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1.
Nature ; 574(7777): 273-277, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31578525

RESUMEN

Transcription and pre-mRNA splicing are key steps in the control of gene expression and mutations in genes regulating each of these processes are common in leukaemia1,2. Despite the frequent overlap of mutations affecting epigenetic regulation and splicing in leukaemia, how these processes influence one another to promote leukaemogenesis is not understood and, to our knowledge, there is no functional evidence that mutations in RNA splicing factors initiate leukaemia. Here, through analyses of transcriptomes from 982 patients with acute myeloid leukaemia, we identified frequent overlap of mutations in IDH2 and SRSF2 that together promote leukaemogenesis through coordinated effects on the epigenome and RNA splicing. Whereas mutations in either IDH2 or SRSF2 imparted distinct splicing changes, co-expression of mutant IDH2 altered the splicing effects of mutant SRSF2 and resulted in more profound splicing changes than either mutation alone. Consistent with this, co-expression of mutant IDH2 and SRSF2 resulted in lethal myelodysplasia with proliferative features in vivo and enhanced self-renewal in a manner not observed with either mutation alone. IDH2 and SRSF2 double-mutant cells exhibited aberrant splicing and reduced expression of INTS3, a member of the integrator complex3, concordant with increased stalling of RNA polymerase II (RNAPII). Aberrant INTS3 splicing contributed to leukaemogenesis in concert with mutant IDH2 and was dependent on mutant SRSF2 binding to cis elements in INTS3 mRNA and increased DNA methylation of INTS3. These data identify a pathogenic crosstalk between altered epigenetic state and splicing in a subset of leukaemias, provide functional evidence that mutations in splicing factors drive myeloid malignancy development, and identify spliceosomal changes as a mediator of IDH2-mutant leukaemogenesis.


Asunto(s)
Empalme Alternativo/genética , Carcinogénesis/genética , Epigénesis Genética , Leucemia Mieloide Aguda/genética , Animales , Línea Celular Tumoral , Proliferación Celular , Metilación de ADN , Proteínas de Unión al ADN/genética , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Isocitrato Deshidrogenasa/genética , Masculino , Mutación/genética , ARN Polimerasa II/metabolismo , Factores de Empalme Serina-Arginina/genética , Transcriptoma
2.
Blood ; 130(6): 732-741, 2017 08 10.
Artículo en Inglés | MEDLINE | ID: mdl-28588019

RESUMEN

Recurrent mutations at R140 and R172 in isocitrate dehydrogenase 2 (IDH2) occur in many cancers, including ∼12% of acute myeloid leukemia (AML). In preclinical models these mutations cause accumulation of the oncogenic metabolite R-2-hydroxyglutarate (2-HG) and induce hematopoietic differentiation block. Single-agent enasidenib (AG-221/CC-90007), a selective mutant IDH2 (mIDH2) inhibitor, produced an overall response rate of 40.3% in relapsed/refractory AML (rrAML) patients with mIDH2 in a phase 1 trial. However, its mechanism of action and biomarkers associated with response remain unclear. Here, we measured 2-HG, mIDH2 allele burden, and co-occurring somatic mutations in sequential patient samples from the clinical trial and correlated these with clinical response. Furthermore, we used flow cytometry to assess inhibition of mIDH2 on hematopoietic differentiation. We observed potent 2-HG suppression in both R140 and R172 mIDH2 AML subtypes, with different kinetics, which preceded clinical response. Suppression of 2-HG alone did not predict response, because most nonresponding patients also exhibited 2-HG suppression. Complete remission (CR) with persistence of mIDH2 and normalization of hematopoietic stem and progenitor compartments with emergence of functional mIDH2 neutrophils were observed. In a subset of CR patients, mIDH2 allele burden was reduced and remained undetectable with response. Co-occurring mutations in NRAS and other MAPK pathway effectors were enriched in nonresponding patients, consistent with RAS signaling contributing to primary therapeutic resistance. Together, these data support differentiation as the main mechanism of enasidenib efficacy in relapsed/refractory AML patients and provide insight into resistance mechanisms to inform future mechanism-based combination treatment studies.


Asunto(s)
Aminopiridinas/uso terapéutico , Antineoplásicos/uso terapéutico , Glutaratos/metabolismo , Hematopoyesis/efectos de los fármacos , Isocitrato Deshidrogenasa/genética , Leucemia Mieloide Aguda/tratamiento farmacológico , Mutación , Triazinas/uso terapéutico , Aminopiridinas/farmacología , Antineoplásicos/farmacología , Femenino , Frecuencia de los Genes , Glutaratos/antagonistas & inhibidores , Humanos , Isocitrato Deshidrogenasa/antagonistas & inhibidores , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/patología , Masculino , Recurrencia Local de Neoplasia/tratamiento farmacológico , Recurrencia Local de Neoplasia/genética , Recurrencia Local de Neoplasia/metabolismo , Recurrencia Local de Neoplasia/patología , Triazinas/farmacología
3.
Haematologica ; 102(11): 1850-1860, 2017 11.
Artículo en Inglés | MEDLINE | ID: mdl-28912174

RESUMEN

Transcriptional deregulation caused by epigenetic or genetic alterations is a major cause of leukemic transformation. The Spi1/PU.1 transcription factor is a key regulator of many steps of hematopoiesis, and limits self-renewal of hematopoietic stem cells. The deregulation of its expression or activity contributes to leukemia, in which Spi1 can be either an oncogene or a tumor suppressor. Herein we explored whether cellular senescence, an anti-tumoral pathway that restrains cell proliferation, is a mechanism by which Spi1 limits hematopoietic cell expansion, and thus prevents the development of leukemia. We show that Spi1 overexpression triggers cellular senescence both in primary fibroblasts and hematopoietic cells. Erythroid and myeloid lineages are both prone to Spi1-induced senescence. In hematopoietic cells, Spi1-induced senescence requires its DNA-binding activity and a functional p38MAPK14 pathway but is independent of a DNA-damage response. In contrast, in fibroblasts, Spi1-induced senescence is triggered by a DNA-damage response. Importantly, using our well-established Spi1 transgenic leukemia mouse model, we demonstrate that Spi1 overexpression also induces senescence in erythroid progenitors of the bone marrow in vivo before the onset of the pre-leukemic phase of erythroleukemia. Remarkably, the senescence response is lost during the progression of the disease and erythroid blasts do not display a higher expression of Dec1 and CDKN1A, two of the induced senescence markers in young animals. These results bring indirect evidence that leukemia develops from cells which have bypassed Spi1-induced senescence. Overall, our results reveal senescence as a Spi1-induced anti-proliferative mechanism that may be a safeguard against the development of acute myeloid leukemia.


Asunto(s)
Células Madre Hematopoyéticas/metabolismo , Proteínas Proto-Oncogénicas/genética , Transactivadores/genética , Animales , Biomarcadores , Médula Ósea/metabolismo , Médula Ósea/patología , Línea Celular , Proliferación Celular , Senescencia Celular/genética , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Expresión Génica Ectópica , Fibroblastos/metabolismo , Humanos , Inmunohistoquímica , Leucemia/genética , Leucemia/metabolismo , Leucemia/patología , Ratones , Ratones Transgénicos , Mutación , Proteínas Proto-Oncogénicas/metabolismo , Transactivadores/metabolismo
4.
Ann Hematol ; 95(12): 1943-1947, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27591990

RESUMEN

Isocitrate dehydrogenase IDH 1 and IDH 2 mutations were reported in several cancer forms, especially in hematological malignancies, but were never been investigated in familial aggregation. The aim of this study is to determine whether germline isocitrate dehydrogenase genes mutations are involved.We targeted IDH1 and IDH2 genes in 104 familial cases belonging to Tunisian and French populations, including several forms of hematological malignancies and cosegregated solid tumors.We report one IDH1 variant: c.315 G>T, p.Gly105Gly in 15 % of cases, which was assigned to the worst outcome in several studies. Three IDH2 variants were found, among them, one intronic substitution c.543+45 G>A (rs142033117) and two new variants not previously described: c.389 A>T, p.Lys130Met and c.414 T>C, p.Thr138Thr. The p.Lys130Met was found in one case diagnosed with Waldenstrom's disease with familial history of cancer. The enrolled in silico analysis, the functional study, and the absence of this variant in control population strengthen the hypothesis of its deleterious effect.From an extended number of candidate genes analyzed in familial hematological malignancies, IDH2 might be considerably involved since we reported a potential damaging effect.


Asunto(s)
Neoplasias Hematológicas/diagnóstico , Neoplasias Hematológicas/genética , Isocitrato Deshidrogenasa/genética , Mutación/genética , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad
5.
J Inherit Metab Dis ; 39(6): 807-820, 2016 11.
Artículo en Inglés | MEDLINE | ID: mdl-27469509

RESUMEN

D-2-hydroxyglutaric aciduria (D2HGA) type II is a rare neurometabolic disorder caused by germline gain-of-function mutations in isocitrate dehydrogenase 2 (IDH2), resulting in accumulation of D-2-hydroxyglutarate (D2HG). Patients exhibit a wide spectrum of symptoms including cardiomyopathy, epilepsy, developmental delay and limited life span. Currently, there are no effective therapeutic interventions. We generated a D2HGA type II mouse model by introducing the Idh2R140Q mutation at the native chromosomal locus. Idh2R140Q mice displayed significantly elevated 2HG levels and recapitulated multiple defects seen in patients. AGI-026, a potent, selective inhibitor of the human IDH2R140Q-mutant enzyme, suppressed 2HG production, rescued cardiomyopathy, and provided a survival benefit in Idh2R140Q mice; treatment withdrawal resulted in deterioration of cardiac function. We observed differential expression of multiple genes and metabolites that are associated with cardiomyopathy, which were largely reversed by AGI-026. These findings demonstrate the potential therapeutic benefit of an IDH2R140Q inhibitor in patients with D2HGA type II.


Asunto(s)
Encefalopatías Metabólicas Innatas/tratamiento farmacológico , Cardiomiopatías/tratamiento farmacológico , Isocitrato Deshidrogenasa/antagonistas & inhibidores , Mutación/efectos de los fármacos , Bibliotecas de Moléculas Pequeñas/farmacología , Animales , Encefalopatías Metabólicas Innatas/genética , Modelos Animales de Enfermedad , Isocitrato Deshidrogenasa/genética , Ratones , Mutación/genética
6.
Nat Med ; 29(6): 1358-1363, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37248298

RESUMEN

D-2-hydroxyglutaric aciduria type II (D2HGA2) is a severe inborn disorder of metabolism caused by heterozygous R140 mutations in the IDH2 (isocitrate dehydrogenase 2) gene. Here we report the results of treatment of two children with D2HGA2, one of whom exhibited severe dilated cardiomyopathy, with the selective mutant IDH2 enzyme inhibitor enasidenib. In both children, enasidenib treatment led to normalization of D-2-hydroxyglutarate (D-2-HG) concentrations in body fluids. At doses of 50 mg and 60 mg per day, no side effects were observed, except for asymptomatic hyperbilirubinemia. For the child with cardiomyopathy, chronic D-2-HG inhibition was associated with improved cardiac function, and for both children, therapy was associated with improved daily functioning, global motility and social interactions. Treatment of the child with cardiomyopathy led to therapy-coordinated changes in serum phospholipid levels, which were partly recapitulated in cultured fibroblasts, associated with complex effects on lipid and redox-related gene pathways. These findings indicate that targeted inhibition of a mutant enzyme can partly reverse the pathology of a chronic neurometabolic genetic disorder.


Asunto(s)
Cardiomiopatías , Isocitrato Deshidrogenasa , Niño , Humanos , Cardiomiopatías/tratamiento farmacológico , Cardiomiopatías/genética , Inhibidores Enzimáticos/efectos adversos , Células Germinativas/metabolismo , Isocitrato Deshidrogenasa/metabolismo , Mutación/genética
7.
Blood ; 116(22): 4464-73, 2010 Nov 25.
Artículo en Inglés | MEDLINE | ID: mdl-20709909

RESUMEN

Adhesion properties of hematopoietic stem cells (HSCs) in the bone marrow (BM) niches control their migration and affect their cell-cycle dynamics. The serum response factor (Srf) regulates growth factor-inducible genes and genes controlling cytoskeleton structures involved in cell spreading, adhesion, and migration. We identified a role for Srf in HSC adhesion and steady-state hematopoiesis. Conditional deletion of Srf in BM cells resulted in a 3-fold expansion of the long- and short-term HSCs and multipotent progenitors (MPPs), which occurs without long-term modification of cell-cycle dynamics. Early differentiation steps to myeloid and lymphoid lineages were normal, but Srf loss results in alterations in mature-cell production and severe thrombocytopenia. Srf-null BM cells also displayed compromised engraftment properties in transplantation assays. Gene expression analysis identified Srf target genes expressed in HSCs, including a network of genes associated with cell migration and adhesion. Srf-null stem cells and MPPs displayed impair expression of the integrin network and decreased adherence in vitro. In addition, Srf-null mice showed increase numbers of circulating stem and progenitor cells, which likely reflect their reduced retention in the BM. Altogether, our results demonstrate that Srf is an essential regulator of stem cells and MPP adhesion, and suggest that Srf acts mainly through cell-matrix interactions and integrin signaling.


Asunto(s)
Hematopoyesis , Células Madre Hematopoyéticas/citología , Factor de Respuesta Sérica/metabolismo , Animales , Adhesión Celular , Ciclo Celular , Linaje de la Célula , Eliminación de Gen , Expresión Génica , Células Madre Hematopoyéticas/metabolismo , Integrinas/metabolismo , Ratones , Factor de Respuesta Sérica/genética
8.
Blood ; 116(13): 2332-5, 2010 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-20558618

RESUMEN

Posttranscriptional modifications of histones play important roles in the control of chromatin structure and transcription. H3K4 (histone H3 lysine 4) methylation by the SET domain of the trithorax-group protein MLL (mixed-lineage leukemia) is important for the control of homeobox (HOX) gene expression during development. MLL is tethered to the HOXA locus through interaction of its amino-terminus with menin. MLL fusion proteins associated with human leukemia contain the menin interaction peptide and frequently recruit H3K79 (histone H3 lysine 79) methylation activity. This allows sustained expression of HOXA genes important for cellular transformation. We have characterized a novel recurrent chromosomal aberration, inv(11)(p15q23), as an isolated chromosomal abnormality in 2 patients with acute myeloid leukemia. This aberration is predicted to result in the expression of an NUP98 (nucleoporin 98 kDa)-MLL fusion protein that is unable to interact with menin. As expected, low levels of HOXA gene expression were observed in the patients' samples. This fusion protein is predicted to participate in cellular transformation by activating MLL targets other than HOXA genes.


Asunto(s)
Leucemia Mieloide Aguda/genética , Proteína de la Leucemia Mieloide-Linfoide/genética , Proteínas de Complejo Poro Nuclear/genética , Proteínas de Fusión Oncogénica/genética , Adulto , Anciano , Secuencia de Bases , Transformación Celular Neoplásica/genética , Inversión Cromosómica , Cromosomas Humanos Par 11/genética , Cartilla de ADN/genética , ADN de Neoplasias/genética , Femenino , Expresión Génica , Genes Homeobox , N-Metiltransferasa de Histona-Lisina , Histonas/metabolismo , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Humanos , Leucemia Mieloide Aguda/metabolismo , Masculino , Proteína de la Leucemia Mieloide-Linfoide/metabolismo , Proteínas de Complejo Poro Nuclear/metabolismo , Fusión de Oncogenes , Proteínas de Fusión Oncogénica/metabolismo , Proteínas Proto-Oncogénicas/metabolismo
9.
Haematologica ; 97(3): 379-87, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22058212

RESUMEN

BACKGROUND: The nucleoporin gene NUP98 is rearranged in more than 27 chromosomal abnormalities observed in childhood and adult, de novo and therapy-related acute leukemias of myeloid and T-lymphoid origins, resulting in the creation of fusion genes and the expression of chimeric proteins. We report here the functional analysis of the NUP98-coiled-coil domain-containing protein 28A (NUP98-CCDC28A) fusion protein, expressed as the consequence of a recurrent t(6;11)(q24.1;p15.5) translocation. DESIGN AND METHODS: To gain insight into the function of the native CCDC28A gene, we collected information on any differential expression of CCDC28A among normal hematologic cell types and within subgroups of acute leukemia. To assess the in vivo effects of the NUP98-CCDC28A fusion, NUP98-CCDC28A or full length CCDC28A were retrovirally transduced into primary murine bone marrow cells and transduced cells were next transplanted into sub-lethally irradiated recipient mice. RESULTS: Our in silico analyses supported a contribution of CCDC28A to discrete stages of murine hematopoietic development. They also suggested selective enrichment of CCDC28A in the French-American-British M6 class of human acute leukemia. Primary murine hematopoietic progenitor cells transduced with NUP98-CCDC28A generated a fully penetrant and transplantable myeloproliferative neoplasm-like myeloid leukemia and induced selective expansion of granulocyte/macrophage progenitors in the bone marrow of transplanted recipients, showing that NUP98-CCDC28A promotes the proliferative capacity and self-renewal potential of myeloid progenitors. In addition, the transformation mediated by NUP98-CCDC28A was not associated with deregulation of the Hoxa-Meis1 pathway, a feature shared by a diverse set of NUP98 fusions. CONCLUSIONS: Our results demonstrate that the recurrent NUP98-CCDC28A is an oncogene that induces a rapid and transplantable myeloid neoplasm in recipient mice. They also provide additional evidence for an alternative leukemogenic mechanism for NUP98 oncogenes.


Asunto(s)
Proteínas de Complejo Poro Nuclear/genética , Proteínas de Fusión Oncogénica/genética , Proteínas de Fusión Oncogénica/metabolismo , Proteínas/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Células de la Médula Ósea/metabolismo , Trasplante de Médula Ósea , Núcleo Celular/metabolismo , Proliferación Celular , Cromosomas Humanos Par 11 , Cromosomas Humanos Par 6 , Expresión Génica , Células Progenitoras de Granulocitos y Macrófagos/patología , Proteínas de Homeodominio/metabolismo , Humanos , Inmunofenotipificación , Ratones , Ratones Endogámicos C57BL , Datos de Secuencia Molecular , Proteína 1 del Sitio de Integración Viral Ecotrópica Mieloide , Trastornos Mieloproliferativos/genética , Trastornos Mieloproliferativos/metabolismo , Trastornos Mieloproliferativos/mortalidad , Proteínas de Neoplasias/metabolismo , Proteínas de Complejo Poro Nuclear/metabolismo , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/metabolismo , Isoformas de Proteínas/genética , Transporte de Proteínas , Proteínas/metabolismo , Alineación de Secuencia , Translocación Genética
10.
Blood ; 112(10): 4220-6, 2008 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-18755984

RESUMEN

Oncogenic activation of tyrosine kinase signaling pathway is recurrent in human leukemia. To gain insight into the oncogenic process leading to acute megakaryoblastic leukemia (AMKL), we performed sequence analyses of a subset of oncogenes known to be activated in human myeloid and myeloproliferative disorders. In a series of human AMKL samples from both Down syndrome and non-Down syndrome patients, mutations were identified within KIT, FLT3, JAK2, JAK3, and MPL genes, with a higher frequency in DS than in non-DS patients. The novel mutations were analyzed using BaF3 cells, showing that JAK3 mutations were activating mutations. Finally, we report a novel constitutively active MPL mutant, MPLT487A, observed in a non-Down syndrome childhood AMKL that induces a myeloproliferative disease in mouse bone marrow transplantation assay.


Asunto(s)
Síndrome de Down/genética , Leucemia Megacarioblástica Aguda/genética , Mutación , Proteínas de Neoplasias/genética , Adulto , Anciano , Animales , Línea Celular Tumoral , Niño , Preescolar , Síndrome de Down/metabolismo , Femenino , Humanos , Lactante , Recién Nacido , Leucemia Megacarioblástica Aguda/metabolismo , Masculino , Ratones , Ratones Endogámicos BALB C , Persona de Mediana Edad , Proteínas de Neoplasias/biosíntesis , Trasplante de Neoplasias
11.
Nat Med ; 24(8): 1167-1177, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-30013198

RESUMEN

Mutations in the gene encoding isocitrate dehydrogenase 2 (IDH2) occur in several types of cancer, including acute myeloid leukemia (AML). In model systems, mutant IDH2 causes hematopoietic differentiation arrest. Enasidenib, a selective small-molecule inhibitor of mutant IDH2, produces a clinical response in 40% of treated patients with relapsed/refractory AML by promoting leukemic cell differentiation. Here, we studied the clonal basis of response and acquired resistance to enasidenib treatment. Using sequential patient samples, we determined the clonal structure of hematopoietic cell populations at different stages of differentiation. Before therapy, IDH2-mutant clones showed variable differentiation arrest. Enasidenib treatment promoted hematopoietic differentiation from either terminal or ancestral mutant clones; less frequently, treatment promoted differentiation of nonmutant cells. Analysis of paired diagnosis/relapse samples did not identify second-site mutations in IDH2 at relapse. Instead, relapse arose by clonal evolution or selection of terminal or ancestral clones, thus highlighting multiple bypass pathways that could potentially be targeted to restore differentiation arrest. These results show how mapping of clonal structure in cell populations at different stages of differentiation can reveal the response and evolution of clones during treatment response and relapse.


Asunto(s)
Aminopiridinas/uso terapéutico , Isocitrato Deshidrogenasa/antagonistas & inhibidores , Leucemia Mieloide Aguda/tratamiento farmacológico , Leucemia Mieloide Aguda/patología , Triazinas/uso terapéutico , Aminopiridinas/farmacología , Diferenciación Celular/efectos de los fármacos , Células Clonales , Estudios de Cohortes , Hematopoyesis , Humanos , Inmunofenotipificación , Isocitrato Deshidrogenasa/metabolismo , Mutación/genética , Recurrencia Local de Neoplasia/patología , Células Madre Neoplásicas/efectos de los fármacos , Células Madre Neoplásicas/metabolismo , Células Madre Neoplásicas/patología , Triazinas/farmacología
12.
ACS Med Chem Lett ; 9(4): 300-305, 2018 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-29670690

RESUMEN

Somatic point mutations at a key arginine residue (R132) within the active site of the metabolic enzyme isocitrate dehydrogenase 1 (IDH1) confer a novel gain of function in cancer cells, resulting in the production of d-2-hydroxyglutarate (2-HG), an oncometabolite. Elevated 2-HG levels are implicated in epigenetic alterations and impaired cellular differentiation. IDH1 mutations have been described in an array of hematologic malignancies and solid tumors. Here, we report the discovery of AG-120 (ivosidenib), an inhibitor of the IDH1 mutant enzyme that exhibits profound 2-HG lowering in tumor models and the ability to effect differentiation of primary patient AML samples ex vivo. Preliminary data from phase 1 clinical trials enrolling patients with cancers harboring an IDH1 mutation indicate that AG-120 has an acceptable safety profile and clinical activity.

13.
Cancer Res ; 65(8): 3281-9, 2005 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-15833861

RESUMEN

The release of transforming growth factor-beta1 (TGF-beta1) in the bone marrow microenvironment is one of the main mechanisms leading to myelofibrosis in murine models and probably in the human idiopathic myelofibrosis (IMF). The regulation of TGF-beta1 synthesis is poorly known but seems regulated by nuclear factor kappaB (NF-kappaB). We previously described the overexpression of an immunophilin, FK506 binding protein 51 (FKBP51), in IMF megakaryocytes. Gel shift and gene assays show that FKBP51's overexpression in a factor-dependent hematopoietic cell line, induces a sustained NF-kappaB activation after cytokine deprivation. This activation correlates with a low level of IkappaBalpha. A spontaneous activation of NF-kappaB was also detected in proliferating megakaryocytes and in circulating CD34(+) patient cells. In normal cells, NF-kappaB activation was only detected after cytokine treatment. The expression of an NF-kappaB superrepressor in FKBP51 overexpressing cells and in derived megakaryocytes from CD34(+) of IMF patients revealed that NF-kappaB activation was not involved in the resistance to apoptosis after cytokine deprivation of these cells but in TGF-beta1 secretion. These results highlight the importance of NF-kappaB's activation in the fibrosis development of this disease. They also suggest that FKBP51's overexpression in IMF cells could play an important role in the pathogenesis of this myeloproliferative disorder.


Asunto(s)
FN-kappa B/metabolismo , Mielofibrosis Primaria/metabolismo , Proteínas de Unión a Tacrolimus/biosíntesis , Factor de Crecimiento Transformador beta/biosíntesis , Antígenos CD34/biosíntesis , Línea Celular Tumoral , Humanos , Proteínas I-kappa B/metabolismo , Inhibidor NF-kappaB alfa , FN-kappa B/antagonistas & inhibidores , Mielofibrosis Primaria/sangre , Mielofibrosis Primaria/patología , Factor de Crecimiento Transformador beta/metabolismo , Factor de Crecimiento Transformador beta1
14.
Cancer Discov ; 7(5): 478-493, 2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-28193778

RESUMEN

Somatic gain-of-function mutations in isocitrate dehydrogenases (IDH) 1 and 2 are found in multiple hematologic and solid tumors, leading to accumulation of the oncometabolite (R)-2-hydroxyglutarate (2HG). 2HG competitively inhibits α-ketoglutarate-dependent dioxygenases, including histone demethylases and methylcytosine dioxygenases of the TET family, causing epigenetic dysregulation and a block in cellular differentiation. In vitro studies have provided proof of concept for mutant IDH inhibition as a therapeutic approach. We report the discovery and characterization of AG-221, an orally available, selective, potent inhibitor of the mutant IDH2 enzyme. AG-221 suppressed 2HG production and induced cellular differentiation in primary human IDH2 mutation-positive acute myeloid leukemia (AML) cells ex vivo and in xenograft mouse models. AG-221 also provided a statistically significant survival benefit in an aggressive IDH2R140Q-mutant AML xenograft mouse model. These findings supported initiation of the ongoing clinical trials of AG-221 in patients with IDH2 mutation-positive advanced hematologic malignancies.Significance: Mutations in IDH1/2 are identified in approximately 20% of patients with AML and contribute to leukemia via a block in hematopoietic cell differentiation. We have shown that the targeted inhibitor AG-221 suppresses the mutant IDH2 enzyme in multiple preclinical models and induces differentiation of malignant blasts, supporting its clinical development. Cancer Discov; 7(5); 478-93. ©2017 AACR.See related commentary by Thomas and Majeti, p. 459See related article by Shih et al., p. 494This article is highlighted in the In This Issue feature, p. 443.


Asunto(s)
Aminopiridinas/farmacología , Antineoplásicos/farmacología , Isocitrato Deshidrogenasa/antagonistas & inhibidores , Leucemia Mieloide Aguda/genética , Triazinas/farmacología , Animales , Línea Celular Tumoral , Humanos , Isocitrato Deshidrogenasa/genética , Ratones , Mutación , Ensayos Antitumor por Modelo de Xenoinjerto
15.
Cancer Cell ; 30(2): 192-194, 2016 08 08.
Artículo en Inglés | MEDLINE | ID: mdl-27505668

RESUMEN

IDH mutants cause aberrant DNA and histone methylation and contribute to hematological and neuronal malignancies. In this issue of Cancer Cell, Inoue et al. describe a potential specific effect of IDH1 mutations that reduces Atm expression via inhibition of H3K9 demethylases, which may represent a first step toward cellular transformation.


Asunto(s)
Histonas/genética , Isocitrato Deshidrogenasa/genética , Metilación de ADN , Humanos , Metilación , Mutación , Neoplasias/genética
16.
Artículo en Inglés | MEDLINE | ID: mdl-27131892

RESUMEN

A recent update of the hallmarks of cancer includes metabolism with deregulating cellular energetics. Activating mutations in isocitrate dehydrogenase (IDH) metabolic enzymes leading to the abnormal accumulation of 2-hydroxyglutaric acid (2-HGA) have been described in hematologic malignancies and solid tumours. The diagnostic value of 2-HGA levels in blood to identify IDH mutations and its prognostic significance have been reported. We developed a liquid chromatography tandem mass spectrometry method allowing a rapid, accurate and precise simultaneous quantification of both L and D enantiomers of 2-HGA in blood samples from acute myeloid leukaemia (AML) patients, suitable for clinical applications. The method was also develop for preclinical applications from cellular and tissues samples. Deuterated (R,S)-2-hydroxyglutaric acid, disodium salt was used as internal standard and added to samples before a solid phase extraction on Phenomenex STRATA™-XL-A (200mg-3mL) 33µm cartridges. A derivatization step with (+)- o,o'-diacetyl-l-tartaric anhydride permitted to separate the two resulting diastereoisomers without chiral stationary phase, on a C18 column combined to a Xevo TQ-MS Waters mass spectrometer with an electrospray ionization (ESI) source. This method allows standard curves to be linear over the range 0.34-135.04µM with r(2) values>0.999 and low matrix effects (<11.7%). This method, which was validated according to current EMA guidelines, is accurate between-run (<3.1%) and within-run (<7.9%) and precise between-run (<5.3CV%) and within-run (<6.2CV%), and is suitable for clinical and preclinical applications.


Asunto(s)
Biomarcadores de Tumor/sangre , Cromatografía Liquida/métodos , Glutaratos/sangre , Isocitrato Deshidrogenasa/metabolismo , Espectrometría de Masas en Tándem/métodos , Biomarcadores de Tumor/química , Biomarcadores de Tumor/metabolismo , Línea Celular Tumoral , Glutaratos/química , Glutaratos/metabolismo , Humanos , Leucemia Mieloide Aguda/metabolismo , Modelos Lineales , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Estereoisomerismo
17.
Oncotarget ; 6(28): 24969-77, 2015 Sep 22.
Artículo en Inglés | MEDLINE | ID: mdl-26327213

RESUMEN

Mismatch-repair (MMR)-deficient cells show increased in vitro tolerance to thiopurines because they escape apoptosis resulting from MMR-dependent signaling of drug-induced DNA damage. Prolonged treatment with immunosuppressants including azathioprine (Aza), a thiopurine prodrug, has been suggested as a risk factor for the development of late onset leukemias/lymphomas displaying a microsatellite instability (MSI) phenotype, the hallmark of a defective MMR system. We performed a dose effect study in mice to investigate the development of MSI lymphomas associated with long term Aza treatment. Over two years, Aza was administered to mice that were wild type, null or heterozygous for the MMR gene Msh2. Ciclosporin A, an immunosuppressant with an MMR-independent signaling, was also administered to Msh2(wt) mice as controls. Survival, lymphoma incidence and MSI tumor phenotype were investigated. Msh2(+/-) mice were found more tolerant than Msh2(wt) mice to the cytotoxicity of Aza. In Msh2(+/-) mice, Aza induced a high incidence of MSI lymphomas in a dose-dependent manner. In Msh2(wt) mice, a substantial lifespan was only observed at the lowest Aza dose. It was associated with the development of lymphomas, one of which displayed the MSI phenotype, unlike the CsA-induced lymphomas. Our findings define Aza as a risk factor for an MSI-driven lymphomagenesis process.


Asunto(s)
Azatioprina/toxicidad , Linfoma/genética , Inestabilidad de Microsatélites , Proteína 2 Homóloga a MutS/genética , Adulto , Anciano , Animales , Reparación de la Incompatibilidad de ADN/genética , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Inmunohistoquímica , Inmunosupresores/toxicidad , Enfermedades Inflamatorias del Intestino/genética , Enfermedades Inflamatorias del Intestino/metabolismo , Estimación de Kaplan-Meier , Linfoma/inducido químicamente , Linfoma/metabolismo , Masculino , Ratones Noqueados , Persona de Mediana Edad , Proteína 2 Homóloga a MutS/metabolismo , Fenotipo , Medición de Riesgo/métodos , Factores de Riesgo , Factores de Tiempo , Adulto Joven
18.
J Clin Oncol ; 32(4): 297-305, 2014 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-24344214

RESUMEN

PURPOSE: Mutated isocitrate dehydrogenases (IDHs) 1 and 2 produce high levels of 2-hydroxyglutarate (2-HG). We investigated whether, in acute myeloid leukemia (AML), serum 2-HG would predict the presence of IDH1/2 mutations at diagnosis and provide a marker of minimal residual disease (MRD). PATIENTS AND METHODS: Serum samples from 82 patients at diagnosis of de novo AML (IDH1/2 mutated, n = 53) and 68 patients without AML were analyzed for total 2-HG and its ratio of D to L stereoisomers by mass spectrometry. We measured 2-HG levels and molecular markers of MRD (WT1 and NPM1) in serial samples of 36 patients with IDH1/2 mutations after induction therapy. RESULTS: In patients with AML with IDH1/2 mutations, 2-HG serum levels were significantly higher than in patients with IDH1/2 wild type (P < .001). Area under the receiver operating characteristic curve was 99%. The optimum diagnostic cutoff between IDH1/2 mutated and normal was 2 µmol/L (sensitivity, 100%; specificity, 79%). Quantification of the D/L stereoisomers increased specificity (100%; 95% CI, 83% to 100%) compared with total 2-HG (P = .031). In patients with IDH2 R172 mutations, 2-HG levels were higher relative to those with other IDH1/2 mutations (P < .05). During follow-up, serum 2-HG levels showed strong positive correlation with WT1 and NPM1 (P < .001). After induction therapy, total 2-HG serum levels < 2 µmol/L were associated with better overall (P = .008) and disease-free survival (P = .005). CONCLUSION: Serum 2-HG is a predictor of the presence of IDH1/2 mutations and outcome in these patients. Discrimination between D/L stereoisomers improved specificity.


Asunto(s)
Biomarcadores de Tumor/sangre , Glutaratos/sangre , Isocitrato Deshidrogenasa/genética , Leucemia Mieloide Aguda/sangre , Leucemia Mieloide Aguda/diagnóstico , Mutación , Adulto , Anciano , Área Bajo la Curva , Femenino , Francia , Humanos , Estimación de Kaplan-Meier , Leucemia Mieloide Aguda/genética , Masculino , Espectrometría de Masas , Persona de Mediana Edad , Neoplasia Residual/sangre , Proteínas Nucleares/sangre , Nucleofosmina , Valor Predictivo de las Pruebas , Pronóstico , Curva ROC , Sensibilidad y Especificidad , Estereoisomerismo , Proteínas WT1/sangre
20.
Science ; 340(6132): 622-6, 2013 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-23558173

RESUMEN

A number of human cancers harbor somatic point mutations in the genes encoding isocitrate dehydrogenases 1 and 2 (IDH1 and IDH2). These mutations alter residues in the enzyme active sites and confer a gain-of-function in cancer cells, resulting in the accumulation and secretion of the oncometabolite (R)-2-hydroxyglutarate (2HG). We developed a small molecule, AGI-6780, that potently and selectively inhibits the tumor-associated mutant IDH2/R140Q. A crystal structure of AGI-6780 complexed with IDH2/R140Q revealed that the inhibitor binds in an allosteric manner at the dimer interface. The results of steady-state enzymology analysis were consistent with allostery and slow-tight binding by AGI-6780. Treatment with AGI-6780 induced differentiation of TF-1 erythroleukemia and primary human acute myelogenous leukemia cells in vitro. These data provide proof-of-concept that inhibitors targeting mutant IDH2/R140Q could have potential applications as a differentiation therapy for cancer.


Asunto(s)
Inhibidores Enzimáticos/farmacología , Hematopoyesis/efectos de los fármacos , Isocitrato Deshidrogenasa/antagonistas & inhibidores , Isocitrato Deshidrogenasa/genética , Leucemia Mieloide Aguda/enzimología , Compuestos de Fenilurea/farmacología , Sulfonamidas/farmacología , Sitio Alostérico , Antineoplásicos/química , Antineoplásicos/metabolismo , Antineoplásicos/farmacología , Dominio Catalítico , Línea Celular Tumoral , Proliferación Celular , Células Cultivadas , Cristalografía por Rayos X , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/metabolismo , Eritropoyesis/efectos de los fármacos , Regulación Leucémica de la Expresión Génica , Glutaratos/metabolismo , Humanos , Isocitrato Deshidrogenasa/química , Isocitrato Deshidrogenasa/metabolismo , Leucemia Eritroblástica Aguda , Leucemia Mieloide Aguda/tratamiento farmacológico , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patología , Terapia Molecular Dirigida , Proteínas Mutantes/antagonistas & inhibidores , Proteínas Mutantes/química , Proteínas Mutantes/metabolismo , Compuestos de Fenilurea/química , Compuestos de Fenilurea/metabolismo , Mutación Puntual , Multimerización de Proteína , Estructura Secundaria de Proteína , Bibliotecas de Moléculas Pequeñas , Sulfonamidas/química , Sulfonamidas/metabolismo
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