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This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 2.0 France Licence. ; The research fields of developmental biology and oncology have always been tightly linked, since the times of Rudolf Virchow's cellular theory (>omnis cellula e cellula>) and embryonal rest hypothesis. On the other side, for many years, contemporary cancer research has been mainly focused on the altered controls of proliferation in tumoral cells. This has been reflected in the therapeutic approaches employed in the clinic to treat the patients: with very few exceptions, anti-cancer treatments are targeted at the mechanisms of abnormal tumoral growth. Such therapies, however, are very unspecific, highly toxic and, ultimately, inefficient in most cases. In the last years, a new recognition of the role of aberrant differentiation at the root of cancer has arisen, mainly driven by the coming of age of the >cancer stem cell> (CSC) theory. From this point of view, the comprehensive knowledge of the developmental mechanisms by which normal cells acquire their identity is essential to understand how these controls are deregulated in tumours. New insights into the mechanisms that maintain the molecular boundaries of cell identity have been gained from the study of induced pluripotency, showing that cell fate can be much more susceptible to change than previously thought. Applied to cancer, these findings imply that the oncogenic events that take place in an otherwise healthy cell lead to a reprogramming of the normal cellular fate and establish a new pathologic developmental program. Therefore, cancer reprogramming and cellular plasticity are closely related, since only some cells possess the plasticity required to allow reprogramming to occur, and only some oncogenic events can, in the right plastic cell, induce this change. Here we discuss the latest findings in the fields of cellular plasticity and reprogramming and we consider their consequences for our understanding of cancer development and treatment. ; Research in C.C. lab was partially supported by FEDER, Fondo de Investigaciones Sanitarias (PI080164), CSIC P.I.E. 200920I055 and 201120E060, from the ARIMMORA project (FP7-ENV-2011, European Union Seventh Framework Program) and from an institutional grant from the "Fundación Ramón Areces". Research in ISG group was partially supported by FEDER and by MICINN (SAF2009- 08803 to ISG), by Junta de Castilla y León (REF. CSI007A11-2 and Proyecto Biomedicina 2009-2010), by MEC OncoBIO Consolider-Ingenio 2010 (Ref. CSD2007-0017), by NIH grant (R01 CA109335- 04A1), by Sandra Ibarra Foundation, by Group of Excellence Grant (GR15) from Junta de Castilla y Leon, and the ARIMMORA project (FP7-ENV-2011, European Union Seventh Framework Program) and by >Proyecto en Red de Investigación en Celulas Madre Tumorales en Cancer de Mama>, supported by Obra Social Kutxa y Conserjería de Sanidad de la Junta de Castilla y León. All Spanish funding is co-sponsored by the European Union FEDER program. ISG is an API lab of the EuroSyStem project. ECS is the recipient of a JAE-predoc Fellowship from CSIC and a "Residencia de Estudiantes" Fellowship. The authors declare no conflict of interest. ; Peer Reviewed

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 Reviewed

Chromosomal translocations involving the MALT1 gene are hallmarks of mucosa-associated lymphoid tissue (MALT) lymphoma. To date, targeting these translocations to mouse B cells has failed to reproduce human disease. Here, we induced MALT1 expression in mouse Sca1 +Lin - hematopoietic stem/progenitor cells, which showed NF-κB activation and early lymphoid priming, being selectively skewed toward B-cell differentiation. These cells accumulated in extranodal tissues and gave rise to clonal tumors recapitulating the principal clinical, biological, and molecular genetic features of MALT lymphoma. Deletion of p53 gene accelerated tumor onset and induced transformation of MALT lymphoma to activated B-cell diffuse large-cell lymphoma (ABC-DLBCL). Treatment of MALT1-induced lymphomas with a specific inhibitor of MALT1 proteolytic activity decreased cell viability, indicating that endogenous Malt1 signaling was required for tumor cell survival. Our study shows that human-like lymphomas can be modeled in mice by targeting MALT1 expression to hematopoietic stem/progenitor cells, demonstrating the oncogenic role of MALT1 in lymphomagenesis. Furthermore, this work establishes a molecular link between MALT lymphoma and ABC-DLBCL, and provides mouse models to test MALT1 inhibitors. Finally, our results suggest that hematopoietic stem/progenitor cells may be involved in the pathogenesis of human mature B-cell lymphomas. ; Spanish Ministry of Science and Innovation; Consejo Superior de Investigaciones Científicas; Junta de Castilla y León; Fundación Ramón Areces; Affymetrix Collaboration in Cancer; Navarra Government; European Union Fondo Europeo de Desarrollo Regional (FEDER) program ; Peer Reviewed

This is an open access article. ; The latest scientific findings in the field of cancer research are redefining our understanding of the molecular and cellular basis of the disease, moving the emphasis toward the study of the mechanisms underlying the alteration of the normal processes of cellular differentiation. The concepts best exemplifying this new vision are those of cancer stem cells and tumoral reprogramming. The study of the biology of acute lymphoblastic leukemias (ALLs) has provided seminal experimental evidences supporting these new points of view. Furthermore, in the case of B-cells, it has been shown that all the stages of their normal development show a tremendous degree of plasticity, allowing them to be reprogrammed to other cellular types, either normal or leukemic. Here we revise the most recent discoveries in the fields of B-cell developmental plasticity and B-ALL research, and discuss their interrelationships and their implications for our understanding of the biology of the disease. © 2011 Landes Bioscience. ; Research in C.C. lab was partially supported by FEDER, Fondo de Investigaciones Sanitarias (PI080164), CSIC P.I.E., 200920I055 and 201120E060, from the ARIMMORA project (FP7-ENV-2011, European Union Seventh Framework Program) and from an institutional grant from the "Fundación Ramón Areces." Research in I.S.G. group was partially supported by FEDER and by MICINN (SAF2009-08803 to I.S.G.), by Junta de Castilla y León (REF. CSI007A11-2 and Proyecto Biomedicina 2009–2010), by MEC OncoBIO Consolider-Ingenio 2010 (Ref. CSD2007-0017), by NIH grant (R01 CA109335-04A1), by Sandra Ibarra Foundation, by Group of Excellence Grant (GR15) from Junta de Castilla y Leon, and the ARIMMORA project (FP7-ENV-2011, European Union Seventh Framework Program) and by Proyecto en Red de Investigación en Celulas Madre Tumorales en Cancer de Mama, supported by Obra Social Kutxa y Conserjería de Sanidad de la Junta de Castilla y Leon. All Spanish funding is co-sponsored by the European Union FEDER program. I.S.G. is an API lab of the EuroSyStem project. E.C.S. and M.B.D. are recipients of JAE-predoc fellowships from CSIC. I.R.C. is recipient of a FPU fellowship from MICINN. E.C.S. is recipient of a "Residencia de Estudiantes" fellowship. ; Peer Reviewed

PMCID: PMC3545406.-- et al. ; The human germinal centre-associated lymphoma gene is specifically expressed in germinal centre B-lymphocytes and germinal centre-derived B-cell lymphomas, but its function is largely unknown. Here we demonstrate that human germinal centre-associated lymphoma directly binds to Syk in B cells, increases its kinase activity on B-cell receptor stimulation and leads to enhanced activation of Syk downstream effectors. To further investigate these findings in vivo, human germinal centre-associated lymphoma transgenic mice were generated. Starting from 12 months of age these mice developed polyclonal B-cell lymphoid hyperplasia, hypergammaglobulinemia and systemic reactive amyloid A (AA) amyloidosis, leading to shortened survival. The lymphoid hyperplasia in the human germinal centre-associated lymphoma transgenic mice are likely attributable to enhanced B-cell receptor signalling as shown by increased Syk phosphorylation, ex vivo B-cell proliferation and increased RhoA activation. Overall, our study shows for the first time that the germinal centre protein human germinal centre-associated lymphoma regulates B-cell receptor signalling in B-lymphocytes which, without appropriate control, may lead to B-cell lymphoproliferation. ; National Institutes of Health (NIH) grants NIH CA109335 and NIH CA122105; the Dwoskin Family Foundations; NIH P01 CA34233 FEDER and by MICINN (SAF2009-08803 and SAF2012-32810 to ISG); Junta de Castilla y León (REF. CSI007A11-2 and Proyecto Biomedicina 2009-2010); MEC OncoBIO Consolider-Ingenio 2010 (Ref. CSD2007-0017); Sandra Ibarra Foundation; Group of Excellence Grant (GR15) from Junta de Castilla y Leon; the ARIMMORA project (FP7-ENV-2011, European Union Seventh Framework Programme) ; Peer Reviewed

This article is licensed under a Creative Commons Attribution-NoncommercialNo DerivativeWorks 3.0 Licence. ; Understanding the cellular origin of cancer can help to improve disease prevention and therapeutics. Human plasma cell neoplasias are thought to develop from either differentiated B cells or plasma cells. However, when the expression of Maf oncogenes (associated to human plasma cell neoplasias) is targeted to mouse B cells, the resulting animals fail to reproduce the human disease. Here, to explore early cellular changes that might take place in the development of plasma cell neoplasias, we engineered transgenic mice to express MafB in haematopoietic stem/progenitor cells (HS/PCs). Unexpectedly, we show that plasma cell neoplasias arise in the MafB-transgenic mice. Beyond their clinical resemblance to human disease, these neoplasias highly express genes that are known to be upregulated in human multiple myeloma. Moreover, gene expression profiling revealed that MafB-expressing HS/PCs were more similar to B cells and tumour plasma cells than to any other subset, including wild-type HS/PCs. Consistent with this, genome-scale DNA methylation profiling revealed that MafB imposes an epigenetic program in HS/PCs, and that this program is preserved in mature B cells of MafB-transgenic mice, demonstrating a novel molecular mechanism involved in tumour initiation. Our findings suggest that, mechanistically, the haematopoietic progenitor population can be the target for transformation in MafB-associated plasma cell neoplasias. © 2012 European Molecular Biology Organization | All Rights Reserved. ; MICINN (SAF2009-08803 to ISG); Junta de Castilla y León (REF. CSI007A11-2 and Proyecto Biomedicina 2009-2010 ); MEC OncoBIO Consolider-Ingenio 2010 (Ref. CSD2007-0017); Sandra Ibarra Foundation; Junta de Castilla y Leon; ARIMMORA project (FP7-ENV-2011, European Union Seventh Framework Program); Obra Social Kutxa; Conserjería de Sanidad de la Junta de Castilla y Leon ; Peer Reviewed