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Boukas L, Luperchio TR, Razi A, Hansen KD, Bjornsson HT. Neuron-specific chromatin disruption at CpG islands and aging-related regions in Kabuki syndrome mice. Genome Res 2024; 34:696-710. [PMID: 38702196 PMCID: PMC11216309 DOI: 10.1101/gr.278416.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 04/15/2024] [Indexed: 05/06/2024]
Abstract
Many Mendelian developmental disorders caused by coding variants in epigenetic regulators have now been discovered. Epigenetic regulators are broadly expressed, and each of these disorders typically shows phenotypic manifestations from many different organ systems. An open question is whether the chromatin disruption-the root of the pathogenesis-is similar in the different disease-relevant cell types. This is possible in principle, because all these cell types are subject to effects from the same causative gene, which has the same kind of function (e.g., methylates histones) and is disrupted by the same germline variant. We focus on mouse models for Kabuki syndrome types 1 and 2 and find that the chromatin accessibility changes in neurons are mostly distinct from changes in B or T cells. This is not because the neuronal accessibility changes occur at regulatory elements that are only active in neurons. Neurons, but not B or T cells, show preferential chromatin disruption at CpG islands and at regulatory elements linked to aging. A sensitive analysis reveals that regulatory elements disrupted in B/T cells do show chromatin accessibility changes in neurons, but these are very subtle and of uncertain functional significance. Finally, we are able to identify a small set of regulatory elements disrupted in all three cell types. Our findings reveal the cellular-context-specific effect of variants in epigenetic regulators and suggest that blood-derived episignatures, although useful diagnostically, may not be well suited for understanding the mechanistic basis of neurodevelopment in Mendelian disorders of the epigenetic machinery.
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Affiliation(s)
- Leandros Boukas
- Department of Pediatrics, Children's National Hospital, Washington, DC 20010, USA
- Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
- Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland 21205, USA
| | - Teresa Romeo Luperchio
- Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| | - Afrooz Razi
- Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| | - Kasper D Hansen
- Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA;
- Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland 21205, USA
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland 21218, USA
| | - Hans T Bjornsson
- Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA;
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
- Faculty of Medicine, University of Iceland, 101 Reykjavík, Iceland
- Landspitali University Hospital, 101 Reykjavík, Iceland
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Katerndahl CDS, Rogers ORS, Day RB, Xu Z, Helton NM, Ramakrishnan SM, Miller CA, Ley TJ. PML::RARA and GATA2 proteins interact via DNA templates to induce aberrant self-renewal in mouse and human hematopoietic cells. Proc Natl Acad Sci U S A 2024; 121:e2317690121. [PMID: 38648485 PMCID: PMC11067031 DOI: 10.1073/pnas.2317690121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 03/15/2024] [Indexed: 04/25/2024] Open
Abstract
The underlying mechanism(s) by which the PML::RARA fusion protein initiates acute promyelocytic leukemia is not yet clear. We defined the genomic binding sites of PML::RARA in primary mouse and human hematopoietic progenitor cells with V5-tagged PML::RARA, using anti-V5-PML::RARA chromatin immunoprecipitation sequencing and CUT&RUN approaches. Most genomic PML::RARA binding sites were found in regions that were already chromatin-accessible (defined by ATAC-seq) in unmanipulated, wild-type promyelocytes, suggesting that these regions are "open" prior to PML::RARA expression. We found that GATA binding motifs, and the direct binding of the chromatin "pioneering factor" GATA2, were significantly enriched near PML::RARA binding sites. Proximity labeling studies revealed that PML::RARA interacts with ~250 proteins in primary mouse hematopoietic cells; GATA2 and 33 others require PML::RARA binding to DNA for the interaction to occur, suggesting that binding to their cognate DNA target motifs may stabilize their interactions. In the absence of PML::RARA, Gata2 overexpression induces many of the same epigenetic and transcriptional changes as PML::RARA. These findings suggested that PML::RARA may indirectly initiate its transcriptional program by activating Gata2 expression: Indeed, we demonstrated that inactivation of Gata2 prior to PML::RARA expression prevented its ability to induce self-renewal. These data suggested that GATA2 binding creates accessible chromatin regions enriched for both GATA and Retinoic Acid Receptor Element motifs, where GATA2 and PML::RARA can potentially bind and interact with each other. In turn, PML::RARA binding to DNA promotes a feed-forward transcriptional program by positively regulating Gata2 expression. Gata2 may therefore be required for PML::RARA to establish its transcriptional program.
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Affiliation(s)
- Casey D. S. Katerndahl
- Division of Oncology, Department of Internal Medicine, Section of Stem Cell Biology, Washington University School of Medicine, St. Louis, MO63110
| | - Olivia R. S. Rogers
- Division of Oncology, Department of Internal Medicine, Section of Stem Cell Biology, Washington University School of Medicine, St. Louis, MO63110
| | - Ryan B. Day
- Division of Oncology, Department of Internal Medicine, Section of Stem Cell Biology, Washington University School of Medicine, St. Louis, MO63110
| | - Ziheng Xu
- Division of Oncology, Department of Internal Medicine, Section of Stem Cell Biology, Washington University School of Medicine, St. Louis, MO63110
| | - Nichole M. Helton
- Division of Oncology, Department of Internal Medicine, Section of Stem Cell Biology, Washington University School of Medicine, St. Louis, MO63110
| | - Sai Mukund Ramakrishnan
- Division of Oncology, Department of Internal Medicine, Section of Stem Cell Biology, Washington University School of Medicine, St. Louis, MO63110
| | - Christopher A. Miller
- Division of Oncology, Department of Internal Medicine, Section of Stem Cell Biology, Washington University School of Medicine, St. Louis, MO63110
| | - Timothy J. Ley
- Division of Oncology, Department of Internal Medicine, Section of Stem Cell Biology, Washington University School of Medicine, St. Louis, MO63110
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Boukas L, Luperchio TR, Razi A, Hansen KD, Bjornsson HT. Neuron-specific chromatin disruption at CpG islands and aging-related regions in Kabuki syndrome mice. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.01.551456. [PMID: 37577516 PMCID: PMC10418197 DOI: 10.1101/2023.08.01.551456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Many Mendelian developmental disorders caused by coding variants in epigenetic regulators have now been discovered. Epigenetic regulators are broadly expressed, and each of these disorders typically exhibits phenotypic manifestations from many different organ systems. An open question is whether the chromatin disruption - the root of the pathogenesis - is similar in the different disease-relevant cell types. This is possible in principle, since all these cell-types are subject to effects from the same causative gene, that has the same kind of function (e.g. methylates histones) and is disrupted by the same germline variant. We focus on mouse models for Kabuki syndrome types 1 and 2, and find that the chromatin accessibility abnormalities in neurons are mostly distinct from those in B or T cells. This is not because the neuronal abnormalities occur at regulatory elements that are only active in neurons. Neurons, but not B or T cells, show preferential chromatin disruption at CpG islands and at regulatory elements linked to aging. A sensitive analysis reveals that the regions disrupted in B/T cells do exhibit chromatin accessibility changes in neurons, but these are very subtle and of uncertain functional significance. Finally, we are able to identify a small set of regulatory elements disrupted in all three cell types. Our findings reveal the cellular-context-specific effect of variants in epigenetic regulators, and suggest that blood-derived "episignatures" may not be well-suited for understanding the mechanistic basis of neurodevelopment in Mendelian disorders of the epigenetic machinery.
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Affiliation(s)
- Leandros Boukas
- Department of Pediatrics, Children’s National Hospital
- Department of Genetic Medicine, Johns Hopkins University School of Medicine
- Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health
| | | | - Afrooz Razi
- Department of Genetic Medicine, Johns Hopkins University School of Medicine
| | - Kasper D. Hansen
- Department of Genetic Medicine, Johns Hopkins University School of Medicine
- Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health
- Department of Biomedical Engineering, Johns Hopkins School of Medicine
| | - Hans T. Bjornsson
- Department of Genetic Medicine, Johns Hopkins University School of Medicine
- Department of Pediatrics, Johns Hopkins University School of Medicine
- Faculty of Medicine, University of Iceland
- Landspitali University Hospital
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Epigenetic regulation in hematopoiesis and its implications in the targeted therapy of hematologic malignancies. Signal Transduct Target Ther 2023; 8:71. [PMID: 36797244 PMCID: PMC9935927 DOI: 10.1038/s41392-023-01342-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 01/03/2023] [Accepted: 01/19/2023] [Indexed: 02/18/2023] Open
Abstract
Hematologic malignancies are one of the most common cancers, and the incidence has been rising in recent decades. The clinical and molecular features of hematologic malignancies are highly heterogenous, and some hematologic malignancies are incurable, challenging the treatment, and prognosis of the patients. However, hematopoiesis and oncogenesis of hematologic malignancies are profoundly affected by epigenetic regulation. Studies have found that methylation-related mutations, abnormal methylation profiles of DNA, and abnormal histone deacetylase expression are recurrent in leukemia and lymphoma. Furthermore, the hypomethylating agents and histone deacetylase inhibitors are effective to treat acute myeloid leukemia and T-cell lymphomas, indicating that epigenetic regulation is indispensable to hematologic oncogenesis. Epigenetic regulation mainly includes DNA modifications, histone modifications, and noncoding RNA-mediated targeting, and regulates various DNA-based processes. This review presents the role of writers, readers, and erasers of DNA methylation and histone methylation, and acetylation in hematologic malignancies. In addition, this review provides the influence of microRNAs and long noncoding RNAs on hematologic malignancies. Furthermore, the implication of epigenetic regulation in targeted treatment is discussed. This review comprehensively presents the change and function of each epigenetic regulator in normal and oncogenic hematopoiesis and provides innovative epigenetic-targeted treatment in clinical practice.
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Shea LK, Akhave NS, Sutton LA, Compton LA, York C, Ramakrishnan SM, Miller CA, Wartman LD, Chen DY. Combined Kdm6a and Trp53 Deficiency Drives the Development of Squamous Cell Skin Cancer in Mice. J Invest Dermatol 2023; 143:232-241.e6. [PMID: 36055401 PMCID: PMC10334302 DOI: 10.1016/j.jid.2022.08.037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 07/18/2022] [Accepted: 08/06/2022] [Indexed: 01/25/2023]
Abstract
Cutaneous squamous cell carcinoma (cSCC) has among the highest mutation burdens of all cancers, reflecting its pathogenic association with the mutagenic effects of UV light exposure. Although mutations in cancer-relevant genes such as TP53 and NOTCH1 are common in cSCC, they are also tolerated in normal skin and suggest that other events are required for transformation; it is not yet clear whether epigenetic regulators cooperate in the pathogenesis of cSCC. KDM6A encodes a histone H3K27me2/me3 demethylase that is frequently mutated in cSCC and other cancers. Previous sequencing studies indicate that roughly 7% of cSCC samples harbor KDM6A mutations, including frequent truncating mutations, suggesting a role for this gene as a tumor suppressor in cSCC. Mice with epidermal deficiency of both Kdm6a and Trp53 exhibited 100% penetrant, spontaneous cSCC development within a year, and exome sequencing of resulting tumors reveals recurrent mutations in Ncstn and Vcan. Four of 16 tumors exhibited deletions in large portions of chromosome 1 involving Ncstn, whereas another 25% of tumors harbored deletions in chromosome 19 involving Pten, implicating the loss of other tumor suppressors as cooperating events for combined KDM6A- and TRP53-dependent tumorigenesis. This study suggests that KDM6A acts as an important tumor suppressor for cSCC pathogenesis.
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Affiliation(s)
- Lauren K Shea
- Division of Oncology, John T. Milliken Department of Medicine, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA
| | - Neal S Akhave
- Division of Oncology, John T. Milliken Department of Medicine, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA
| | - Leslie A Sutton
- Division of Dermatology, John T. Milliken Department of Medicine, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA
| | - Leigh A Compton
- Division of Dermatology, John T. Milliken Department of Medicine, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA; Department of Pathology & Immunology, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA
| | - Conner York
- Division of Oncology, John T. Milliken Department of Medicine, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA
| | - Sai Mukund Ramakrishnan
- Division of Oncology, John T. Milliken Department of Medicine, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA
| | - Christopher A Miller
- Division of Oncology, John T. Milliken Department of Medicine, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA
| | - Lukas D Wartman
- Division of Oncology, John T. Milliken Department of Medicine, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA
| | - David Y Chen
- Division of Dermatology, John T. Milliken Department of Medicine, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA.
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Li J, Kalev-Zylinska ML. Advances in molecular characterization of myeloid proliferations associated with Down syndrome. Front Genet 2022; 13:891214. [PMID: 36035173 PMCID: PMC9399805 DOI: 10.3389/fgene.2022.891214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 07/11/2022] [Indexed: 11/13/2022] Open
Abstract
Myeloid leukemia associated with Down syndrome (ML-DS) has a unique molecular landscape that differs from other subtypes of acute myeloid leukemia. ML-DS is often preceded by a myeloproliferative neoplastic condition called transient abnormal myelopoiesis (TAM) that disrupts megakaryocytic and erythroid differentiation. Over the last two decades, many genetic and epigenetic changes in TAM and ML-DS have been elucidated. These include overexpression of molecules and micro-RNAs located on chromosome 21, GATA1 mutations, and a range of other somatic mutations and chromosomal alterations. In this review, we summarize molecular changes reported in TAM and ML-DS and provide a comprehensive discussion of these findings. Recent advances in the development of CRISPR/Cas9-modified induced pluripotent stem cell-based disease models are also highlighted. However, despite significant progress in this area, we still do not fully understand the pathogenesis of ML-DS, and there are no targeted therapies. Initial diagnosis of ML-DS has a favorable prognosis, but refractory and relapsed disease can be difficult to treat; therapeutic options are limited in Down syndrome children by their stronger sensitivity to the toxic effects of chemotherapy. Because of the rarity of TAM and ML-DS, large-scale multi-center studies would be helpful to advance molecular characterization of these diseases at different stages of development and progression.
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Affiliation(s)
- Jixia Li
- Blood and Cancer Biology Laboratory, Department of Molecular Medicine and Pathology, University of Auckland, Auckland, New Zealand
- Department of Laboratory Medicine, School of Medicine, Foshan University, Foshan, China
- *Correspondence: Jixia Li, ; Maggie L. Kalev-Zylinska,
| | - Maggie L. Kalev-Zylinska
- Blood and Cancer Biology Laboratory, Department of Molecular Medicine and Pathology, University of Auckland, Auckland, New Zealand
- Haematology Laboratory, Department of Pathology and Laboratory Medicine, Auckland City Hospital, Auckland, New Zealand
- *Correspondence: Jixia Li, ; Maggie L. Kalev-Zylinska,
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