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Zhang CR, Ostrander EL, Kukhar O, Mallaney C, Sun J, Haussler E, Celik H, Koh WK, King KY, Gontarz P, Challen GA. Txnip Enhances Fitness of Dnmt3a-Mutant Hematopoietic Stem Cells via p21. Blood Cancer Discov 2022; 3:220-239. [PMID: 35394496 PMCID: PMC9414740 DOI: 10.1158/2643-3230.bcd-21-0132] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 02/01/2022] [Accepted: 02/28/2022] [Indexed: 11/16/2022] Open
Abstract
Clonal hematopoiesis (CH) refers to the age-related expansion of specific clones in the blood system, and manifests from somatic mutations acquired in hematopoietic stem cells (HSCs). Most CH variants occur in the gene DNMT3A, but while DNMT3A-mutant CH becomes almost ubiquitous in aging humans, a unifying molecular mechanism to illuminate how DNMT3A-mutant HSCs outcompete their counterparts is lacking. Here, we used interferon gamma (IFNγ) as a model to study the mechanisms by which Dnmt3a mutations increase HSC fitness under hematopoietic stress. We found Dnmt3a-mutant HSCs resist IFNγ-mediated depletion, and IFNγ-signaling is required for clonal expansion of Dnmt3a-mutant HSCs in vivo. Mechanistically, DNA hypomethylation-associated overexpression of Txnip in Dnmt3a-mutant HSCs leads to p53 stabilization and upregulation of p21. This preserves the functional potential of Dnmt3a-mutant HSCs through increased quiescence and resistance to IFNγ-induced apoptosis. These data identify a previously undescribed mechanism to explain increased fitness of DNMT3A-mutant clones under hematopoietic stress. SIGNIFICANCE DNMT3A mutations are common variants in clonal hematopoiesis, and recurrent events in blood cancers. Yet the mechanisms by which these mutations provide hematopoietic stem cells a competitive advantage as a precursor to malignant transformation remain unclear. Here, we use inflammatory stress to uncover molecular mechanisms leading to this fitness advantage. See related article by De Dominici and James DeGregori .
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Affiliation(s)
- Christine R Zhang
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Elizabeth L Ostrander
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Ostap Kukhar
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Cates Mallaney
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Jiameng Sun
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Emily Haussler
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Hamza Celik
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Won Kyun Koh
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Katherine Y King
- Section of Infectious Diseases, Department of Pediatrics, Baylor College of Medicine, Houston, Texas
| | - Paul Gontarz
- Center of Regenerative Medicine, Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri
| | - Grant A Challen
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
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2
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Ostrander EL, Kramer AC, Mallaney C, Celik H, Koh WK, Fairchild J, Haussler E, Zhang CRC, Challen GA. Divergent Effects of Dnmt3a and Tet2 Mutations on Hematopoietic Progenitor Cell Fitness. Stem Cell Reports 2020; 14:551-560. [PMID: 32220332 PMCID: PMC7160307 DOI: 10.1016/j.stemcr.2020.02.011] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 02/25/2020] [Accepted: 02/26/2020] [Indexed: 12/14/2022] Open
Abstract
The DNA methylation regulators DNMT3A and TET2 are recurrently mutated in hematological disorders. Despite possessing antagonistic biochemical activities, loss-of-function murine models show overlapping phenotypes in terms of increased hematopoietic stem cell (HSC) fitness. Here, we directly compared the effects of these mutations on hematopoietic progenitor function and disease initiation. In contrast to Dnmt3a-null HSCs, which possess limitless self-renewal in vivo, Tet2-null HSCs unexpectedly exhaust at the same rate as control HSCs in serial transplantation assays despite an initial increase in self-renewal. Moreover, loss of Tet2 more acutely sensitizes hematopoietic cells to the addition of a common co-operating mutation (Flt3ITD) than loss of Dnmt3a, which is associated with a more rapid expansion of committed progenitor cells. The effect of Tet2 mutation manifests more profound myeloid lineage skewing in committed hematopoietic progenitor cells rather than long-term HSCs. Molecular characterization revealed divergent transcriptomes and chromatin accessibility underlying these functional differences. Tet2-null HSCs exhaust at the same rate as wild-type HSCs in serial transplantation Loss of Tet2 sensitizes cells to Flt3ITD mutation more dramatically than Dnmt3a Loss of Dnmt3a permits epigenetic plasticity between hematopoietic progenitors Tet2 deficiency manifests profound myeloid lineage skewing in progenitor cells
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Affiliation(s)
- Elizabeth L Ostrander
- Division of Oncology, Department of Medicine, Washington University School of Medicine, 660 Euclid Avenue, St. Louis, MO 63110, USA
| | - Ashley C Kramer
- Division of Oncology, Department of Medicine, Washington University School of Medicine, 660 Euclid Avenue, St. Louis, MO 63110, USA
| | - Cates Mallaney
- Division of Oncology, Department of Medicine, Washington University School of Medicine, 660 Euclid Avenue, St. Louis, MO 63110, USA
| | - Hamza Celik
- Division of Oncology, Department of Medicine, Washington University School of Medicine, 660 Euclid Avenue, St. Louis, MO 63110, USA
| | - Won Kyun Koh
- Division of Oncology, Department of Medicine, Washington University School of Medicine, 660 Euclid Avenue, St. Louis, MO 63110, USA
| | - Jake Fairchild
- Division of Oncology, Department of Medicine, Washington University School of Medicine, 660 Euclid Avenue, St. Louis, MO 63110, USA
| | - Emily Haussler
- Division of Oncology, Department of Medicine, Washington University School of Medicine, 660 Euclid Avenue, St. Louis, MO 63110, USA
| | - Christine R C Zhang
- Division of Oncology, Department of Medicine, Washington University School of Medicine, 660 Euclid Avenue, St. Louis, MO 63110, USA
| | - Grant A Challen
- Division of Oncology, Department of Medicine, Washington University School of Medicine, 660 Euclid Avenue, St. Louis, MO 63110, USA.
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3
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Zhang CRC, Nix D, Gregory M, Ciorba MA, Ostrander EL, Newberry RD, Spencer DH, Challen GA. Inflammatory cytokines promote clonal hematopoiesis with specific mutations in ulcerative colitis patients. Exp Hematol 2019; 80:36-41.e3. [PMID: 31812712 PMCID: PMC7031927 DOI: 10.1016/j.exphem.2019.11.008] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 11/22/2019] [Accepted: 11/25/2019] [Indexed: 01/01/2023]
Abstract
Epidemiological sequencing studies have revealed that somatic mutations characteristic of myeloid neoplasms can be detected in the blood of asymptomatic individuals decades prior to presentation of any clinical symptoms. This premalignant condition is known as clonal hematopoiesis of indeterminate potential (CHIP). Despite the fact these mutant clones become readily detectable in the blood of elderly individuals (∼10% of people over the age of 65), the overall rate of disease progression remains relatively low. Thus, in addition to genetic mutations, there are likely environmental factors that contribute to clonal evolution in people with CHIP. One environmental stress that increases with age is inflammation. Although chronic inflammation is detrimental to the long-term function of normal hematopoietic stem cells, several recent studies in animal models have indicated hematopoietic stem cells with CHIP mutations may be resistant to these deleterious effects. However, direct evidence indicating a correlation between increased inflammation and accelerated CHIP in humans is currently lacking. In this study, we sequenced the peripheral blood cells of a cohort of patients with ulcerative colitis, an autoimmune disease characterized by increased levels of pro-inflammatory cytokines. This analysis revealed that the inflammatory environment of ulcerative colitis promoted CHIP with a distinct mutational spectrum, notably positive selection of clones with DNMT3A and PPM1D mutations. We also show a specific association between elevated levels of serum interferon gamma and DNMT3A mutations. These data add to our understanding of how cell extrinsic factors select for clones with specific mutations to promote clonal hematopoiesis.
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Affiliation(s)
- Christine RC Zhang
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA, 63110
| | - Darren Nix
- Division of Gastroenterology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA, 63110
| | - Martin Gregory
- Division of Gastroenterology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA, 63110
| | - Matthew A. Ciorba
- Division of Gastroenterology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA, 63110
| | - Elizabeth L. Ostrander
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA, 63110
| | - Rodney D. Newberry
- Division of Gastroenterology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA, 63110
| | - David H. Spencer
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA, 63110
| | - Grant A. Challen
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA, 63110
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4
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Jeong M, Park HJ, Celik H, Ostrander EL, Reyes JM, Guzman A, Rodriguez B, Lei Y, Lee Y, Ding L, Guryanova OA, Li W, Goodell MA, Challen GA. Loss of Dnmt3a Immortalizes Hematopoietic Stem Cells In Vivo. Cell Rep 2019; 23:1-10. [PMID: 29617651 PMCID: PMC5908249 DOI: 10.1016/j.celrep.2018.03.025] [Citation(s) in RCA: 123] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 01/19/2018] [Accepted: 03/07/2018] [Indexed: 12/22/2022] Open
Abstract
Somatic mutations in DNMT3A are recurrent events across a range of blood cancers. Dnmt3a loss of function in hematopoietic stem cells (HSCs) skews divisions toward self-renewal at the expense of differentiation. Moreover, DNMT3A mutations can be detected in the blood of aging individuals, indicating that mutant cells outcompete normal HSCs over time. It is important to understand how these mutations provide a competitive advantage to HSCs. Here we show that Dnmt3a-null HSCs can regenerate over at least 12 transplant generations in mice, far exceeding the lifespan of normal HSCs. Molecular characterization reveals that this in vivo immortalization is associated with gradual and focal losses of DNA methylation at key regulatory regions associated with self-renewal genes, producing a highly stereotypical HSC phenotype in which epigenetic features are further buttressed. These findings lend insight into the preponderance of DNMT3A mutations in clonal hematopoiesis and the persistence of mutant clones after chemotherapy.
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Affiliation(s)
- Mira Jeong
- Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Hyun Jung Park
- Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Hamza Celik
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Elizabeth L Ostrander
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Jaime M Reyes
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Anna Guzman
- Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Benjamin Rodriguez
- Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Yong Lei
- Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, TX 77030, USA
| | - Yeojin Lee
- Columbia Stem Cell Initiative, Department of Rehabilitation and Regenerative Medicine, Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY 10032, USA
| | - Lei Ding
- Columbia Stem Cell Initiative, Department of Rehabilitation and Regenerative Medicine, Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY 10032, USA
| | - Olga A Guryanova
- Department of Pharmacology and Therapeutics, University of Florida College of Medicine, and UF Health Cancer Center, Gainesville, FL 32610, USA
| | - Wei Li
- Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Margaret A Goodell
- Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
| | - Grant A Challen
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA; Developmental, Regenerative and Stem Cell Biology Program, Division of Biology and Biomedical Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA.
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5
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Mallaney C, Ostrander EL, Celik H, Kramer AC, Martens A, Kothari A, Koh WK, Haussler E, Iwamori N, Gontarz P, Zhang B, Challen GA. Kdm6b regulates context-dependent hematopoietic stem cell self-renewal and leukemogenesis. Leukemia 2019; 33:2506-2521. [PMID: 30936419 PMCID: PMC6773521 DOI: 10.1038/s41375-019-0462-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 02/28/2019] [Accepted: 03/18/2019] [Indexed: 12/20/2022]
Abstract
The histone demethylase KDM6B (JMJD3) is upregulated in blood disorders, suggesting it may have important pathogenic functions. Here we examined the function of Kdm6b in hematopoietic stem cells (HSC) to evaluate its potential as a therapeutic target. Loss of Kdm6b lead to depletion of phenotypic and functional HSCs in adult mice, and Kdm6b is necessary for HSC self-renewal in response to inflammatory and proliferative stress. Loss of Kdm6b leads to a pro-differentiation poised state in HSCs due to the increased expression of the AP-1 transcription factor complex (Fos and Jun) and immediate early response (IER) genes. These gene expression changes occurred independently of chromatin modifications. Targeting AP-1 restored function of Kdm6b-deficient HSCs, suggesting Kdm6b regulates this complex during HSC stress response. We also show Kdm6b supports developmental context-dependent leukemogenesis for T-cell acute lymphoblastic leukemia (T-ALL) and M5 acute myeloid leukemia (AML). Kdm6b is required for effective fetal-derived T-ALL and adult-derived AML, but not vice versa. These studies identify a crucial role for Kdm6b in regulating HSC self-renewal in different contexts, and highlight the potential of KDM6B as a therapeutic target in different hematopoietic malignancies.
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Affiliation(s)
- Cates Mallaney
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Elizabeth L Ostrander
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Hamza Celik
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Ashley C Kramer
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Andrew Martens
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Alok Kothari
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Won Kyun Koh
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Emily Haussler
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Naoki Iwamori
- Laboratory of Biomedicine, Division of Pathobiology, Department of Basic Medicine, Faculty of Medicine, Kyushu University, Fukuoka, 812-8582, Japan
| | - Paul Gontarz
- Center of Regenerative Medicine, Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Bo Zhang
- Center of Regenerative Medicine, Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Grant A Challen
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA.
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6
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Celik H, Koh WK, Kramer AC, Ostrander EL, Mallaney C, Fisher DAC, Xiang J, Wilson WC, Martens A, Kothari A, Fishberger G, Tycksen E, Karpova D, Duncavage EJ, Lee Y, Oh ST, Challen GA. JARID2 Functions as a Tumor Suppressor in Myeloid Neoplasms by Repressing Self-Renewal in Hematopoietic Progenitor Cells. Cancer Cell 2018; 34:741-756.e8. [PMID: 30423295 PMCID: PMC6237100 DOI: 10.1016/j.ccell.2018.10.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 08/20/2018] [Accepted: 10/15/2018] [Indexed: 12/18/2022]
Abstract
How specific genetic lesions contribute to transformation of non-malignant myeloproliferative neoplasms (MPNs) and myelodysplastic syndromes (MDSs) to secondary acute myeloid leukemia (sAML) are poorly understood. JARID2 is lost by chromosomal deletions in a proportion of MPN/MDS cases that progress to sAML. In this study, genetic mouse models and patient-derived xenografts demonstrated that JARID2 acts as a tumor suppressor in chronic myeloid disorders. Genetic deletion of Jarid2 either reduced overall survival of animals with MPNs or drove transformation to sAML, depending on the timing and context of co-operating mutations. Mechanistically, JARID2 recruits PRC2 to epigenetically repress self-renewal pathways in hematopoietic progenitor cells. These studies establish JARID2 as a bona fide hematopoietic tumor suppressor and highlight potential therapeutic targets.
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MESH Headings
- Animals
- CRISPR-Cas Systems
- Cell Line, Tumor
- Cell Self Renewal/genetics
- Cell Self Renewal/physiology
- Cell Transformation, Neoplastic/genetics
- Cell Transformation, Neoplastic/pathology
- Female
- Gene Deletion
- Gene Knockdown Techniques
- Genes, Tumor Suppressor
- Humans
- Leukemia, Myeloid, Acute/genetics
- Leukemia, Myeloid, Acute/pathology
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Myelodysplastic Syndromes/genetics
- Myelodysplastic Syndromes/pathology
- Myeloproliferative Disorders/genetics
- Myeloproliferative Disorders/pathology
- N-Myc Proto-Oncogene Protein/metabolism
- Polycomb Repressive Complex 2/genetics
- Polycomb Repressive Complex 2/metabolism
- RUNX1 Translocation Partner 1 Protein/metabolism
- Transplantation, Heterologous
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Affiliation(s)
- Hamza Celik
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Won Kyun Koh
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Ashley C Kramer
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Elizabeth L Ostrander
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Cates Mallaney
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Daniel A C Fisher
- Division of Hematology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Jingyu Xiang
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - William C Wilson
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Andrew Martens
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Alok Kothari
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Gregory Fishberger
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Eric Tycksen
- Genome Technology Access Center, Department of Genetics, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Darja Karpova
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Eric J Duncavage
- Department of Pathology & Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Youngsook Lee
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Stephen T Oh
- Division of Hematology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Grant A Challen
- Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA; Developmental, Regenerative and Stem Cell Biology Program, Division of Biology and Biomedical Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA.
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7
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Xu Y, Milazzo JP, Somerville TDD, Tarumoto Y, Huang YH, Ostrander EL, Wilkinson JE, Challen GA, Vakoc CR. A TFIID-SAGA Perturbation that Targets MYB and Suppresses Acute Myeloid Leukemia. Cancer Cell 2018; 33:13-28.e8. [PMID: 29316427 PMCID: PMC5764110 DOI: 10.1016/j.ccell.2017.12.002] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 09/22/2017] [Accepted: 12/05/2017] [Indexed: 01/08/2023]
Abstract
Targeting of general coactivators is an emerging strategy to interfere with oncogenic transcription factors (TFs). However, coactivator perturbations often lead to pleiotropic effects by influencing numerous TFs. Here we identify TAF12, a subunit of TFIID and SAGA coactivator complexes, as a selective requirement for acute myeloid leukemia (AML) progression. We trace this dependency to a direct interaction between the TAF12/TAF4 histone-fold heterodimer and the transactivation domain of MYB, a TF with established roles in leukemogenesis. Ectopic expression of the TAF4 histone-fold fragment can efficiently squelch TAF12 in cells, suppress MYB, and regress AML in mice. Our study reveals a strategy for potent MYB inhibition in AML and highlights how an oncogenic TF can be selectively neutralized by targeting a general coactivator complex.
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Affiliation(s)
- Yali Xu
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA; Molecular and Cellular Biology Program, Stony Brook University, New York, NY 11794, USA
| | - Joseph P Milazzo
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | | | - Yusuke Tarumoto
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Yu-Han Huang
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Elizabeth L Ostrander
- Division of Oncology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - John E Wilkinson
- ULAM/Department of Pathology, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA
| | - Grant A Challen
- Division of Oncology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
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8
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Ostrander EL, Koh WK, Mallaney C, Kramer AC, Wilson WC, Zhang B, Challen GA. The GNAS R201C mutation associated with clonal hematopoiesis supports transplantable hematopoietic stem cell activity. Exp Hematol 2017; 57:14-20. [PMID: 28939416 DOI: 10.1016/j.exphem.2017.09.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 09/05/2017] [Accepted: 09/07/2017] [Indexed: 12/29/2022]
Abstract
Genome sequencing efforts have identified virtually all of the important mutations in adult myeloid malignancies. More recently, population studies have identified cancer-associated variants in the blood of otherwise healthy individuals as they age, a phenomenon termed clonal hematopoiesis of indeterminate potential (CHIP). This suggests that these mutations may occur in hematopoietic stem cells (HSCs) long before any clinical presentation but are not necessarily harbingers of transformation because only a fraction of individuals with CHIP develop hematopoietic pathologies. Delineation between CHIP variants that predispose for disease versus those that are more benign could be used as a prognostic factor to identify individuals at greater risk for transformation. To achieve this, the biological impact of CHIP variants on HSC function must be validated. One variant that has been identified recurrently in CHIP is a gain-of-function missense mutation in the imprinted gene GNAS (Guanine Nucleotide Binding Protein, Alpha Stimulating). In this study, we examined the effect of the GNASR201C variant on HSC function. Ectopic expression of GNASR201C supported transplantable HSC activity and improved lymphoid output in secondary recipients. Because declining lymphoid output is a hallmark of aging, GNASR201C mutations may sustain lymphoid-biased HSCs over time and maintain them in a developmental state favorable for transformation.
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Affiliation(s)
- Elizabeth L Ostrander
- Division of Oncology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO, USA; Human and Statistical Genetics, Division of Biology and Biomedical Sciences, Washington University School of Medicine, St. Louis, MO, USA
| | - Won Kyun Koh
- Division of Oncology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Cates Mallaney
- Division of Oncology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO, USA; Human and Statistical Genetics, Division of Biology and Biomedical Sciences, Washington University School of Medicine, St. Louis, MO, USA
| | - Ashley C Kramer
- Division of Oncology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - W Casey Wilson
- Division of Oncology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Bo Zhang
- Center of Regenerative Medicine, Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, USA
| | - Grant A Challen
- Division of Oncology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO, USA; Developmental, Regenerative and Stem Cell Biology Program, Division of Biology and Biomedical Sciences, Washington University School of Medicine, St. Louis, MO, USA.
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9
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Ge X, d'Avignon DA, Ackerman JJH, Collavo A, Sattin M, Ostrander EL, Hall EL, Sammons RD, Preston C. Vacuolar glyphosate-sequestration correlates with glyphosate resistance in ryegrass (Lolium spp.) from Australia, South America, and Europe: a 31P NMR investigation. J Agric Food Chem 2012; 60:1243-50. [PMID: 22224711 DOI: 10.1021/jf203472s] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Lolium spp., ryegrass, variants from Australia, Brazil, Chile, and Italy showing differing levels of glyphosate resistance were examined by (31)P NMR. Extents of glyphosate (i) resistance (LD(50)), (ii) inhibition of 5-enopyruvyl-shikimate-3-phosphate synthase (EPSPS) activity (IC(50)), and (iii) translocation were quantified for glyphosate-resistant (GR) and glyphosate-sensitive (GS) Lolium multiflorum Lam. variants from Chile and Brazil. For comparison, LD(50) and IC(50) data for Lolium rigidum Gaudin variants from Italy were also analyzed. All variants showed similar cellular uptake of glyphosate by (31)P NMR. All GR variants showed glyphosate sequestration within the cell vacuole, whereas there was minimal or no vacuole sequestration in the GS variants. The extent of vacuole sequestration correlated qualitatively with the level of resistance. Previous (31)P NMR studies of horseweed ( Conyza canadensis (L.) Cronquist) revealed that glyphosate sequestration imparted glyphosate resistance. Data presented herein suggest that glyphosate vacuolar sequestration is strongly contributing, if not the major contributing, resistance mechanism in ryegrass as well.
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Affiliation(s)
- Xia Ge
- Department of Chemistry, Washington University, St. Louis, Missouri 63130, United States
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Ostrander EL, Larson JD, Schuermann JP, Tanner JJ. A conserved active site tyrosine residue of proline dehydrogenase helps enforce the preference for proline over hydroxyproline as the substrate. Biochemistry 2009; 48:951-9. [PMID: 19140736 DOI: 10.1021/bi802094k] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Proline dehydrogenase (PRODH) catalyzes the oxidation of l-proline to Delta-1-pyrroline-5-carboxylate. PRODHs exhibit a pronounced preference for proline over hydroxyproline (trans-4-hydroxy-l-proline) as the substrate, but the basis for specificity is unknown. The goal of this study, therefore, is to gain insight into the structural determinants of substrate specificity of this class of enzyme, with a focus on understanding how PRODHs discriminate between the two closely related molecules, proline and hydroxyproline. Two site-directed mutants of the PRODH domain of Escherichia coli PutA were created: Y540A and Y540S. Kinetics measurements were performed with both mutants. Crystal structures of Y540S complexed with hydroxyproline, proline, and the proline analogue l-tetrahydro-2-furoic acid were determined at resolutions of 1.75, 1.90, and 1.85 A, respectively. Mutation of Tyr540 increases the catalytic efficiency for hydroxyproline 3-fold and decreases the specificity for proline by factors of 20 (Y540S) and 50 (Y540A). The structures show that removal of the large phenol side chain increases the volume of the substrate-binding pocket, allowing sufficient room for the 4-hydroxyl of hydroxyproline. Furthermore, the introduced serine residue participates in recognition of hydroxyproline by forming a hydrogen bond with the 4-hydroxyl. This result has implications for understanding the substrate specificity of the related enzyme human hydroxyproline dehydrogenase, which has serine in place of tyrosine at this key active site position. The kinetic and structural results suggest that Tyr540 is an important determinant of specificity. Structurally, it serves as a negative filter for hydroxyproline by clashing with the 4-hydroxyl group of this potential substrate.
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