RESUMEN
Chronic lymphocytic leukemia (CLL) is characterized by a low CD20 expression, in part explained by an epigenetic-driven downregulation triggered by mutations of the NOTCH1 gene. In the present study, by taking advantage of a wide and well-characterized CLL cohort (n=537), we demonstrate that CD20 expression is downregulated in SF3B1-mutated CLL in an extent similar to NOTCH1-mutated CLL. In fact, SF3B1-mutated CLL cells show common features with NOTCH1-mutated CLL cells, including a gene expression profile enriched of NOTCH1-related gene sets and elevated expression of the active intracytoplasmic NOTCH1. Activation of the NOTCH1 signaling and down-regulation of surface CD20 in SF3B1-mutated CLL cells correlate with over-expression of an alternatively spliced form of DVL2, a component of the Wnt pathway and negative regulator of the NOTCH1 pathway. These findings are confirmed by separately analyzing the CD20-dim and CD20-bright cell fractions from SF3B1-mutated cases as well as by DVL2 knock-out experiments in CLL-like cell models. Altogether, the clinical and biological features that characterize NOTCH1-mutated CLL may also be recapitulated in SF3B1-mutated CLL, contributing to explain the poor prognosis of this CLL subset and providing the rationale for expanding novel agents-based therapies to SF3B1-mutated CLL.
Asunto(s)
Leucemia Linfocítica Crónica de Células B , Antígenos CD20 , Regulación hacia Abajo , Humanos , Leucemia Linfocítica Crónica de Células B/genética , Mutación , Fosfoproteínas/genética , Pronóstico , Factores de Empalme de ARN/genética , Receptor Notch1/genéticaRESUMEN
Children with Down syndrome (DS) are at increased risk for acute myeloid leukemias (ML-DS) characterized by mixed megakaryocytic and erythroid phenotype and by acquired mutations in the GATA1 gene resulting in a short GATA1s isoform. The chromosome 21 microRNA (miR)-125b cluster has been previously shown to cooperate with GATA1s in transformation of fetal hematopoietic progenitors. In this study, we report that the expression of miR-486-5p is increased in ML-DS compared with non-DS acute megakaryocytic leukemias (AMKLs). miR-486-5p is regulated by GATA1 and GATA1s that bind to the promoter of its host gene ANK1. miR-486-5p is highly expressed in mouse erythroid precursors and knockdown (KD) in ML-DS cells reduced their erythroid phenotype. Ectopic expression and KD of miR-486-5p in primary fetal liver hematopoietic progenitors demonstrated that miR-486-5p cooperates with Gata1s to enhance their self renewal. Consistent with its activation of AKT, overexpression and KD experiments showed its importance for growth and survival of human leukemic cells. Thus, miR-486-5p cooperates with GATA1s in supporting the growth and survival, and the aberrant erythroid phenotype of the megakaryocytic leukemias of DS.
Asunto(s)
Síndrome de Down/genética , Eritropoyesis/genética , Leucemia Mieloide Aguda/genética , MicroARNs/fisiología , Animales , Diferenciación Celular/genética , Proliferación Celular/genética , Transformación Celular Neoplásica/genética , Preescolar , Síndrome de Down/complicaciones , Síndrome de Down/fisiopatología , Células Eritroides/metabolismo , Células HEK293 , Humanos , Células K562 , Leucemia Mieloide Aguda/patología , Megacariocitos/fisiología , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , MicroARNs/genética , Células Tumorales CultivadasRESUMEN
The prognostic relevance of CRLF2 -rearrangements in childhood acute B-cell precursor lymphoblastic leukaemia (ALL), was assessed by a comparative analysis of 114 non-Down-syndrome patients (99 P2RY8-CRLF2+ , 15 IGH@-CRLF2+ ), 76 from the AIEOP-BFM ALL 2000 and 38 from the MRC ALL97 trials. The 6-year cumulative relapse incidence of P2RY8-CRLF2+ patients treated on the two trials was not statistically different: 0·37 ± 0·06 vs. 0·25 ± 0·08 (P = 0·194). In contrast, 0/9 IGH@-CRLF2+ AIEOP-BFM, but 5/6 ALL97 patients relapsed. Conclusively, P2RY8-CRLF2+ patients had an intermediate protocol-independent outcome while the different prognosis of IGH@-CRLF2+ patients could be related to the different structures of the applied treatment protocols.
Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Estudios Multicéntricos como Asunto/estadística & datos numéricos , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Ensayos Clínicos Controlados Aleatorios como Asunto/estadística & datos numéricos , Receptores de Citocinas/análisis , Adolescente , Niño , Preescolar , Europa (Continente) , Femenino , Estudios de Seguimiento , Humanos , Lactante , Estimación de Kaplan-Meier , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidad , Recurrencia , Inducción de Remisión , Riesgo , Resultado del TratamientoRESUMEN
We report gene expression and other analyses to elucidate the molecular characteristics of acute lymphoblastic leukemia (ALL) in children with Down syndrome (DS). We find that by gene expression DS-ALL is a highly heterogeneous disease not definable as a unique entity. Nevertheless, 62% (33/53) of the DS-ALL samples analyzed were characterized by high expression of the type I cytokine receptor CRLF2 caused by either immunoglobulin heavy locus (IgH@) translocations or by interstitial deletions creating chimeric transcripts P2RY8-CRLF2. In 3 of these 33 patients, a novel activating somatic mutation, F232C in CRLF2, was identified. Consistent with our previous research, mutations in R683 of JAK2 were identified in 10 specimens (19% of the patients) and, interestingly, all 10 had high CRLF2 expression. Cytokine receptor-like factor 2 (CRLF2) and mutated Janus kinase 2 (Jak2) cooperated in conferring cytokine-independent growth to BaF3 pro-B cells. Intriguingly, the gene expression signature of DS-ALL is enriched with DNA damage and BCL6 responsive genes, suggesting the possibility of B-cell lymphocytic genomic instability. Thus, DS confers increased risk for genetically highly diverse ALLs with frequent overexpression of CRLF2, associated with activating mutations in the receptor itself or in JAK2. Our data also suggest that the majority of DS children with ALL may benefit from therapy blocking the CRLF2/JAK2 pathways.
Asunto(s)
Síndrome de Down/genética , Janus Quinasa 2/genética , Mutación , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Receptores de Citocinas/genética , Animales , Western Blotting , Línea Celular , Niño , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Síndrome de Down/complicaciones , Síndrome de Down/metabolismo , Citometría de Flujo , Perfilación de la Expresión Génica , Regulación Leucémica de la Expresión Génica , Heterogeneidad Genética , Humanos , Hibridación Fluorescente in Situ , Janus Quinasa 2/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/complicaciones , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Proteínas Proto-Oncogénicas c-bcl-6 , Receptores de Citocinas/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción de SeñalRESUMEN
KRAS mutations account for the most frequent mutations in human cancers, and are generally correlated with disease aggressiveness, poor prognosis, and poor response to therapies. KRAS is required for adult hematopoiesis and plays a key role in B cell development and mature B cell proliferation and survival, proved to be critical for B cell receptor-induced ERK pathway activation. In mature B cell neoplasms, commonly seen in adults, KRAS and RAS-MAPK pathway aberrations occur in a relevant fraction of patients, reaching high recurrence in some specific subtypes like multiple myeloma and hairy cell leukemia. As inhibitors targeting the RAS-MAPK pathway are being developed and improved, it is of outmost importance to precisely identify all subgroups of patients that could potentially benefit from their use. Herein, we review the role of KRAS and RAS-MAPK signaling in malignant hematopoiesis, focusing on mature B cell lymphoproliferative disorders. We discuss KRAS and RAS-MAPK pathway aberrations describing type, incidence, mutual exclusion with other genetic abnormalities, and association with prognosis. We review the current therapeutic strategies applied in mature B cell neoplasms to counteract RAS-MAPK signaling in pre-clinical and clinical studies, including most promising combination therapies. We finally present an overview of genetically engineered mouse models bearing KRAS and RAS-MAPK pathway aberrations in the hematopoietic compartment, which are valuable tools in the understanding of cancer biology and etiology.
RESUMEN
BACKGROUND: Despite intensive risk-based treatment protocols, 15% of paediatric patients with B-Cell Precursor Acute Lymphoblastic Leukaemia (BCP-ALL) experience relapse. There is urgent need of novel strategies to target poor prognosis subgroups, like PAX5 translocated. METHODS: We considered 289 childhood BCP-ALL cases consecutively enrolled in Italy in the AIEOP-BFM ALL2000/R2006 protocols and we performed extensive molecular profiling, integrating gene expression, copy number analyses and fusion genes discovery by target-capture NGS. We developed preclinical strategies to target PAX5 fusion genes. FINDINGS: We identified 135 cases without recurrent genetic rearrangements. Among them, 59 patients (43·7%) had a Ph-like signature; the remaining cases were identified as ERG-related (26%), High-Hyperdiploid-like (17%), ETV6::RUNX1-like (8·9%), MEF2D-rearranged (2·2%) or KMT2A-like (1·5%). A poor prognosis was associated with the Ph-like signature, independently from other high-risk features. Interestingly, PAX5 was altered in 54·4% of Ph-like compared to 16·2% of non-Ph-like cases, with 7 patients carrying PAX5 fusions (PAX5t), involving either novel (ALDH18A1, IKZF1, CDH13) or known (FBRSL1, AUTS2, DACH2) partner genes. PAX5t cases have a specific driver activity signature, extending to multiple pathways including LCK hyperactivation. Among FDA-approved drugs and inhibitors, we selected Dasatinib, Bosutinib and Foretinib, in addition to Nintedanib, known to be LCK ligands. We demonstrated the efficacy of the LCK-inhibitor BIBF1120/Nintedanib, as single agent or in combination with conventional chemotherapy, both ex vivo and in patient-derived xenograft model, showing a synergistic effect with dexamethasone. INTERPRETATION: This study provides new insights in high-risk Ph-like leukaemia and identifies a potential therapy for targeting PAX5-fusion poor risk group. FUNDING: Ricerca Finalizzata-Giovani Ricercatori (Italian Ministry of Health), AIRC, Transcall, Fondazione Cariparo.
Asunto(s)
Leucemia-Linfoma Linfoblástico de Células Precursoras B , Leucemia-Linfoma Linfoblástico de Células Precursoras , Niño , Subunidad alfa 2 del Factor de Unión al Sitio Principal , Dasatinib , Dexametasona , Humanos , Indoles , Recurrencia Local de Neoplasia , Factor de Transcripción PAX5/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/tratamiento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/genéticaRESUMEN
PURPOSE: In chronic lymphocytic leukemia (CLL), TP53 mutations are associated with reduced survival and resistance to standard chemoimmunotherapy (CIT). Nevertheless, the clinical impact of subclonal TP53 mutations below 10% to 15% variant allele frequency (VAF) remains unclear. EXPERIMENTAL DESIGN: Using a training/validation approach, we retrospectively analyzed the clinical and biological features of TP53 mutations above (high-VAF) or below (low-VAF) the previously reported 10.0% VAF threshold, as determined by deep next-generation sequencing. Clinical impact of low-VAF TP53 mutations was also confirmed in a cohort (n = 251) of CLL treated with fludarabine-cyclophosphamide-rituximab (FCR) or FCR-like regimens from two UK trials. RESULTS: In the training cohort, 97 of 684 patients bore 152 TP53 mutations, while in the validation cohort, 71 of 536 patients had 109 TP53 mutations. In both cohorts, patients with the TP53 mutation experienced significantly shorter overall survival (OS) than TP53 wild-type patients, regardless of the TP53 mutation VAF. By combining TP53 mutation and 17p13.1 deletion (del17p) data in the total cohort (n = 1,220), 113 cases were TP53 mutated only (73/113 with low-VAF mutations), 55 del17p/TP53 mutated (3/55 with low-VAF mutations), 20 del17p only, and 1,032 (84.6%) TP53 wild-type. A model including low-VAF cases outperformed the canonical model, which considered only high-VAF cases (c-indices 0.643 vs. 0.603, P < 0.0001), and improved the prognostic risk stratification of CLL International Prognostic Index. Clinical results were confirmed in CIT-treated cases (n = 552) from the retrospective cohort, and the UK trials cohort. CONCLUSIONS: TP53 mutations affected OS regardless of VAF. This finding can be used to update the definition of TP53 mutated CLL for clinical purposes.
Asunto(s)
Frecuencia de los Genes , Variación Genética , Leucemia Linfocítica Crónica de Células B/genética , Mutación , Proteína p53 Supresora de Tumor/genética , Humanos , Pronóstico , Estudios Retrospectivos , Tasa de Supervivencia , Factores de TiempoRESUMEN
Most relapses of acute lymphoblastic leukemia (ALL) occur in patients with a medium risk (MR) for relapse on the Associazione Italiana di Ematologia e Oncologia Pediatrica and Berlin-Frankfurt-Münster (AIEOP-BFM) ALL protocol, based on persistence of minimal residual disease (MRD). New insights into biological features that are associated with MRD are needed. Here, we identify the glycosylphosphatidylinositol-anchored cell surface protein vanin-2 (VNN2; GPI-80) by charting the cell surface proteome of MRD very high-risk (HR) B-cell precursor (BCP) ALL using a chemoproteomics strategy. The correlation between VNN2 transcript and surface protein expression enabled a retrospective analysis (ALL-BFM 2000; N = 770 cases) using quantitative polymerase chain reaction to confirm the association of VNN2 with MRD and independent prediction of worse outcome. Using flow cytometry, we detected VNN2 expression in 2 waves, in human adult bone marrow stem and progenitor cells and in the mature myeloid compartment, in line with proposed roles for fetal hematopoietic stem cells and inflammation. Prospective validation by flow cytometry in the ongoing clinical trial (AIEOP-BFM 2009) identified 10% (103/1069) of VNN2+ BCP ALL patients at first diagnosis, primarily in the MRD MR (48/103, 47%) and HR (37/103, 36%) groups, across various cytogenetic subtypes. We also detected frequent mutations in epigenetic regulators in VNN2+ ALLs, including histone H3 methyltransferases MLL2, SETD2, and EZH2 and demethylase KDM6A. Inactivation of the VNN2 gene did not impair leukemia repopulation capacity in xenografts. Taken together, VNN2 marks a cellular state of increased resistance to chemotherapy that warrants further investigations. Therefore, this marker should be included in diagnostic flow cytometry panels.
Asunto(s)
Resistencia a Antineoplásicos , Leucemia-Linfoma Linfoblástico de Células Precursoras , Amidohidrolasas/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica , Linfocitos B , Moléculas de Adhesión Celular , Niño , Resistencia a Antineoplásicos/genética , Proteínas Ligadas a GPI , Células Madre Hematopoyéticas , Humanos , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Estudios Prospectivos , Estudios RetrospectivosRESUMEN
ERG-related leukemia is a B cell precursor acute lymphoblastic leukemia (BCP ALL) subtype characterized by aberrant expression of DUX4 and ERG transcription factors, and highly recurrent ERG intragenic deletions. ERG-related patients have remarkably favorable outcome despite a high incidence of inauspicious IKZF1 aberrations.We describe clinical and genomic features of the ERG-related cases in an unselected cohort of B-other BCP ALL pediatric patients enrolled in the AIEOP ALL 2000 therapeutic protocol. We report a small noncoding RNA signature specific of ERG-related group, with up-regulation of miR-125b-2 cluster on chromosome 21 and several snoRNAs in the Prader-Willi locus at 15q11.2, including the orphan SNORD116 cluster.
Asunto(s)
Expresión Génica , MicroARNs/genética , Familia de Multigenes , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/metabolismo , ARN Nucleolar Pequeño/genética , Regulador Transcripcional ERG/metabolismo , Adolescente , Antineoplásicos/uso terapéutico , Biomarcadores , Niño , Preescolar , Aberraciones Cromosómicas , Cromosomas Humanos Par 15 , Cromosomas Humanos Par 21/genética , Estudios de Cohortes , Femenino , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Humanos , Lactante , Masculino , Síndrome de Prader-Willi/genética , Síndrome de Prader-Willi/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras B/tratamiento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras B/patología , Sitios de Carácter Cuantitativo , Eliminación de Secuencia , Regulador Transcripcional ERG/genética , Transcriptoma , Resultado del TratamientoAsunto(s)
Cromosomas Humanos Par 12 , GTP Fosfohidrolasas/genética , Leucemia Linfocítica Crónica de Células B/genética , Proteínas de la Membrana/genética , Mutación , Proteínas Proto-Oncogénicas B-raf/genética , Proteínas Proto-Oncogénicas p21(ras)/genética , Trisomía , Adulto , Anciano , Femenino , Humanos , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , Leucemia Linfocítica Crónica de Células B/mortalidad , Masculino , Persona de Mediana EdadRESUMEN
We investigated the engraftment properties and impact on patient outcome of 50 pediatric acute lymphoblastic leukemia (ALL) samples transplanted into NOD/SCID mice. Time to leukemia (TTL) was determined for each patient sample engrafted as weeks from transplant to overt leukemia. Short TTL was strongly associated with high risk for early relapse, identifying an independent prognostic factor. This high-risk phenotype is reflected by a gene signature that upon validation in an independent patient cohort (n = 197) identified a high-risk cluster of patients with early relapse. Furthermore, the signature points to independent pathways, including mTOR, involved in cell growth and apoptosis. The pathways identified can directly be targeted, thereby offering additional treatment approaches for these high-risk patients.