau
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Michael Andreeff
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Markus Müschen
- Department of Laboratory Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Patrick A Zweidler-McKay
- Division of Pediatrics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - James C Mulloy
- Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Anthony Letai
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - Thomas A Milne
- Weatherall Institute of Molecular Medicine, Molecular Haematology Unit, NIHR Oxford Biomedical Research Centre Programme, University of Oxford, Headington, Oxford OX3 9DS, UK.
| | - Marina Konopleva
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
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34
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Context-dependent actions of Polycomb repressors in cancer. Oncogene 2015; 35:1341-52. [DOI: 10.1038/onc.2015.195] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Revised: 04/15/2015] [Accepted: 05/05/2015] [Indexed: 12/21/2022]
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35
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Ui A, Nagaura Y, Yasui A. Transcriptional Elongation Factor ENL Phosphorylated by ATM Recruits Polycomb and Switches Off Transcription for DSB Repair. Mol Cell 2015; 58:468-82. [DOI: 10.1016/j.molcel.2015.03.023] [Citation(s) in RCA: 109] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Revised: 02/09/2015] [Accepted: 03/18/2015] [Indexed: 12/21/2022]
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36
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Kuntimaddi A, Achille NJ, Thorpe J, Lokken AA, Singh R, Hemenway CS, Adli M, Zeleznik-Le NJ, Bushweller JH. Degree of recruitment of DOT1L to MLL-AF9 defines level of H3K79 Di- and tri-methylation on target genes and transformation potential. Cell Rep 2015; 11:808-20. [PMID: 25921540 DOI: 10.1016/j.celrep.2015.04.004] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 02/18/2015] [Accepted: 03/30/2015] [Indexed: 12/16/2022] Open
Abstract
The MLL gene is a common target of chromosomal translocations found in human leukemia. MLL-fusion leukemia has a consistently poor outcome. One of the most common translocation partners is AF9 (MLLT3). MLL-AF9 recruits DOT1L, a histone 3 lysine 79 methyltransferase (H3K79me1/me2/me3), leading to aberrant gene transcription. We show that DOT1L has three AF9 binding sites and present the nuclear magnetic resonance (NMR) solution structure of a DOT1L-AF9 complex. We generate structure-guided point mutations and find that they have graded effects on recruitment of DOT1L to MLL-AF9. Chromatin immunoprecipitation sequencing (ChIP-seq) analyses of H3K79me2 and H3K79me3 show that graded reduction of the DOT1L interaction with MLL-AF9 results in differential loss of H3K79me2 and me3 at MLL-AF9 target genes. Furthermore, the degree of DOT1L recruitment is linked to the level of MLL-AF9 hematopoietic transformation.
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Affiliation(s)
- Aravinda Kuntimaddi
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22908, USA
| | - Nicholas J Achille
- Oncology Institute, Department of Medicine, Loyola University Chicago, Maywood, IL 60153, USA
| | - Jeremy Thorpe
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA 22908, USA
| | - Alyson A Lokken
- Oncology Institute, Department of Medicine, Loyola University Chicago, Maywood, IL 60153, USA
| | - Ritambhara Singh
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA 22908, USA
| | - Charles S Hemenway
- Oncology Institute, Department of Pediatrics, Loyola University Chicago, Maywood, IL 60153, USA
| | - Mazhar Adli
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA 22908, USA
| | - Nancy J Zeleznik-Le
- Oncology Institute, Department of Medicine, Loyola University Chicago, Maywood, IL 60153, USA.
| | - John H Bushweller
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22908, USA.
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37
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Molecular mechanisms of MLL-associated leukemia. Int J Hematol 2015; 101:352-61. [PMID: 25773519 DOI: 10.1007/s12185-015-1774-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2015] [Revised: 03/02/2015] [Accepted: 03/02/2015] [Indexed: 01/04/2023]
Abstract
Gene rearrangements of the mixed lineage leukemia (MLL) gene cause aggressive leukemia. The fusion of MLL and its partner genes generates various MLL fusion genes, and their gene products trigger aberrant self-renewal of hematopoietic progenitors leading to leukemia. Since the identification of the MLL gene two decades ago, a substantial amount of information has been obtained regarding the mechanisms by which MLL mutations cause leukemia. Wild-type MLL maintains the expression of Homeobox (HOX) genes during development. MLL activates the expression of posterior HOX-A genes in the hematopoietic lineage to stimulate the expansion of immature progenitors. MLL fusion proteins constitutively activate the HOX genes, causing aberrant self-renewal. The modes of transcriptional activation vary depending on the fusion partners and can be categorized into at least four groups. Here I review the recent progress in research related to the molecular mechanisms of MLL fusion-dependent leukemogenesis.
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38
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Ma RG, Zhang Y, Sun TT, Cheng B. Epigenetic regulation by polycomb group complexes: focus on roles of CBX proteins. J Zhejiang Univ Sci B 2015; 15:412-28. [PMID: 24793759 DOI: 10.1631/jzus.b1400077] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Polycomb group (PcG) complexes are epigenetic regulatory complexes that conduct transcriptional repression of target genes via modifying the chromatin. The two best characterized forms of PcG complexes, polycomb repressive complexes 1 and 2 (PRC1 and PRC2), are required for maintaining the stemness of embryonic stem cells and many types of adult stem cells. The spectra of target genes for PRCs are dynamically changing with cell differentiation, which is essential for proper decisions on cell fate during developmental processes. Chromobox (CBX) family proteins are canonical components in PRC1, responsible for targeting PRC1 to the chromatin. Recent studies highlight the function specifications among CBX family members in undifferentiated and differentiated stem cells, which reveal the interplay between compositional diversity and functional specificity of PRC1. In this review, we summarize the current knowledge about targeting and functional mechanisms of PRCs, emphasizing the recent breakthroughs related to CBX proteins under a number of physiological and pathological conditions.
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Affiliation(s)
- Rong-gang Ma
- School of Life Sciences, Lanzhou University, Lanzhou 730000, China
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39
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Li BE, Ernst P. Two decades of leukemia oncoprotein epistasis: the MLL1 paradigm for epigenetic deregulation in leukemia. Exp Hematol 2014; 42:995-1012. [PMID: 25264566 PMCID: PMC4307938 DOI: 10.1016/j.exphem.2014.09.006] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Accepted: 09/16/2014] [Indexed: 12/12/2022]
Abstract
MLL1, located on human chromosome 11, is disrupted in distinct recurrent chromosomal translocations in several leukemia subsets. Studying the MLL1 gene and its oncogenic variants has provided a paradigm for understanding cancer initiation and maintenance through aberrant epigenetic gene regulation. Here we review the historical development of model systems to recapitulate oncogenic MLL1-rearrangement (MLL-r) alleles encoding mixed-lineage leukemia fusion proteins (MLL-FPs) or internal gene rearrangement products. These largely mouse and human cell/xenograft systems have been generated and used to understand how MLL-r alleles affect diverse pathways to result in a highly penetrant, drug-resistant leukemia. The particular features of the animal models influenced the conclusions of mechanisms of transformation. We discuss significant downstream enablers, inhibitors, effectors, and collaborators of MLL-r leukemia, including molecules that directly interact with MLL-FPs and endogenous mixed-lineage leukemia protein, direct target genes of MLL-FPs, and other pathways that have proven to be influential in supporting or suppressing the leukemogenic activity of MLL-FPs. The use of animal models has been complemented with patient sample, genome-wide analyses to delineate the important genomic and epigenomic changes that occur in distinct subsets of MLL-r leukemia. Collectively, these studies have resulted in rapid progress toward developing new strategies for targeting MLL-r leukemia and general cell-biological principles that may broadly inform targeting aberrant epigenetic regulators in other cancers.
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Affiliation(s)
- Bin E Li
- Department of Genetics, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Patricia Ernst
- Department of Genetics, Geisel School of Medicine at Dartmouth, Hanover, NH, USA; Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA; Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth, Hanover, NH, USA; Department of Pediatrics Hematology/Oncology/BMT, University of Colorado Anschutz Medical Center, Aurora, CO, USA.
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40
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Garcia-Cuellar MP, Füller E, Mäthner E, Breitinger C, Hetzner K, Zeitlmann L, Borkhardt A, Slany RK. Efficacy of cyclin-dependent-kinase 9 inhibitors in a murine model of mixed-lineage leukemia. Leukemia 2014; 28:1427-35. [PMID: 24445865 DOI: 10.1038/leu.2014.40] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Revised: 01/10/2014] [Accepted: 01/15/2014] [Indexed: 01/06/2023]
Abstract
Mixed-lineage leukemia fusion proteins activate their target genes predominantly by stimulating transcriptional elongation. A core component necessary for this activity is cyclin-dependent kinase 9. Here we explored the effectiveness of small molecules targeting this enzyme as potential therapeutics. A screen of seven compounds with anti-CDK9 activity applied to a panel of leukemia cell lines identified flavopiridol and the experimental inhibitor PC585 as superior in efficacy with inhibitory concentrations in the submicromolar range. Both substances induced rapid dephosphorylation of the RNA polymerase II C-terminal domain, accompanied by downregulation of CDK9-dependent transcripts for MYC and HOXA9. Global gene expression analysis indicated the induction of a general stress response program, culminating in widespread apoptosis. Importantly, colony-forming activity in leukemia lines and primary patient samples could be completely inhibited under conditions that did not affect native precursors from bone marrow. In vivo application in a mouse transplant model significantly delayed disease with PC585 showing also oral activity. These results suggest CDK9 inhibition as novel treatment option for mixed-lineage leukemia.
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Affiliation(s)
| | - E Füller
- Department of Genetics, University Erlangen, Erlangen, Germany
| | - E Mäthner
- Department of Genetics, University Erlangen, Erlangen, Germany
| | - C Breitinger
- Department of Genetics, University Erlangen, Erlangen, Germany
| | - K Hetzner
- Department of Genetics, University Erlangen, Erlangen, Germany
| | - L Zeitlmann
- Ingenium Pharmaceuticals AG, Munich, Germany
| | - A Borkhardt
- Clinic of Paediatric Oncology, Haematology and Clinical Immunology, Centre for Child and Adolescent Health, Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - R K Slany
- Department of Genetics, University Erlangen, Erlangen, Germany
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41
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Malik B, Hemenway CS. CBX8, a component of the Polycomb PRC1 complex, modulates DOT1L-mediated gene expression through AF9/MLLT3. FEBS Lett 2013; 587:3038-44. [PMID: 23891621 DOI: 10.1016/j.febslet.2013.07.034] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2013] [Revised: 07/03/2013] [Accepted: 07/05/2013] [Indexed: 11/15/2022]
Abstract
AF9 is known to interact with multiple proteins including activators and repressors of transcription. Our data indicate that other AF9 binding proteins compete with the histone methyltransferase DOT1L for AF9 binding thus diminishing its ability to methylate lysine 79 of histone 3. Specifically, we show that AF9 is part of a protein multimer containing members of Polycomb group (PcG) PRC1 complex, CBX8, RING1B, and BMI1. Interaction with CBX8 precludes AF9-DOT1L binding. Knockdown of CBX8 with short-hairpin RNA (shRNA) leads to decreased expression of the AF9 target gene ENaCα. In contrast, CBX8 overexpression results in increased ENaCα mRNA levels and this effect can be partially overcome by co-overexpression of AF9.
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Affiliation(s)
- Bhavna Malik
- Department of Molecular and Cellular Biochemistry, Loyola University Chicago, Stritch School of Medicine, Maywood, IL 60153, USA
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