Cancer Stem Cells

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Genetically engineered mouse models of human B-cell precursor leukemias

This is an Open Access article distributed under the terms of the Creative Commons Attribution-Non-Commercial License.B-cell precursor acute lymphoblastic leukemias (pB-ALLs) are the most frequent type of malignancies of the childhood, and also affect an important proportion of adult patients. In spite of their apparent homogeneity, pB-ALL comprises a group of diseases very different both clinically and pathologically, and with very diverse outcomes as a consequence of their biology, and underlying molecular alterations. Their understanding (as a prerequisite for their cure) will require a sustained multidisciplinary effort from professionals coming from many different fields. Among all the available tools for pB-ALL research, the use of animal models stands, as of today, as the most powerful approach, not only for the understanding of the origin and evolution of the disease, but also for the development of new therapies. In this review we go over the most relevant (historically, technically or biologically) genetically engineered mouse models (GEMMs) of human pB-ALLs that have been generated over the last 20 years. Our final aim is to outline the most relevant guidelines that should be followed to generate an “ideal” animal model that could become a standard for the study of human pB-ALL leukemia, and which could be shared among research groups and drug development companies in order to unify criteria for studies like drug testing, analysis of the influence of environmental risk factors, or studying the role of both low-penetrance mutations and cancer susceptibility alterations.This work was supported by the German “Bundesamt fur Strah-lenschutz (BfS)” pilot project on childhood leukemia no. 3612S70029. JH 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. AB has been supported by the German Children’s Cancer Foundation and the Federal Ministry of Education and Research, Bonn, Germany. Research in ISG group is partially supported by FEDER and by MICINN (SAF2012-32810), by NIH grant (R01 CA109335-04A1), by Junta de Castilla y León (BIO/SA06/13) and by the ARIMMORA project (FP7-ENV-2011, European Union Seventh Framework Program). ISG lab is a member of the EuroSyStem and the DECIDE Network funded by the European Union under the FP7 program. Research at CC’s lab was partially supported by FEDER, Fondo de Investigaciones Sanitarias (PI13/00160), CSIC P.I.E., Junta de Castilla y León, and from an institutional grant from the Fundación Ramón Areces.Peer Reviewe

Dynamic properties of Newcastle Disease Virus envelope and their relations with viral hemagglutinin-neuraminidase membrane glycoprotein

AbstractThe lipid composition of Newcastle Disease Virus (NDV) Clone-30 strain shows a low lipid/protein ratio, a high cholesterol/phospholipid molar ratio, and major phospholipids being qualitatively different to other NDV strains. The major fatty acyl constituents are palmitic, stearic, oleic, and linoleic acids; cerebrosides, sulfatides and two kinds of gangliosides are also found in the NDV membrane. It is reported for the first time in NDV that phospholipid classes are asymmetrically distributed over the two leaflets of the membrane: 60±4.5% of the phosphatidylcholine and 70±5.0% of the sphingomyelin are in the outer monolayer. Intact viral membranes and reconstituted NDV envelopes showed similar dynamic properties. Hemagglutinin-neuraminidase (HN) and fusion (F) proteins of NDV membrane affect the lipid thermotropic behaviour in reconstituted proteoliposomes made up of a single class of phospholipids. It is shown that the lipid composition is more important than the bulk membrane fluidity/order for both sialidase (neuraminidase) and hemagglutinating HN activities. Sialidase and hemagglutinating activities requires the presence of definite phospholipids (phosphatidylethanolamine) in its environment

Homeobox NKX2-3 promotes marginal-zone lymphomagenesis by activating B-cell receptor signalling and shaping lymphocyte dynamics

NKX2 homeobox family proteins have a role in cancer development. Here we show that NKX2-3 is overexpressed in tumour cells from a subset of patients with marginal-zone lymphomas, but not with other B-cell malignancies. While Nkx2-3-deficient mice exhibit the absence of marginal-zone B cells, transgenic mice with expression of NKX2-3 in B cells show marginal-zone expansion that leads to the development of tumours, faithfully recapitulating the principal clinical and biological features of human marginal-zone lymphomas. NKX2-3 induces B-cell receptor signalling by phosphorylating Lyn/Syk kinases, which in turn activate multiple integrins (LFA-1, VLA-4), adhesion molecules (ICAM-1, MadCAM-1) and the chemokine receptor CXCR4. These molecules enhance migration, polarization and homing of B cells to splenic and extranodal tissues, eventually driving malignant transformation through triggering NF-κB and PI3K-AKT pathways. This study implicates oncogenic NKX2-3 in lymphomagenesis, and provides a valid experimental mouse model for studying the biology and therapy of human marginal-zone B-cell lymphomas.Instituto de Salud Carlos III (ISCIII), Spanish Ministry of Economy and Competitiveness, FIS-PI12/00202 (to J.A.M.-C.), RTICC-RD12/0036/0063 (to J.A.M-C.), RTICC-RD12/0036/0068 (to M.J.C and F.P.), RTICC-RD12/0036/0022 (to J.L.F-L.), RTICC-RD12/ 0036/0070 (to J.C.), RTICC-RD12/0036/0010 (to B.B.), RTICC- RD12/0036/0044 (to M.J.B.) and RTICC-RD12/0036/0069 (to J.M.H.R. and M.G.); by Worldwide Cancer Research project grant 15-1322 (to J.A.M.-C., Y.R.C. and M.-Q.D.); by BFU2011-30097 (to Y.R.C); by MINECO SAF2013-45787-R and Marie Curie Programme FP7-PIIF-2012-328177 (to S.R.); by the French-Spanish CITTIL project (to F.P., X.A., J.A.M.-C., C.B. and P. Brousset); by SAF2012-32810, SAF2014-57791-REDC; PIE14/00066, BIO/SA32/ 14 and CSI001U14 (to I.S.G); by FIS-ISCIII projects PI13/00160 and PI14/00025, and Fundación Inocente Inocente (to C.C.); by Deutsche Krebshilfe, Molecular Mechanisms in Malignant Lymphomas Network Project (to R.S.); by the Institut Universitaire de France (to P. Brousset); by the Broad Medical Research Program of The Eli and Edythe Broad Foundation and the Hungarian Scientific Research Fund (OTKA K108429) (to P. Balogh);Peer Reviewe

Childhood leukaemia risks: Towards a better understanding of unexplained results

Conclusiones al 4th International MELODI Workshop, celebrado en Helsinki (Finlandia) del 12 al 14 de septiembre de 2012.-- et al.Peer Reviewe

Childhood B-Cell Preleukemia Mouse Modeling

Leukemia is the most usual childhood cancer, and B-cell acute lymphoblastic leukemia (B-ALL) is its most common presentation. It has been proposed that pediatric leukemogenesis occurs through a “multi-step” or “multi-hit” mechanism that includes both in utero and postnatal steps. Many childhood leukemia-initiating events, such as chromosomal translocations, originate in utero, and studies so far suggest that these “first-hits” occur at a far higher frequency than the incidence of childhood leukemia itself. The reason why only a small percentage of the children born with such preleukemic “hits” will develop full-blown leukemia is still a mystery. In order to better understand childhood leukemia, mouse modeling is essential, but only if the multistage process of leukemia can be recapitulated in the model. Therefore, mouse models naturally reproducing the “multi-step” process of childhood B-ALL will be essential to identify environmental or other factors that are directly linked to increased risk of disease.Research in CV-D group has been funded by Instituto de Salud Carlos III (ISCIII), through a “Miguel Servet Grant” (CPII19/00024-AES 2017–2020); co-funded by the European Union. Research in IS-G group is partially supported by FEDER and by SAF2015-64420-R MINECO/FEDER, UE, RTI2018-093314-B-I00 MCIU/AEI/FEDER, UE, by PID2021-122185OB-I00 MCIU/AEI/FEDER, UE, and by Junta de Castilla y León (UIC-017, CSI001U16, CSI234P18, and CSI144P20). IS-G have been supported by the Fundacion Unoentrecienmil (CUNINA project). CC and IS-G have been supported by the Fundación Científica de la Asociación Española contra el Cáncer (PRYCO211305SANC). Research at CC’s laboratory was partially supported by Ministerio de Ciencia e Innovación/AEI/FEDER (PID2021-122787OB-I00), FEDER MINECO (SAF2017-83061-R), the “Fundación Ramón Areces” and a Research Contract with the “Fundación Síndrome de Wolf-Hirschhorn o 4p-”. Institutional grants from the “Fundación Ramón Areces” and “Banco de Santander” to the CBMSO are also acknowledged. J.M.-C. is the recipient of a UAM FPU fellowship. AC-G (CSI067-18) and MI-H (CSI021-19) are supported by FSE-Conserjería de Educación de la Junta de Castilla y León 2019 and 2020 (ESF—European Social Fund) fellowship, respectively. SA-A is supported by an Ayuda para Contratos predoctorales para la formación de doctores (PRE2019-088887). L.S. is supported by a scholarship from University of Salamanca co-financed by Banco Santander and ESF

Lineage-specific function of Engrailed-2 in the progression of chronic myelogenous leukemia to T-cell blast crisis

In hematopoietic malignancies, oncogenic alterations interfere with cellular differentiation and lead to tumoral development. Identification of the proteins regulating differentiation is essential to understand how they are altered in malignancies. Chronic myelogenous leukemia (CML) is a biphasic disease initiated by an alteration taking place in hematopoietic stem cells. CML progresses to a blast crisis (BC) due to a secondary differentiation block in any of the hematopoietic lineages. However, the molecular mechanisms of CML evolution to T-cell BC remain unclear. Here, we have profiled the changes in DNA methylation patterns in human samples from BC-CML, in order to identify genes whose expression is epigenetically silenced during progression to T-cell lineage-specific BC. We have found that the CpG-island of the ENGRAILED-2 (EN2) gene becomes methylated in this progression. Afterwards, we demonstrate that En2 is expressed during T-cell development in mice and humans. Finally, we further show that genetic deletion of En2 in a CML transgenic mouse model induces a T-cell lineage BC that recapitulates human disease. These results identify En2 as a new regulator of T-cell differentiation whose disruption induces a malignant T-cell fate in CML progression, and validate the strategy used to identify new developmental regulators of hematopoiesis.Research at C.C.’s lab was partially supported by FEDER, Fondo de Investigaciones Sanitarias, CSIC P.I.E., Junta de Castilla y León, and from an institutional grant from the Fundación Ramón Areces. Research in ISG group is partially supported by FEDER and by MICINN (SAF2012-32810), by MEC OncoBIO Consolider-Ingenio 2010 (Ref. CSD2007-0017), by NIH grant (R01 CA109335-04A1), the ARIMMORA project (FP7-ENV-2011, European Union Seventh Framework Program), by Junta de Castilla y León (BIO/SA06/13) and by “Proyecto en red de investigación en células madre tumorales” supported by Obra Social Kutxa y Consejería de Sanidad de la Junta de Castilla y Leon. C.V.D.’s research is supported by Junta de Castilla y León (proyecto de investigación en biomedicina SAN/39/2010). J.A.M.C.’s research is supported by the Instituto de Salud Carlos III (ISCIII), grants FIS-PI12/00202 and RTICC-RD12/0036/0063. All Spanish funding is co-sponsored by the European Union FEDER program. I.S.G. is an API lab of the EuroSyStem project and a partner of DECIDE European network. F.A.-J. and E.C.S. were supported by Spanish Ministry of Science and Innovation fellowships. E.C.-S. was a “Residencia de Estudiantes” Fellow. A.T.N. was the recipient of a “Beca de Postgrado de la Fundación Ramón Areces/UAM.”Peer Reviewe

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

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