RESUMEN
MiR-126 and miR-155 are key microRNAs (miRNAs) that regulate, respectively, hematopoietic cell quiescence and proliferation. Herein we showed that in acute myeloid leukemia (AML), the biogenesis of these two miRNAs is interconnected through a network of regulatory loops driven by the FMS-like tyrosine kinase 3-internal tandem duplication (FLT3-ITD). In fact, FLT3-ITD induces the expression of miR-155 through a noncanonical mechanism of miRNA biogenesis that implicates cytoplasmic Drosha ribonuclease III (DROSHA). In turn, miR-155 down-regulates SH2-containing inositol phosphatase 1 (SHIP1), thereby increasing phosphor-protein kinase B (AKT) that in turn serine-phosphorylates, stabilizes, and activates Sprouty related EVH1 domain containing 1 (SPRED1). Activated SPRED1 inhibits the RAN/XPO5 complex and blocks the nucleus-to-cytoplasm transport of pre-miR-126, which cannot then complete the last steps of biogenesis. The net result is aberrantly low levels of mature miR-126 that allow quiescent leukemia blasts to be recruited into the cell cycle and proliferate. Thus, miR-126 down-regulation in proliferating AML blasts is downstream of FLT3-ITDdependent miR-155 expression that initiates a complex circuit of concatenated regulatory feedback (i.e., miR-126/SPRED1, miR-155/human dead-box protein 3 [DDX3X]) and feed-forward (i.e., miR-155/SHIP1/AKT/miR-126) regulatory loops that eventually converge into an output signal for leukemic growth.
Asunto(s)
Leucemia Mieloide Aguda , MicroARNs , Tirosina Quinasa 3 Similar a fms , ARN Helicasas DEAD-box/metabolismo , Regulación hacia Abajo , Humanos , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , MicroARNs/metabolismo , Mutación , Tirosina Quinasa 3 Similar a fms/genética , Tirosina Quinasa 3 Similar a fms/metabolismoRESUMEN
Differentiation blockade is a hallmark of acute myeloid leukemia (AML). A strategy to overcome such a blockade is a promising approach against the disease. The lack of understanding of the underlying mechanisms hampers development of such strategies. Dysregulated ribonucleotide reductase (RNR) is considered a druggable target in proliferative cancers susceptible to deoxynucleoside triphosphate (dNTP) depletion. Herein, we report an unanticipated discovery that hyperactivating RNR enables differentiation and decreases leukemia cell growth. We integrate pharmacogenomics and metabolomics analyses to identify that pharmacologically (eg, nelarabine) or genetically upregulating RNR subunit M2 (RRM2) creates a dNTP pool imbalance and overcomes differentiation arrest. Moreover, R-loop-mediated DNA replication stress signaling is responsible for RRM2 activation by nelarabine treatment. Further aggravating dNTP imbalance by depleting the dNTP hydrolase SAM domain and HD domain-containing protein 1 (SAMHD1) enhances ablation of leukemia stem cells by RRM2 hyperactivation. Mechanistically, excessive activation of extracellular signal-regulated kinase (ERK) signaling downstream of the imbalance contributes to cellular outcomes of RNR hyperactivation. A CRISPR screen identifies a synthetic lethal interaction between loss of DUSP6, an ERK-negative regulator, and nelarabine treatment. These data demonstrate that dNTP homeostasis governs leukemia maintenance, and a combination of DUSP inhibition and nelarabine represents a therapeutic strategy.
Asunto(s)
Leucemia Mieloide Aguda , Ribonucleótido Reductasas , Replicación del ADN , Homeostasis , Humanos , Leucemia Mieloide Aguda/tratamiento farmacológico , Leucemia Mieloide Aguda/genética , Polifosfatos , Ribonucleótido Reductasas/genética , Ribonucleótido Reductasas/metabolismoRESUMEN
The role of plasticity and epigenetics in shaping cancer evolution and response to therapy has taken center stage with recent technological advances including single cell sequencing. This roadmap article is focused on state-of-the-art mathematical and experimental approaches to interrogate plasticity in cancer, and addresses the following themes and questions: is there a formal overarching framework that encompasses both non-genetic plasticity and mutation-driven somatic evolution? How do we measure and model the role of the microenvironment in influencing/controlling non-genetic plasticity? How can we experimentally study non-genetic plasticity? Which mathematical techniques are required or best suited? What are the clinical and practical applications and implications of these concepts?
Asunto(s)
Epigénesis Genética , Neoplasias , Epigenómica , Humanos , Mutación , Neoplasias/tratamiento farmacológico , Neoplasias/genética , Microambiente TumoralRESUMEN
Venetoclax (VEN) in combination with hypomethylating agents induces disease remission in patients with de novo AML, however, most patients eventually relapse. AML relapse is attributed to the persistence of drug-resistant leukemia stem cells (LSCs). LSCs need to maintain low intracellular levels of reactive oxygen species (ROS). Arsenic trioxide (ATO) induces apoptosis via upregulation of ROS-induced stress to DNA-repair mechanisms. Elevated ROS levels can trigger the Nrf2 antioxidant pathway to counteract the effects of high ROS levels. We hypothesized that ATO and VEN synergize in targeting LSCs through ROS induction by ATO and the known inhibitory effect of VEN on the Nrf2 antioxidant pathway. Using cell fractionation, immunoprecipitation, RNA-knockdown, and fluorescence assays we found that ATO activated nuclear translocation of Nrf2 and increased transcription of antioxidant enzymes, thereby attenuating the induction of ROS by ATO. VEN disrupted ATO-induced Nrf2 translocation and augmented ATO-induced ROS, thus enhancing apoptosis in LSCs. Using metabolic assays and electron microscopy, we found that the ATO+VEN combination decreased mitochondrial membrane potential, mitochondria size, fatty acid oxidation and oxidative phosphorylation, all of which enhanced apoptosis of LSCs derived from both VEN-sensitive and VEN-resistant AML primary cells. Our results indicate that ATO and VEN cooperate in inducing apoptosis of LSCs through potentiation of ROS induction, suggesting ATO+VEN is a promising regimen for treatment of VEN-sensitive and -resistant AML.
Asunto(s)
Antineoplásicos , Arsenicales , Leucemia Mieloide Aguda , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Antioxidantes/farmacología , Apoptosis , Trióxido de Arsénico/farmacología , Trióxido de Arsénico/uso terapéutico , Arsenicales/farmacología , Compuestos Bicíclicos Heterocíclicos con Puentes , Humanos , Leucemia Mieloide Aguda/tratamiento farmacológico , Leucemia Mieloide Aguda/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Óxidos/farmacología , Especies Reactivas de Oxígeno/metabolismo , Recurrencia , SulfonamidasRESUMEN
The presence of FMS-like receptor tyrosine kinase-3 internal tandem duplication (FLT3-ITD) mutations in patients with acute myeloid leukemia (AML) is associated with poor clinical outcome. FLT3 tyrosine kinase inhibitors (TKIs), although effective in kinase ablation, do not eliminate primitive FLT3-ITD+ leukemia cells, which are potential sources of relapse. Thus, understanding the mechanisms underlying FLT3-ITD+ AML cell persistence is essential to devise future AML therapies. Here, we show that expression of protein arginine methyltransferase 1 (PRMT1), the primary type I arginine methyltransferase, is increased significantly in AML cells relative to normal hematopoietic cells. Genome-wide analysis, coimmunoprecipitation assay, and PRMT1-knockout mouse studies indicate that PRMT1 preferentially cooperates with FLT3-ITD, contributing to AML maintenance. Genetic or pharmacological inhibition of PRMT1 markedly blocked FLT3-ITD+ AML cell maintenance. Mechanistically, PRMT1 catalyzed FLT3-ITD protein methylation at arginine 972/973, and PRMT1 promoted leukemia cell growth in an FLT3 methylation-dependent manner. Moreover, the effects of FLT3-ITD methylation in AML cells were partially due to cross talk with FLT3-ITD phosphorylation at tyrosine 969. Importantly, FLT3 methylation persisted in FLT3-ITD+ AML cells following kinase inhibition, indicating that methylation occurs independently of kinase activity. Finally, in patient-derived xenograft and murine AML models, combined administration of AC220 with a type I PRMT inhibitor (MS023) enhanced elimination of FLT3-ITD+ AML cells relative to AC220 treatment alone. Our study demonstrates that PRMT1-mediated FLT3 methylation promotes AML maintenance and suggests that combining PRMT1 inhibition with FLT3 TKI treatment could be a promising approach to eliminate FLT3-ITD+ AML cells.
Asunto(s)
Arginina/metabolismo , Duplicación de Gen , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Proteína-Arginina N-Metiltransferasas/metabolismo , Proteínas Represoras/metabolismo , Tirosina Quinasa 3 Similar a fms/genética , Tirosina Quinasa 3 Similar a fms/metabolismo , Animales , Biomarcadores de Tumor , Catálisis , Modelos Animales de Enfermedad , Perfilación de la Expresión Génica , Humanos , Leucemia Mieloide Aguda/mortalidad , Leucemia Mieloide Aguda/patología , Metilación , Ratones , Ratones Noqueados , Modelos Moleculares , Pronóstico , Unión Proteica , Conformación Proteica , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/uso terapéutico , Proteína-Arginina N-Metiltransferasas/antagonistas & inhibidores , Proteína-Arginina N-Metiltransferasas/química , Proteínas Represoras/antagonistas & inhibidores , Proteínas Represoras/química , Ensayos Antitumor por Modelo de Xenoinjerto , Tirosina Quinasa 3 Similar a fms/químicaRESUMEN
Transcription initiation factor 90 (TIF-90), an alternatively spliced variant of TIF-IA, differs by a 90 base pair deletion of exon 6. TIF-90 has been shown to regulate ribosomal RNA (rRNA) synthesis by interacting with polymerase I (Pol I) during the initiation of ribosomal DNA (rDNA) transcription in the nucleolus. Recently, we showed that TIF-90-mediated rRNA synthesis can play an important role in driving tumorigenesis in human colon cancer cells. Here we show that TIF-90 binds GTP at threonine 310, and that GTP binding is required for TIF-90-enhanced rRNA synthesis. Overexpression of activated AKT induces TIF-90 T310, but not a GTP-binding site (TIF-90 T310N) mutant, to translocate into the nucleolus and increase rRNA synthesis. Complementing this result, treatment with mycophenolic acid (MPA), an inhibitor of GTP production, dissociates TIF-90 from Pol I and hence abolishes AKT-increased rRNA synthesis by way of TIF-90 activation. Thus, TIF-90 requires bound GTP to fulfill its function as an enhancer of rRNA synthesis. Both TIF variants are highly expressed in colon cancer cells, and depletion of TIF-IA expression in these cells results in significant sensitivity to MPA-inhibited rRNA synthesis and reduced cell proliferation. Finally, a combination of MPA and AZD8055 (an inhibitor of both AKT and mTOR) synergistically inhibits rRNA synthesis, in vivo tumor growth, and other oncogenic activities of primary human colon cancer cells, suggesting a potential avenue for the development of therapeutic treatments by targeting the regulation of rRNA synthesis by TIF proteins.
Asunto(s)
Carcinogénesis/genética , Neoplasias del Colon/genética , Guanosina Trifosfato/genética , ARN Ribosómico/genética , Ribosomas/genética , Factores de Transcripción/genética , Transcripción Genética/genética , Línea Celular Tumoral , Proliferación Celular/genética , ADN Ribosómico/genética , Células HCT116 , Humanos , ARN Polimerasa I/genética , Transducción de Señal/genéticaRESUMEN
The maintenance and functional integrity of long-term hematopoietic stem cells (LT-HSCs) is critical for lifelong hematopoietic regeneration. Histone deacetylases (HDACs) modulate acetylation of lysine residues, a protein modification important for regulation of numerous biological processes. Here, we show that Hdac8 is most highly expressed in the phenotypic LT-HSC population within the adult hematopoietic hierarchy. Using an Hdac8-floxed allele and a dual-fluorescence Cre reporter allele, largely normal hematopoietic differentiation capacity of Hdac8-deficient cells was observed. However, the frequency of phenotypic LT-HSC population was significantly higher shortly after Hdac8 deletion, and the expansion had shifted to the phenotypic multipotent progenitor population by 1 year. We show that Hdac8-deficient hematopoietic progenitors are compromised in colony-forming cell serial replating in vitro and long-term serial repopulating activity in vivo. Mechanistically, we demonstrate that the HDAC8 protein interacts with the p53 protein and modulates p53 activity via deacetylation. Hdac8-deficient LT-HSCs displayed hyperactivation of p53 and increased apoptosis under genotoxic and hematopoietic stress. Genetic inactivation of p53 reversed the increased apoptosis and elevated expression of proapoptotic targets Noxa and Puma seen in Hdac8-deleted LT-HSCs. Dramatically compromised hematopoietic recovery and increased lethality were seen in Hdac8-deficient mice challenged with serial 5-fluorouracil treatment. This hypersensitivity to hematopoietic ablation was completely rescued by inactivation of p53. Altogether, these results indicate that HDAC8 functions to modulate p53 activity to ensure LT-HSC maintenance and cell survival under stress.
Asunto(s)
Regulación de la Expresión Génica , Células Madre Hematopoyéticas/metabolismo , Histona Desacetilasas/genética , Proteína p53 Supresora de Tumor/genética , Acetilación , Animales , Antimetabolitos/farmacología , Diferenciación Celular/efectos de los fármacos , Diferenciación Celular/genética , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/genética , Fluorouracilo/farmacología , Células Madre Hematopoyéticas/efectos de los fármacos , Histona Desacetilasas/metabolismo , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Estrés Fisiológico/genética , Factores de Tiempo , Proteína p53 Supresora de Tumor/metabolismoRESUMEN
Acute myeloid leukemia (AML) arises through multistep clonal evolution characterized by stepwise accumulation of successive alterations affecting the homeostasis of differentiation, proliferation, self-renewal, and survival programs. The persistence and dynamic clonal evolution of leukemia-initiating cells and preleukemic stem cells during disease progression and treatment are thought to contribute to disease relapse and poor outcome. Inv(16)(p13q22) or t(16;16)(p13.1;q22), one of the most common cytogenetic abnormalities in AML, leads to expression of a fusion protein CBFß-SMMHC (CM) known to disrupt myeloid and lymphoid differentiation. Anemia is often observed in AML but is presumed to be a secondary consequence of leukemic clonal expansion. Here, we show that CM expression induces marked deficiencies in erythroid lineage differentiation and early preleukemic expansion of a phenotypic pre-megakaryocyte/erythrocyte (Pre-Meg/E) progenitor population. Using dual-fluorescence reporter mice in lineage tracking and repopulation assays, we show that CM expression cell autonomously causes expansion of abnormal Pre-Meg/E progenitors with compromised erythroid specification and differentiation capacity. The preleukemic Pre-Meg/Es display dysregulated erythroid and megakaryocytic fate-determining factors including increased Spi-1, Gata2, and Gfi1b and reduced Zfpm1, Pf4, Vwf, and Mpl expression. Furthermore, these abnormal preleukemic Pre-Meg/Es have enhanced stress resistance and are prone to leukemia initiation upon acquiring cooperative signals. This study reveals that the leukemogenic CM fusion protein disrupts adult erythropoiesis and creates stress-resistant preleukemic Pre-Meg/E progenitors predisposed to malignant transformation. Abnormality in Meg/E or erythroid progenitors could potentially be considered an early predictive risk factor for leukemia evolution.
Asunto(s)
Diferenciación Celular , Transformación Celular Neoplásica/patología , Leucemia Experimental/patología , Células Progenitoras de Megacariocitos y Eritrocitos/patología , Proteínas de Fusión Oncogénica/metabolismo , Animales , Western Blotting , Proliferación Celular , Transformación Celular Neoplásica/genética , Transformación Celular Neoplásica/metabolismo , Células Cultivadas , Femenino , Leucemia Experimental/genética , Leucemia Experimental/metabolismo , Masculino , Células Progenitoras de Megacariocitos y Eritrocitos/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Proteínas de Fusión Oncogénica/genética , ARN Mensajero/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
Targeting oncogenic transcription factor signal transducer and activator of transcription 3 (STAT3) in acute myeloid leukemia (AML) can reduce blast survival and tumor immune evasion. Decoy oligodeoxynucleotides (dODNs), which comprise STAT3-specific DNA sequences are competitive inhibition of STAT3 transcriptional activity. To deliver STAT3dODN specifically to myeloid cells, we linked STAT3dODN to the Toll-like receptor 9 (TLR9) ligand, cytosine guanine dinucleotide (CpG). The CpG-STAT3dODN conjugates are quickly internalized by human and mouse TLR9(+)immune cells (dendritic cells, B cells) and the majority of patients' derived AML blasts, including leukemia stem/progenitor cells. Following uptake, CpG-STAT3dODNs are released from endosomes, and bind and sequester cytoplasmic STAT3, thereby inhibiting downstream gene expression in target cells. STAT3 inhibition in patients' AML cells limits their immunosuppressive potential by reduced arginase expression, thereby partly restoring T-cell proliferation. Partly chemically modified CpG-STAT3dODNs have >60 hours serum half-life which allows for IV administration to leukemia-bearing mice (50% effective dose â¼ 2.5 mg/kg). Repeated administration of CpG-STAT3dODN resulted in regression of human MV4-11 AML in mice. The antitumor efficacy of this strategy is further enhanced in immunocompetent mice by combining direct leukemia-specific cytotoxicity with immunogenic effects of STAT3 blocking/TLR9 triggering. CpG-STAT3dODN effectively reducedCbfb/MYH11/MplAML burden in various organs and eliminated leukemia stem/progenitor cells, mainly through CD8/CD4 T-cell-mediated immune responses. In contrast, small-molecule Janus kinase 2/STAT3 inhibitor failed to reproduce therapeutic effects of cell-selective CpG-STAT3dODN strategy. These results demonstrate therapeutic potential of CpG-STAT3dODN inhibitors with broad implications for treatment of AML and potentially other hematologic malignancies.
Asunto(s)
Islas de CpG , Genes cdc/efectos de los fármacos , Leucemia Mieloide Aguda , Oligodesoxirribonucleótidos/farmacología , Factor de Transcripción STAT3/antagonistas & inhibidores , Escape del Tumor/efectos de los fármacos , Animales , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/inmunología , Estabilidad de Medicamentos , Genes cdc/inmunología , Terapia Genética/métodos , Humanos , Leucemia Mieloide Aguda/inmunología , Leucemia Mieloide Aguda/patología , Leucemia Mieloide Aguda/terapia , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Terapia Molecular Dirigida , Oligodesoxirribonucleótidos/química , Oligodesoxirribonucleótidos/uso terapéutico , Factor de Transcripción STAT3/química , Factor de Transcripción STAT3/genética , Suero/fisiología , Transducción de Señal/efectos de los fármacosRESUMEN
Signal transducer and activator of transcription 3 (STAT3) is an oncogene and immune checkpoint commonly activated in cancer cells and in tumor-associated immune cells. We previously developed an immunostimulatory strategy based on targeted Stat3 silencing in Toll-like receptor 9 (TLR9)-positive hematopoietic cells using CpG-small interfering RNA (siRNA) conjugates. Here, we assessed the therapeutic effect of systemic STAT3 blocking/TLR9 triggering in disseminated acute myeloid leukemia (AML). We used mouse Cbfb-MYH11/Mpl-induced leukemia model, which mimics human inv(16) AML. Our results demonstrate that intravenously delivered CpG-Stat3 siRNA, but not control oligonucleotides, can eradicate established AML and impair leukemia-initiating potential. These antitumor effects require host's effector T cells but not TLR9-positive antigen-presenting cells. Instead, CpG-Stat3 siRNA has direct immunogenic effect on AML cells in vivo upregulating major histocompatibility complex class-II, costimulatory and proinflammatory mediators, such as interleukin-12, while downregulating coinhibitory PD-L1 molecule. Systemic injections of CpG-Stat3 siRNA generate potent tumor antigen-specific immune responses, increase the ratio of tumor-infiltrating CD8(+) T cells to regulatory T cells in various organs, and result in CD8(+) T-cell-dependent regression of leukemia. Our findings underscore the potential of using targeted STAT3 inhibition/TLR9 triggering to break tumor tolerance and induce immunity against AML and potentially other TLR9-positive blood cancers.
Asunto(s)
Regulación Leucémica de la Expresión Génica , Leucemia/inmunología , Leucemia/metabolismo , Factor de Transcripción STAT3/genética , Receptor Toll-Like 9/metabolismo , Animales , Linfocitos T CD8-positivos/citología , Línea Celular Tumoral , Islas de CpG , Silenciador del Gen , Tolerancia Inmunológica , Interferón gamma/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos NOD , Ratones Noqueados , Ratones SCID , Ratones Transgénicos , ARN Interferente Pequeño/metabolismo , Factor de Transcripción STAT3/metabolismoRESUMEN
The SRC family kinases (SFKs) and the receptor tyrosine kinase c-Kit are activated in human acute myeloid leukemia (AML) cells. We show here that the SFKs LYN, HCK, or FGR are overexpressed and activated in AML progenitor cells. Treatment with the SFK and c-KIT inhibitor dasatinib selectively inhibits human AML stem/progenitor cell growth in vitro. Importantly, dasatinib markedly increases the elimination of AML stem cells capable of engrafting immunodeficient mice by chemotherapeutic agents. In vivo dasatinib treatment enhances chemotherapy-induced targeting of primary murine AML stem cells capable of regenerating leukemia in secondary recipients. Our studies suggest that enhanced targeting of AML cells by the combination of dasatinib with daunorubicin may be related to inhibition of AKT-mediated human mouse double minute 2 homolog phosphorylation, resulting in enhanced p53 activity in AML cells. Combined treatment using dasatinib and chemotherapy provides a novel approach to increasing p53 activity and enhancing targeting of AML stem cells.
Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Leucemia Mieloide Aguda/tratamiento farmacológico , Células Madre Neoplásicas/efectos de los fármacos , Proteína p53 Supresora de Tumor/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Animales , Dasatinib , Daunorrubicina/administración & dosificación , Femenino , Humanos , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones SCID , Persona de Mediana Edad , Células Madre Neoplásicas/metabolismo , Células Madre Neoplásicas/patología , Fosforilación/efectos de los fármacos , Inhibidores de Proteínas Quinasas/administración & dosificación , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas c-kit/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-kit/genética , Proteínas Proto-Oncogénicas c-kit/metabolismo , Pirimidinas/administración & dosificación , Pirimidinas/farmacología , Interferencia de ARN , Tiazoles/administración & dosificación , Tiazoles/farmacología , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de Xenoinjerto , Adulto Joven , Familia-src Quinasas/antagonistas & inhibidores , Familia-src Quinasas/genética , Familia-src Quinasas/metabolismoRESUMEN
Oncogenic mutations in components of cytokine signaling pathways elicit ligand-independent activation of downstream signaling, enhancing proliferation and survival in acute myeloid leukemia (AML). The myeloproliferative leukemia virus oncogene, MPL, a homodimeric receptor activated by thrombopoietin (THPO), is mutated in myeloproliferative disorders but rarely in AML. Here we show that wild-type MPL expression is increased in a fraction of human AML samples expressing RUNX1-ETO, a fusion protein created by chromosome translocation t(8;21), and that up-regulation of Mpl expression in mice induces AML when coexpressed with RUNX1-ETO. The leukemic cells are sensitive to THPO, activating survival and proliferative responses. Mpl expression is not regulated by RUNX1-ETO in mouse hematopoietic progenitors or leukemic cells. Moreover, we find that activation of PI3K/AKT but not ERK/MEK pathway is a critical mediator of the MPL-directed antiapoptotic function in leukemic cells. Hence, this study provides evidence that up-regulation of wild-type MPL levels promotes leukemia development and maintenance through activation of the PI3K/AKT axis, and suggests that inhibitors of this axis could be effective for treatment of MPL-positive AML.
Asunto(s)
Subunidad alfa 2 del Factor de Unión al Sitio Principal/metabolismo , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/patología , Proteínas de Fusión Oncogénica/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Receptores de Trombopoyetina/metabolismo , Trombopoyetina/metabolismo , Secuencia de Aminoácidos , Animales , Western Blotting , Médula Ósea/metabolismo , Médula Ósea/patología , Trasplante de Médula Ósea , Ciclo Celular , Proliferación Celular , Cromosomas Humanos Par 21/genética , Cromosomas Humanos Par 8/genética , Subunidad alfa 2 del Factor de Unión al Sitio Principal/genética , Humanos , Técnicas para Inmunoenzimas , Leucemia Mieloide Aguda/genética , Ratones , Datos de Secuencia Molecular , Proteínas de Fusión Oncogénica/genética , Fosfatidilinositol 3-Quinasas/genética , Proteínas Proto-Oncogénicas c-akt/genética , ARN Mensajero/genética , Proteína 1 Compañera de Translocación de RUNX1 , Reacción en Cadena en Tiempo Real de la Polimerasa , Receptores de Trombopoyetina/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción de Señal , Tasa de Supervivencia , Trombopoyetina/genética , Translocación Genética , Células Tumorales CultivadasRESUMEN
Hematopoietic stem cells (HSCs) reside in a specialized bone marrow (BM) microenvironment that supports the maintenance and functional integrity of long-term (LT)-HSCs throughout postnatal life. The objective of this work is to study the role of activated leukocyte cell adhesion molecule (Alcam) in HSC differentiation and self-renewal using an Alcam-null (Alcam(-/-) ) mouse model. We show here that Alcam is differentially regulated in adult hematopoiesis and is highly expressed in LT-HSCs where its level progressively increases with age. Young adult Alcam(-/-) mice had normal homeostatic hematopoiesis and normal numbers of phenotypic HSCs. However, Alcam(-/-) HSCs had reduced long-term replating capacity in vitro and reduced long-term engraftment potential upon transplantation. We show that Alcam(-/-) BM contain a markedly lower frequency of long-term repopulating cells than wild type. Further, the long-term repopulating potential and engraftment efficiency of Alcam(-/-) LT-HSCs was greatly compromised despite a progressive increase in phenotypic LT-HSC numbers during long-term serial transplantation. In addition, an age-associated increase in phenotypic LT-HSC cellularity was observed in Alcam(-/-) mice. This increase was predominately within the CD150(hi) fraction and was accompanied by significantly reduced leukocyte output. Consistent with an aging-like phenotype, older Alcam(-/-) LT-HSCs display myeloid-biased repopulation activity upon transplantation. Finally, Alcam(-/-) LT-HSCs display premature elevation of age-associated gene expression, including Selp, Clu, Cdc42, and Foxo3. Together, this study indicates that Alcam regulates functional integrity and self-renewal of LT-HSCs.
Asunto(s)
Molécula de Adhesión Celular del Leucocito Activado/fisiología , Células Madre Hematopoyéticas/fisiología , Molécula de Adhesión Celular del Leucocito Activado/metabolismo , Animales , Adhesión Celular/efectos de los fármacos , Diferenciación Celular/fisiología , Técnicas de Silenciamiento del Gen , Células Madre Hematopoyéticas/citología , Células Madre Hematopoyéticas/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones NoqueadosRESUMEN
The acute myeloid leukemia (AML)-associated CBF beta-SMMHC fusion protein impairs hematopoietic differentiation and predisposes to leukemic transformation. The mechanism of leukemia progression, however, is poorly understood. In this study, we report a conditional Cbfb-MYH11 knockin mouse model that develops AML with a median latency of 5 months. Cbf beta-SMMHC expression reduced the multilineage repopulation capacity of hematopoietic stem cells (HSCs) while maintaining their numbers under competitive conditions. The fusion protein induced abnormal myeloid progenitors (AMPs) with limited proliferative potential but leukemic predisposition similar to that of HSCs in transplanted mice. In addition, Cbf beta-SMMHC blocked megakaryocytic maturation at the CFU-Meg to megakaryocyte transition. These data show that a leukemia oncoprotein can inhibit differentiation and proliferation while not affecting the maintenance of long-term HSCs.
Asunto(s)
Leucemia Mieloide/patología , Células Progenitoras Mieloides/patología , Proteínas de Fusión Oncogénica/metabolismo , Preleucemia/patología , Enfermedad Aguda , Animales , Linfocitos B/patología , Plaquetas/patología , Proliferación Celular , Hematopoyesis , Leucemia Mieloide/metabolismo , Megacariocitos/metabolismo , Megacariocitos/patología , Ratones , Ratones Endogámicos C57BL , Ratones Mutantes , Células Progenitoras Mieloides/metabolismo , Proteínas de Fusión Oncogénica/genética , Preleucemia/metabolismoRESUMEN
Acute myeloid leukemia (AML) is prevalent in both adult and pediatric patients. Despite advances in patient categorization, the heterogeneity of AML remains a challenge. Recent studies have explored the use of gene expression data to enhance AML diagnosis and prognosis, however, alternative approaches rooted in physics and chemistry may provide another level of insight into AML transformation. Utilizing publicly available databases, we analyze 884 human and mouse blood and bone marrow samples. We employ a personalized medicine strategy, combining state-transition theory and surprisal analysis, to assess the RNA transcriptome of individual patients. The transcriptome is transformed into physical parameters that represent each sample's steady state and the free energy change (FEC) from that steady state, which is the state with the lowest free energy.We found the transcriptome steady state was invariant across normal and AML samples. FEC, representing active molecular processes, varied significantly between samples and was used to create patient-specific barcodes to characterize the biology of the disease. We discovered that AML samples that were in a transition state had the highest FEC. This disease state may be characterized as the most unstable and hence the most therapeutically targetable since a change in free energy is a thermodynamic requirement for disease progression. We also found that distinct sets of ongoing processes may be at the root of otherwise similar clinical phenotypes, implying that our integrated analysis of transcriptome profiles may facilitate a personalized medicine approach to cure AML and restore a steady state in each patient.
Asunto(s)
Leucemia Mieloide Aguda , Transcriptoma , Adulto , Animales , Ratones , Humanos , Niño , Transcriptoma/genética , Perfilación de la Expresión Génica , Leucemia Mieloide Aguda/genética , Biomarcadores de Tumor/genética , FenotipoRESUMEN
Chronic myeloid leukemia (CML) is initiated and maintained by BCR::ABL which is clinically targeted using tyrosine kinase inhibitors (TKIs). TKIs can induce long-term remission but are also not curative. Thus, CML is an ideal system to test our hypothesis that transcriptome-based state-transition models accurately predict cancer evolution and treatment response. We collected time-sequential blood samples from tetracycline-off (Tet-Off) BCR::ABL-inducible transgenic mice and wild-type controls. From the transcriptome, we constructed a CML state-space and a three-well leukemogenic potential landscape. The potential's stable critical points defined observable disease states. Early states were characterized by anti-CML genes opposing leukemia; late states were characterized by pro-CML genes. Genes with expression patterns shaped similarly to the potential landscape were identified as drivers of disease transition. Re-introduction of tetracycline to silence the BCR::ABL gene returned diseased mice transcriptomes to a near healthy state, without reaching it, suggesting parts of the transition are irreversible. TKI only reverted the transcriptome to an intermediate disease state, without approaching a state of health; disease relapse occurred soon after treatment. Using only the earliest time-point as initial conditions, our state-transition models accurately predicted both disease progression and treatment response, supporting this as a potentially valuable approach to time clinical intervention, before phenotypic changes become detectable.
Asunto(s)
Leucemia Mielógena Crónica BCR-ABL Positiva , Transcriptoma , Ratones , Animales , Proteínas de Fusión bcr-abl/metabolismo , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/uso terapéutico , Leucemia Mielógena Crónica BCR-ABL Positiva/tratamiento farmacológico , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Tetraciclinas/uso terapéutico , Resistencia a AntineoplásicosRESUMEN
Acute myeloid leukemia (AML) cells resist differentiation stimuli despite high expression of innate immune receptors, such as Toll-like receptor 9 (TLR9). We previously demonstrated that targeting Signal Transducer and Activator of Transcription 3 (STAT3) using TLR9-targeted decoy oligodeoxynucleotide (CpG-STAT3d) increases immunogenicity of human and mouse AML cells. Here, we elucidated molecular mechanisms of inv(16) AML reprogramming driven by STAT3-inhibition/TLR9-activation in vivo. At the transcriptional levels, AML cells isolated from mice after intravenous administration of CpG-STAT3d or leukemia-targeted Stat3 silencing and TLR9 co-stimulation, displayed similar upregulation of myeloid cell differentiation (Irf8, Cebpa, Itgam) and antigen-presentation (Ciita, Il12a, B2m)-related genes with concomitant reduction of leukemia-promoting Runx1. Single-cell transcriptomics revealed that CpG-STAT3d induced multilineage differentiation of AML cells into monocytes/macrophages, erythroblastic and B cell subsets. As shown by an inducible Irf8 silencing in vivo, IRF8 upregulation was critical for monocyte-macrophage differentiation of leukemic cells. TLR9-driven AML cell reprogramming was likely enabled by downregulation of STAT3-controlled methylation regulators, such as DNMT1 and DNMT3. In fact, the combination of DNA methyl transferase (DNMT) inhibition using azacitidine with CpG oligonucleotides alone mimicked CpG-STAT3d effects, resulting in AML cell differentiation, T cell activation, and systemic leukemia regression. These findings highlight immunotherapeutic potential of bi-functional oligonucleotides to unleash TLR9-driven differentiation of leukemic cells by concurrent STAT3 and/or DNMT inhibition.
RESUMEN
Current anticancer therapies cannot eliminate all cancer cells, which hijack normal arginine methylation as a means to promote their maintenance via unknown mechanisms. Here we show that targeting protein arginine N-methyltransferase 9 (PRMT9), whose activities are elevated in blasts and leukemia stem cells (LSCs) from patients with acute myeloid leukemia (AML), eliminates disease via cancer-intrinsic mechanisms and cancer-extrinsic type I interferon (IFN)-associated immunity. PRMT9 ablation in AML cells decreased the arginine methylation of regulators of RNA translation and the DNA damage response, suppressing cell survival. Notably, PRMT9 inhibition promoted DNA damage and activated cyclic GMP-AMP synthase, which underlies the type I IFN response. Genetically activating cyclic GMP-AMP synthase in AML cells blocked leukemogenesis. We also report synergy of a PRMT9 inhibitor with anti-programmed cell death protein 1 in eradicating AML. Overall, we conclude that PRMT9 functions in survival and immune evasion of both LSCs and non-LSCs; targeting PRMT9 may represent a potential anticancer strategy.
Asunto(s)
Arginina , Leucemia Mieloide Aguda , Células Madre Neoplásicas , Nucleotidiltransferasas , Proteína-Arginina N-Metiltransferasas , Proteína-Arginina N-Metiltransferasas/metabolismo , Humanos , Células Madre Neoplásicas/efectos de los fármacos , Células Madre Neoplásicas/inmunología , Células Madre Neoplásicas/metabolismo , Leucemia Mieloide Aguda/inmunología , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/tratamiento farmacológico , Nucleotidiltransferasas/metabolismo , Arginina/metabolismo , Metilación/efectos de los fármacos , Animales , Ratones , Interferón Tipo I/metabolismo , Daño del ADN , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacosRESUMEN
Chronic myeloid leukemia (CML) is initiated and maintained by BCR::ABL which is clinically targeted using tyrosine kinase inhibitors (TKIs). TKIs can induce long-term remission but are also not curative. Thus, CML is an ideal system to test our hypothesis that transcriptome-based state-transition models accurately predict cancer evolution and treatment response. We collected time-sequential blood samples from tetracycline-off (Tet-Off) BCR::ABL-inducible transgenic mice and wild-type controls. From the transcriptome, we constructed a CML state-space and a three-well leukemogenic potential landscape. The potential's stable critical points defined observable disease states. Early states were characterized by anti-CML genes opposing leukemia; late states were characterized by pro-CML genes. Genes with expression patterns shaped similarly to the potential landscape were identified as drivers of disease transition. Re-introduction of tetracycline to silence the BCR::ABL gene returned diseased mice transcriptomes to a near healthy state, without reaching it, suggesting parts of the transition are irreversible. TKI only reverted the transcriptome to an intermediate disease state, without approaching a state of health; disease relapse occurred soon after treatment. Using only the earliest time-point as initial conditions, our state-transition models accurately predicted both disease progression and treatment response, supporting this as a potentially valuable approach to time clinical intervention even before phenotypic changes become detectable.
RESUMEN
OBJECTIVE: Amyotrophic lateral sclerosis (ALS) is a heterogeneous disease with a complex etiology that lacks biomarkers predicting disease progression. The objective of this study was to use longitudinal cerebrospinal fluid (CSF) samples to identify biomarkers that distinguish fast progression (FP) from slow progression (SP) and assess their temporal response. METHODS: We utilized mass spectrometry (MS)-based proteomics to identify candidate biomarkers using longitudinal CSF from a discovery cohort of SP and FP ALS patients. Immunoassays were used to quantify and validate levels of the top biomarkers. A state-transition mathematical model was created using the longitudinal MS data that also predicted FP versus SP. RESULTS: We identified a total of 1148 proteins in the CSF of all ALS patients. Pathway analysis determined enrichment of pathways related to complement and coagulation cascades in FPs and synaptogenesis and glucose metabolism in SPs. Longitudinal analysis revealed a panel of 59 candidate markers that could segregate FP and SP ALS. Based on multivariate analysis, we identified three biomarkers (F12, RBP4, and SERPINA4) as top candidates that segregate ALS based on rate of disease progression. These proteins were validated in the discovery and a separate validation cohort. Our state-transition model determined that the overall variance of the proteome over time was predictive of the disease progression rate. INTERPRETATION: We identified pathways and protein biomarkers that distinguish rate of ALS disease progression. A mathematical model of the CSF proteome determined that the change in entropy of the proteome over time was predictive of FP versus SP.