Found 10 publicacions matching the indicated search criteria.
García-Hernández V, Arambilet D, Guillén Y, Lobo-Jarne T, Maqueda M, Gekas C, González J, Iglesias A, Vega-García N, Sentís I, Trincado JL, Márquez-López I, Heyn H, Camós M, Espinosa L, Bigas A
β-Catenin activity induces an RNA biosynthesis program promoting therapy resistance in T-cell acute lymphoblastic leukemia.
EMBO Molecular Medecine4 Jan 2023, e16554. Epub 4 Jan 2023
Understanding the molecular mechanisms that contribute to the appearance of chemotherapy resistant cell populations is necessary to improve cancer treatment. We have now investigated the role of β-catenin/CTNNB1 in the evolution of T-cell Acute Lymphoblastic Leukemia (T-ALL) patients and its involvement in therapy resistance. We have identified a specific gene signature that is directly regulated by β-catenin, TCF/LEF factors and ZBTB33/Kaiso in T-ALL cell lines, which is highly and significantly represented in five out of six refractory patients from a cohort of 40 children with T-ALL. By subsequent refinement of this gene signature, we found that a subset of β-catenin target genes involved with RNA-processing function are sufficient to segregate T-ALL refractory patients in three independent cohorts. We demonstrate the implication of β-catenin in RNA and protein synthesis in T-ALL and provide in vitro and in vivo experimental evidence that β-catenin is crucial for the cellular response to chemotherapy, mainly in the cellular recovery phase after treatment. We propose that combination treatments involving chemotherapy plus β-catenin inhibitors will enhance chemotherapy response and prevent disease relapse in T-ALL patients.
González-Gil C, Morgades M, Lopes T, Fuster-Tormo F, García-Chica J, Zhao R, Montesinos P, Torrent A, Diaz-Beya M, Coll R, Hermosín L, Mercadal S, González-Campos J, Zamora L, Artola T, Vall-Llovera F, Tormo M, Gil-Cortés C, Barba P, Novo A, Ribera J, Bernal T, De Ugarriza PL, Queipo MP, Martínez-Sánchez P, Giménez A, González-Martínez T, Cladera A, Cervera J, Fernández-Martín R, Ardaiz MÁ, Vidal MJ, Baena Á, López-Bigas N, Bigas A, Maciejewski J, Orfao A, Ribera JM, Genescà E
Genomics improves risk stratification of adults with T-cell acute lymphoblastic leukemia patients enrolled in measurable residual disease-oriented trials.
Haematologica3 Nov 2022, . Epub 3 Nov 2022
Genetic information has been crucial to understand the pathogenesis of T-cell acute lymphoblastic leukemia (T-ALL) at diagnosis and at relapse, but still nowadays has a limited value in a clinical context. Few genetic markers are associated with the outcome of T-ALL patients, independently of measurable residual disease (MRD) status after therapy. In addition, the prognostic relevance of genetic features may be modulated by the specific treatment used. We analyzed the genetic profile of 145 T-ALL patients by targeted deep sequencing. Genomic information was integrated with the clinical-biological and survival data of a subset of 116 adult patients enrolled in two consecutive MRD-oriented trials of the Spanish PETHEMA (Programa Español de Tratamientos en Hematología) group. Genetic analysis revealed a mutational profile defined by DNMT3A/ N/KRAS/ MSH2/ U2AF1 gene mutations that identified refractory/resistant patients. Mutations in the DMNT3A gene were also found in the nonleukemic cell fraction of patients with T-ALL, revealing a possible mutational-driven clonal hematopoiesis event to prime T-ALL in elderly. The prognostic impact of this adverse genetic profile was independent of MRD status on day +35 of induction therapy. The combined WOG signature and MRD on day +35 allowed risk-stratification of T-ALL into standard or high-risk groups with significantly different 5-year overall survival (OS) (95% confidence interval [CI]) of 52% (37-67 %) and 17% (1-33%), respectively. These results confirm the relevance of the tumor genetic profile in predicting patient outcome in adult T-ALL and highlight the need for novel gene-targeted chemotherapeutic schedules to improve the OS of poor-prognosis T-ALL patients.
Galindo-Campos MA, Lutfi N, Bonnin S, Martínez C, Velasco-Hernandez T, García-Hernández V, Martin-Caballero J, Ampurdanés C, Gimeno R, Colomo L, Roue G, Guilbaud G, Dantzer F, Navarro P, Murga M, Fernandez-Capetillo O, Bigas A, Menendez P, Sale J, Yélamos J
Distinct roles for PARP-1 and PARP-2 in c-Myc-driven B-cell lymphoma in mice.
Blood6 Aug 2021, . Epub 6 Aug 2021
Dysregulation of the c-Myc oncogene occurs in a wide variety of haematologic malignancies and its overexpression has been linked with aggressive tumour progression. Here, we show that Poly (ADP-ribose) polymerase (PARP)-1 and PARP-2 exert opposing influences on progression of c-Myc-driven B-cell lymphomas. PARP-1 and PARP-2 catalyse the synthesis and transfer of ADP-ribose units onto amino acid residues of acceptor proteins in response to DNA-strand breaks, playing a central role in the response to DNA damage. Accordingly, PARP inhibitors have emerged as promising new cancer therapeutics. However, the inhibitors currently available for clinical use are not able to discriminate between individual PARP proteins. We found that genetic deletion of PARP-2 prevents c-Myc-driven B-cell lymphomas, while PARP-1-deficiency accelerates lymphomagenesis in the Em-Myc mouse model of aggressive B-cell lymphoma. Loss of PARP-2 aggravates replication stress in pre-leukemic Em-Myc B cells resulting in accumulation of DNA damage and concomitant cell death that restricts the c-Myc-driven expansion of B cells, thereby providing protection against B-cell lymphoma. In contrast, PARP-1-deficiency induces a proinflammatory response, and an increase in regulatory T cells likely contributing to immune escape of B-cell lymphomas, resulting in an acceleration of lymphomagenesis. These findings pinpoint specific functions for PARP-1 and PARP-2 in c-Myc-driven lymphomagenesis with antagonistic consequences that may help inform the design of new PARP-centred therapeutic strategies with selective PARP-2 inhibition potentially representing a new therapeutic approach for the treatment of c-Myc-driven tumours.
The Notch/Hes1 pathway sustains NFkB activation through CYLD repression in T cell leukemia
Cancer Cell . 2010 Sep 14;18(3):268-81 , .
It was previously shown that the NF-κB pathway is downstream of oncogenic Notch1 in T cell acute lymphoblastic leukemia (T-ALL). Here, we visualize Notch-induced NF-κB activation using both human T-ALL cell lines and animal models. We demonstrate that Hes1, a canonical Notch target and transcriptional repressor, is responsible for sustaining IKK activation in T-ALL. Hes1 exerts its effects by repressing the deubiquitinase CYLD, a negative IKK complex regulator. CYLD expression was found to be significantly suppressed in primary T-ALL. Finally, we demonstrate that IKK inhibition is a promising option for the targeted therapy of T-ALL as specific suppression of IKK expression and function affected both the survival of human T-ALL cells and the maintenance of the disease in vivo
Jordi Guiu, Ritsuko Shimizu, Teresa D’Altri, Stuart T. Fraser, Jun Hatakeyama, Emery H. Bresnick, Ryoichiro Kageyama, Elaine Dzierzak, Masayuki Yamamoto, Lluis Espinosa and Anna Bigas (*equal contribution
Hes repressors are essential regulators of Hematopoietic Stem Cell Development downstream of Notch signaling
J Exp Med . 2013 Jan 14;210(1):71-84 , .
Previous studies have identified Notch as a key regulator of hematopoietic stem cell (HSC) development, but the underlying downstream mechanisms remain unknown. The Notch target Hes1 is widely expressed in the aortic endothelium and hematopoietic clusters, though Hes1-deficient mice show no overt hematopoietic abnormalities. We now demonstrate that Hes is required for the development of HSC in the mouse embryo, a function previously undetected as the result of functional compensation by de novo expression of Hes5 in the aorta/gonad/mesonephros (AGM) region of Hes1 mutants. Analysis of embryos deficient for Hes1 and Hes5 reveals an intact arterial program with overproduction of nonfunctional hematopoietic precursors and total absence of HSC activity. These alterations were associated with increased expression of the hematopoietic regulators Runx1, c-myb, and the previously identified Notch target Gata2. By analyzing the Gata2 locus, we have identified functional RBPJ-binding sites, which mutation results in loss of Gata2 reporter expression in transgenic embryos, and functional Hes-binding sites, which mutation leads to specific Gata2 up-regulation in the hematopoietic precursors. Together, our findings show that Notch activation in the AGM triggers Gata2 and Hes1 transcription, and next HES-1 protein represses Gata2, creating an incoherent feed-forward loop required to restrict Gata2 expression in the emerging HSCs.
Notch signal strength controls cell fate in the haemogenic endothelium
Nat Commun . 2015 Oct 14;6:8510 , .
Acquisition of the arterial and haemogenic endothelium fates concurrently occur in the aorta-gonad-mesonephros (AGM) region prior to haematopoietic stem cell (HSC) generation. The arterial programme depends on Dll4 and the haemogenic endothelium/HSC on Jag1-mediated Notch1 signalling. How Notch1 distinguishes and executes these different programmes in response to particular ligands is poorly understood. By using two Notch1 activation trap mouse models with different sensitivity, here we show that arterial endothelial cells and HSCs originate from distinct precursors, characterized by different Notch1 signal strengths. Microarray analysis on AGM subpopulations demonstrates that the Jag1 ligand stimulates low Notch strength, inhibits the endothelial programme and is permissive for HSC specification. In the absence of Jag1, endothelial cells experience high Dll4-induced Notch activity and select the endothelial programme, thus precluding HSC formation. Interference with the Dll4 signal by ligand-specific blocking antibodies is sufficient to inhibit the endothelial programme and favour specification of the haematopoietic lineage.
Christos Gekas, Teresa D’Altri, Rosa Aligué, Jessica González1, Lluis Espinosa, Anna Bigas
β-Catenin is required for T cell leucemia initiation and MYC transcription downstream of Notch1
Leukemia . 2016 Oct;30(10):2002-2010 , .
Notch activation is instrumental in the development of most T-cell acute lymphoblastic leukemia (T-ALL) cases, yet Notch mutations alone are not sufficient to recapitulate the full human disease in animal models. We here found that Notch1 activation at the fetal liver (FL) stage expanded the hematopoietic progenitor population and conferred it transplantable leukemic-initiating capacity. However, leukemogenesis and leukemic-initiating cell capacity induced by Notch1 was critically dependent on the levels of β-Catenin in both FL and adult bone marrow contexts. In addition, inhibition of β-Catenin compromised survival and proliferation of human T-ALL cell lines carrying activated Notch1. By transcriptome analyses, we identified the MYC pathway as a crucial element downstream of β-Catenin in these T-ALL cells and demonstrate that the MYC 3' enhancer required β-Catenin and Notch1 recruitment to induce transcription. Finally, PKF115-584 treatment prevented and partially reverted leukemogenesis induced by active Notch1.
Cristina Porcheri, Ohad Golan, Fernando J.Calero-Nieto, Roshana Thambyrajah, Cristina Ruiz-Herguido, Xiaonan Wang, Francesca Cato, Yolanda Guillén, Roshani Sinha, Jessica González, Sarah J.Kinston, Samanta Mariani, Antonio Maglitto, Chris Vink, Elaine Dzierzak, Pierre Charbord, Bertie Gottgens, Lluis Espinosa, David Sprinzak, Anna Bigas
Notch ligand Dll4 impairs cell recruitment into aortic clusters and limits hematopoietic stem cells
EMBO J . 2020 Apr 15;39(8):e104270 , .
Hematopoietic stem cells (HSCs) develop from the hemogenic endothelium in cluster structures that protrude into the embryonic aortic lumen. Although much is known about the molecular characteristics of the developing hematopoietic cells, we lack a complete understanding of their origin and the three-dimensional organization of the niche. Here, we use advanced live imaging techniques of organotypic slice cultures, clonal analysis, and mathematical modeling to show the two-step process of intra-aortic hematopoietic cluster (IACH) formation. First, a hemogenic progenitor buds up from the endothelium and undergoes division forming the monoclonal core of the IAHC. Next, surrounding hemogenic cells are recruited into the IAHC, increasing their size and heterogeneity. We identified the Notch ligand Dll4 as a negative regulator of the recruitment phase of IAHC. Blocking of Dll4 promotes the entrance of new hemogenic Gfi1+ cells into the IAHC and increases the number of cells that acquire HSC activity. Mathematical modeling based on our data provides estimation of the cluster lifetime and the average recruitment time of hemogenic cells to the cluster under physiologic and Dll4-inhibited conditions.