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1.
Mol Cell ; 67(1): 5-18.e19, 2017 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-28673542

RESUMO

Processive elongation of RNA Polymerase II from a proximal promoter paused state is a rate-limiting event in human gene control. A small number of regulatory factors influence transcription elongation on a global scale. Prior research using small-molecule BET bromodomain inhibitors, such as JQ1, linked BRD4 to context-specific elongation at a limited number of genes associated with massive enhancer regions. Here, the mechanistic characterization of an optimized chemical degrader of BET bromodomain proteins, dBET6, led to the unexpected identification of BET proteins as master regulators of global transcription elongation. In contrast to the selective effect of bromodomain inhibition on transcription, BET degradation prompts a collapse of global elongation that phenocopies CDK9 inhibition. Notably, BRD4 loss does not directly affect CDK9 localization. These studies, performed in translational models of T cell leukemia, establish a mechanism-based rationale for the development of BET bromodomain degradation as cancer therapy.


Assuntos
Quinase 9 Dependente de Ciclina/metabolismo , Proteínas Nucleares/metabolismo , Leucemia-Linfoma Linfoblástico de Células T Precursoras/metabolismo , Elongação da Transcrição Genética , Fatores de Transcrição/metabolismo , Proteínas Adaptadoras de Transdução de Sinal , Animais , Antineoplásicos/farmacologia , Proteínas de Ciclo Celular , Quinase 9 Dependente de Ciclina/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Relação Dose-Resposta a Droga , Feminino , Regulação Leucêmica da Expressão Gênica , Células HCT116 , Células HEK293 , Humanos , Células Jurkat , Camundongos Endogâmicos NOD , Camundongos SCID , Camundongos Transgênicos , Complexos Multiproteicos , Proteínas Nucleares/genética , Peptídeo Hidrolases/genética , Peptídeo Hidrolases/metabolismo , Leucemia-Linfoma Linfoblástico de Células T Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Estabilidade Proteica , Proteólise , RNA Polimerase II/metabolismo , Fatores de Tempo , Elongação da Transcrição Genética/efeitos dos fármacos , Fatores de Transcrição/genética , Transfecção , Ubiquitina-Proteína Ligases , Ensaios Antitumorais Modelo de Xenoenxerto
2.
Blood ; 137(4): 500-512, 2021 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-33507291

RESUMO

Glucocorticoid (GC) resistance remains a clinical challenge in pediatric acute lymphoblastic leukemia where response to GC is a reliable prognostic indicator. To identify GC resistance pathways, we conducted a genome-wide, survival-based, short hairpin RNA screen in murine T-cell acute lymphoblastic leukemia (T-ALL) cells. Genes identified in the screen interfere with cyclic adenosine monophosphate (cAMP) signaling and are underexpressed in GC-resistant or relapsed ALL patients. Silencing of the cAMP-activating Gnas gene interfered with GC-induced gene expression, resulting in dexamethasone resistance in vitro and in vivo. We demonstrate that cAMP signaling synergizes with dexamethasone to enhance cell death in GC-resistant human T-ALL cells. We find the E prostanoid receptor 4 expressed in T-ALL samples and demonstrate that prostaglandin E2 (PGE2) increases intracellular cAMP, potentiates GC-induced gene expression, and sensitizes human T-ALL samples to dexamethasone in vitro and in vivo. These findings identify PGE2 as a target for GC resensitization in relapsed pediatric T-ALL.


Assuntos
AMP Cíclico/fisiologia , Dexametasona/farmacologia , Dinoprostona/farmacologia , Leucemia-Linfoma Linfoblástico de Células T Precursoras/tratamento farmacológico , Sistemas do Segundo Mensageiro/efeitos dos fármacos , 1-Metil-3-Isobutilxantina/farmacologia , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Linhagem Celular Tumoral , Criança , Cromograninas/antagonistas & inibidores , Colforsina/farmacologia , AMP Cíclico/farmacologia , Dexametasona/administração & dosagem , Dinoprostona/administração & dosagem , Dinoprostona/antagonistas & inibidores , Dinoprostona/fisiologia , Resistencia a Medicamentos Antineoplásicos/genética , Resistencia a Medicamentos Antineoplásicos/fisiologia , Feminino , Subunidades alfa Gs de Proteínas de Ligação ao GTP/antagonistas & inibidores , Subunidades alfa Gs de Proteínas de Ligação ao GTP/deficiência , Regulação Leucêmica da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Camundongos , Modelos Animais , Terapia de Alvo Molecular , Proteínas de Neoplasias/biossíntese , Proteínas de Neoplasias/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/metabolismo , Leucemia-Linfoma Linfoblástico de Células T Precursoras/patologia , Interferência de RNA , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/farmacologia , Quimera por Radiação , Receptores de Glucocorticoides/biossíntese , Receptores de Glucocorticoides/genética , Receptores de Glucocorticoides/fisiologia , Receptores de Prostaglandina E Subtipo EP4/biossíntese , Receptores de Prostaglandina E Subtipo EP4/genética , Ensaios Antitumorais Modelo de Xenoenxerto
3.
J Immunol ; 200(2): 737-748, 2018 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-29212904

RESUMO

Necroptosis is a form of cell death associated with inflammation; however, the biological consequences of chronic necroptosis are unknown. Necroptosis is mediated by RIPK1, RIPK3, and MLKL kinases but in hematopoietic cells RIPK1 has anti-inflammatory roles and functions to prevent necroptosis. Here we interrogate the consequences of chronic necroptosis on immune homeostasis by deleting Ripk1 in mouse dendritic cells. We demonstrate that deregulated necroptosis results in systemic inflammation, tissue fibrosis, and autoimmunity. We show that inflammation and autoimmunity are prevented upon expression of kinase inactive RIPK1 or deletion of RIPK3 or MLKL. We provide evidence that the inflammation is not driven by microbial ligands, but depends on the release of danger-associated molecular patterns and MyD88-dependent signaling. Importantly, although the inflammation is independent of type I IFN and the nucleic acid sensing TLRs, blocking these pathways rescues the autoimmunity. These mouse genetic studies reveal that chronic necroptosis may underlie human fibrotic and autoimmune disorders.


Assuntos
Autoimunidade , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Imunidade , Inflamação/etiologia , Inflamação/metabolismo , Proteína Serina-Treonina Quinases de Interação com Receptores/genética , Animais , Autoanticorpos/imunologia , Autoimunidade/genética , Linfócitos B/imunologia , Linfócitos B/metabolismo , Citocinas/metabolismo , Modelos Animais de Doenças , Fibrose , Perfilação da Expressão Gênica , Inflamação/patologia , Inflamação/prevenção & controle , Linfadenopatia/genética , Linfadenopatia/imunologia , Linfadenopatia/metabolismo , Linfadenopatia/patologia , Camundongos , Camundongos Knockout , Fator 88 de Diferenciação Mieloide/genética , Fator 88 de Diferenciação Mieloide/metabolismo , Necrose/genética , Necrose/metabolismo , Proteína Serina-Treonina Quinases de Interação com Receptores/deficiência , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Transdução de Sinais , Receptores Toll-Like/metabolismo
4.
Nature ; 513(7516): 65-70, 2014 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-25079319

RESUMO

The translational control of oncoprotein expression is implicated in many cancers. Here we report an eIF4A RNA helicase-dependent mechanism of translational control that contributes to oncogenesis and underlies the anticancer effects of silvestrol and related compounds. For example, eIF4A promotes T-cell acute lymphoblastic leukaemia development in vivo and is required for leukaemia maintenance. Accordingly, inhibition of eIF4A with silvestrol has powerful therapeutic effects against murine and human leukaemic cells in vitro and in vivo. We use transcriptome-scale ribosome footprinting to identify the hallmarks of eIF4A-dependent transcripts. These include 5' untranslated region (UTR) sequences such as the 12-nucleotide guanine quartet (CGG)4 motif that can form RNA G-quadruplex structures. Notably, among the most eIF4A-dependent and silvestrol-sensitive transcripts are a number of oncogenes, superenhancer-associated transcription factors, and epigenetic regulators. Hence, the 5' UTRs of select cancer genes harbour a targetable requirement for the eIF4A RNA helicase.


Assuntos
Regiões 5' não Traduzidas/genética , Fator de Iniciação 4A em Eucariotos/metabolismo , Quadruplex G , Proteínas Oncogênicas/biossíntese , Proteínas Oncogênicas/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/metabolismo , Biossíntese de Proteínas , Animais , Antineoplásicos Fitogênicos/farmacologia , Antineoplásicos Fitogênicos/uso terapêutico , Sequência de Bases , Linhagem Celular Tumoral , Epigênese Genética , Feminino , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Motivos de Nucleotídeos , Leucemia-Linfoma Linfoblástico de Células T Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Biossíntese de Proteínas/efeitos dos fármacos , Ribossomos/metabolismo , Fatores de Transcrição/metabolismo , Transcrição Gênica/efeitos dos fármacos , Transcrição Gênica/genética , Triterpenos/farmacologia
5.
Blood ; 130(15): 1722-1733, 2017 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-28790107

RESUMO

The gene encoding the RUNX1 transcription factor is mutated in a subset of T-cell acute lymphoblastic leukemia (T-ALL) patients, and RUNX1 mutations are associated with a poor prognosis. These mutations cluster in the DNA-binding Runt domain and are thought to represent loss-of-function mutations, indicating that RUNX1 suppresses T-cell transformation. RUNX1 has been proposed to have tumor suppressor roles in T-cell leukemia homeobox 1/3-transformed human T-ALL cell lines and NOTCH1 T-ALL mouse models. Yet, retroviral insertional mutagenesis screens identify RUNX genes as collaborating oncogenes in MYC-driven leukemia mouse models. To elucidate RUNX1 function(s) in leukemogenesis, we generated Tal1/Lmo2/Rosa26-CreERT2Runx1f/f mice and examined leukemia progression in the presence of vehicle or tamoxifen. We found that Runx1 deletion inhibits mouse leukemic growth in vivo and that RUNX silencing in human T-ALL cells triggers apoptosis. We demonstrate that a small molecule inhibitor, designed to interfere with CBFß binding to RUNX proteins, impairs the growth of human T-ALL cell lines and primary patient samples. We demonstrate that a RUNX1 deficiency alters the expression of a crucial subset of TAL1- and NOTCH1-regulated genes, including the MYB and MYC oncogenes, respectively. These studies provide genetic and pharmacologic evidence that RUNX1 has oncogenic roles and reveal RUNX1 as a novel therapeutic target in T-ALL.


Assuntos
Subunidade alfa 2 de Fator de Ligação ao Core/metabolismo , Elementos Facilitadores Genéticos/genética , Oncogenes , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Proteínas Proto-Oncogênicas c-myb/genética , Proteínas Proto-Oncogênicas c-myc/genética , Animais , Apoptose , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Linhagem Celular Transformada , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular , Cromatina/metabolismo , Subunidade beta de Fator de Ligação ao Core/metabolismo , Deleção de Genes , Regulação Leucêmica da Expressão Gênica , Humanos , Camundongos , Ligação Proteica , Proteínas Proto-Oncogênicas/metabolismo , Receptores Notch/metabolismo , Proteína 1 de Leucemia Linfocítica Aguda de Células T
6.
Proc Natl Acad Sci U S A ; 113(52): 15024-15029, 2016 12 27.
Artigo em Inglês | MEDLINE | ID: mdl-27956626

RESUMO

The p53 tumor suppressor acts as a guardian of the genome by preventing the propagation of DNA damage-induced breaks and mutations to subsequent generations of cells. We have previously shown that phosphorylation of the Mdm2 oncoprotein at Ser394 by the ATM kinase is required for robust p53 stabilization and activation in cells treated with ionizing radiation, and that loss of Mdm2 Ser394 phosphorylation leads to spontaneous tumorigenesis and radioresistance in Mdm2S394A mice. Previous in vitro data indicate that the c-Abl kinase phosphorylates Mdm2 at the neighboring residue (Tyr393) in response to DNA damage to regulate p53-dependent apoptosis. In this present study, we have generated an Mdm2 mutant mouse (Mdm2Y393F) to determine whether c-Abl phosphorylation of Mdm2 regulates the p53-mediated DNA damage response or p53 tumor suppression in vivo. The Mdm2Y393F mice develop accelerated spontaneous and oncogene-induced tumors, yet display no defects in p53 stabilization and activity following acute genotoxic stress. Although apoptosis is unaltered in these mice, they recover more rapidly from radiation-induced bone marrow ablation and are more resistant to whole-body radiation-induced lethality. These data reveal an in vivo role for c-Abl phosphorylation of Mdm2 in regulation of p53 tumor suppression and bone marrow failure. However, c-Abl phosphorylation of Mdm2 Tyr393 appears to play a lesser role in governing Mdm2-p53 signaling than ATM phosphorylation of Mdm2 Ser394. Furthermore, the effects of these phosphorylation events on p53 regulation are not additive, as Mdm2Y393F/S394A mice and Mdm2S394A mice display similar phenotypes.


Assuntos
Regulação Neoplásica da Expressão Gênica , Neoplasias/metabolismo , Proteínas Proto-Oncogênicas c-abl/metabolismo , Proteínas Proto-Oncogênicas c-mdm2/química , Tolerância a Radiação , Proteína Supressora de Tumor p53/metabolismo , Alelos , Animais , Apoptose , Dano ao DNA , Éxons , Feminino , Fibroblastos/metabolismo , Perfilação da Expressão Gênica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neoplasias/genética , Neoplasias/radioterapia , Fosforilação , Processamento de Proteína Pós-Traducional , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Transdução de Sinais
7.
Proc Natl Acad Sci U S A ; 111(40): 14436-41, 2014 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-25246544

RESUMO

Receptor-interacting serine/threonine-protein kinase 1 (RIPK1) is recruited to the TNF receptor 1 to mediate proinflammatory signaling and to regulate TNF-induced cell death. RIPK1 deficiency results in postnatal lethality, but precisely why Ripk1(-/-) mice die remains unclear. To identify the lineages and cell types that depend on RIPK1 for survival, we generated conditional Ripk1 mice. Tamoxifen administration to adult RosaCreER(T2)Ripk1(fl/fl) mice results in lethality caused by cell death in the intestinal and hematopoietic lineages. Similarly, Ripk1 deletion in cells of the hematopoietic lineage stimulates proinflammatory cytokine and chemokine production and hematopoietic cell death, resulting in bone marrow failure. The cell death reflected cell-intrinsic survival roles for RIPK1 in hematopoietic stem and progenitor cells, because Vav-iCre Ripk1(fl/fl) fetal liver cells failed to reconstitute hematopoiesis in lethally irradiated recipients. We demonstrate that RIPK3 deficiency partially rescues hematopoiesis in Vav-iCre Ripk1(fl/fl) mice, showing that RIPK1-deficient hematopoietic cells undergo RIPK3-mediated necroptosis. However, the Vav-iCre Ripk1(fl/fl) Ripk3(-/-) progenitors remain TNF sensitive in vitro and fail to repopulate irradiated mice. These genetic studies reveal that hematopoietic RIPK1 deficiency triggers both apoptotic and necroptotic death that is partially prevented by RIPK3 deficiency. Therefore, RIPK1 regulates hematopoiesis and prevents inflammation by suppressing RIPK3 activation.


Assuntos
Apoptose/fisiologia , Medula Óssea/metabolismo , Proteína Serina-Treonina Quinases de Interação com Receptores/deficiência , Animais , Apoptose/efeitos dos fármacos , Apoptose/genética , Medula Óssea/patologia , Células Cultivadas , Citocinas/sangue , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Antagonistas de Estrogênios/farmacologia , Citometria de Fluxo , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/metabolismo , Mediadores da Inflamação/sangue , Mucosa Intestinal/citologia , Mucosa Intestinal/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Necrose , Proteína Serina-Treonina Quinases de Interação com Receptores/genética , Baço/citologia , Baço/metabolismo , Tamoxifeno/farmacologia , Timo/citologia , Timo/metabolismo , Fator de Necrose Tumoral alfa/farmacologia
8.
Blood ; 123(7): 1040-50, 2014 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-24394663

RESUMO

Although prognosis has improved for children with T-cell acute lymphoblastic leukemia (T-ALL), 20% to 30% of patients undergo induction failure (IF) or relapse. Leukemia-initiating cells (LICs) are hypothesized to be resistant to chemotherapy and to mediate relapse. We and others have shown that Notch1 directly regulates c-Myc, a known regulator of quiescence in stem and progenitor populations, leading us to examine whether c-Myc inhibition results in efficient targeting of T-ALL-initiating cells. We demonstrate that c-Myc suppression by small hairpin RNA or pharmacologic approaches prevents leukemia initiation in mice by eliminating LIC activity. Consistent with its anti-LIC activity in mice, treatment with the BET bromodomain BRD4 inhibitor JQ1 reduces C-MYC expression and inhibits the growth of relapsed and IF pediatric T-ALL samples in vitro. These findings demonstrate a critical role for c-Myc in LIC maintenance and provide evidence that MYC inhibition may be an effective therapy for relapsed/IF T-ALL patients.


Assuntos
Antineoplásicos/uso terapêutico , Proliferação de Células/efeitos dos fármacos , Transformação Celular Neoplásica/efeitos dos fármacos , Quimioterapia de Indução , Células-Tronco Neoplásicas/efeitos dos fármacos , Leucemia-Linfoma Linfoblástico de Células T Precursoras/patologia , Proteínas Proto-Oncogênicas c-myc/antagonistas & inibidores , RNA Interferente Pequeno/farmacologia , Animais , Transformação Celular Neoplásica/genética , Células Cultivadas , Criança , Inativação Gênica , Humanos , Camundongos , Camundongos Transgênicos , Células-Tronco Neoplásicas/patologia , Leucemia-Linfoma Linfoblástico de Células T Precursoras/tratamento farmacológico , Proteínas Proto-Oncogênicas c-myc/genética , RNA Interferente Pequeno/uso terapêutico , Recidiva , Falha de Tratamento
10.
Leukemia ; 38(5): 951-962, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38553571

RESUMO

Relapse in T-cell acute lymphoblastic leukemia (T-ALL) may signify the persistence of leukemia-initiating cells (L-ICs). Ectopic TAL1/LMO expression defines the largest subset of T-ALL, but its role in leukemic transformation and its impact on relapse-driving L-ICs remain poorly understood. In TAL1/LMO mouse models, double negative-3 (DN3; CD4-CD8-CD25+CD44-) thymic progenitors harbored L-ICs. However, only a subset of DN3 leukemic cells exhibited L-IC activity, and studies linking L-ICs and chemotolerance are needed. To investigate L-IC heterogeneity, we used mouse models and applied single-cell RNA-sequencing and nucleosome labeling techniques in vivo. We identified a DN3 subpopulation with a cell cycle-restricted profile and heightened TAL1/LMO2 activity, that expressed genes associated with stemness and quiescence. This dormant DN3 subset progressively expanded throughout leukemogenesis, displaying intrinsic chemotolerance and enrichment in genes linked to minimal residual disease. Examination of TAL/LMO patient samples revealed a similar pattern in CD7+CD1a- thymic progenitors, previously recognized for their L-IC activity, demonstrating cell cycle restriction and chemotolerance. Our findings substantiate the emergence of dormant, chemotolerant L-ICs during leukemogenesis, and demonstrate that Tal1 and Lmo2 cooperate to promote DN3 quiescence during the transformation process. This study provides a deeper understanding of TAL1/LMO-induced T-ALL and its clinical implications in therapy failure.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Proteínas com Domínio LIM , Leucemia-Linfoma Linfoblástico de Células T Precursoras , Proteína 1 de Leucemia Linfocítica Aguda de Células T , Animais , Camundongos , Leucemia-Linfoma Linfoblástico de Células T Precursoras/patologia , Leucemia-Linfoma Linfoblástico de Células T Precursoras/metabolismo , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Proteína 1 de Leucemia Linfocítica Aguda de Células T/metabolismo , Proteína 1 de Leucemia Linfocítica Aguda de Células T/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas com Domínio LIM/metabolismo , Proteínas com Domínio LIM/genética , Timo/metabolismo , Timo/patologia , Humanos , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia
12.
Blood Adv ; 4(13): 3154-3168, 2020 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-32658986

RESUMO

Synthetic glucocorticoids (GCs), such as dexamethasone and prednisone, remain key components of therapy for patients with lymphoid malignancies. For pediatric patients with acute lymphoblastic leukemia (ALL), response to GCs remains the most reliable prognostic indicator; failure to respond to GC correlates with poor event-free survival. To uncover GC resistance mechanisms, we performed a genome-wide, survival-based short hairpin RNA screen and identified the orphan nuclear receptor estrogen-related receptor-ß (ESRRB) as a critical transcription factor that cooperates with the GC receptor (GR) to mediate the GC gene expression signature in mouse and human ALL cells. Esrrb knockdown interfered with the expression of genes that were induced and repressed by GR and resulted in GC resistance in vitro and in vivo. Dexamethasone treatment stimulated ESRRB binding to estrogen-related receptor elements (ERREs) in canonical GC-regulated genes, and H3K27Ac Hi-chromatin immunoprecipitation revealed increased interactions between GR- and ERRE-containing regulatory regions in dexamethasone-treated human T-ALL cells. Furthermore, ESRRB agonists enhanced GC target gene expression and synergized with dexamethasone to induce leukemic cell death, indicating that ESRRB agonists may overcome GC resistance in ALL, and potentially, in other lymphoid malignancies.


Assuntos
Glucocorticoides , Leucemia-Linfoma Linfoblástico de Células Precursoras , Animais , Linhagem Celular Tumoral , Criança , Expressão Gênica , Glucocorticoides/farmacologia , Humanos , Camundongos , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Receptores de Estrogênio , Receptores de Glucocorticoides/genética
13.
Front Immunol ; 9: 1718, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30967879

RESUMO

The NOTCH (1-4) family of receptors are highly conserved and are critical in regulating many developmental processes and in the maintenance of tissue homeostasis. Our laboratory and numerous others have demonstrated that aberrant NOTCH signaling is oncogenic in several different cancer types. Conversely, there is also evidence that NOTCH can also function as a tumor suppressor. In addition to playing an essential role in tumor development, NOTCH receptors regulate T-cell development, maintenance, and activation. Recent studies have determined that NOTCH signaling is required for optimal T-cell-mediated anti-tumor immunity. Consequently, tumor cells and the tumor microenvironment have acquired mechanisms to suppress NOTCH signaling to evade T-cell-mediated killing. Tumor-mediated suppression of NOTCH signaling in T-cells can be overcome by systemic administration of NOTCH agonistic antibodies and ligands or proteasome inhibitors, resulting in sustained NOTCH signaling and T-cell activation. In addition, NOTCH receptors and ligands are being utilized to improve the generation and specificity of T-cells for adoptive transplant immunotherapies. In this review, we will summarize the role(s) of NOTCH signaling in T-cell anti-tumor immunity as well as TCR- and chimeric antigen receptor-based immunotherapies.


Assuntos
Imunidade Celular , Neoplasias/imunologia , Neoplasias/metabolismo , Neoplasias/terapia , Receptores Notch/metabolismo , Transdução de Sinais , Linfócitos T/imunologia , Linfócitos T/metabolismo , Animais , Regulação da Expressão Gênica , Humanos , Imunoterapia Adotiva , Ligantes , Ativação Linfocitária/imunologia , Neoplasias/genética , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores de Antígenos Quiméricos/genética , Receptores de Antígenos Quiméricos/metabolismo , Microambiente Tumoral
14.
J Clin Invest ; 128(5): 2064-2075, 2018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-29664014

RESUMO

Receptor interacting protein kinase 1 (RIPK1) has important kinase-dependent and kinase-independent scaffolding functions that activate or prevent apoptosis or necroptosis in a cell context-dependent manner. The kinase activity of RIPK1 mediates hypothermia and lethality in a mouse model of TNF-induced shock, reflecting the hyperinflammatory state of systemic inflammatory response syndrome (SIRS), where the proinflammatory "cytokine storm" has long been viewed as detrimental. Here, we demonstrate that cytokine and chemokine levels did not predict survival and, importantly, that kinase-inactive Ripk1D138N/D138N hematopoietic cells afforded little protection from TNF- or TNF/zVAD-induced shock in reconstituted mice. Unexpectedly, RIPK1 kinase-inactive mice transplanted with WT hematopoietic cells remained resistant to TNF-induced shock, revealing that a nonhematopoietic lineage mediated protection. TNF-treated Ripk1D138N/D138N mice exhibited no significant increases in intestinal or vascular permeability, nor did they activate the clotting cascade. We show that TNF administration damaged the liver vascular endothelium and induced phosphorylated mixed lineage kinase domain-like (phospho-MLKL) reactivity in endothelial cells isolated from TNF/zVAD-treated WT, but not Ripk1D138N/D138N, mice. These data reveal that the tissue damage present in this SIRS model is reflected, in part, by breaks in the vasculature due to endothelial cell necroptosis and thereby predict that RIPK1 kinase inhibitors may provide clinical benefit to shock and/or sepsis patients.


Assuntos
Endotélio Vascular/enzimologia , Fígado/enzimologia , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Síndrome de Resposta Inflamatória Sistêmica/enzimologia , Clorometilcetonas de Aminoácidos/toxicidade , Animais , Endotélio Vascular/lesões , Endotélio Vascular/patologia , Células-Tronco Hematopoéticas , Fígado/patologia , Camundongos , Camundongos da Linhagem 129 , Camundongos Mutantes , Necrose , Proteína Serina-Treonina Quinases de Interação com Receptores/genética , Síndrome de Resposta Inflamatória Sistêmica/induzido quimicamente , Síndrome de Resposta Inflamatória Sistêmica/genética , Síndrome de Resposta Inflamatória Sistêmica/patologia , Fator de Necrose Tumoral alfa/toxicidade
15.
Cell Rep ; 16(10): 2618-2629, 2016 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-27568562

RESUMO

ATM phosphorylation of Mdm2-S394 is required for robust p53 stabilization and activation in DNA-damaged cells. We have now utilized Mdm2(S394A) knockin mice to determine that phosphorylation of Mdm2-S394 regulates p53 activity and the DNA damage response in lymphatic tissues in vivo by modulating Mdm2 stability. Mdm2-S394 phosphorylation delays lymphomagenesis in Eµ-myc transgenic mice, and preventing Mdm2-S394 phosphorylation obviates the need for p53 mutation in Myc-driven tumorigenesis. However, irradiated Mdm2(S394A) mice also have increased hematopoietic stem and progenitor cell functions, and we observed decreased lymphomagenesis in sub-lethally irradiated Mdm2(S394A) mice. These findings document contrasting effects of ATM-Mdm2 signaling on p53 tumor suppression and reveal that destabilizing Mdm2 by promoting its phosphorylation by ATM would be effective in treating oncogene-induced malignancies, while inhibiting Mdm2-S394 phosphorylation during radiation exposure or chemotherapy would ameliorate bone marrow failure and prevent the development of secondary hematological malignancies.


Assuntos
Carcinogênese/metabolismo , Carcinogênese/efeitos da radiação , Oncogenes , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Radiação Ionizante , Animais , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Medula Óssea/patologia , Medula Óssea/efeitos da radiação , Células-Tronco Hematopoéticas/metabolismo , Células-Tronco Hematopoéticas/efeitos da radiação , Tecido Linfoide/metabolismo , Tecido Linfoide/patologia , Tecido Linfoide/efeitos da radiação , Camundongos Transgênicos , Fosforilação/efeitos da radiação , Fosfosserina/metabolismo , Estabilidade Proteica/efeitos da radiação , Proteínas Proto-Oncogênicas c-myc/metabolismo , Tolerância a Radiação/efeitos da radiação , Transdução de Sinais/efeitos da radiação , Proteína Supressora de Tumor p53/metabolismo
16.
Cancer Cell ; 25(3): 263-5, 2014 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-24651006

RESUMO

Individual cancer cells can exhibit striking differences in tumorigenic potential following experimental transplantation, but the molecular pathways that regulate this activity remain poorly understood. In this issue of Cancer Cell, Blackburn and colleagues report that Akt signaling regulates both leukemia-propagating potential and proliferation rate via distinct pathways in T-ALL.


Assuntos
Evolução Clonal/genética , Complexos Multiproteicos/metabolismo , Leucemia-Linfoma Linfoblástico de Células T Precursoras/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Animais , Humanos , Alvo Mecanístico do Complexo 1 de Rapamicina
17.
Cancer Discov ; 4(9): 1074-87, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24994123

RESUMO

UNLABELLED: Acute lymphoblastic leukemia (ALL) is a hematopoietic malignancy derived from immature B-lymphoid and T-lymphoid cells (T-ALL). In T-ALL, there is an early T-cell progenitor (ETP) subgroup that has a very high risk for relapse. In this study, we used mitochondrial BH3 profiling to determine antiapoptotic protein dependencies in T-ALL. We found that T-ALL cell lines and primary patient samples are dependent upon BCL-XL, except when the cancer bears an ETP phenotype, in which case it is BCL-2 dependent. These distinctions directly relate to differential sensitivity to the BH3 mimetics ABT-263 and ABT-199, both in vitro and in vivo. We thus describe for the first time a change of antiapoptotic protein dependence that is related to the differentiation stage of the leukemic clone. Our findings demonstrate that BCL-2 is a clinically relevant target for therapeutic intervention with ABT-199 in ETP-ALL. SIGNIFICANCE: ETP T-ALL is a treatment-resistant subtype of T-ALL for which novel targeted therapies are urgently needed. We have discovered, through BH3 profiling, that ETP-ALL is BCL-2 dependent and is very sensitive to in vitro and in vivo treatment with ABT-199, a drug well tolerated in clinical trials.


Assuntos
Antineoplásicos/farmacologia , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Resistencia a Medicamentos Antineoplásicos , Leucemia-Linfoma Linfoblástico de Células T Precursoras/metabolismo , Leucemia-Linfoma Linfoblástico de Células T Precursoras/patologia , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Sulfonamidas/farmacologia , Proteína bcl-X/metabolismo , Animais , Linhagem Celular Tumoral , Modelos Animais de Doenças , Resistencia a Medicamentos Antineoplásicos/genética , Expressão Gênica , Humanos , Modelos Biológicos , Gradação de Tumores , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/metabolismo , Fragmentos de Peptídeos/metabolismo , Leucemia-Linfoma Linfoblástico de Células T Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/genética , Ensaios Antitumorais Modelo de Xenoenxerto , Proteína bcl-X/genética
18.
Nat Genet ; 46(4): 364-70, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24584072

RESUMO

The identification of activating NOTCH1 mutations in T cell acute lymphoblastic leukemia (T-ALL) led to clinical testing of γ-secretase inhibitors (GSIs) that prevent NOTCH1 activation. However, responses to these inhibitors have been transient, suggesting that resistance limits their clinical efficacy. Here we modeled T-ALL resistance, identifying GSI-tolerant 'persister' cells that expand in the absence of NOTCH1 signaling. Rare persisters are already present in naive T-ALL populations, and the reversibility of their phenotype suggests an epigenetic mechanism. Relative to GSI-sensitive cells, persister cells activate distinct signaling and transcriptional programs and exhibit chromatin compaction. A knockdown screen identified chromatin regulators essential for persister viability, including BRD4. BRD4 binds enhancers near critical T-ALL genes, including MYC and BCL2. The BRD4 inhibitor JQ1 downregulates expression of these targets and induces growth arrest and apoptosis in persister cells, at doses well tolerated by GSI-sensitive cells. Consistently, the GSI-JQ1 combination was found to be effective against primary human leukemias in vivo. Our findings establish a role for epigenetic heterogeneity in leukemia resistance that may be addressed by incorporating epigenetic modulators in combination therapy.


Assuntos
Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Cromatina/genética , Resistencia a Medicamentos Antineoplásicos/genética , Inibidores Enzimáticos/uso terapêutico , Epigênese Genética/genética , Proteínas Nucleares/metabolismo , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Fatores de Transcrição/metabolismo , Animais , Azepinas/farmacologia , Proteínas de Ciclo Celular , Linhagem Celular Tumoral , Cromatina/metabolismo , Imunoprecipitação da Cromatina , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/genética , Histonas/metabolismo , Humanos , Indóis , Camundongos , Proteínas Nucleares/antagonistas & inibidores , Proteínas Nucleares/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/tratamento farmacológico , Reação em Cadeia da Polimerase em Tempo Real , Receptor Notch1/antagonistas & inibidores , Receptor Notch1/genética , Transdução de Sinais/genética , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/genética , Triazóis/farmacologia
19.
J Exp Med ; 210(7): 1311-29, 2013 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-23733784

RESUMO

Severe aplastic anemia (AA) is a bone marrow (BM) failure (BMF) disease frequently caused by aberrant immune destruction of blood progenitors. Although a Th1-mediated pathology is well described for AA, molecular mechanisms driving disease progression remain ill defined. The NOTCH signaling pathway mediates Th1 cell differentiation in the presence of polarizing cytokines, an action requiring enzymatic processing of NOTCH receptors by γ-secretase. Using a mouse model of AA, we demonstrate that expression of both intracellular NOTCH1(IC) and T-BET, a key transcription factor regulating Th1 cell differentiation, was increased in spleen and BM-infiltrating T cells during active disease. Conditionally deleting Notch1 or administering γ-secretase inhibitors (GSIs) in vivo attenuated disease and rescued mice from lethal BMF. In peripheral T cells from patients with untreated AA, NOTCH1(IC) was significantly elevated and bound to the TBX21 promoter, showing NOTCH1 directly regulates the gene encoding T-BET. Treating patient cells with GSIs in vitro lowered NOTCH1(IC) levels, decreased NOTCH1 detectable at the TBX21 promoter, and decreased T-BET expression, indicating that NOTCH1 signaling is responsive to GSIs during active disease. Collectively, these results identify NOTCH signaling as a primary driver of Th1-mediated pathogenesis in AA and may represent a novel target for therapeutic intervention.


Assuntos
Anemia Aplástica/imunologia , Anemia Aplástica/terapia , Medula Óssea/imunologia , Medula Óssea/patologia , Receptor Notch1/fisiologia , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Anemia Aplástica/patologia , Animais , Modelos Animais de Doenças , Inibidores Enzimáticos/uso terapêutico , Feminino , Transplante de Células-Tronco Hematopoéticas , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Receptor Notch1/deficiência , Receptor Notch1/genética , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/imunologia
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