We are pleased to be able the recipients of the 2016 research awards in bone marrow failure. This year we had dozens of worthy applications and our committee worked diligently to review and score each proposal. The following grantees will each receive an award in the amount of $30,000 to be used to further their research efforts in aplastic anemia, MDS or PNH.
In the category of MDS, Tushar Bhagat, Ph.D., a Research Associate at Albert Einstein College of Medicine, received an award for his project; Targeting stromal mediated WNT activation in MDS transformation.
Myelodysplastic syndromes (MDS) are a heterogeneous set of clonal disorders characterized by ineffective blood cell development. These diseases are driven by many complex genetic and non-genetic changes. Recent findings have uncovered that alterations in the bone marrow microenvironment contribute to the disease. In our preliminary data, we have found that the beta-catenin pathway is activated in the bone marrow and in the blood of patients with MDS and this predicts a poor clinical outcome. We demonstrate that changes in the stroma increase beta-catenin in the MDS cells and can be targeted by new drugs. We will utilize mouse models, cells lines and patient samples to understand how the bone marrow environment is altered in patients and utilize newly developed beta-catenin pathway inhibitors to reverse the disease.
For research in PNH, Ailina Dulau Florea, M.D., Senior Research Fellow at the National Institutes of Health, received an award for her project: Determination of GPI-anchored protein expression, cell proliferation and cell death in bone marrow of patients with PNH and aplastic anemia or myelodysplastic syndrome.
Our study involves the analysis of normal and abnormal cells in the bone marrow of patients with Paroxysmal Nocturnal Hemoglobinuria (PNH). In this condition, due to a gene mutation, some bone marrow cells and their progeny in the blood lack an important cell surface component that functions as an anchor for other proteins, some of which attach to blood cells and protect them from destruction by complement, part our immune system. The result of this deficiency is a breakdown of red cells. If large quantities of red cells are destroyed, people become very tired, or have pain in the belly, head or when swallowing, or develop blood clots. The cause of the gene mutation is unknown. Some patients with other conditions, such as aplastic anemia (AA, a disease where marrow stops producing blood cells), or myelodysplasia (MDS, a disease associated with a tendency to transform into leukemia), may develop PNH. It is not clear what makes this change occur, and when it happens, patient may not even be aware of it, because patients with AA and MDS usually have few cells of the PNH type. However, over time, the symptoms could worsen due to an increase in the number of affected cells, and patients may need treatment to prevent red cell destruction.
Tests for PNH
These tests include a complete blood count (the number of cells in blood), and tests assessing red cell breakdown. For detecting PNH, doctors use an instrument called flow cytometer, which detects and counts cells with anchor protein deficiencies on the surface of cells in blood. If PNH is present, it is important to know how many cells are affected and to what degree (they can be partially or completely abnormal), because patients symptoms vary according to these parameters. A new reagent, called FLAER, allows the detection of cells missing the critical anchor proteins in PNH patients and is widely used in the detection and counting of abnormal cells in blood.
Why study the marrow in patients with PNH?
In many patients with AA and MDS, we often detect PNH cells in the blood. In these patients, we plan to determine which marrow cells and how severe, they are affected. Using the power of flow cytometer in recognizing distinctive types of cells, we will use FLAER to study the presence and distribution of anchor proteins in the various populations of cells residing in the human marrow, in normal individuals and in patients with PNH. This information should provide unique insights into the biology of PNH and may help diagnosing PNH in patients with cytopenias in whom marrows are examined for diagnostic purposes without a clinical suspicion of PNH. Furthermore, since cells in both, normal or diseased marrows actively proliferate and many naturally die, we plan to measure the fraction of normal and PNH cells undergoing cell division and cell death in the same marrow. We expect that this information would allow us to predict changes in PNH clonal size over time that should have clinical relevance.
In the category of aplastic anemia, Kate MacNamara, Ph.D., Assistant Professor, Albany Medical College, received an award for her project: Macrophages in the Pathogenesis of Aplastic Anemia.
Bone marrow failure is the rare but devastating collapse of blood production, and if left untreated the disease is invariably fatal. Our current therapies are inadequate in the sense that they involve general immunosuppression or highly invasive treatments via bone marrow transplantation. In both genetic and acquired cases of bone marrow failure, excessive inflammation ultimately causes destruction of the stem cells required to maintain daily production of all blood cells. Inflammatory molecules such as interferon gamma (IFN-gamma) are known to contribute to pathology, yet exactly how stem cell function is compromised by these factors is not clear and remains an important question in understanding the pathogenesis of bone marrow failure.
We utilized a mouse model of bone marrow failure to investigate the mechanisms whereby IFN-gamma drives hematopoietic failure. We made the unexpected observation that IFN-gamma signaling in stem cells themselves was not required for the loss of blood stem cells. We identified macrophages, key phagocytic cells of the immune system, as the direct targets of IFN-gamma in driving the decline of stem cells during bone marrow failure. Ablation of the macrophage population during disease preserved stem cell function and prevented death caused by hematopoietic failure. Preventing IFN-gamma signaling exclusively in macrophages was also able to rescue disease. Our observation was particularly striking because we observed similar numbers of activated T lymphocytes and similar levels of pro-inflammatory cytokines, including IFN-gamma, in mice with severe disease, relative to those rescued through manipulation of the macrophage population. We identified one factor, the chemokine CCL5, to be selectively increased during severe disease in manner that required both macrophages and IFN-gamma. Neutralization of this factor was able to rescue the loss of hematopoietic stem cells seen during aplastic anemia. Thus, we have revealed a previously unknown mechanism whereby IFN-gamma and macrophages contribute to hematopoietic failure. Here we propose to investigate further how macrophages and CCL5 contribute to aplastic anemia. Our ultimate goal is to identify novel pathways that can be targeted to rescue hematopoiesis in patients with bone marrow failure.
For work in aplastic anemia, Simona Pagliuca, MD., University "Federico II" Naples, Italy received an award for the project: Impact of Eltrombopag treatment in combination with immunosuppression on immune derangements of aplastic anemia: (translational) research from the randomized EBMT race study.
Aplastic anaemia, is a rare disease in which the bone marrow and the hematopoietic stem cells that reside there are damaged. This causes a deficiency of all three blood cell types (pancytopenia): red blood cells (anemia), white blood cells (leukopenia), and platelets (thrombocytopenia). If untreated, this disease has a high risk of death. Research of last decades characterize aplastic anemia as an immune disorder in which aberrant immune effector are directed against hematopoietic stem cells. That is the reason why main treatment approaches of this disease concern allogeneic hematopoietic stem cell transplantation and immunosuppressive therapy based on two drugs: "cyclosporine" and "anti-thymoglobuline".
Unfortunately not all patients are eligible to transplantation and standard therapies have a risk of recurrence of this disease.
In 2014 the experimental study named RACE has been approved to try to improve the results of standard therapy, by association with an other drug, called "eltrombopag". Researchers want to answer a simple question: Which is the best treatment for patients with a diagnosis of aplastic anemia? cyclosporine and anti-thymoglobuline or cyclosporine, anti-thymoglobuline + eltrombopag? So patients accepting to participate to this study will be assigned by chance to one of the two groups and treated accordingly.
However this study is not merely “clinic”: it includes also a research laboratory part concerning a biological intention: to study the immune defect existing in patients with aplastic anemia and to define the biological response after each treatment. Our work is centred on this part of the study. We will perform the prefixed objectives by analysing blood and marrow samples of patients participating to the study and giving their consensus to the research. We will expect that the normal immunological background seeing in a healthy subject could be entirely devastated in an aplastic anemia patient, and that the peculiar immunological profile of those patients could predict the response to the treatment. We are also confident that both standard immunosuppressive treatment and experimental eltrombopag-associated treatment could regulate the immunological dysfunction in different ways. In this context experimental treatment is expected to give a more promising immune-modulation, restoring damaged hematopoietic stem cells in a shorter laps.
In the category of MDS, Yoshimi Akihide, M.D., Ph.D., Visiting Investigator, Memorial Sloan-Kettering Cancer Center received an award the project: Modulation of Splicing Catalysis in the Therapy of Myelodysplastic Syndrome with Spliceosomal Mutations.
Myelodysplastic syndromes (MDS) are a heterogeneous group of disorders characterized by inefficient blood production. MDS represents the most common cause of acquired bone marrow failure in adults and there are few effective therapies for the majority of MDS patients. In 2011, it was discovered that mutations in proteins encoding RNA splicing factors (SFs) are the most common class of mutations in patients with MDS and chronic myelomonocytic leukemia (CMML). Despite these discoveries, however, we do not yet fully understand why abnormal RNA splicing results in MDS nor do we have therapies that specifically target MDS cells bearing this common class of mutations. The goals of this proposal are two-fold: (1) to determine the efficacy of clinical-grade novel spliceosome inhibitors in splicing factor-mutant versus wildtype MDS and CMML models and (2) to determine the mechanistic basis for the therapeutic efficacy of spliceosomal inhibitory compounds in more detail. We hypothesize that the presence of any of the commonly occurring SF mutations found in myeloid malignancies will sensitize cells bearing these mutations to further perturbation of spliceosome function. To accomplish our goals and test these hypotheses, we propose to use novel patient-derived xenograft (PDX) models of MDS and CMML as well as isogenic cells with and without SF mutations. We will then use these models to understand the specific mechanisms for the therapeutic efficacy of a novel spliceosome inhibitor with immediate clinical potential.
The innovative aspects of this proposal include the use of novel PDX model of MDS and CMML. Our preliminary data highlight the applicability of this xenograft model to MDS and CMML. We expect our research to further our understanding of how MDS develops, and ultimately to lead to the identification of new drugs and therapeutic approaches for treating MDS. If successful, this proposal could have tremendous therapeutic impact for patients with bone marrow failure due to MDS.