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1.
Nat Genet ; 53(10): 1443-1455, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34556857

RESUMO

Altered transcription is a cardinal feature of acute myeloid leukemia (AML); however, exactly how mutations synergize to remodel the epigenetic landscape and rewire three-dimensional DNA topology is unknown. Here, we apply an integrated genomic approach to a murine allelic series that models the two most common mutations in AML: Flt3-ITD and Npm1c. We then deconvolute the contribution of each mutation to alterations of the epigenetic landscape and genome organization, and infer how mutations synergize in the induction of AML. Our studies demonstrate that Flt3-ITD signals to chromatin to alter the epigenetic environment and synergizes with mutations in Npm1c to alter gene expression and drive leukemia induction. These analyses also allow the identification of long-range cis-regulatory circuits, including a previously unknown superenhancer of Hoxa locus, as well as larger and more detailed gene-regulatory networks, driven by transcription factors including PU.1 and IRF8, whose importance we demonstrate through perturbation of network members.


Assuntos
Montagem e Desmontagem da Cromatina/genética , DNA de Neoplasias/química , Regulação Leucêmica da Expressão Gênica , Histonas/metabolismo , Leucemia Mieloide Aguda/genética , Mutação/genética , Processamento de Proteína Pós-Traducional , Animais , Sequência de Bases , Modelos Animais de Doenças , Elementos Facilitadores Genéticos/genética , Redes Reguladoras de Genes , Loci Gênicos , Humanos , Camundongos Endogâmicos C57BL , Proteínas Nucleares/metabolismo , Análise de Componente Principal , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transcrição Genética , Tirosina Quinase 3 Semelhante a fms/metabolismo
2.
Blood Adv ; 5(9): 2412-2425, 2021 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-33956058

RESUMO

Advances in cancer genomics have revealed genomic classes of acute myeloid leukemia (AML) characterized by class-defining mutations, such as chimeric fusion genes or in genes such as NPM1, MLL, and CEBPA. These class-defining mutations frequently synergize with internal tandem duplications in FLT3 (FLT3-ITDs) to drive leukemogenesis. However, ∼20% of FLT3-ITD-positive AMLs bare no class-defining mutations, and mechanisms of leukemic transformation in these cases are unknown. To identify pathways that drive FLT3-ITD mutant AML in the absence of class-defining mutations, we performed an insertional mutagenesis (IM) screening in Flt3-ITD mice, using Sleeping Beauty transposons. All mice developed acute leukemia (predominantly AML) after a median of 73 days. Analysis of transposon insertions in 38 samples from Flt3-ITD/IM leukemic mice identified recurrent integrations at 22 loci, including Setbp1 (20/38), Ets1 (11/38), Ash1l (8/38), Notch1 (8/38), Erg (7/38), and Runx1 (5/38). Insertions at Setbp1 led exclusively to AML and activated a transcriptional program similar, but not identical, to those of NPM1-mutant and MLL-rearranged AMLs. Guide RNA targeting of Setbp1 was highly detrimental to Flt3ITD/+/Setbp1IM+, but not to Flt3ITD/+/Npm1cA/+, AMLs. Also, analysis of RNA-sequencing data from hundreds of human AMLs revealed that SETBP1 expression is significantly higher in FLT3-ITD AMLs lacking class-defining mutations. These findings propose that SETBP1 overexpression collaborates with FLT3-ITD to drive a subtype of human AML. To identify genetic vulnerabilities of these AMLs, we performed genome-wide CRISPR-Cas9 screening in Flt3ITD/+/Setbp1IM+ AMLs and identified potential therapeutic targets, including Kdm1a, Brd3, Ezh2, and Hmgcr. Our study gives new insights into epigenetic pathways that can drive AMLs lacking class-defining mutations and proposes therapeutic approaches against such cases.


Assuntos
Leucemia Mieloide Aguda , Doença Aguda , Animais , Proteínas de Ligação a DNA , Histona-Lisina N-Metiltransferase , Leucemia Mieloide Aguda/genética , Camundongos , Mutação , Proteínas Nucleares/genética
3.
Nature ; 593(7860): 597-601, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33902106

RESUMO

N6-methyladenosine (m6A) is an abundant internal RNA modification1,2 that is catalysed predominantly by the METTL3-METTL14 methyltransferase complex3,4. The m6A methyltransferase METTL3 has been linked to the initiation and maintenance of acute myeloid leukaemia (AML), but the potential of therapeutic applications targeting this enzyme remains unknown5-7. Here we present the identification and characterization of STM2457, a highly potent and selective first-in-class catalytic inhibitor of METTL3, and a crystal structure of STM2457 in complex with METTL3-METTL14. Treatment of tumours with STM2457 leads to reduced AML growth and an increase in differentiation and apoptosis. These cellular effects are accompanied by selective reduction of m6A levels on known leukaemogenic mRNAs and a decrease in their expression consistent with a translational defect. We demonstrate that pharmacological inhibition of METTL3 in vivo leads to impaired engraftment and prolonged survival in various mouse models of AML, specifically targeting key stem cell subpopulations of AML. Collectively, these results reveal the inhibition of METTL3 as a potential therapeutic strategy against AML, and provide proof of concept that the targeting of RNA-modifying enzymes represents a promising avenue for anticancer therapy.

4.
Leukemia ; 35(4): 1012-1022, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-32764680

RESUMO

Histone acetyltransferases (HATs) catalyze the transfer of an acetyl group from acetyl-CoA to lysine residues of histones and play a central role in transcriptional regulation in diverse biological processes. Dysregulation of HAT activity can lead to human diseases including developmental disorders and cancer. Through genome-wide CRISPR-Cas9 screens, we identified several HATs of the MYST family as fitness genes for acute myeloid leukemia (AML). Here we investigate the essentiality of lysine acetyltransferase KAT7 in AMLs driven by the MLL-X gene fusions. We found that KAT7 loss leads to a rapid and complete loss of both H3K14ac and H4K12ac marks, in association with reduced proliferation, increased apoptosis, and differentiation of AML cells. Acetyltransferase activity of KAT7 is essential for the proliferation of these cells. Mechanistically, our data propose that acetylated histones provide a platform for the recruitment of MLL-fusion-associated adaptor proteins such as BRD4 and AF4 to gene promoters. Upon KAT7 loss, these factors together with RNA polymerase II rapidly dissociate from several MLL-fusion target genes that are essential for AML cell proliferation, including MEIS1, PBX3, and SENP6. Our findings reveal that KAT7 is a plausible therapeutic target for this poor prognosis AML subtype.


Assuntos
Rearranjo Gênico , Predisposição Genética para Doença , Histona Acetiltransferases/genética , Histona-Lisina N-Metiltransferase/genética , Leucemia Mieloide Aguda/genética , Proteína de Leucina Linfoide-Mieloide/genética , Apoptose/genética , Biomarcadores Tumorais , Diferenciação Celular , Linhagem Celular Tumoral , Gerenciamento Clínico , Epigênese Genética , Técnicas de Inativação de Genes , Estudos de Associação Genética , Histona Acetiltransferases/metabolismo , Histona-Lisina N-Metiltransferase/metabolismo , Histonas/metabolismo , Humanos , Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/terapia , Células Mieloides/metabolismo , Células Mieloides/patologia , Proteína de Leucina Linfoide-Mieloide/metabolismo , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/metabolismo , Regiões Promotoras Genéticas , Ligação Proteica
5.
J Exp Med ; 216(4): 966-981, 2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-30890554

RESUMO

Epigenetic regulators, such as EZH2, are frequently mutated in cancer, and loss-of-function EZH2 mutations are common in myeloid malignancies. We have examined the importance of cellular context for Ezh2 loss during the evolution of acute myeloid leukemia (AML), where we observed stage-specific and diametrically opposite functions for Ezh2 at the early and late stages of disease. During disease maintenance, WT Ezh2 exerts an oncogenic function that may be therapeutically targeted. In contrast, Ezh2 acts as a tumor suppressor during AML induction. Transcriptional analysis explains this apparent paradox, demonstrating that loss of Ezh2 derepresses different expression programs during disease induction and maintenance. During disease induction, Ezh2 loss derepresses a subset of bivalent promoters that resolve toward gene activation, inducing a feto-oncogenic program that includes genes such as Plag1, whose overexpression phenocopies Ezh2 loss to accelerate AML induction in mouse models. Our data highlight the importance of cellular context and disease phase for the function of Ezh2 and its potential therapeutic implications.


Assuntos
Progressão da Doença , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/mortalidade , Mutação com Perda de Função , Animais , Células da Medula Óssea/metabolismo , Transplante de Medula Óssea , Linhagem Celular Tumoral , Estudos de Coortes , Modelos Animais de Doenças , Frequência do Gene , Histonas/metabolismo , Humanos , Leucemia Mieloide Aguda/sangue , Leucemia Mieloide Aguda/patologia , Camundongos , Camundongos Endogâmicos C57BL , Prognóstico , Taxa de Sobrevida , Transdução Genética , Transplante Homólogo
6.
Nat Commun ; 9(1): 5378, 2018 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-30568163

RESUMO

We recently identified the splicing kinase gene SRPK1 as a genetic vulnerability of acute myeloid leukemia (AML). Here, we show that genetic or pharmacological inhibition of SRPK1 leads to cell cycle arrest, leukemic cell differentiation and prolonged survival of mice transplanted with MLL-rearranged AML. RNA-seq analysis demonstrates that SRPK1 inhibition leads to altered isoform levels of many genes including several with established roles in leukemogenesis such as MYB, BRD4 and MED24. We focus on BRD4 as its main isoforms have distinct molecular properties and find that SRPK1 inhibition produces a significant switch from the short to the long isoform at the mRNA and protein levels. This was associated with BRD4 eviction from genomic loci involved in leukemogenesis including BCL2 and MYC. We go on to show that this switch mediates at least part of the anti-leukemic effects of SRPK1 inhibition. Our findings reveal that SRPK1 represents a plausible new therapeutic target against AML.


Assuntos
Leucemia Mieloide Aguda/metabolismo , Proteínas Nucleares/metabolismo , Fatores de Transcrição/metabolismo , Pontos de Checagem do Ciclo Celular , Proteínas de Ciclo Celular , Diferenciação Celular , Cromatina/metabolismo , Epigênese Genética , Células HL-60 , Hematopoese , Humanos , Células K562 , Isoformas de Proteínas/metabolismo , /genética , Splicing de RNA
7.
Nat Genet ; 50(6): 883-894, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29736013

RESUMO

The histone H3 Lys27-specific demethylase UTX (or KDM6A) is targeted by loss-of-function mutations in multiple cancers. Here, we demonstrate that UTX suppresses myeloid leukemogenesis through noncatalytic functions, a property shared with its catalytically inactive Y-chromosome paralog, UTY (or KDM6C). In keeping with this, we demonstrate concomitant loss/mutation of KDM6A (UTX) and UTY in multiple human cancers. Mechanistically, global genomic profiling showed only minor changes in H3K27me3 but significant and bidirectional alterations in H3K27ac and chromatin accessibility; a predominant loss of H3K4me1 modifications; alterations in ETS and GATA-factor binding; and altered gene expression after Utx loss. By integrating proteomic and genomic analyses, we link these changes to UTX regulation of ATP-dependent chromatin remodeling, coordination of the COMPASS complex and enhanced pioneering activity of ETS factors during evolution to AML. Collectively, our findings identify a dual role for UTX in suppressing acute myeloid leukemia via repression of oncogenic ETS and upregulation of tumor-suppressive GATA programs.


Assuntos
Cromatina/genética , Elementos Facilitadores Genéticos , Fatores de Transcrição GATA/genética , Histona Desmetilases/genética , Leucemia Mieloide/genética , Proteínas Proto-Oncogênicas c-ets/genética , Animais , Linhagem Celular , Montagem e Desmontagem da Cromatina/genética , Regulação Leucêmica da Expressão Gênica , Células HEK293 , Histonas/genética , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Proteômica/métodos , Sequências Reguladoras de Ácido Nucleico/genética , Ativação Transcricional
8.
Cell Rep ; 17(4): 1193-1205, 2016 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-27760321

RESUMO

Acute myeloid leukemia (AML) is an aggressive cancer with a poor prognosis, for which mainstream treatments have not changed for decades. To identify additional therapeutic targets in AML, we optimize a genome-wide clustered regularly interspaced short palindromic repeats (CRISPR) screening platform and use it to identify genetic vulnerabilities in AML cells. We identify 492 AML-specific cell-essential genes, including several established therapeutic targets such as DOT1L, BCL2, and MEN1, and many other genes including clinically actionable candidates. We validate selected genes using genetic and pharmacological inhibition, and chose KAT2A as a candidate for downstream study. KAT2A inhibition demonstrated anti-AML activity by inducing myeloid differentiation and apoptosis, and suppressed the growth of primary human AMLs of diverse genotypes while sparing normal hemopoietic stem-progenitor cells. Our results propose that KAT2A inhibition should be investigated as a therapeutic strategy in AML and provide a large number of genetic vulnerabilities of this leukemia that can be pursued in downstream studies.


Assuntos
Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/genética , Testes Genéticos , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/terapia , Terapia de Alvo Molecular , Adulto , Apoptose , Diferenciação Celular , Linhagem Celular Tumoral , Proliferação de Células , Histona Acetiltransferases/antagonistas & inibidores , Histona Acetiltransferases/metabolismo , Humanos , Reprodutibilidade dos Testes
9.
Cell Rep ; 9(4): 1361-74, 2014 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-25456131

RESUMO

JNK and p38 phosphorylate a diverse set of substrates and, consequently, can act in a context-dependent manner to either promote or inhibit tumor growth. Elucidating the functions of specific substrates of JNK and p38 is therefore critical for our understanding of these kinases in cancer. ATF2 is a phosphorylation-dependent transcription factor and substrate of both JNK and p38. Here, we show ATF2 suppresses tumor formation in an orthotopic model of liver cancer and cellular transformation in vitro. Furthermore, we find that suppression of tumorigenesis by JNK requires ATF2. We identify a transcriptional program activated by JNK via ATF2 and provide examples of JNK- and ATF2-dependent genes that block cellular transformation. Significantly, we also show that ATF2-dependent gene expression is frequently downregulated in human cancers, indicating that amelioration of JNK-ATF2-mediated suppression may be a common event during tumor development.


Assuntos
Fator 2 Ativador da Transcrição/metabolismo , Carcinogênese/genética , Carcinogênese/patologia , Regulação Neoplásica da Expressão Gênica , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Fator 2 Ativador da Transcrição/química , Fator 2 Ativador da Transcrição/genética , Animais , Apoptose/genética , Linhagem Celular Tumoral , Proliferação de Células , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/patologia , Humanos , Neoplasias Hepáticas/enzimologia , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Camundongos , Fosforilação , Estrutura Terciária de Proteína , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transcrição Genética , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Proteínas ras/metabolismo
10.
Biochem Soc Trans ; 40(1): 230-4, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22260696

RESUMO

MAPK (mitogen-activated protein kinase) pathways are among the most frequently deregulated signalling events in cancer. Among the critical targets of MAPK activities are members of the AP-1 (activator protein 1) transcription factor, a dimeric complex consisting of Jun, Fos, Maf and ATF (activating transcription factor) family DNA-binding proteins. Depending on the cellular context, the composition of the dimeric complexes determines the regulation of growth, survival or apoptosis. JNK (c-Jun N-terminal kinase), p38 and a number of Jun and Fos family proteins have been analysed for their involvement in oncogenic transformation and tumour formation. These data are also emerging for the ATF components of the AP-1 factor. The aim of the present review is to provide an overview of the functions of two ATF family proteins, ATF2 and ATF7, in mammalian development and their potential functions in tumour formation.


Assuntos
Fator 2 Ativador da Transcrição/metabolismo , Transformação Celular Neoplásica , Fator 2 Ativador da Transcrição/genética , Fatores Ativadores da Transcrição/genética , Fatores Ativadores da Transcrição/metabolismo , Animais , Regulação Neoplásica da Expressão Gênica , Técnicas de Inativação de Genes , Genes Supressores de Tumor , Humanos , Sistema de Sinalização das MAP Quinases , Neoplasias/genética , Oncogenes , Fosforilação
11.
PLoS One ; 4(6): e5803, 2009 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-19495412

RESUMO

Heme oxygenase-1 (HO-1), a cytoprotective, pro-angiogenic and anti-inflammatory enzyme, is strongly induced in injured tissues. Our aim was to clarify its role in cutaneous wound healing. In wild type mice, maximal expression of HO-1 in the skin was observed on the 2(nd) and 3(rd) days after wounding. Inhibition of HO-1 by tin protoporphyrin-IX resulted in retardation of wound closure. Healing was also delayed in HO-1 deficient mice, where lack of HO-1 could lead to complete suppression of reepithelialization and to formation of extensive skin lesions, accompanied by impaired neovascularization. Experiments performed in transgenic mice bearing HO-1 under control of keratin 14 promoter showed that increased level of HO-1 in keratinocytes is enough to improve the neovascularization and hasten the closure of wounds. Importantly, induction of HO-1 in wounded skin was relatively weak and delayed in diabetic (db/db) mice, in which also angiogenesis and wound closure were impaired. In such animals local delivery of HO-1 transgene using adenoviral vectors accelerated the wound healing and increased the vascularization. In summary, induction of HO-1 is necessary for efficient wound closure and neovascularization. Impaired wound healing in diabetic mice may be associated with delayed HO-1 upregulation and can be improved by HO-1 gene transfer.


Assuntos
Heme Oxigenase-1/fisiologia , Cicatrização , Adenoviridae , Inibidores da Angiogênese/farmacologia , Animais , Anti-Inflamatórios/farmacologia , Diabetes Mellitus Experimental/patologia , Técnicas de Transferência de Genes , Humanos , Inflamação , Queratinas/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Regiões Promotoras Genéticas , Transgenes
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