Epigenetic control of infant b cell precursor acute lymphoblastic leukemia

Altres ajuts: Asociación Española Contra el Cáncer (POSTD20024DEBA)B-cell precursor acute lymphoblastic leukemia (BCP-ALL) is a highly aggressive malig-nancy, with poorer prognosis in infants than in adults. A genetic signature has been associated with this outcome but, remarkably, leukemogenesis is commonly triggered by genetic alterations of embryonic origin that involve the deregulation of chromatin remodelers. This review considers in depth how the alteration of epigenetic profiles (at DNA and histone levels) induces an aberrant phenotype in B lymphocyte progenitors by modulating the oncogenic drivers and tumor suppres-sors involved in key cancer hallmarks. DNA methylation patterns have been widely studied in BCP- ALL and their correlation with survival has been established. However, the effect of methylation on histone residues can be very different. For instance, methyltransferase KMT2A gene participates in chromosomal rearrangements with several partners, imposing an altered pattern of methylated H3K4 and H3K79 residues, enhancing oncogene promoter activation, and conferring a worse outcome on affected infants. In parallel, acetylation processes provide an additional layer of epigenetic regulation and can alter the chromatin conformation, enabling the binding of regulatory factors. Therefore, an integrated knowledge of all epigenetic disorders is essential to understand the molecular basis of BCP-ALL and to identify novel entry points that can be exploited to improve therapeutic options and disease prognosis

MYC's Fine Line Between B Cell Development and Malignancy

The transcription factor MYC is transiently expressed during B lymphocyte development, and its correct modulation is essential in defined developmental transitions. Although temporary downregulation of MYC is essential at specific points, basal levels of expression are maintained, and its protein levels are not completely silenced until the B cell becomes fully differentiated into a plasma cell or a memory B cell. MYC has been described as a proto-oncogene that is closely involved in many cancers, including leukemia and lymphoma. Aberrant expression of MYC protein in these hematological malignancies results in an uncontrolled rate of proliferation and, thereby, a blockade of the differentiation process. MYC is not activated by mutations in the coding sequence, and, as reviewed here, its overexpression in leukemia and lymphoma is mainly caused by gene amplification, chromosomal translocations, and aberrant regulation of its transcription. This review provides a thorough overview of the role of MYC in the developmental steps of B cells, and of how it performs its essential function in an oncogenic context, highlighting the importance of appropriate MYC regulation circuitry

HDAC7 is a major contributor in the pathogenesis of infant t(4;11) proB acute lymphoblastic leukemia

This paper was funded by grants to MP by the Spanish Ministry of Science, Innovation and Universities (SAF2017-87990-R and EUR2019-103835) and elaborated at the Josep Carreras Leukaemia Research Institute (IJC, Badalona, Barcelona) and IDIBELL Research Institute (L’Hospitalet de Llobregat, Barcelona). OdB is funded by a Juan de la Cierva—Formación fellowship from the Spanish Ministry of Science, Innovation and Universities (FJCI-2017-32430). AM is funded by the Spanish Ministry of Science, Innovation and Universities, which is part of the Agencia Estatal de Investigación (AEI), through grant PRE2018-083183 (cofunded by the European Social Fund). Work in PM and CB’s lab was supported by the European Research Council (CoG-2014646903), the Spanish Ministry of Economy and Competitiveness (SAF-2016-80481-R), Uno entre Cien Mil Foundation, the Leo Messi Foundation, the Asociación Española Contra el Cáncer (AECC-CI-2015), and the ISCIII/FEDER (PI17/01028).

The HDAC7-TET2 epigenetic axis is essential during early B lymphocyte development

Correct B cell identity at each stage of cellular differentiation during B lymphocyte development is critically dependent on a tightly controlled epigenomic landscape. We previously identified HDAC7 as an essential regulator of early B cell development and its absence leads to a drastic block at the pro-B to pre-B cell transition. More recently, we demonstrated that HDAC7 loss in pro-B-ALL in infants associates with a worse prognosis. Here we delineate the molecular mechanisms by which HDAC7 modulates early B cell development. We find that HDAC7 deficiency drives global chromatin de-condensation, histone marks deposition and deregulates other epigenetic regulators and mobile elements. Specifically, the absence of HDAC7 induces TET2 expression, which promotes DNA 5-hydroxymethylation and chromatin de-condensation. HDAC7 deficiency also results in the aberrant expression of microRNAs and LINE-1 transposable elements. These findings shed light on the mechanisms by which HDAC7 loss or misregulation may lead to B cell-based hematological malignancies.FUNDING: Spanish Ministry of Economy and Competitiveness (MINECO) [SAF2017-87990-R]; Spanish Ministry of Science and Innovation (MICINN) [EUR2019-103835]; Josep Carreras Leukaemia Research Institute (IJC, Badalona, Barcelona); IDIBELL Research Institute (L’Hospitalet de Llobregat, Barcelona); A.M. is funded by the Spanish Ministry of Science, Innovation and Universities, which is part of the Agencia Estatal de Investigacion (AEI) [PRE2018-083183] (cofunded by the European Social Fund]; OdB. was funded by a Juan de la Cierva Formacion Fellowship from the Spanish Ministry of Science, Innovation and Universities [FJCI-2017-32430]; Postdoctoral Fellowship from the Asociacion Española Contra el Cáncer (AECC) ´ Foundation [POSTD20024DEBA]; B.M. is awardee of the Ayudas para la formacion del profesorado universitario [FPU18/00755, Ministerio de Universidades]; B.M.J. is funded by La Caixa Banking Foundation Junior Leader project [LCF/BQ/PI19/11690001]; FEDER/Spanish Ministry of Science and Innovation [RTI2018-094788-A-I00]; L.T.-D. is funded by the FPI Fellowship [PRE2019- 088005]; L.R. is funded by an AGAUR FI fellowship [2019FI-B00017]; J.L.S. is funded by ISCIII [CP19/00176], co-funded by ESF, ‘Investing in your future’ and the Spanish Ministry of Science, Innovation and Universities [PID2019-111243RA-I00]. CRG acknowledge the support of the Spanish Ministry of Science and Innovation through the Centro de Excelencia Severo Ochoa (CEX2020-001049- S, MCIN/AEI /10.13039/501100011033). Funding for open access charge: Spanish Ministry of Science, Innovation and Universities (MICIU) [SAF2017-87990-R, EUR2019-103835].ACKNOWLEDGEMENTS: We thank CERCA Programme/Generalitat de Catalunya and the Josep Carreras Foundation for institutional support. We thank Dr Eric Olson (UT Southwestern Medical Center, Dallas, TX, USA) and Dr Michael Reth (Max Planck Institute of Immunology and Epigenetics, Freiburg, Germany) for kindly providing the Hdac7loxp/- and mb1- Cre mice, respectively. We thank Luc´ıa Fanlo for her assistance in technical issues and bioinformatics analysis of ChIP-seq and ATAC-seq experiments. We thank Alberto Bueno for deep analysis of our RNA-seq and hMeDIP-seq data, in order to assess the presence of differentially expressed dsRNA species. We also thank Drs Pura Munoz ˜ Canoves and Tokameh Mahmoudi for helpful comments on ´ the manuscript

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Role of ZEB1 in Tumor Progression: Regulation of Cell Invasion and Senescence

[eng] The members of ZEB family of transcription factors (ZEB1 and ZEB2) are widely known for its role in epithelial-to-mesenchymal transition (EMT), a highly relevant process during development and tumor progression. In this process, cells lose their epithelial features and acquire mesenchymal markers, thus increasing their motility and invasive capacity. However, it has been recently described that ZEB factors can function beyond the EMT induction, and that are associated with other tumor hallmarks: apoptosis inhibition, chemotherapy resistance, etc. Regarding colorectal cancer (CRC), ZEB1 is activated by the Wnt signaling pathway, which is active in around 80% of the cases. Consequently, ZEB1 is expressed in the invasive cells at the tumor front, providing the tumor with higher aggressiveness and metastatic capacity. Taking this background into account, the general aim of the Thesis was to characterize new potential mechanisms through which ZEB1 regulates oncogenic transformation and tumor progression in CRC, beyond EMT induction. The specific aims were: 1) Describe the role of ZEB1 in the regulation of initial steps of tumor invasiveness, such as the remodeling of the extracellular matrix (ECM); 2) Identify new ZEB1 target genes at the tumor front of CRCs, investigating a potential modulation of Wnt signaling, as well as characterizing the in vivo relevance of these potential targets; 3) Identify other hallmarks of cancer that may be regulated by ZEB1 during CRC progression. The results of the Thesis are presented as a summary of publications. The first paper (Clin Cancer Res, 2013. 19(5):1071-82) describes the role of ZEB1 in the opposite regulation of the Plasminogen Activation System (PAS) members (uPA and PAI-1). This regulation promotes the migration of CRC cells through the ECM. The conclusions obtained from this first paper are: 1- ZEB1 modulates CRC cells migration through the peritumoral stroma by means of uPA activation and PAI-1 repression 2- ZEB1 activates uPA at the transcriptional level through its direct binding to the promoter region, in a mechanism involving the coactivator p300 and Wnt signaling. 3- ZEB1 represses PAI-1 by reducing its mRNA stability, which supposes a new gene regulation mechanism for ZEB1. 4- During ZEB1-induced CRC cells migration and invasion, uPA expression is required. 5- ZEB1 correlates positively with uPA, but not with PAI-1, at the invasive front of CRCs, cooperating in its role in ECM remodeling. The results of the second paper (Gut, 2016. doi:10.1136/gutjnl-2015-310838) have identified a new mechanism through which ZEB1 inhibits cancer cells entrance in senescence, a tumor suppressor mechanism. ZEB1 activates the Wnt-antagonnist DKK1, triggering the activation of a signaling cascade that involves mutant p53, MDM2 and CtBP. This ultimate corepressor cooperates with ZEB1 in the repression of macroH2A1, key in senescence induction. The conclusions obtained from this second paper are: 1- The maximum effect of ZEB1 in predicting poor CRC survival requires high Wnt- antagonist DKK1 simultaneous expression. Both genes correlate positively in CRCs. 2- ZEB1 activates DKK1 transcriptionally, through a mechanism that involves the coactivator p300 and the Wnt-effector TCF4. 3- The combined expression of ZEB1 and DKK1 inhibits a senescence-related genes group in CRC patients. Some of these genes, including H2AFY (that codifies for macroH2A1), are cooperatively repressed by ZEB1 and DKK1. 4- ZEB1 requires the presence of DKK1 to repress the formation of senescence- associated heterochromatin foci and the consequent cellular senescence. 5- ZEB1 represses macroH2A1 by direct binding to its promoter. 6- ZEB1 represses cellular senescence through the subsequent activation of DKK1, mutant p53, MDM2 and CtBP. The activation of CtBP enhances ZEB1’s repressor activity on macroH2A1 promoter. 7- ZEB1 correlates positively with DKK1 at CRC tumor front. Conversely, macroH2A1 displays an inverse expression pattern. 8- Reduction of ZEB1 levels in vivo is sufficient to induce senescence, reduce colorectal tumor formation and improve survival in a mouse model of CRC. 9- The tumorigenic capacity of ZEB1 depends on the concomitant low levels of macroH2A1. 10- The role of ZEB1 in determining poor CRC prognosis depends on its ability to repress macroH2A1 and other senescence markers, such as GLB1.[cat] Els factors de transcripció ZEB (ZEB1 i ZEB2) son àmpliament coneguts pel seu paper en la transició epitelial-mesenquimal (EMT). A través d’aquest procés, les cèl·lules perden les característiques que les defineixen com a epitelials i adquireixen marcadors mesenquimals, augmentant així la seva capacitat invasiva. Tot i això, recentment s’ha descrit que els factors ZEB tenen funcions més enllà de l’EMT, com ara la resistència a la quimioterapia, que promouen la progressió tumoral. En el cas del càncer colorectal (CCR), s’ha descrit que ZEB1 és activat per la via de senyalització de Wnt, activa en un 80% dels casos. En conseqüència, ZEB1 s’expressa en les cèl·lules invasives del front tumoral. Tenint en compte aquests antecedents, l’objectiu general de la Tesi ha estat el de caracteritzar nous mecanismes a través dels quals ZEB1 regula la transformació oncogènica i la progressió tumoral en CCR, més enllà de la inducció de l’EMT. Els objectius específics han estat: 1) descriure el paper de ZEB1 en la regulació de les etapes inicials d’invasivitat, com la remodelació de la matriu extracel·lular; 2) identificar nous gens diana de ZEB1 al front tumoral de CCR, així com caracteritzar la rellevància d’aquestes dianes in vivo; i 3) identificar processos comuns a tots els tipus de càncer que puguin estar regulades per ZEB1 en la progressió del CCR. Els resultats es presenten com a compendi de publicacions. En el primer dels articles (Clin Cancer Res, 2013. 19(5):1071-82), es descriu el paper de ZEB1 en la regulació oposada dels membres del sistema activador del plasminogen (uPA i PAI-1). Aquesta regulació promou la migració de les cèl·lules a través de la matriu extracel·lular. En el segon dels articles (Gut, 2016. doi:10.1136/gutjnl-2015-310838), s’ha identificat un nou mecanisme a través del qual ZEB1 està inhibint l’entrada de les cèl·lules tumorals a l’estat de senescència, un conegut mecanisme supressor tumoral. ZEB1 activa l’inhibidor de la via Wnt DKK1, desencadenant l’activació d’una ruta de senyalització que implica a p53 mutat, MDM2 i CtBP. Aquest darrer coopera amb ZEB1 en la repressió de la histona macroH2A1, clau en la inducció de la senescència

Epigenetic Control of Infant B Cell Precursor Acute Lymphoblastic Leukemia

B-cell precursor acute lymphoblastic leukemia (BCP-ALL) is a highly aggressive malignancy, with poorer prognosis in infants than in adults. A genetic signature has been associated with this outcome but, remarkably, leukemogenesis is commonly triggered by genetic alterations of embryonic origin that involve the deregulation of chromatin remodelers. This review considers in depth how the alteration of epigenetic profiles (at DNA and histone levels) induces an aberrant phenotype in B lymphocyte progenitors by modulating the oncogenic drivers and tumor suppressors involved in key cancer hallmarks. DNA methylation patterns have been widely studied in BCP-ALL and their correlation with survival has been established. However, the effect of methylation on histone residues can be very different. For instance, methyltransferase KMT2A gene participates in chromosomal rearrangements with several partners, imposing an altered pattern of methylated H3K4 and H3K79 residues, enhancing oncogene promoter activation, and conferring a worse outcome on affected infants. In parallel, acetylation processes provide an additional layer of epigenetic regulation and can alter the chromatin conformation, enabling the binding of regulatory factors. Therefore, an integrated knowledge of all epigenetic disorders is essential to understand the molecular basis of BCP-ALL and to identify novel entry points that can be exploited to improve therapeutic options and disease prognosis

Structural analysis and thermodynamics of the ionotropic glutamate receptor GluA2 modulator BPAM-97

Ionotropic glutamate receptors are tetrameric ligand gated ion channels that mediate in ux and ef ux of metal ions in response to glutamate. Positive allosteric modulators of the ionotropic glutamate receptor 2 (GluA2) are promising lead compounds for drugs against cognitive disorders. These compounds bind within the dimeric interface formed by the receptor ligand binding domains (LBDs) attenuating deactivation and desensitisation. In this study we determined the structure of the complex formed between a dimeric GluA2 LBD-L483Y-N754S mutant and the potent novel modulator BPAM-97 by X-ray crystallography. We provide a molecular explanation for the 200 fold increased potency of BPAM-97 compared to its parent compound IDRA-21. We also utilized isothermal titration calorimetry to measure the binding af nity and thermodynamics of the LBD-L483Y-N754S:BPAM-97 complex formation as well as that for the non-dimeric LBD-N754S:BPAM-97

Tumor-associated macrophages (TAMs) depend on ZEB1 for their cancer-promoting roles

Accumulation of tumor-associated macrophages (TAMs) associates with malignant progression in cancer. However, the mechanisms that drive the pro-tumor functions of TAMs are not fully understood. ZEB1 is best known for driving an epithelial-to-mesenchymal transition (EMT) in cancer cells to promote tumor progression. However, a role for ZEB1 in macrophages and TAMs has not been studied. Here we describe that TAMs require ZEB1 for their tumor-promoting and chemotherapy resistance functions in a mouse model of ovarian cancer. Only TAMs that expressed full levels of Zeb1 accelerated tumor growth. Mechanistically, ZEB1 expression in TAMs induced their polarization toward an F4/80low pro-tumor phenotype, including direct activation of Ccr2. In turn, expression of ZEB1 by TAMs induced Ccl2, Cd74, and a mesenchymal/stem-like phenotype in cancer cells. In human ovarian carcinomas, TAM infiltration and CCR2 expression correlated with ZEB1 in tumor cells, where along with CCL2 and CD74 determined poorer prognosis. Importantly, ZEB1 in TAMs was a factor of poorer survival in human ovarian carcinomas. These data establish ZEB1 as a key factor in the tumor microenvironment and for maintaining TAMs’ tumor-promoting functions. © 2017 The Author

Thermodynamics and structural analysis of positive allosteric modulation of the ionotropic glutamate receptor GluA2

Positive allosteric modulators of the ionotropic glutamate receptor-2 (GluA2) are promising compounds for the treatment of cognitive disorders, e.g. Alzheimer’s disease. These modulators bind within the dimer interface of the LBD (ligand-binding domain) and stabilize the agonist-bound conformation slowing receptor desensitization and/or deactivation. In the present study, we employ isothermal titration calorimetry to determine binding affinities and thermodynamic details of binding of modulators of GluA2. A mutant of the LBD of GluA2 (LBD-L483Y-N754S) that forms a stable dimer in solution was used. The potent GluA2 modulator BPAM-97 was used as a reference compound. Evidence that BPAM-97 binds in the same pocket as the well-known GluA2 modulator cyclothiazide was obtained from X-ray structures. The LBD-L483Y-N754S:BPAM-97 complex has aKd of 5.6 μM (Δ H = − 4.9 kcal/mol, − T Δ S = − 2.3 kcal/mol; where 1 kcal ≈4.187 kJ). BPAM-97 was used in a displacement assay to determine a Kd of 0.46 mM (Δ H = − 1.2 kcal/mol, − T Δ S = − 3.3 kcal/mol) for the LBD-L483Y-N754S:IDRA-21 complex. The major structural factors increasing the potency of BPAM-97 over IDRA-21 are the increased van der Waals contacts to, primarily, Met496 in GluA2 imposed by the ethyl substituent of BPAM-97. These results add important information on binding affinities and thermodynamic details, and provide a new tool in the development of drugs against cognitive disorders. Key words: binding affinity, crystal structure, ionotropic glutamate receptor, isothermal titration calorimetry, positive allosteric modulato