Grant: 5470-18 | Career Development Program (CDP):
Location:Board of Trustees of the Leland Stanford Junior University, San Francisco, California 94144-4253
Project Title: Dissecting The Topological Consequences Of Mutations In The Cohesin Complex And Their Contribution To Human Leukemia Initiation And Progression.Project Summary:
The human genome is exquisitely organized, packing five feet of DNA into a microscopic nucleus. This level of compaction requires an equally impressive level of organization. Not only does the DNA have to fit into such a tiny space; the genes required for the cell’s function must be properly expressed with high fidelity. To accomplish this seemingly insurmountable task, the genome is organized into a cascading series of loops whose formation is mediated by a multi-protein complex called the cohesin complex. This complex forms a ring-like structure that holds the ends of each loop together much like the clasp of a necklace. Recently, mutations in the cohesin complex have been identified as major drivers of acute myeloid leukemia initiation and progression. With such an important basic cellular function as the organization of DNA, it remains of vital importance to understand how mutations in the cohesin complex mechanistically cause leukemia and to identify avenues for therapeutic intervention.
Of the core components of the cohesin complex, the STAG2 gene is the most frequently mutated and is often lost altogether. Using state-of-the-art technologies, we will study how the composition and function of the cohesin complex changes in the context of a loss of the STAG2 protein. These technologies include the ability to map the three-dimensional organization of the genome, enabling us to study how the DNA loops that are orchestrated by the cohesin complex are disrupted in AML. These molecular and mechanistic studies will be accompanied by genetic and pharmacologic screening to identify putative therapeutic targets. Ultimately, this research will bring us closer to understanding how acute myeloid leukemia develops and how dysregulation of genome organization contributes to this process. We hope that our work will identify promising drug targets and facilitate the treatment of this otherwise deadly disease.
Grant: R6509-18 | Translational Research Program (TRP):
Location:University Health Network, Toronto, Ontario M5G 1Z5
Project Title: Phase I Study Of Allogeneic Double Negative T Cells In Patients With High Risk AMLProject Summary:
Acute Myeloid Leukemia (AML) is a cancer affecting the bone marrow that requires intensive chemotherapy for disease control. This may be associated with significant toxicity. Treatment for AML aims to destroy the leukemia cells and allow the bone marrow to work normally again. Chemotherapies help most AML patients to achieve a state of remission in which the leukemic cells have fallen to a very low level and normal blood cell production has returned. However, despite decades of using chemotherapy to treat AML patients, there continues to be a very high chance of the disease coming back as the cancer cells develop resistance to chemotherapies. Once the disease comes back, few treatment options are available to patients. Consequently, overall survival is about 40% for those <50 years of age and is significantly worse for older patients. Thus, new treatments that are effective at targeting chemotherapy-resistant AML with low toxicity are needed for this unmet challenge.
Double negative T cells (DNTs) are a type of white blood cell in the blood that has the ability to selectively kill cancer cells while sparing normal cells and tissues. In peripheral blood, DNTs are quite rare. To be of value in the treatment of cancer it is necessary to have large numbers of these cells. We have developed methods in the laboratory to grow DNTs from healthy volunteers to large numbers and have shown that these DNTs have potent anti-leukemia effect without detectable toxicity on normal cells and tissues in animal models. In this first-in-man clinical trial, DNTs will be obtained from healthy donors and expanded (increased in numbers) in the laboratory, in order to enhance their tumor destroying potential. In addition, the most potent DNT donor will be selected for each patient by screening before his/her DNT treatment. DNTs will be administered at 3 different dose levels (different numbers of DNT cells) into 3 different groups of patients. After infusion of the first (lowest cell number) dose level, patients will be monitored to make sure they do not experience any severe adverse side effects. Only after the confirmation of the safety of the previous dose, the next group of patients will be given the next dose (higher cell number). In addition to determining the safety of DNT treatment, we will take blood samples from the treated patients at several time points after infusion to assess how long the DNT cells are detectable in the patients, which will provide guidance on the optimal number of injections and the time between each injection required to achieve the best results. In addition, we will determine if infusion of DNT cells changed the amount of time for the patients’ immune cells to recover from chemotherapy. Furthermore, whether DNT treatment will decrease AML cells and reduce the rate of the disease returning will be monitored. The results from this study will indicate whether DNTs can be safely used as a new treatment for AML to save patient lives.
Grant: 6547-18 | Translational Research Program (TRP):
Location:The University of Adelaide, Adelaide, South Australia 5000
Project Title: Targeting Stromal Cell-derived Gremlin1 To Control Multiple Myeloma Disease DevelopmentProject Summary:
Multiple myeloma (MM) is a bone marrow (BM) cancer of antibody producing plasma cells (PC). MM PCs are thought to spread throughout the BM in a manner similar to the way in which solid tumours spread. However, which cells and/or factors within the BM are important in helping PCs establish and grow, remains largely unknown. Using newly developed microscopic and genetic marking techniques: we have shown that there are very few sites within the BM that are capable of supporting the growth of PC tumours. In fact, we have found that the majority of the PCs that migrate to, and “land” in the BM remain “dormant” and fail to grow. These findings suggest that in order to grow, MM PCs must encounter an environment that has the right type of cells and factors, which support their growth. We believe that a rare type of cell, called an osteochondroreticular stem cell (OCR-SC), which we recently discovered, plays an essential role in “switching on” the growth of MM PC. OCR-SCs are unique in their ability to make a protein called Gremlin 1 (Grem1), which has been shown in other types of cancer, to stimulate tumour growth. Our early studies show that Grem1 can potently stimulate MM PC growth and that very high levels of Grem1 are found in areas of the BM that are occupied by tumour. We have assembled a team of experienced researchers with unique skills and established relationships with industry to enable us to investigate whether inhibiting Grem1 activity can provide a way to limit the growth of MM PC and prevent MM disease development.
1. We will use a technique known as laser scanning cytometry (LSC) and BM samples from patients with a asymptomatic forms of MM known as monoclonal gammopathy of unknown significance (MGUS) or smouldering MM (SMM) and samples from patients with MM, to determine whether Grem1-expressing cells are found in areas of active tumour growth, and not in areas in which the PC remain dormant. Similarly, we will use LSC to examine the bones from mice in which we have induced a MM-like disease to show that Grem1-expressing OCR-SCs are a key component of the “activating” areas of BM which support MM PC growth.
2. We will use genetically altered mice, in which Grem1 has been removed from OCR-SCs, to show without doubt, that Grem1 is required for the growth and development of MM. In addition, we will inject an antibody that blocks the function of Grem1 into mice with MM, to see if this will lead to MM PC tumour death or dormancy. These studies will be the first important steps to see if Grem1 is a good therapeutic target to stop disease development in MM patients.
3. We will measure the levels of Grem1 in the blood in a large number of samples that we have collected from patients with MGUS, SMM or MM. This will allow us to determine if Grem1 levels are associated with the amount of disease a patient has, or whether Grem1 levels predict the risk of a patient with benign disease developing advanced disease.
Grant: 6538-18 | Translational Research Program (TRP):
Location:The Ohio State University, Columbus, Ohio 43210
Project Title: Novel Strategies For The Therapy Of Genomic High Risk CLLProject Summary:
Cancers such as chronic lymphocytic leukemia (CLL) are characterized by a slow accumulation of a specialized kind of white blood cell called a B-lymphocyte. It starts in the bone marrow and spills over to accumulate in the blood, lymph node, liver and spleen. The reason CLL is problematic is that the leukemic B-cells are non- functional and live for a long time either because they have proteins that help them survive for a long time or lose proteins that normally would cause them to die.
CLL undergoes changes in its genes. For instance, it often loses a very important gene called p53. p53 is called the guardian of the genome and is necessary to kill the CLL cells after treatment with drugs. Every cell of the body has two copies of this gene. In CLL, one copy of p53 is lost due to deletions and the other copy sometimes gets altered by mutations. The mutated p53 supports the survival of the CLL cells and help the disease become resistant to treatment. Both deletions and mutations of p53 have been found to decrease survival in patients whose CLL cells carry these abnormalities.
Mutated p53 depends on HSP90, a protein that binds to mutated p53 and helps it carry out its cancer supporting function. One of the key functions of mutated p53 is to block the cell death inducing action of normal p53 and in addition activate other genes that support CLL cell survival. We plan to use drugs that stop the action of HSP90 (HSP90i). Blocking HSP90 will prevent it from stabilizing mutated p53 and cause it to be destroyed, which in turn, will kill CLL cells that carry deletions or mutations of p53. Therefore, HSP90i treatment may represent a new treatment that can treat this poor prognosis group of CLL patients (del17p/mutant p53) either alone or in combination with drugs such as ibrutinib that are currently in use used to treat the disease.
Grant: 6553-18 | Translational Research Program (TRP):
Location:IRIC - Institut de Recherche en Immunovirologie et en Cancerologie, Montreal, Quebec H3C 3J7
Project Title: RUNX1 Mutations That Confer Exquisite Sensitivity To GlucocorticoidsProject Summary:
Acute myeloid leukemia (AML) is a disease caused by several genetic alterations, including mutations in the RUNX1 gene. The presence of RUNX1 mutations in AML cells is generally associated with bad prognosis for these AML patients, and RUNX1 mutations are also the cause of Family platelet disorder, which predisposes these patients to AML development. In order to discover novel cures for patients suffering from RUNX1-mutated AML, we identified glucocorticoids as effective drugs that kill AML cells carrying RUNX1 mutations. In this proposal, we plan to perform experiments to better understand how these molecules kill these AML cells and test the ability of GCs to cure mice that we will engineer to develop AMLs harboring RUNX1 mutations, in the hope of bringing this discovery to the clinic to improve treatment of patients suffering from RUNX1- mutated AML.
Grant: 5471-18 | Career Development Program (CDP):
Location:Harvard Medical School, Boston, Massachusetts 02241-5649
Project Title: Studying The Function Of Co-activator MAML1 In Notch-associated T-cell Acute Lymphoblastic LeukemiaProject Summary:
Normal cell growth and differentiation relies on a small number of signaling pathways that direct the gene expression patterns unique to each cell type. One pathway particularly important in cell-cell communication is the Notch pathway, which normally relies on direct contact between a signal-sending cell and a signal-receiving cell. After the signal is activated, a portion of the Notch protein enters the cell nucleus and forms a complex with two other proteins, called RBPJ and MAML1, to regulate the expression of genes that control cell growth and cell fate decisions. Aberrant activation of the Notch pathway by mutations, however, leads to the development of T cell acute lymphoblastic leukemia (T-ALL). In fact, Notch1 mutations are found in more than half of all human T-ALL cases. The goal of my project is to understand how the MAML1 gene cooperates with Notch to induce the production of Notch-responsive genes. In one line of study, I will use a Notch inhibitor to toggle the Notch pathway between “on” and “off” states, and determine what protein partners MAML1 chooses in the “Notch active” state and how these partnerships affect its function. I will also analyze the temporal sequence of events that take place in the nucleus after Notch is switched on in leukemic cells, focusing on the role of MAML1 in the induction of target gene expression. These studies will help us understand how Notch and MAML1 cooperate to stimulate aberrant gene expression in leukemic cells and may lead to new strategies for therapeutic development in T-ALL.
Grant: 1348-18 | Career Development Program (CDP):
Location:Northwestern University, Evanston, Illinois 60208
Project Title: The Role Of Plek2 In The Pathogenesis Of Myeloproliferative NeoplasmsProject Summary:
Myeloproliferative neoplasms (MPNs) are a group of bone marrow diseases with overproduction of mature blood cells and increased risk of evolving to acute leukemia. A specific mutation on one of the blood cell surface proteins called Jak2 is the leading cause of this group of diseases. The discovery of this mutation led to the development of inhibitors specifically targeting Jak2. However, these inhibitors are not curative. In addition, MPN patients treated with these inhibitors often develop drug resistance and significant side effects due to the indispensable roles of this blood surface protein in normal blood production. We have been studying new approaches to treating MPNs, especially focusing on the proteins that are important for the development of MPN disease but not essential for normal blood cells. We identified one of these proteins, Plek2, which a part of normal red blood cell development but may also be involved in the disease state in some MPNs. Our studies using mouse models and tumor cell lines demonstrated that Plek2 is critical for the MPN disease development and is a mediator of Jak2 signaling. In addition,mice that lose Plek2 do not exhibit obvious side effects. These novel discoveries made Plek2 an attractive drug target for the treatment of MPNs. The overall goal of my research is to better understand how Plek2 reverts the disease progression in MPNs using mouse models and bone marrow cells from MPN patients. We will analyze how Plek2 mediates Jak2 signaling as well as how Plek2 may be involved in other MPN mutations, such as CALR and MPL. Successful completion of this project will lay the foundation for targeting Plek2 as a novel therapeutic approach for the clinical management of MPNs.
Grant: 3375-18 | Career Development Program (CDP):
Location:Fred Hutchinson Cancer Research Center, Seattle, Washington 98109-1024
Project Title: Enhancing Adoptive Immunotherapy Of AML With Engineered T Cells By Expressing Immunomodulatory Fusion Proteins That Overcome Inhibitory SignalsProject Summary:
Acute myeloid leukemia (AML) is the most common acute leukemia in adults and has the worst survival rate of all leukemias, with only 26% of AML patients surviving 5 years. Since our immune cells can have the ability to eradicate tumors, immunotherapeutic approaches are being developed as treatment options with the goals of providing better efficacy and fewer side effects. One form of immunotherapy is adoptive immunotherapy, which provides an opportunity to genetically modify T cells to recognize and destroy tumors and generate a population of memory cells that can serve as a “living drug.” We identified a T cell receptor (TCR) that recognizes and tightly binds WT1 – a well-validated protein that promotes the cancerous activity of tumors – and observed clinical activity in patients with T cells modified to express this TCR. However, tumor cells can express inhibitory proteins that block activation of the T cells that recognize the tumor and thereby avoid immune-mediated eradication. To overcome this inhibition and further enhance efficacy, we engineered immunomodulatory fusion proteins (IFPs)that combine a tumor-specific inhibitory receptor with a costimulatory signaling domain, essentially to replace a “brake” with an “accelerator” for the immune response. By this method, we have effectively targeted several inhibitory proteins, demonstrated that we can significantly improve T cell therapy in a mouse model of AML, and acquired initial evidence of function in human T cells. To obtain data needed to translate our findings into the clinic, we plan to assess safety and potential toxicity to normal tissues in mouse models with T cells expressing different IFPs targeting AML cells expressing the relevant proteins. We will also assess efficacy with human IFPs in human T cells targeting AML cells in mouse models. Our long-term goals are to validate this approach in clinical trials, advancing a novel, safe and effective T cell immunotherapy that ultimately will improve AML patient outcomes.
Grant: 8012-18 | Screen to Lead Program (SLP):
Location:H. Lee Moffitt Cancer Center & Research Institute, Atlanta, Georgia 30374-2801
Project Title: Rationally Designed Dual BRD4-Kinase Inhibitors For The Treatment Of Myeloid CancerProject Summary:
Current anti-cancer targeted drugs often fail due to ineffectiveness or drug resistance, suggesting alternative strategies are needed to develop effective therapies. We recently determined that certain drugs bind to and inhibit two different classes of proteins that play important roles in cancer. These two classes are called kinases and BET proteins, which have completely different functions in the cell. The general approach in drug discovery has been to optimize a single drug to target a single protein. Our identification of the dual inhibitory activity of BET-kinase inhibitors provides an opportunity to optimize inhibiting both targets with a single drug. To this end, we have developed drugs that exhibit improved kinase and BET inhibitor activity. The ability of these compounds to target multiple regulators of cancer may provide superior effectiveness against blood cancers that are known to require both targets of the drug. For example, one of the dual inhibitors targets the JAK2 kinase, which is a major driver of myeloid cancers. JAK2 kinase inhibitors, which have been designed to solely target kinase activity, have not been successful in patients due to ineffectiveness and drug resistance. As these cancer cells also require BET protein function, our dual inhibitors may improve effectiveness and prevent drug resistance, a concept support by our initial studies. This proposal is written to support our optimization and development of our lead compounds for blood cancers.
Grant: 5474-18 | Career Development Program (CDP):
Location:The University of Chicago, Chicago, Illinois 60637
Project Title: Transcriptional And Epigenetic Roles For β-catenin In The Genomic Instability And Oncogenic Transformation Of T-cell Leukemia/lymphomaProject Summary:
Cancer arises from changes in DNA, and these changes can come in various forms. In the case of leukemia and lymphoma, most have genomic instability, meaning the normal organization of DNA (the genome) is disrupted due to improper repairing of DNA breaks. DNA is organized into structures known as chromosomes, and changes to normal chromosomal structure is evidence of genomic instability in a cell. Chromosomal defects mark approximately 80% of T-cell leukemia and often involve the moving of cancer-causing genes to other chromosomes (translocation) into positions that switch them “on.” This instability of the genome is a continuous process and allows for selection of ever more aggressive and therapy-resistant tumor cells. Our protein of interest, beta-catenin, has very tightly controlled, low expression levels in normal cells; however, uncontrolled beta-catenin expression has been linked to genomic instability in cancer through mechanisms that remain unclear.
Previous work from our lab showed that uncontrolled beta-catenin expression causes mice to develop T-cell leukemia. These leukemias have genomic instability and chromosomal defects similar to those seen in T-ALL patients. The pattern of DNA breaks suggests that the excess beta-catenin impairs mechanisms (known as checkpoints) that ensure that DNA is replicated and repaired correctly. In fact, these mice have lower than normal expression levels of genes required for DNA checkpoints and repair. Based on observations of this model, I hypothesize that beta-catenin affects multiple levels of gene regulation to impair DNA checkpoints and repair. Beta-catenin controls transcriptional mechanisms of gene expression, which switch genes “on” or “off,” as well as epigenetic mechanisms, which change the shape of DNA to allow various kinds of gene regulators to interact. Using state-of-the-art genomic technologies, I will examine DNA checkpoint and repair mechanisms to understand both transcriptional and epigenetic changes that happen in cells with uncontrolled beta-catenin. I will also examine cells from leukemia patients to apply what I see in my mouse model to human disease.
Chromosomal defects are a driving force in cancer and reflect a fundamental failure of the checkpoints that maintain genome integrity. My goal is to increase our understanding of how beta-catenin controls these intricate cellular processes. My studies aim to identify novel strategies for the treatment of this complex blood cancer.