Ontogenic changes in hematopoietic hierarchy determine pediatric specificity and disease phenotype in fusion oncogene-driven myeloid leukemia

Fusion oncogenes are prevalent in several pediatric cancers, yet little is known about the specific associations between age and phenotype. We observed that fusion oncogenes, such as ETO2–GLIS2, are associated with acute megakaryoblastic or other myeloid leukemia subtypes in an age-dependent manner. Analysis of a novel inducible transgenic mouse model showed that ETO2–GLIS2 expression in fetal hematopoietic stem cells induced rapid megakaryoblastic leukemia whereas expression in adult bone marrow hematopoietic stem cells resulted in a shift toward myeloid transformation with a strikingly delayed in vivo leukemogenic potential. Chromatin accessibility and single-cell transcriptome analyses indicate ontogeny-dependent intrinsic and ETO2–GLIS2-induced differences in the activities of key transcription factors, including ERG, SPI1, GATA1, and CEBPA. Importantly, switching off the fusion oncogene restored terminal differentiation of the leukemic blasts. Together, these data show that aggressiveness and phenotypes in pediatric acute myeloid leukemia result from an ontogeny-related differential susceptibility to transformation by fusion oncogenes. SIGNIFICANCE: This work demonstrates that the clinical phenotype of pediatric acute myeloid leukemia is determined by ontogeny-dependent susceptibility for transformation by oncogenic fusion genes. The phenotype is maintained by potentially reversible alteration of key transcription factors, indicating that targeting of the fusions may overcome the differentiation blockage and revert the leukemic state

The European Hematology Association Roadmap for European Hematology Research. A Consensus Document

Abstract The European Hematology Association (EHA) Roadmap for European Hematology Research highlights major achievements in diagnosis and treatment of blood disorders and identifies the greatest unmet clinical and scientific needs in those areas to enable better funded, more focused European hematology research. Initiated by the EHA, around 300 experts contributed to the consensus document, which will help European policy makers, research funders, research organizations, researchers, and patient groups make better informed decisions on hematology research. It also aims to raise public awareness of the burden of blood disorders on European society, which purely in economic terms is estimated at Euro 23 billion per year, a level of cost that is not matched in current European hematology research funding. In recent decades, hematology research has improved our fundamental understanding of the biology of blood disorders, and has improved diagnostics and treatments, sometimes in revolutionary ways. This progress highlights the potential of focused basic research programs such as this EHA Roadmap. The EHA Roadmap identifies nine sections in hematology: normal hematopoiesis, malignant lymphoid and myeloid diseases, anemias and related diseases, platelet disorders, blood coagulation and hemostatic disorders, transfusion medicine, infections in hematology, and hematopoietic stem cell transplantation. These sections span 60 smaller groups of diseases or disorders. The EHA Roadmap identifies priorities and needs across the field of hematology, including those to develop targeted therapies based on genomic profiling and chemical biology, to eradicate minimal residual malignant disease, and to develop cellular immunotherapies, combination treatments, gene therapies, hematopoietic stem cell treatments, and treatments that are better tolerated by elderly patients. Received December 15, 2015. Accepted January 27, 2016. Copyright © 2016, Ferrata Storti Foundatio

The European Hematology Association Roadmap for European Hematology Research: a consensus document

The European Hematology Association (EHA) Roadmap for European Hematology Research highlights major achievements in diagnosis and treatment of blood disorders and identifies the greatest unmet clinical and scientific needs in those areas to enable better funded, more focused European hematology research. Initiated by the EHA, around 300 experts contributed to the consensus document, which will help European policy makers, research funders, research organizations, researchers, and patient groups make better informed decisions on hematology research. It also aims to raise public awareness of the burden of blood disorders on European society, which purely in economic terms is estimated at €23 billion per year, a level of cost that is not matched in current European hematology research funding. In recent decades, hematology research has improved our fundamental understanding of the biology of blood disorders, and has improved diagnostics and treatments, sometimes in revolutionary ways. This progress highlights the potential of focused basic research programs such as this EHA Roadmap. The EHA Roadmap identifies nine ‘sections’ in hematology: normal hematopoiesis, malignant lymphoid and myeloid diseases, anemias and related diseases, platelet disorders, blood coagulation and hemostatic disorders, transfusion medicine, infections in hematology, and hematopoietic stem cell transplantation. These sections span 60 smaller groups of diseases or disorders. The EHA Roadmap identifies priorities and needs across the field of hematology, including those to develop targeted therapies based on genomic profiling and chemical biology, to eradicate minimal residual malignant disease, and to develop cellular immunotherapies, combination treatments, gene therapies, hematopoietic stem cell treatments, and treatments that are better tolerated by elderly patients

Patient-derived xenograft (PDX) models in basic and translational breast cancer research

Patient-derived xenograft (PDX) models of a growing spectrum of cancers are rapidly supplanting long-established traditional cell lines as preferred models for conducting basic and translational preclinical research. In breast cancer, to complement the now curated collection of approximately 45 long-established human breast cancer cell lines, a newly formed consortium of academic laboratories, currently from Europe, Australia, and North America, herein summarizes data on over 500 stably transplantable PDX models representing all three clinical subtypes of breast cancer (ER+, HER2+, and "Triple-negative" (TNBC)). Many of these models are well-characterized with respect to genomic, transcriptomic, and proteomic features, metastatic behavior, and treatment response to a variety of standard-of-care and experimental therapeutics. These stably transplantable PDX lines are generally available for dissemination to laboratories conducting translational research, and contact information for each collection is provided. This review summarizes current experiences related to PDX generation across participating groups, efforts to develop data standards for annotation and dissemination of patient clinical information that does not compromise patient privacy, efforts to develop complementary data standards for annotation of PDX characteristics and biology, and progress toward "credentialing" of PDX models as surrogates to represent individual patients for use in preclinical and co-clinical translational research. In addition, this review highlights important unresolved questions, as well as current limitations, that have hampered more efficient generation of PDX lines and more rapid adoption of PDX use in translational breast cancer research

Adoptive transfer of viable motheaten (mev) humoral autoimmunity: IgM to IgG switch of the hyperglobulinaemia in nude, beige recipient mice.

Homozygous C57BL/6 nude, beige mice (B6 nu,bg) were used as recipients for the transfer of lymphoid cells from autoimmune homozygous B6 'viable motheaten' mice (B6 mev) and from either normal B6 mice (B6 wild) or B6 bg mice as controls. Surprisingly, the mev cell grafts prolonged survival of these short-living doubly immunodeficient recipients. Although the [mev----nu,bg] chimeras did not develop the mev external necrosis phenotype, they showed a hyperglobulinaemia and a significant increase of their anti-single-stranded DNA (ssDNA) antibody titres, compared to control chimeras ([bg----nu,bg] and [wild----nu,bg]). However, this hyperglobulinaemia was quite different from the mev-type hyperglobulinaemia, with poor contribution of the IgM isotype. Moreover, the anti-ssDNA antibodies were more distributed among the various Ig classes than the anti-ssDNA antibodies of the mev homozygous mice. Though the adoptive transfer of some mev-type humoral autoimmunity symptoms were achieved in this chimera model, the recipient mice did not suffer from the several other features of the mev syndrom, such as the severe pathology and the extremely high IgM serological levels

Adoptive transfer of viable motheaten humoral autoimmunity in cyclophosphamide-immunodepressed beige recipient mice.

Cyclophosphamide-pretreated homozygous C57BL/6 beige mice (B6 bg) were used as recipients for the transfer of lymphoid cells either of short-living autoimmune homozygous B6 'viable motheaten' mice (B6 mev) or of normal B6 mice (B6+) or B6 bg mice as controls. The grafts had no incidence on the survival of the recipients, whatever protocol used. The [mev----bg] chimeras did not develop the mev external phenotype, but there was a transfer of humoral autoimmunity. Compared to control Compared to control chimeras ([bg----bg] and [+----bg]), recipients of mev cells always showed an increase in anti-single-stranded DNA (ssDNA) antibody titres, reaching 2/3 of the mev ones 40 weeks after the cell transfers. Moreover, the anti-ssDNA were mainly of IgM class, correlating with the higher total IgM level found in [mev----bg] chimeras, thus reflecting the serological phenotype of the mev homozygous mice. Though the adoptive transfer of some mev-type humoral autoimmunity symptoms was clearly achieved in this chimera model, the recipient mice did not suffer from the several other features of the mev syndrome, such as the hyperglobulinemia and the severe pathology. This indicates that microenvironmental influences act in concert with B cells to produce pathology in mev mice

Stem cell leukemia: how a TALented actor can go awry on the hematopoietic stage

© 2016 Macmillan Publishers Limited, part of Springer Nature. All rights reserved.TAL1/SCL/TCL5 is a critical transcription factor for hematopoietic stem cell maintenance and regulation of early hematopoiesis. However, aberrant expression of TAL1 in committed T-cell precursors is also directly implicated in the development of T-cell leukemia. Roughly 25 years ago TAL1 was identified in early hematopoietic cells and involved in leukemia. Here, we review the wealth of knowledge gained since then on its physiological roles and mechanisms by which TAL1 ectopic expression contributes to leukemogenesis. We emphasize recent findings that shed light into the intricacies of TAL1 (epi)genetic regulation and the transcription network orchestrated by this major T-cell oncogene. Importantly, an exciting time is coming when data using the mechanistic knowledge accumulated on TAL1 may be used to develop novel anti-leukemia targeted therapies.Work conducted in JTB’s lab that relates to this review was supported by Liga Portuguesa Contra o Cancro (Terry Fox Award) and by Fundação para a Ciência e a Tecnologia (project PTDC/BIM-ONC/1548/2012). JTB is an FCT investigator (consolidation grant). FP’s lab is funded by INSERM, Ligue Nationale contre le Cancer, Institut du Cancer and RISK-IR networkinfo:eu-repo/semantics/publishedVersio

Phenotype and function of human hematopoietic cells engrafting immune-deficient CB17-severe combined immunodeficiency mice and nonobese diabetic-severe combined immunodeficiency mice after transplantation of human cord blood mononuclear cells.

In an attempt to understand better the regulation of stem cell function in chimeric immunodeficient mice transplanted with human cells, and the filiation between progenitor cells identified in vitro and in vivo, we assessed the different compartments of hematopoietic progenitors found in the marrow of CB17-severe combined immunodeficiency (SCID) mice (34 mice, 9 experiments) after intravenous injection of 2 to 3 x 10(7) cord blood mononuclear cells. On average 6.3 +/- 4 x 10(5) human cells were detected per four long bones 4 to 6 weeks after the transplant predominantly represented by granulomonocytic (CD11b+) and B lymphoid (CD19+) cells. Twenty five percent of these human cells expressed the CD34 antigen, of which 90% coexpressed the CD38 antigen and 50% the CD19 antigen. Functional assessment of progenitor cells (both clonogenic and long-term culture-initiating cells [LTC-IC]) was performed after human CD34+ cells and CD34+/CD38- cells have been sorted from chimeric CB17-SCID marrow 3 to 10 weeks after intravenous (IV) injection of human cells. The frequency of both colony-forming cells and LTC-IC was low (4% and 0.4%, respectively in the CD34+ fraction) when compared with the frequencies of cells with similar function in CD34+ cells from the starting cord blood mononuclear cells (26% +/- 7% and 7.2% +/- 5%, respectively). More surprisingly, the frequency of LTC-IC was also low in the human CD34+ CD38- fraction sorted from chimeric mice. This observation might be partly accounted for by the expansion of the CD34+ CD19+ B-cell precursor compartment. Despite their decreased frequency and absolute numbers, the differentiation capability of these LTC-IC, assessed by their clonogenic progeny output after 5 weeks in coculture with murine stromal cells was intact when compared with that of input LTC-IC. Furthermore the ratio between clonogenic progenitor cells and LTC-IC was similar in severe combined immunodeficiency (SCID) mice studied 4 weeks after transplant and in adult marrow or cord blood suspensions. Results generated in experiments where nonobese diabetic (NOD)-SCID mice were used as recipients indicate a higher level of engraftment but no change in the distribution of clonogenic cells or LTC-IC. These results suggest that the hierarchy of hematopoietic differentiation classically defined in human hematopoietic tissues can be reconstituted in immunodeficient SCID or NOD-SCID mice