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: 1351-18 | Career Development Program (CDP):
Location:The Ohio State University, Columbus, Ohio 43210
Project Title: Understanding And Overcoming Resistance To Bruton Tyrosine Kinase Inhibitors In Chronic Lymphocytic LeukemiaProject Summary:
Chronic lymphocytic leukemia (CLL) is the most common adult leukemia and until recently was treated with therapies toxic to the patient. Our clinical and research team at The Ohio State University Comprehensive Cancer Center helped provide critical information which led to the FDA approval of ibrutinib, a less toxic targeted therapy. Ibrutinib inhibits the BTK protein, which is a protein that CLL uses for its own pathological survival. Ibrutinib shows remarkable clinical activity that is more durable than any therapy ever studied in CLL. Unlike some CLL treatments, ibrutinib can be given to all age groups, making it a more widespread therapy. Ibrutinib’s success should form the basis for its inclusion in even more effective combination therapies that may someday lead to a cure. Historical experience indicates that effective new therapeutics for CLL will also have a major role in treatment of non-Hodgkin lymphoma and autoimmune diseases.
While ibrutinib is effective for many patients, some develop resistance to this treatment. My research team seeks to determine predictive genomic factors that result in BTK inhibitor therapy resistance. We discovered that some patients acquire mutations that then confer resistance to ibrutinib. The large group of patients treated with ibrutinib, including our collection of samples from patients with resistance mutations, represents an invaluable resource to pursue pre-clinical and clinical work to identify more effective CLL treatments. Exploring the mutations and their associated signaling pathways (which we will continue to discover) will help us understand ways to overcome treatment-related resistance by either early recognition or, potentially, novel therapeutic approaches.
Our experiments use primary CLL cells from patients whom are seen by our clinical team. We are also using the most appropriate laboratory-based model available for understanding preclinical drug development and CLL biology. Our experimental approach will directly address the Leukemia & Lymphoma Society’s mission to cure blood cancer by discovering new potentially curative treatment strategies for CLL.
Grant: 3374-18 | Career Development Program (CDP):
Location:Brigham and Women’s Hospital, Boston, Massachusetts 02241-3149
Project Title: Functional Characterization Of The Mutant Calreticulin-MPL Interaction In Myeloproliferative NeoplasmsProject Summary:
Myeloproliferative neoplasms (MPN) are a group of rare blood cancers that occur when the body produces too many white blood cells, red blood bloods, or platelets. Though the overall prognosis for MPN tends to be favorable, more advanced forms of these diseases can lead to severe anemia, increased risk of blood clots, and transformation to leukemia. MPN were first described in 1951 by hematologist William Dameshek, but the underlying genetic cause of these diseases remained a mystery for over 50 years. In 2005, four different research groups simultaneously discovered that approximately 63% of MPN patients harbor mutations in the gene JAK2. This was a tremendous breakthrough in the MPN field and led to the development of the FDA-approved drug ruxolitinib (Jakafi), a compound that inhibits JAK2 activity, for the treatment of MPN. Despite this advance however, the causal genetic abnormalities in the remaining 40% of non-mutated JAK2 MPN patients remained unknown for nearly a decade thereafter. In 2013, two different groups performed sequencing experiments on blood cells from non-mutated JAK2 MPN patients, and found that the majority of these patients harbor mutations in the gene calreticulin (CALR). The CALR gene encodes a “housekeeping” protein that resides in the endoplasmic reticulum (ER) and ensures quality control of protein folding in the cell. We currently have an incomplete understanding of the mechanism by which CALR mutations transform normal blood cells to cause MPN.
Unlike normal CALR, mutant CALR is found near the cell surface. Our recent research has shown that the mutations enable an interaction with a cell surface receptor protein called MPL. We have further shown that this interaction leads to an activation of the JAK2 pathway. A central hypothesis from this research is that mutant CALR binds to proteins that it does not normally bind to, and some of these proteins may be essential for the oncogenic activity of CALR. Building on this work, we will utilize state-of-the-art technology to determine the proteins mutant CALR binds to in the cell that are not bound by normal, non-mutated CALR. Through this work, we hope to gain a comprehensive understanding of the protein partners with which mutant CALR interacts in the cell to drive disease development, which would ultimately inform new targets for therapeutic intervention. Ultimately, we hope that our work will lead to improved therapeutic strategies for MPN patients, particularly those who do not respond well to ruxolitinib and other existing treatments.
Grant: 5461-18 | Career Development Program (CDP):
Location:The Trustees of Columbia University in the City of New York, Columbia University Medical Center, New York, New York 10027
Project Title: The Role Of NOTCH1 Controlled Micropeptides In T-ALLProject Summary:
Acute lymphoblastic leukemia (ALL) is the most common form of pediatric cancer and a leading cause of disease-driven death in children. Understanding the causes and mechanisms of leukemia is essential in order to develop specific highly active and less toxic treatments. One of the most common drivers of leukemia growth and survival is the NOTCH1 gene. NOTCH1 is frequently mutated in leukemia, and these mutations cause increased NOTCH1 activity, which in turn triggers a cellular program driving uncontrolled cell proliferation. Our understanding of the specifics of how NOTCH1 promotes leukemia transformation remains rudimentary.
Though most of our knowledge of T-ALL comes from the genetic dissection of known protein-coding genes, it is likely that other components of the genome contribute to T-ALL as well. A recently discovered component of the genome gives rise to very small proteins, called micropeptides that likely have profound effects on gene expression. Our research aims to investigate the role of this new family of gene-encoding proteins as potential key drivers of leukemia growth. Our central hypothesis is that among the multiple proteins controlled by NOTCH1, micropeptides are of particular importance for leukemia growth and survival. While large proteins function as molecular machines, micropeptides function as keys or switches that bind to and turn these molecular machines “on” and “off”. We are using the latest genomic technologies and refined computational approaches to identify the complete repertoire of NOTCH1-controlled micropeptides operating in leukemia. We will then evaluate the specific role and mechanisms by which these short proteins contribute to leukemia cell growth. Dissecting the mechanism of action of these key leukemia-driving micropeptides may identify novel targets for the treatment of ALL.
Grant: 6527-18 | Translational Research Program (TRP):
Location:Dana-Farber Cancer Institute, Boston, Massachusetts 02215
Project Title: Assessment Of Epigenetic Reprogramming Of The T Cell Response To CTLA-4 Blockade In AMLProject Summary:
The prognosis for patients with relapsed or refractory acute myeloid leukemia (AML)/myelodysplastic syndrome (MDS) whose disease comes back is poor, and innovative new therapeutic approaches are urgently needed. We conducted and published results from a clinical trial for patients whose blood cancer came back after bone marrow transplantation with ipilimumab, which is an antibody drug that uses the immune system to kill cancer cells. A small number of patients, including those with relapsed AML, had durable clinical responses. This clinical activity prompted us to develop a new proposal to evaluate whether or not we could safely boost response by adding a hypomethylating agent, decitabine, to ipilimumab treatment. Decitabine is a drug commonly used in the treatment of MDS/AML that is well-tolerated with modest clinical activity. Decitabine has the ability to affect the expression of genes. We now have a new approved clinical trial to assess the safety and clinical activity of the novel combination of decitabine plus ipilimumab in patients with relapsed or refractory AML/MDS who are post-transplant and who are transplant naïve. Using peripheral blood and bone marrow samples collected throughout treatment on study, we will evaluate the hypothesis that decitabine treatment might sensitize leukemia cells to ipilimumab by altering the immune response within the sites of leukemia infiltrates. Together with local expert collaborators we will perform a comprehensive analysis using patient samples collected from the clinical trial to evaluate for transcriptional (gene expression) and epigenetic (changes in a chromosome that alters gene activity and expression) changes within the immune cells present at leukemia sites including bone marrow and other tissues. We will then study which immune cells subpopulations are present and whether or not they have functional activity. We will correlate these laboratory findings with clinical activity to decitabine and ipilimumab to help us to understand treatment response or resistance. Knowledge gained from this investigation will help us to improve the design of future immunotherapy-based regimens with curative potential for patients.
Grant: 6534-18 | Translational Research Program (TRP):
Location:Yale University, New Haven, Connecticut 06520-8327
Project Title: Exploiting Mutant IDH1/2-induced BRCAness With PARP Inhibitors As A Novel AML/MDS Therapy.Project Summary:
We have identified a novel approach to treat certain types of leukemias that harbor a mutation in key genes that are involved in cellular metabolism. We found that these mutations create an altered chemical in the cell, which blocks the ability of tumor cells to repair broken DNA. This "achilles heel" can be exploited by treating such tumors with DNA damaging agents combined with DNA repair inhibitors. We have already demonstrated that this therapeutic approach is highly effective in brain tumors and other solid cancers which harbor mutations in these genes, and we now seek to determine whether the same is true in leukemias. Current strategies to treat tumors with these mutations are focused on suppressing the production of the altered metabolite. Our data suggest that this approach actually may not be ideal, as the metabolic vulnerability should be exploited rather than suppressed. The studies proposed here represent a highly translational, cross-disciplinary collaboration between researchers in hematology and oncology, radiation oncology, small molecule screening, and DNA repair basic science research. We expect that these studies will directly lead to a novel clinical trial in the future for leukemias with these mutations.
Grant: 6532-18 | Translational Research Program (TRP):
Location:The Regents of the University of California, San Francisco, San Francisco, California 94143
Project Title: Inducing Effective Anti-leukemic Immunity With Novel AML Vaccines Expressing CD80/IL-15/IL-15R-alphaProject Summary:
Patients with high-risk acute myelogenous leukemia (AML) have poor outcomes because current drug regimens fail to eradicate disease. Transplants of bone marrow or peripheral blood stem cells from matched related, or unrelated donors (allo-transplants) improve survival due to elimination of residual AML by immune cells present in donor cell populations. However, many patients are not eligible for allo-transplants, either because they lack suitable donors, or because they have pre-existing conditions making transplant too risky. Other therapies based on stimulating anti-leukemic immune responses have been tested, but achieving reproducible clinical efficacy has been elusive. In one approach, patients’ AML cells are collected before treatment, frozen, and later used as inactivated cell vaccines in order to stimulate immune responses specific to patients’ own tumor. However, to date, anti-leukemic immunity stimulated by unmodified AML cell vaccines has been inadequate.
Our strategy to improve the efficacy of AML cell vaccines is to increase their immune stimulatory activity by viral mediated transfer of a unique combination of three genes. Viral constructs express 1) a protein required to initiate recognition by immune cells, CD80, 2) a hormone shown to stimulate unprecedented levels of anti-tumor immunity, IL-15, and 3) a carrier protein required for efficient production and secretion of IL-15 in leukemic cells, IL-15 receptor alpha (IL-15Ra). For proof of concept studies, vaccines were made by inactivating mouse AML cells with x-ray treatment to prevent introduction of live leukemia cells with skin injections. Serial vaccination with AML cells, in the absence of viral modification, was minimally effective in slowing progression of disease in leukemia-bearing mice. However, injection of mouse leukemia vaccines engineered to express IL-15/IL-15Ra/CD80, induced immune responses that permanently eradicated leukemia in 80% of vaccinated mice.
We now propose to test the effects of engineered, patient-derived AML cell vaccines in stimulating effective anti-leukemic responses. The function of a newly constructed lentivirus expressing human IL-15, IL-15Ra, and CD80, has already been validated in selected patient AML samples. Our aims are to: 1) quantify the level and duration of transferred gene expression in human AML; 2) evaluate the responses of immune cells from normal and leukemic individuals after stimulation with IL-15/IL-15Ra/CD80-expressing human AML cell vaccines. Responses will be evaluated both in cell culture, and by transplanting responding immune cells and human AML cells into immune deficient mouse models; 3) test the specificity of immune responses stimulated by IL-15/IL-15Ra/CD80-expressing AML cell vaccines by comparing effects of stimulated immune cells on AML versus normal bone marrow cells. The additional data provided by these studies will support the design and application for funding of a Phase 1 vaccine trial.