Neoplasias linfoides, célula de origen e identidad tumoral

[ES]El cáncer es una enfermedad clonal, que tiene su origen en una célula específica, llamada célula de origen del cáncer. Hasta el momento, la mayoría de estudios publicados han centrado sus esfuerzos en determinar el papel de los oncogenes en el desarrollo del cáncer, pero muy pocos se han centrado en estudiar cómo se establece la identidad tumoral. En general, se piensa que el cáncer surge en una célula con identidad prefijada, que es la responsable del fenotipo tumoral. Además, este modelo actual del cáncer sostiene que, en los cánceres humanos, la función de los oncogenes es homogénea en todas las células cancerosas, con independencia de la heterogeneidad celular existente dentro del tumor. Desafortunadamente, las terapias basadas en este modelo de cáncer no logran erradicar los tumores humanos, sugiriendo que la función de los oncogenes en la masa tumoral no es homogénea. Por el contrario, nuestra hipótesis sostiene que el cáncer surge como consecuencia de un mecanismo de reprogramación tumoral de la célula de origen7. Este mecanismo modificaría el estado epigenético de la célula iniciadora del cáncer, estableciendo en ella un programa de diferenciación celular patológico. Así, como consecuencia de la escasez de estudios sobre la célula iniciadora del cáncer, no se han desarrollado modelos animales que reproduzcan fielmente la enfermedad humana. Por ello, en este trabajo de tesis doctoral nos planteamos determinar si el linfoma de células B asociado a alteraciones de CREBBP y la leucemia linfoblástica aguda de células T vinculada a LMO2 son consecuencia de un mecanismo de reprogramación tumoral de la célula de origen y cuál es la célula donde se originan

Early epigenetic cancer decisions

A cancer dogma states that inactivation of oncogene(s) can cause cancer remission, implying that oncogenes are the Achilles' heel of cancers. This current model of cancer has kept oncogenes firmly in focus as therapeutic targets and is in agreement with the fact that in human cancers all cancerous cells, with independence of the cellular heterogeneity existing within the tumour, carry the same oncogenic genetic lesions. However, recent studies of the interactions between an oncogene and its target cell have shown that oncogenes contribute to cancer development via developmental reprogramming of the epigenome within the target cell. These results provide the first evidence that carcinogenesis can be initiated by epigenetic stem cell reprogramming, and uncover a new role for oncogenes in the origin of cancer. Here we analyse these evidences and discuss how this vision offers new avenues for developing novel anti-cancer interventions.Research in our group is partially supported by FEDER and by MICINN (SAF2012-32810), by NIH grant (R01 CA109335-04A1), by the ARIMMORA project (FP7-ENV-2011, European Union Seventh Framework Program), by Junta de Castilla y Leon (BIO/SA06/13), and by the Deutsche José Carreras Leukämie-Stiftung (DJCLS project 13/26). All Spanish funding is co-sponsored by the European Union FEDER program. ISG is an API lab of the EuroSyStem project and a partner within the Marie Curie Initial Training Network DECIDE (Decision-making within cells and differentiation entity therapies) funded by the European Union’s Seventh Programme under grant agreement n° 315902.Peer Reviewe

Molecular and cellular responses of the pathogenic fungus Lomentospora prolificans to the antifungal drug voriconazole

The filamentous fungus Lomentospora (Scedosporium) prolificans is an emerging opportunistic pathogen associated with fatal infections in patients with disturbed immune function. Unfortunately, conventional therapies are hardly of any use against this fungus due to its intrinsic resistance. Therefore, we performed an integrated study of the L. prolificans responses to the first option to treat these mycoses, namely voriconazole, with the aim of unveiling mechanisms involved in the resistance to this compound. To do that, we used a wide range of techniques, including fluorescence and electron microscopy to study morphological alterations, ion chromatography to measure changes in cell-wall carbohydrate composition, and proteomics-based techniques to identify the proteins differentially expressed under the presence of the drug. Significantly, we showed drastic changes occurring in cell shape after voriconazole exposure, L. prolificans hyphae being shorter and wider than under control conditions. Interestingly, we proved that the architecture and carbohydrate composition of the cell wall had been modified in the presence of the drug. Specifically, L. prolificans constructed a more complex organelle with a higher presence of glucans and mannans. In addition to this, we identified several differentially expressed proteins, including Srp1 and heat shock protein 70 (Hsp70), as the most overexpressed under voriconazole-induced stress conditions. The mechanisms described in this study, which may be directly related to L. prolificans antifungal resistance or tolerance, could be used as targets to improve existing therapies or to develop new ones in order to successfully eliminate these mycoses.This work has been supported by grants (GIU15/36 and UFI11/25) from the UPV/EHU. AP was supported by a predoctoral fellowship from the UPV/EHU, and IB and AA were supported by predoctoral fellowships from the Basque Government. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Cyclophilin and enolase are the most prevalent conidial antigens of Lomentospora prolificans recognized by healthy human salivary IgA and cross-react with Aspergillus fumigatus

Purpose: The study of the immunocompetent airways immune response may provide important information to improve the therapeutic efficacy against Lomentospora (Scedosporium) prolificans. So, this study aimed to identify the most prevalent conidial antigens of this multiresistant fungus recognized by healthy human salivary immunoglobulin A, and to study their expression and cross-reactivity with other fungal species. Experimental design: Twenty saliva from immunocompetent donors were used to detect and identify the immunoreactive proteins by 2D immunoblotting and LC-MS/MS. Moreover, anti-Aspergillus antibodies were purified to study their cross-reactivity. Results: Ten proteins of L. prolificans conidia showed reactivity with more than 50% of the saliva samples. Among them, cyclophilin and enolase were the most prevalent antigens recognized by 85 and 80% of the samples, respectively. These enzymes were also identified on the cell wall surface of L. prolificans and on the immunomes of Scedosporium apiospermum and Scedosporium aurantiacum. Additionally, they showed cross-reactivity with the most common pathogenic filamentous fungus Aspergillus fumigatus. Conclusion and clinical relevance: These results show that the immunocompetent immune response might offer a pan-fungal recognition of conserved antigens such as enolase and cyclophilins, making them potential candidates for study as therapeutic targets.This work has been partially supported by several grants (EHUA13/14, UFI11/25, GIU15/36) from the University of the Basque Country (UPV/EHU). I. B. and A. A. were supported by a fellowship from the Basque Government, and Aize Pellon was supported by a fellowship from the UPV/EHU

Infection exposure is a causal factor in B-cell precursor acute lymphoblastic leukemia as a result of Pax5-inherited susceptibility

Earlier in the past century, infections were regarded as the most likely cause of childhood B-cell precursor acute lymphoblastic leukemia (pB-ALL). However, there is a lack of relevant biologic evidence supporting this hypothesis. We present in vivo genetic evidence mechanistically connecting inherited susceptibility to pB-ALL and postnatal infections by showing that pB-ALL was initiated in Pax5 heterozygous mice only when they were exposed to common pathogens. Strikingly, these murine pB-ALLs closely resemble the human disease. Tumor exome sequencing revealed activating somatic, nonsynonymous mutations of Jak3 as a second hit. Transplantation experiments and deep sequencing suggest that inactivating mutations in Pax5 promote leukemogenesis by creating an aberrant progenitor compartment that is susceptible to malignant transformation through accumulation of secondary Jak3 mutations. Thus, treatment of Pax5 leukemic cells with specific JAK1/3 inhibitors resulted in increased apoptosis. These results uncover the causal role of infection in pB-ALL development. [Significance]: These results demonstrate that delayed infection exposure is a causal factor in pB-ALL. Therefore, these findings have critical implications for the understanding of the pathogenesis of leukemia and for the development of novel therapies for this disease.J. Hauer has been supported by the German Children’s Cancer Foundation and from the “Forschungskommission” of the medical faculty of the Heinrich Heine University and the “Strategischer Forschungsfond” of the Heinrich Heine University. S. Ginzel has been supported by a scholarship from the Hochschule Bonn-Rhein-Sieg. A. Borkhardt has been supported by the German Children’s Cancer Foundation and the Federal Ministry of Education and Research, Bonn, Germany. Funding to S.N. Constantinescu from Salus Sanguinis, Fondation contre le cancer Belgium; Interuniversity Attraction Poles IAP, and ARC 10/15-027 is acknowledged. Research in the I. Sánchez-García group is partially supported by FEDER and MINECO (SAF2012-32810 and Red de Excelencia Consolider OncoBIO SAF2014-57791-REDC), Instituto de Salud Carlos III (PIE14/00066), Junta de Castilla y León (BIO/SA32/14 , BIO/SA51/15, and CSI001U14), Fundacion Inocente Inocente, and the ARIMMORA project [European Union’s Seventh Framework Programme (FP7/2007- 2013) under grant agreement no. 282891]. The I. Sánchez-García lab is a member of the EuroSyStem and the DECIDE Network funded by the European Union under the FP7 program. A. Borkhardt and I. SánchezGarcía have been supported by the German Carreras Foundation (DJCLS R13/26). Research in the C. Vicente-Dueñas group is partially supported by a “Miguel Servet” Grant (CP14/00082 - AES 2013-2016) from the Instituto de Salud Carlos III (Ministerio de Economía y Competitividad). Research at C. Cobaleda’s lab was partially supported by FEDER, Fondo de Investigaciones Sanitarias (PI13/00160 and PI14/00025), and from an institutional grant from the Fundacion Ramon Areces. A. MartínLorenzo was supported by FSE-Conserjería de Educación de la Junta de Castilla y León (CSI001-13).Peer Reviewe

The Host Immune Response to Scedosporium/Lomentospora

Infections caused by the opportunistic pathogens Scedosporium/Lomentospora are on the rise. This causes problems in the clinic due to the difficulty in diagnosing and treating them. This review collates information published on immune response against these fungi, since an understanding of the mechanisms involved is of great interest in developing more effective strategies against them. Scedosporium/Lomentospora cell wall components, including peptidorhamnomannans (PRMs), α-glucans and glucosylceramides, are important immune response activators following their recognition by TLR2, TLR4 and Dectin-1 and through receptors that are yet unknown. After recognition, cytokine synthesis and antifungal activity of different phagocytes and epithelial cells is species-specific, highlighting the poor response by microglial cells against L. prolificans. Moreover, a great number of Scedosporium/Lomentospora antigens have been identified, most notably catalase, PRM and Hsp70 for their potential medical applicability. Against host immune response, these fungi contain evasion mechanisms, inducing host non-protective response, masking fungal molecular patterns, destructing host defense proteins and decreasing oxidative killing. In conclusion, although many advances have been made, many aspects remain to be elucidated and more research is necessary to shed light on the immune response to Scedosporium/Lomentospora.This research was funded by the Basque Government, grant number IT1362-19. L.M.-S., M.A., and L.A.-F. were funded by the Basque Government

A new ETV6-RUNX1 in vivo model produces a phenocopy of the human Pb-ALL

Resumen del trabajo presentado al 57th American Society of Hematology (ASH) Annual Meeting and Exposition, celebrado en Orlando (Florida-US) del 5 al 8 de diciembre de 2015.-- et al.[Introduction]: The ETV6-RUNX1 fusion gene, the most common subtype of childhood pB-ALL, is acquired in utero, producing a persistent and hidden preleukemic clone. However, the underlying mechanism explaining how the preleukemic clone evolves to pB-ALL remains to be identified. The lack of genetically engineered human-like ETV6-RUNX1pB-ALL models has hampered our understanding of the pathogenesis of this disease. [Methods]: We have used a novel experimental approach to generate a murine strain that mimics the human ETV6-RUNX1 pB-ALL. We expressed ETV6-RUNX1 specifically in hematopoietic stem cells (HSC) of C57BL/6 x CBA mice by placing ETV6-RUNX1 under the control of the Sca1 promoter. Two founder mice were obtained for the Sca1-ETV6-RUNX1 transgene, which had normal gestation, were viable and developed normally. Sca1-ETV6-RUNX1 transgenic mice were characterized with respect to clinical, immunephenotypic and genetic characteristics. For the detection of shared secondary genomic alterations we analyzed three murine Sca1-ETV6-RUNX1 and 11 ETV6-RUNX1positive human pB-ALL and corresponding germline by whole-exome (WES) and whole-genome sequencing using a HiSeq 2500 (Illumina) platform.[Results]: In our transgenic murine model Sca1-ETV6-RUNX1 transgene expression was detected in HSCs, while there was no detectable expression in pro B cells or later stages of B-cell development, which mimics human ETV6-RUNX1 preleukemic biology. Sca1-ETV6-RUNX1 mice developed exclusively pB-ALL at a low penetrance (7.5%; 3 out of 40) with a CD19+B220+IgM- cell surface phenotype. Overall survival was not significantly reduced compared to wild-type mice (P value = 0.7901). pB-ALL in Sca1-ETV6-RUNX1 mice manifested with splenomegaly, disruption of splenic architecture, and appearance of blast cells in the peripheral blood (PB). All leukemic cells displayed clonal immature BCR rearrangement. Tumor pro B cells grew independent of IL-7 and were able to propagate the disease when transplanted into sub-lethally irradiated syngeneic recipient mice. Whole-exome sequencing of murine pB-ALL revealed in one mouse a deletion of three amino acids in the B-cell differentiation factor EBF1, which is well known in the context of human ETV6-RUNX1 leukemia. Additionally we found mutations in genes implicated in histone modification, i.e. in KDM5Ccausing a premature translation stop. We compared the genomic alterations detected in the mouse model to published genomic data of pediatric ETV6-RUNX1 pB-ALL and identified multiple copy number variations, which are shared between the murine and human ETV6-RUNX1 pB-ALL. Among them were copy number gains and losses including i.e. the tumorsuppressor locus CDKN2A/B with a well-known role in human and mouse pB-ALL. A high proportion of genes implicated in histone modification was also mutated in published data of human ETV6-RUNX1 positive pB-ALL. We validated this novel finding of recurrent alterations of histone modifying genes in both the murine model and the human disease using an independent human ETV6-RUNX1 cohort of 11 patients. In this cohort were able to reproduce this finding. Similar to the murine model, we also detected a missense mutation in the methyltransferase KDM5C in one patient of our cohort of ETV6-RUNX1positive patients.[Conclusion]: In summary, we have characterized a new Sca1-ETV6-RUNX1 mouse model and this is, to our knowledge the first model, which represents a phenocopy of the human pB-ALL. Sca1-ETV6-RUNX1 mice develop exclusively pB-ALL at a very low penetrance as it is the case in human ETV6-RUNX1 positive pB-ALL. The acquisition of secondary mutations in pB-ALL with a high proportion in histone modifying genes confers the second hit for the conversion of a preleukemic clone into the clinically overt ETV6-RUNX1 positive pB-ALL disease. These findings are important for encouraging novel interventions that might help to prevent or treat ETV6-RUNX1 positive childhood leukemias.Peer Reviewe

ELISA Test for the Serological Detection of Scedosporium/Lomentospora in Cystic Fibrosis Patients

The detection and diagnosis of the opportunistic fungi Scedosporium spp. and Lomentospora prolificans still relies mainly on low-sensitive culture-based methods. This fact is especially worrying in Cystic Fibrosis (CF) patients in whom these fungal species are frequently isolated and may increase the risk of suffering from an infection or other health problems. Therefore, with the purpose of developing a serologic detection method for Scedosporium/Lomentospora, four different Scedosporium boydii protein extracts (whole cell protein extract, secretome, total cell surface and conidial surface associated proteins) were studied by ELISA to select the most useful for IgG detection in sera from CF patients. The four extracts were able to discriminate the Scedosporium/Lomentospora-infected from Aspergillus-infected and non-infected patients. However, the whole cell protein extract was the one selected, as it was the one with the highest output in terms of protein concentration per ml of fungal culture used, and its discriminatory capacity was the best. The ELISA test developed was then assayed with 212 sera from CF patients and it showed to be able to detect Scedosporium spp. and Lomentospora prolificans with very high sensitivity and specificity, 86%-100% and 93%-99%, respectively, depending on the cut-off value chosen (four values were proposed A(450nm)= 0.5837, A(450nm)= 0.6042, A(450nm)= 0.6404, and A(450nm)= 0.7099). Thus, although more research is needed to reach a standardized method, this ELISA platform offers a rapid, low-cost and easy solution to detect these elusive fungi through minimally invasive sampling, allowing the monitoring of the humoral response to fungal presenceThis research was funded by the Basque Government, grant number IT1362-19. IB, LM-S, and LA-F received a predoctoral fellowship from the Basque Government. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the result

The monoclonal antibody Ca37, developed against Candida albicans alcohol dehydrogenase, inhibits the yeast in vitro and in vivo

Candida albicans is a commensal yeast able to cause life threatening invasive infections particularly in immunocompromised patients. Despite the availability of antifungal treatments, mortality rates are still unacceptably high and drug resistance is increasing. We, therefore, generated the Ca37 monoclonal antibody against the C. albicans alcohol dehydrogenase (Adh) 1. Our data showed that Ca37 was able to detect C. albicans cells, and it bound to Adh1 in yeast and Adh2 in hyphae among the cell wall-associated proteins. Moreover, Ca37 was able to inhibit candidal growth following 18h incubation time and reduced the minimal inhibitory concentration of amphotericin B or fluconazole when used in combination with those antifungals. In addition, the antibody prolonged the survival of C. albicans infected-Galleria mellonella larvae, when C. albicans was exposed to antibody prior to inoculating G. mellonella or by direct application as a therapeutic agent on infected larvae. In conclusion, the Ca37 monoclonal antibody proved to be effective against C. albicans, both in vitro and in vivo, and to act together with antifungal drugs, suggesting Adh proteins could be interesting therapeutic targets against this pathogen.Technical and human support provided by the Proteomics Core Facility-SGIker at the UPV/EHU is gratefully acknowledged. We thank the member of the Chartered of Linguists, No 022913 for improving the English in the manuscript. This work was supported by Basque Government (Grant IT1362-19). AA, IB and LMS have received a predoctoral Grant from Basque Government and LAF from UPV/EH

Loss of Pax5 exploits sca1-BCR-ABLp190 susceptibility to confer the metabolic shift essential for pB-ALL

Preleukemic clones carrying BCR-ABLp190 oncogenic lesions are found in neonatal cord blood, where the majority of preleukemic carriers do not convert into precursor B-cell acute lymphoblastic leukemia (pB-ALL). However, the critical question of how these preleukemic cells transform into pB-ALL remains undefined. Here, we model a BCR-ABLp190 preleukemic state and show that limiting BCR-ABLp190 expression to hematopoietic stem/progenitor cells (HS/PC) in mice (Sca1-BCR-ABLp190) causes pB-ALL at low penetrance, which resembles the human disease. pB-ALL blast cells were BCR-ABL–negative and transcriptionally similar to pro-B/pre-B cells, suggesting disease onset upon reduced Pax5 functionality. Consistent with this, double Sca1-BCR-ABLp190+Pax5+/− mice developed pB-ALL with shorter latencies, 90% incidence, and accumulation of genomic alterations in the remaining wild-type Pax5 allele. Mechanistically, the Pax5-deficient leukemic pro-B cells exhibited a metabolic switch toward increased glucose utilization and energy metabolism. Transcriptome analysis revealed that metabolic genes (IDH1, G6PC3, GAPDH, PGK1, MYC, ENO1, ACO1) were upregulated in Pax5-deficient leukemic cells, and a similar metabolic signature could be observed in human leukemia. Our studies unveil the first in vivo evidence that the combination between Sca1-BCR-ABLp190 and metabolic reprogramming imposed by reduced Pax5 expression is sufficient for pB-ALL development. These findings might help to prevent conversion of BCR-ABLp190 preleukemic cells.J. Hauer has been supported by the German Cancer Aid (Project 110997 and Translational Oncology Program 70112951), the German Jose Carreras Foundation (DJCLS 02R/2016), the Kinderkrebsstiftung (2016/17), and the "Elterninitiative Kinderkrebstiftung e.V." S. Ginzel has been supported by a scholarship of the Hochschule Bonn-Rhein-Sieg. M. Muschen is an HHMI Faculty Scholar (HHMI- € 55108547) and supported by NIH/NCI through an Outstanding Investigator Award (R35CA197628, R01CA137060, R01CA157644, R01CA172558, R01CA213138) to M. Muschen, a Wellcome Trust Senior Investigator Award, € the Leukemia and Lymphoma Society, the Norman and Sadie Lee Foundation (for Pediatric Cancer, to M. Muschen), and the Dr. Ralph and Marian € Falk Medical Research Trust (to M. Muschen), Cancer Research Institute € through a Clinic and Laboratory Integration Program grant (to M. Muschen) € and the California Institute for Regenerative Medicine (CIRM) through DISC2-10061. A. Borkhardt has been supported by the German Children's Cancer Foundation and the Federal Ministry of Education and Research, Bonn, Germany. Research in I. Sanchez-García's group is partially supported by FEDER and by MINECO (SAF2012-32810, SAF2015-64420-R, and Red de Excelencia Consolider OncoBIO SAF2014-57791-REDC), Instituto de Salud Carlos III (PIE14/00066), ISCIII- Plan de Ayudas IBSAL 2015 Proyectos Integrados (IBY15/00003), by Junta de Castilla y Leon (BIO/SA51/15, CSI001U14, UIC-017, and CSI001U16), Fundacion Inocente Inocente and by the ARIMMORA project [European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement no. 282891]. I. Sanchez-García's lab is a member of the EuroSyStem and the DECIDE Network funded by the European Union under the FP7 program. A. Borkhardt and I. Sanchez-García have been supported by the German Carreras Foundation (DJCLS R13/26). Research in C. Vicente-Duenas's ~ group is partially supported by FEDER, Ministerio de Economía y Competitividad ("Miguel Servet" Grant - CP14/00082 - AES 2013-2016) and (PI17/00167) from the Instituto de Salud Carlos III. A. Martín-Lorenzo and G. Rodríguez-Hernandez were supported by FSE-Conserjería de Educacion de la Junta de Castilla y Leon (CSI001-13 and CSI001-15, respectively). F. Auer was supported by a Deutsche Forschungsgemeinschaft (DFG) fellowship (AU 525/1-1)