Publicaciones científicas

Se han encontrado 1594 publicaciones con los criterios indicados.
Llabata P, Torres-Diz M, Gomez A, Tomas-Daza L, Romero OA, Grego-Bessa J, Llinas-Arias P, Valencia A, Esteller M, Javierre BM, Zhang X, Sanchez-Cespedes M

MAX mutant small-cell lung cancers exhibit impaired activities of MGA-dependent noncanonical polycomb repressive complex.

Proc Natl Acad Sci U S A 14 Sep 2021, 118 (37) .
The MYC axis is disrupted in cancer, predominantly through activation of the MYC family oncogenes but also through inactivation of the MYC partner MAX or of the MAX partner MGA. MGA and MAX are also members of the polycomb repressive complex, ncPRC1.6. Here, we use genetically modified MAX-deficient small-cell lung cancer (SCLC) cells and carry out genome-wide and proteomics analyses to study the tumor suppressor function of MAX. We find that MAX mutant SCLCs have ASCL1 or NEUROD1 or combined ASCL1/NEUROD1 characteristics and lack MYC transcriptional activity. MAX restitution triggers prodifferentiation expression profiles that shift when MAX and oncogenic MYC are coexpressed. Although ncPRC1.6 can be formed, the lack of MAX restricts global MGA occupancy, selectively driving its recruitment toward E2F6-binding motifs. Conversely, MAX restitution enhances MGA occupancy to repress genes involved in different functions, including stem cell and DNA repair/replication. Collectively, these findings reveal that MAX mutant SCLCs have either ASCL1 or NEUROD1 or combined characteristics and are MYC independent and exhibit deficient ncPRC1.6-mediated gene repression.
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Diaz de la Guardia R, Velasco-Hernandez T, Gutierrez-Agüera F, Roca-Ho H, Molina O, Nombela-Arrieta C, Bataller A, Fuster JL, Anguita E, Vives S, Zamora L, Nomdedeu JF, Gomez-Casares MT, Ramírez-Orellana M, Lapillonne H, Ramos-Mejia V, Rodríguez-Manzaneque JC, Bueno C, Lopez-Millan B, Menendez P

Engraftment characterization of risk-stratified AML patients in NSGS mice.

Blood Adv 1 Sep 2021, . Epub 1 Sep 2021
Acute myeloid leukemia (AML) is the commonest acute leukemia in adults. Disease heterogeneity is well-documented and patient stratification determines treatment decisions. Patient-derived xenografts (PDXs) of risk-stratified AMLs are crucial for studying AML biology and testing novel therapeutics. Despite recent advances in PDX modeling of AML, reproducible engraftment of human AML is mainly limited to high-risk (HR) cases, with inconsistent or very protracted engraftment observed for favorable-risk (FR) and intermediate-risk (IR) patients. We have characterized the engraftment robustness/kinetics in NSGS mice of 28 AML patients grouped according to molecular/cytogenetic classification, and have assessed whether the orthotopic co-administration of patient-matched bone marrow mesenchymal stromal cells (BM-MSCs) improves AML engraftment. PDX event-free survival correlated well with the predictable prognosis of risk-stratified AML patients. The majority (85%-94%) of the mice were engrafted in BM independently of the risk group, although HR-AML patients showed engraftment levels significantly superior to those of FR- and IR-AML patients. Importantly, the engraftment levels observed in NSGS mice by week 6 remained stable overtime. Serial transplantation and long-term culture-initiating cell (LTC-IC) assays revealed long-term engraftment limited to HR-AML patients, fitter leukemia-initiating cells (LICs) in HR- than in FR- or IR-AML samples, and the presence of AML-LICs in the CD34- leukemic fraction, regardless the risk group. Finally, orthotopic co-administration of patient-matched BM-MSCs with AML cells resulted dispensable for BM engraftment levels but favored peripheralization of engrafted AML cells. This comprehensive characterization of human AML engraftment in NSGS mice offers a valuable platform for in vivo testing of targeted therapies in risk-stratified AML patient samples.
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Zanetti SR, Velasco-Hernandez T, Gutierrez-Agüera F, Díaz VM, Romecín PA, Roca-Ho H, Sánchez-Martínez D, Tirado N, Baroni ML, Petazzi P, Torres-Ruiz R, Molina O, Bataller A, Fuster JL, Ballerini P, Juan M, Jeremias I, Bueno C, Menéndez P

A novel and efficient tandem CD19- and CD22-directed CAR for B-cell ALL.

Mol Ther 31 Ago 2021, . Epub 31 Ago 2021
CD19-directed chimeric antigen receptor (CAR) T-cells have yielded impressive response rates in refractory/relapse B-cell acute lymphoblastic leukemia (B-ALL);however, most patients ultimately relapse due to poor CAR T-cell persistence or resistance of either CD19+ or CD19- B-ALL clones. CD22 is a pan-B marker whose expression is maintained in both CD19+ and CD19- relapses. Indeed, CD22-CAR T-cells have been clinically used in B-ALL patients, although relapse also occurs. Tcells engineered with a tandem CAR (Tan-CAR) containing in a single contruct both CD19 and CD22 scFvs, might be advantageus in achieving higher remission rates and/or preventing antigen loss. We have generated and functionally validated using cutting-edge assays a 4-1BB-based CD22/CD19 Tan-CAR using in-house-developed novel CD19 and CD22 scFvs. Tan-CAR-expressing T-cells showed similar in vitro expansion than CD19-CAR T-cells with no increased of tonic signaling. CRISPR/Cas9-edited B-ALL cells confirmed the bispecificity of the Tan-CAR. Tan-CAR was as efficient as CD19-CAR in vitro and in vivo using B-ALL cell lines, patient samples and patient-derived xenografts (PDXs). Strikingly, the robust anti-leukemic activity of the Tan-CAR was slightly more effective in controling the disease in long-term follow-up PDX models. This Tan-CAR construct warrants a clinical appraisal to test whether simultaneous targeting of CD19 and CD22 enhances leukemia eradication and reduces/delays relapse rates and antigen loss.
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Rosa Hernández, Cristina Jiménez-Luna, Raúl Ortiz, Fernando Setién, Miguel López, Gloria Perazzoli, Manel Esteller, María Berdasco, Jose Prados, Consolación Melguizo

Impact of the Epigenetically Regulated Hoxa-5 Gene in Neural Differentiation from Human Adipose-Derived Stem Cells

Biology 2021, 10(8), 802 19 Ago 2021, .
Human adipose-derived mesenchymal stem cells (hASCs) may be used in some nervous system pathologies, although obtaining an adequate degree of neuronal differentiation is an important barrier to their applicability. This requires a deep understanding of the expression and epigenetic changes of the most important genes involved in their differentiation. We used hASCs from human lipoaspirates to induce neuronal-like cells through three protocols (Neu1, 2, and 3), determined the degree of neuronal differentiation using specific biomarkers in culture cells and neurospheres, and analyzed epigenetic changes of genes involved in this differentiation. Furthermore, we selected the Hoxa-5 gene to determine its potential to improve neuronal differentiation. Our results showed that an excellent hASC neuronal differentiation process using Neu1 which efficiently modulated NES, CHAT, SNAP25, or SCN9A neuronal marker expression. In addition, epigenetic studies showed relevant changes in Hoxa-5, GRM4, FGFR1, RTEL1, METRN, and PAX9 genes. Functional studies of the Hoxa-5 gene using CRISPR/dCas9 and lentiviral systems showed that its overexpression induced hASCs neuronal differentiation that was accelerated with the exposure to Neu1. These results suggest that Hoxa-5 is an essential gene in hASCs neuronal differentiation and therefore, a potential candidate for the development of cell therapy strategies in neurological disorders.
Carini Picardi Morais de Castro, Maria Cadefau, Sergi Cuartero

The Mutational Landscape of Myeloid Leukaemia in Down Syndrome

Cancers 2021, 13(16), 4144 18 Ago 2021, .
Children with Down syndrome (DS) are particularly prone to haematopoietic disorders. Paediatric myeloid malignancies in DS occur at an unusually high frequency and generally follow a well-defined stepwise clinical evolution. First, the acquisition of mutations in the GATA1 transcription factor gives rise to a transient myeloproliferative disorder (TMD) in DS newborns. While this condition spontaneously resolves in most cases, some clones can acquire additional mutations, which trigger myeloid leukaemia of Down syndrome (ML-DS). These secondary mutations are predominantly found in chromatin and epigenetic regulators—such as cohesin, CTCF or EZH2—and in signalling mediators of the JAK/STAT and RAS pathways. Most of them are also found in non-DS myeloid malignancies, albeit at extremely different frequencies. Intriguingly, mutations in proteins involved in the three-dimensional organization of the genome are found in nearly 50% of cases. How the resulting mutant proteins cooperate with trisomy 21 and mutant GATA1 to promote ML-DS is not fully understood. In this review, we summarize and discuss current knowledge about the sequential acquisition of genomic alterations in ML-DS.
Anderluh M, Berti F, Bzducha-Wróbel A, Chiodo F, Colombo C, Compostella F, Durlik K, Ferhati X, Holmdahl R, Jovanovic D, Kaca W, Lay L, Marinovic-Cincovic M, Marradi M, Ozil M, Polito L, Reina-Martin JJ, Reis CA, Sackstein R, Silipo A, Švajger U, Vaněk O, Yamamoto F, Richichi B, van Vliet SJ

Emerging glyco-based strategies to steer immune responses.

FEBS J 16 Ago 2021, 288 (16) 4746-4772.
Glycan structures are common posttranslational modifications of proteins, which serve multiple important structural roles (for instance in protein folding), but also are crucial participants in cell-cell communications and in the regulation of immune responses. Through the interaction with glycan-binding receptors, glycans are able to affect the activation status of antigen-presenting cells, leading either to induction of pro-inflammatory responses or to suppression of immunity and instigation of immune tolerance. This unique feature of glycans has attracted the interest and spurred collaborations of glyco-chemists and glyco-immunologists to develop glycan-based tools as potential therapeutic approaches in the fight against diseases such as cancer and autoimmune conditions. In this review, we highlight emerging advances in this field, and in particular, we discuss on how glycan-modified conjugates or glycoengineered cells can be employed as targeting devices to direct tumor antigens to lectin receptors on antigen-presenting cells, like dendritic cells. In addition, we address how glycan-based nanoparticles can act as delivery platforms to enhance immune responses. Finally, we discuss some of the latest developments in glycan-based therapies, including chimeric antigen receptor (CAR)-T cells to achieve targeting of tumor-associated glycan-specific epitopes, as well as the use of glycan moieties to suppress ongoing immune responses, especially in the context of autoimmunity.
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David Ortega-Alarcon, Rafael Claveria-Gimeno, Sonia Vega, Olga C. Jorge-Torres, Manel Esteller, Olga Abian, Adrian Velazquez-Campoy

Stabilization Effect of Intrinsically Disordered Regions on Multidomain Proteins: The Case of the Methyl-CpG Protein 2, MeCP2

Biomolecules 2021, 11(8), 1216 16 Ago 2021, .
Intrinsic disorder plays an important functional role in proteins. Disordered regions are linked to posttranslational modifications, conformational switching, extra/intracellular trafficking, and allosteric control, among other phenomena. Disorder provides proteins with enhanced plasticity, resulting in a dynamic protein conformational/functional landscape, with well-structured and disordered regions displaying reciprocal, interdependent features. Although lacking well-defined conformation, disordered regions may affect the intrinsic stability and functional properties of ordered regions. MeCP2, methyl-CpG binding protein 2, is a multifunctional transcriptional regulator associated with neuronal development and maturation. MeCP2 multidomain structure makes it a prototype for multidomain, multifunctional, intrinsically disordered proteins (IDP). The methyl-binding domain (MBD) is one of the key domains in MeCP2, responsible for DNA recognition. It has been reported previously that the two disordered domains flanking MBD, the N-terminal domain (NTD) and the intervening domain (ID), increase the intrinsic stability of MBD against thermal denaturation. In order to prove unequivocally this stabilization effect, ruling out any artifactual result from monitoring the unfolding MBD with a local fluorescence probe (the single tryptophan in MBD) or from driving the protein unfolding by temperature, we have studied the MBD stability by differential scanning calorimetry (reporting on the global unfolding process) and chemical denaturation (altering intramolecular interactions by a different mechanism compared to thermal denaturation).
Justin Brumbaugh, Bruno Di Stefano, José Luis Sardina

Editorial: Chromatin Regulation in Cell Fate Decisions

Front. Cell Dev. Biol. | doi: 10.3389/fcell.2021.734020 12 Ago 2021, .
Many epigenetic marks change dramatically during embryogenesis, suggesting that they have a fundamental role in developmental decisions. For example, the early embryo experiences an initial, widespread loss of DNA methylation that is reacquired around the time of implantation. In this edition, Maxim Greenberg reviews the mechanisms responsible for these dynamics, with a focus on key regions that escape DNA methylation during its reestablishment. It remains unresolved whether this early round of DNA demethylation is passive (i.e., DNA methylation is diluted over multiple rounds of cell division) or active (i.e., resulting from enzymatic action). In any case, the Ten-eleven translocation (TET) class of DNA demethylases, and specifically TET2, is crucial for exiting pluripotency and initiating differentiation (Dai et al., 2016). Garcia-Outeiral and colleagues provide an updated perspective on TET2's role in these processes as well as reprogramming, and discuss the possibility that TET2 is also responsible for oxidizing methylation on RNA. Together, these publications highlight the importance of DNA/RNA methylation in the early embryo.[...]
García-Castillo J, Alcaraz-Pérez F, Martínez-Balsalobre E, García-Moreno D, Rossmann MP, Fernández-Lajarín M, Bernabé-García M, Pérez-Oliva AB, Rodríguez-Cortez VC, Bueno C, Adatto I, Agarwal S, Menéndez P, Zon LI, Mulero V, Cayuela ML

Telomerase RNA recruits RNA polymerase II to target gene promoters to enhance myelopoiesis.

Proc Natl Acad Sci U S A 10 Ago 2021, 118 (32) .
Dyskeratosis congenita (DC) is a rare inherited bone marrow failure and cancer predisposition syndrome caused by mutations in telomerase or telomeric proteins. Here, we report that zebrafish telomerase RNA (terc) binds to specific DNA sequences of master myeloid genes and controls their expression by recruiting RNA Polymerase II (Pol II). Zebrafish terc harboring the CR4-CR5 domain mutation found in DC patients hardly interacted with Pol II and failed to regulate myeloid gene expression in vivo and to increase their transcription rates in vitro. Similarly, TERC regulated myeloid gene expression and Pol II promoter occupancy in human myeloid progenitor cells. Strikingly, induced pluripotent stem cells derived from DC patients with a TERC mutation in the CR4-CR5 domain showed impaired myelopoiesis, while those with mutated telomerase catalytic subunit differentiated normally. Our findings show that TERC acts as a transcription factor, revealing a target for therapeutic intervention in DC patients.
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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.

Blood 6 Ago 2021, . Epub 6 Ago 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.
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