Grant: 1350-18 | Career Development Program (CDP):
Location:Brigham and Women’s Hospital, Boston, Massachusetts 02241-3149
Project Title: Enhancing The Clonal Selectivity Of Current Drug Therapies In Myeloproliferative NeoplasmsProject Summary:
The objective of my proposal is to develop better treatments for patients with a group of blood cancers called myeloproliferative neoplasms (MPN). There are currently no curative treatment options for MPN apart from stem cell transplantation, which is a high-risk and sometimes life-threatening procedure.
None of the currently available drug treatments for MPN can cure the disease. They can only improve the symptoms. In 2011, the Food and Drug Administration approved a new type of drug treatment for MPN, called JAK2 inhibitors. With the approval of JAK2 inhibitors, MPN patients and their doctors had high hopes that these drugs would have the ability to change the course of MPN, rather than just control symptoms. Unfortunately, JAK2 inhibitors have disappointed in this regard, and although useful at controlling MPN-related symptoms, they cannot eradicate the disease or prevent it from turning into leukemia. In view of this, we are asking the following questions: (1) Why are JAK2 inhibitors not as effective in the treatment of MPN as was initially hoped? (2) What are the mechanisms by which MPN patients are resistant to JAK2 inhibitors? (3) What novel drug targets, if also inhibited, could make JAK2 inhibitors more effective?
We propose to identify (i) the genes that confer resistance to JAK2 inhibitors and (ii) the genes that when inhibited increase the efficacy of JAK2 inhibitors. We plan to do this using a new technology called CRISPR gene editing. With this powerful technique we can target every gene in the human genome in a completely unbiased fashion to identify the genes that underlie JAK2 inhibitor treatment failure. The goal of this work is to identify the “Achilles heel” in MPN cells treated with JAK2 inhibitors and to target this to eradicate MPN. The benefits are the development of potentially curative treatments for MPN. This study will significantly advance the field of blood cancer research through the development of personalized anti-cancer treatment approaches (i.e. precision medicine) and improve the treatment options for MPN patients.
Grant: 3370-18 | Career Development Program (CDP):
Location:Boston Children's Hospital, Boston, Massachusetts 02241-4413
Project Title: Mechanisms Of Orientation-specific RAG Activity In Mediating V(D)J Recombination And Promoting B Cell LymphomaProject Summary:
A properly functioning human immune system recognizes disease-causing pathogens via a diverse set of antibodies and T cell receptors (TCRs). These molecules, expressed in a subset of white blood cells termed B and T lymphocytes, can bind pathogens and initiate an immune response. The enormous diversity of antibodies and TCRs is generated by the development of lymphoid cells through a DNA “cut-and-paste” process termed V(D)J recombination. The genes encoding the components of the antibodies and TCRs are diversified by the “cutting” and “pasting” of different segments (V, D, and J). The cutting of these gene segments is executed by an enzyme called RAG. Though DNA breaks are required for normal immune development, they can be improperly joined to other DNA breaks across the genome to create mutagenic events that contribute to the development of cancer.
Restricting V(D)J recombination to specific chromosomal loops is critical to prevent RAG from escaping and breaking non-intended targets. Genes are contained in larger structures called chromosomes, which are organized within the cell in a series of large chromosomal loops. Chromosome-bound RAG moves directionally, like a train on a track, to locate its target gene cassettes and only stops when it encounters the roadblocks formed by the loop boundaries. We are studying the nature of the engine that moves RAG along the tracks and how normal RAG "tracking" generates diverse antibody repertoires and minimizes potential collateral damage that could lead to blood cancers. We will use genetically engineered cell lines and mouse models to investigate this process. Our research may provide insights into mechanisms that promote normal immune development and the mechanisms that prevent the potent mutagenic activity of RAG, causing unwanted chromosomal lesions underlying some blood cancers. Our over-arching goal is to identify mechanisms and pathways that suppress tumorigenic lesions in developing lymphocytes and to generate information that can potentially serve the development of new therapeutic targets for lymphoid cancers.
Grant: 1347-18 | Career Development Program (CDP):
Location:Sloan Kettering Institute for Cancer Research, New York, New York 10087
Project Title: Uncovering The Dysregulated RNA Binding Protein Network In Normal And Malignant HematopoiesisProject Summary:
Although molecular targeted therapy has dramatically changed how we treat cancer, the treatment for acute myeloid leukemia (AML) remains focused on the use of cytotoxic drugs with many patients eventually relapsing with their disease. One of the major drivers of resistance is the persistence of cells that retain the immature properties of stem cells. Cancer cells are made up of proteins expressed by the genes in the nucleus of the cell. Many RNA molecules comprise the information that is the intermediary between genes and proteins. An emerging focus of study is how these RNA molecules may be involved in disease processes. Our laboratory and others have identified that there are specific RNA binding proteins that regulate gene expression programs that are essential for the survival and immature state of acute myeloid leukemia cells. This network of RNA binding proteins is engaged in the most aggressive leukemias and predicts a poor outcome. We developed a screening strategy to identify other RNA binding proteins that contribute to the leukemic state. Using this novel approach, we identified an RNA binding protein called SYNCRIP that we found to be critical for myeloid leukemia and the response of leukemia patients to therapy. Our studies will further explore SYNCRIP’s role in genetic mouse models,human leukemia cell lines, and primary AML patient samples. We plan to understand the mechanism for the regulation of the dysregulated RNA binding protein network in leukemia and to develop therapeutic strategies for treating this aggressive and devastating disease.
Grant: 6551-18 | Translational Research Program (TRP):
Location:The Board of Regents of the University of Wisconsin System, Madison, Wisconsin 53715-1218
Project Title: Matrix Remodeling In The Myeloma Niche: Implications For Minimal Residual Disease And ImmunotherapyProject Summary:
Despite a revolution in the way we treat myeloma in the last 10-15 years, the disease remains incurable for the vast majority of patients. We have devised powerful novel agents and strategies that kill myeloma cells efficiently, yet not at 100%. Some residual cells remain even after the best of treatments and act as the “seed” from which the disease relapses and ultimately claims human lives. In the last 4-5 years, we have become much better at measuring this “minimal residual disease”. Ultimately however, we should not only recognize and size the enemy, we should eliminate it. The burning question therefore becomes: how are these remaining cells protected and shielded from harm? What is the best way to go after them?
We believe that the best strategy against residual myeloma cells is to mobilize the immune system to attack them. This is called “immunotherapy”. Immunotherapy can be a powerful weapon against cancers because it is endowed with inherent specificity and “memory” (in a manner illustrated by how vaccines work): once the immune system recognizes the tumor as foreign and undesirable, it can keep it in check for long time- hopefully, for ever. However, only a small number of patients have so far benefited from cutting-edge immunotherapies that have seen the front page of the New York Times. Part of the reason is that tumors are very capable at putting up bulwarks that fend off the immune system’s “killer” cells. New immunotherapies, such as drugs called “checkpoint inhibitors” work to remove the “brakes” from the immune killer cells. Still, they do not work for all patients.
Our approach is to “breach the bulwarks” that tumors put up to ward off the immune-killer cells. Once the defenses are gone, immunotherapy-mobilized killer cells have a better chance to work. We recently found that a component of the bone marrow environment in which myeloma cells and immune cells interact with each other is a “double-agent”. The “double-agent” is a bone marrow matrix component called versican. In its intact form, versican helps the myeloma tumor cells by neutering the immune system. However, in many cases, a bit from versican’s end (called “versikine”) gets broken off by specialized enzymes, called ADAMTS proteases. Versikine then stimulates the immune system to fight myeloma cancer cells. In other words, versikine (the “daughter” molecule) antagonizes versican (the “mother” molecule). The current proposal aims to investigate the role of versican and versikine in mobilizing the immune system to attack myeloma cells. Tipping the versican-versikine balance may provide powerful marching orders to anti-myeloma immune fighter cells.
Grant: 6528-18 | Translational Research Program (TRP):
Location:Board of Trustees of the Leland Stanford Junior University, San Francisco, California 94144-4253
Project Title: Identifying Relapse Associated Populations At Diagnosis In LeukemiaProject Summary:
Despite high rates of initial response to frontline treatment in many human cancers, mortality largely results from relapse or metastasis. Diverse clinical outcomes occur because all cells within a given tumor do not possess the same behavior or response to therapy. Although there is debate as to whether resistant populations of cancer cells are present at the time of initial diagnosis or whether these traits develop under the pressure of therapy, many studies have suggested that it is the former. Remission, by definition, is the reduction of cancer cells to undetectable levels. Consequently, if cellular populations predictive of relapse exist at diagnosis, it is reasonable to assume that these cells are a minority of the bulk tumor cells. In order to uncover these key populations, it is required to study cancer at the single cell level. Following this reasoning, we propose to perform analysis of primary leukemia cells at diagnosis by examining over 40 proteins on individual cells from patients with B-cell progenitor acute lymphoblastic leukemia (BCP-ALL), the most common leukemia of childhood. The goal of this research is to identify cells associated with relapse at the time of diagnosis. By identifying such populations, we may begin to understand how these cells survive treatment and cause later relapse. In order to organize diverse single-cell data from many primary patient samples, we will use a tool to match each leukemia cell to it's most similar healthy B-cell population. This allows us to compare leukemia cell subsets across patients.
We have optimized this approach in an early study and have identified specific populations of immature B-cells present at diagnosis which are predictive of relapse by applying advanced computational approaches to this single-cell data. This letter of intent outlines a proposal to extend our initial studies using this approach to validate the proposed cellular population which confers relapse risk and to understand how these cells are treatment resistant. To do so, we propose the following efforts:
1. Validate our relapse prediction model in a large cohort of pediatric patient samples and determine if the same cells exist in adult B-cell progenitor acute lymphoblastic leukemia (BCP-ALL) diagnostic samples
2. Determine if primary treatment-resistant cells, taken from patients early in therapy, are similar to the cells we have identified to be predictive of relapse
3. Determine if treatment resistant cells are better suited to grow in commonly used models of BCP-ALL
This proposal presents a novel approach to bring single-cell studies combined with advanced computational approaches to improve outcomes for patients with BCP-ALL.
Grant: 6546-18 | Translational Research Program (TRP):
Location:Boston Children's Hospital, Boston, Massachusetts 02241-4413
Project Title: Deciphering Epigenetic Cross-talk In Diffuse Large B-cell LymphomaProject Summary:
With an estimated 73,000 new cases of non-Hodgkin lymphoma (NHL) and 20,000 deaths in the year 2016 alone from NHL, novel therapeutic strategies are urgently required. Specifically, the diffuse large B-cell lymphoma (DLBCL) is the most common form of NHL, and contributes about 30% of new NHL diagnosis every year. Our interest in blood biology, and its mis-regulation is several blood disorders including blood cancers, led us to investigate the role of chemical modifications on one of the most fundamental proteins of like- the histone proteins. We investigated if various histone modifications would be critical for the survival of DLBCL cells. Interestingly, we discovered a unique chemical that specifically abrogates the survival of DLBCL cells but not of any other type of blood cancer cells. We have found that cells commit ‘suicide’ after treatment with our chemical, using a very specific pathway. Furthermore, we have identified a key protein responsible for gene regulation as a likely target of our chemical. This novel target is highly expressed in DLBCL patients, who fare worse after the standard-of-care therapy for DLBCL. Additionally, by performing high throughput gene expression studies, we have identified a completely unique mechanism that bypasses three very frequent mutations found in DLBCL patients, and also explains why our chemical is not very effective against cells that are not coming from DLBCL patients. In essence, we have identified a histone modification pathway that when manipulated kills multiple types of DLBCL cells, but not other types of hematological cancers. We will employ cutting-edge molecular and cell biology, biochemistry, and mouse genetics to carry out specific aims that will a) establish the novel mechanism that allows DLBCL cells to survive. b) Establishes our chemical as a potent strategy against DLBCL through experiments conducted in mouse and c) reveal new details about how histone modifications regulate the formation, and development of B and T cells in humans.
Grant: 6533-18 | Translational Research Program (TRP):
Location:Sloan Kettering Institute for Cancer Research, New York, New York 10087
Project Title: Chemotherapy-Free Targeted Therapeutic Approaches For New And Relapsed Hairy Cell LeukemiaProject Summary:
Classic hairy cell leukemia (cHCL) is a relatively rare form of adult blood cancer that causes massive enlargement of spleen and low white blood, red or platelet cell count. It remains incurable despite high initial response rates to DNA-damaging chemotherapy such as cladribine and pentostatin, and 40% of the patients will experience recurrent disease. In order to develop an effective personalized treatment in these patients, our group previously conducted a clinical trial studying the safety and efficacy of the oral drug called vemurafenib specifically targeting the BRAFV600E mutation that is known to occur in almost all patients with cHCL. In that study, we observed a remarkable overall response rate of 96% in cHCL patients who have failed chemotherapy or experienced recurrent disease. However, we also observed key limitations from the study: 1) vemurafenib alone failed to eliminate all leukemic cells from the bone marrow; 2) disease relapsed in over 30% of the patients; and 3) some patients developed resistant disease, no longer responsive to vemurafenib. These limitations were partly addressed by another recent study that showed adding antibody targeting CD20 called rituximab to vemurafenib significantly improved response rates and more effectively eliminated leukemic cells from bone marrow in patients with relapsed cHCL. However, this promising combination has not been studied in untreated patients who would otherwise receive chemotherapy. Furthermore, vemurafenib is not effective in patients with the related disease called HCL variant (HCLv) and high-risk cHCL that does not carry the BRAFV600E mutation. These disease subtypes tends to be more aggressive, respond poorly to standard therapies, and very little is known about the disease biology. While HCLv does not carry the BRAFV600E mutation, it frequently carries MAP2K1 (MEK1) mutations that may be treated by another oral drug inhibiting its downstream target called ERK. Based on the above findings, we believe that (1) the BRAF inhibitor, vemurafenib, plus a potent CD20-specific antibody, obinutuzumab, will be more effective in eliminating leukemic cells from bone marrow, resulting in more durable responses in patients with previously untreated BRAFV600E+ cHCL and (2) ERK inhibition may be a novel and safe targeted therapy for HCLv and cHCL without the BRAF mutation. Therefore, we propose to develop a comprehensive clinical and laboratory program to study rational, chemotherapy-free, targeted therapeutic approaches in all subtypes of HCL for both untreated and relapsed patients. To this end, we will perform a phase 2 clinical trial of vemurafenib plus obinutuzumab in untreated BRAFV600E+ cHCL patients and, in parallel, a phase 1 clinical trial of the ERK inhibitor BVD-523 in patients with HCLv and relapsed cHCL. In addition, we will perform studies involving mouse models and comprehensive genome profiling of patient samples to understand treatment responses and disease biology.
Grant: 3371-18 | Career Development Program (CDP):
Location:The University of Chicago, Chicago, Illinois 60637
Project Title: Single-cell Technologies To Dissect 5hmC And 5mC Heterogeneity In Normal And Malignant HematopoiesisProject Summary:
Blood cells arise from stem cells found in our bone marrow. Through a process called differentiation, stem cells develop into the diverse blood cell types with their various functions. Cells of the same blood subtype are often thought of as homogeneous populations, but this extreme simplification imposes limitations on our ability to understand normal and malignant blood cells. Therefore, it is critical to understand the more complicated reality of blood cell diversity. Our laboratory is devising cutting-edge strategies to map normal and diseased blood stem cells and differentiated cells in both healthy and diseased situations. These approaches will allow a better understanding of the differences among cells types, within subtypes, and in different pathological contexts, which will provide the basis for therapeutic approaches in the future.
DNA is the molecule that codes for proteins that help provide the functional attributes of cells. DNA is often changed by a process called epigenetic modification. One common form of epigenetic modification is DNA methylation, which can come in different forms, such as 5mC and 5hmC, and can occur at a large number of places in the billions of building blocks of DNA. We hypothesize that a critical component of understanding the identity and function of a cell, whether healthy or diseased, is in the precise characterization of the complex DNA methylation pattern within each single cell. However, stem cells and cells of various differentiated blood cell subtypes are often found in limited numbers. Therefore, the ability to measure 5mC and 5hmC in various cell types, and at a single cell-level, is essential for a more complete understanding of normal and diseased blood cells.
Our single-cell 5hmC/5mC profiling approach will allow us to identify leukemia-specific, differential methylated regions that could harbor known and novel disease-specific target genes, providing quantitative information to precisely reveal methylation changes during normal and leukemic blood cell development. Ultimately, this research will bring us closer to understanding how acute myeloid leukemia develops and how dysregulation of methylation contributes to this process. Our approach will identify promising ways of targeting leukemia cells, facilitating the treatment of this deadly disease.
Grant: 5472-18 | Career Development Program (CDP):
Location:British Columbia Cancer Agency Branch, Vancouver, British Columbia V5Z 1L3
Project Title: Roles Of MicroRNA MiR-146a In Hematopoietic Stem Cell FunctionProject Summary:
Myelodysplastic syndrome (MDS) is a cancer of blood stem cells, the blood-forming cells in the bone marrow. In MDS, cancerous blood stem cells lose the ability to make blood cells, and can also block the function of the remaining normal blood cells. Aging and environmental factors are associated with developing MDS, but how these processes affect the function of both cancerous and coexisting normal blood stem cells in MDS remains poorly understood. Few treatments are available for MDS, and treatment resistance develops in most patients; therefore, understanding the molecular mechanisms that disrupt blood stem cell function in MDS is critical for improving patient outcomes.
I aim to study the molecular mechanisms affecting the function of coexisting cancerous and normal blood stem cells in a mouse model of MDS. I will focus in particular on a subtype of MDS that lacks the gene miR-146a, as we have found that miR-146a deletion in a mouse model causes aggressive MDS symptoms with severe defects in blood stem cell function. To better recreate the bone marrow of MDS patients in which normal and mutant cells coexist, I will co-transplant equal amounts of normal bone marrow with miR-146a-deleted bone marrow, and study the function of both cancerous (miR-146a deleted) and normal (miR-146a intact) blood stem cells. Our data suggest that miR-146a deletion activates inflammation, increases cellular aging, and disrupts energy metabolism in blood stem cells. I will use chemical and genetic strategies to manipulate inflammation, aging pathways, and energy metabolism, with the hope of reversing the dysfunctions of cancerous and normal blood stem cells in this mouse model.
This research will provide the first evidence as to whether drugs targeting inflammation, aging pathways, or energy metabolism may be useful additions to current treatment regimens for MDS. As few effective long-term treatments are available for MDS, my research may one day improve the prognosis for patients with MDS.
Grant: 2317-18 | Career Development Program (CDP):
Location:Washington University in St. Louis, St. Louis , Missouri 63130
Project Title: Targeting Leukemia Stromal Interactions In T-ALLProject Summary:
T-cell acute lymphoblastic leukemia (T-ALL) is a subtype which comprises about 20% of all cases of acute lymphoblastic leukemia. T-ALL is a particularly rare disease in adults, with only about 600 new cases per year in the United States. Furthermore, the prognosis of adults is poor; only 40% of adults with T-ALL are cured with current treatments.
Our laboratory work has demonstrated that T-ALL cells interact with normal cells present in their local environment (called the “microenvironment”), which provides key signals that regulate tumor growth and survival. Our research has focused on a specific protein, CXCR4, which is present in T-ALL cells. In T-ALL, the tumor microenvironment provides a potent growth and survival signal, which is mediated by CXCR4, to T-ALL.
We hypothesize that it is possible to disrupt this tumor-microenvironmental interaction as a means to treat T-ALL patients. We will disrupt the key survival signal to T-ALL cells using a novel inhibitor of CXCR4 known as BL-8040. We are currently conducting a multicenter study to combine BL-8040 treatment with chemotherapy in patients with T-ALL that has relapsed or is refractory to standard treatments. As part of this study, we will test blood and bone marrow samples from patients after treatment to determine the effects of BL-8040 on leukemia cells. We will also conduct additional preclinical studies to test the effects of new combinations of drugs to improve the effectiveness of BL-8040. The overall goal of this project is to target tumor-microenvironment interactions to improve the outcomes of patients with T-ALL.