Patients with relapsed blood cancers after allogeneic stem cell transplant are often treated with donor lymphocyte infusion (DLI), a type of immunotherapy that boosts the anti-tumor response and aims to induce cancer remission. The success of DLI varies from patient to patient. Dr. Bachireddy aims to investigate the determinants of DLI success and failure by studying the leukemic and immune cells during response to immunotherapy. Careful study of successful anti-tumor immune responses may reveal insights into tumor-immune interactions that may be relevant to predicting patient response to novel immunotherapies in other tumors.
Blood Cancers
Current Projects

Myeloid neoplasms (MN), including acute myeloid leukemia and myelodysplastic syndrome, are lethal blood cancers. The genetic mutations in the blood that lead to MN can occur years before diagnosis and maintain almost normal function before transformation. Certain mutations, including those in the gene IDH2, have been identified as high-risk for developing MN. Individuals with a reduction in the number of mature blood cells (cytopenias) who harbor acquired mutations in their blood, yet do not meet criteria for a cancer diagnosis, have a condition called cytopenias of undetermined significance (CCUS). These individuals almost invariably develop MN. Dr. Bolton will conduct a clinical trial to evaluate whether the IDH2 inhibitor enasidenib can be used as a therapy for CCUS. She will assess mechanisms of resistance and determine whether enasidenib can prevent the development of MN. This represents the first use of genetically targeted therapy for cancer prevention.

Dr. Crosse focuses on myelodysplastic syndromes (MDS), blood cancers that occur predominantly in the elderly. These cancers are initiated in the bone marrow when blood stem cells acquire a genetic mutation that causes them to divide and multiply uncontrollably. Through proliferation and acquisition of further mutations, the disease can evolve into acute myeloid leukemia, for which prognosis and survival rate are typically poor. Dr. Crosse aims to identify the specific blood stem cells that are most impacted by the mutation in the early stages of MDS and determine how they contribute to disease progression. The goal is to design therapies that inhibit these mechanisms and halt MDS cancer progression.

The human gut is home to trillions of microorganisms, collectively called the microbiota, which affect health and disease. For example, in patients receiving hematopoietic stem cell transplantation as treatment for leukemias, lymphomas and other blood cancers, disruptions in the microbiota have been linked to disease relapse, infections and reduced survival. To address these treatment complications, Drs. David and Sung are developing ways to manipulate the microbiota through prebiotics, carbohydrates that a patient can ingest to stimulate the growth and maintenance of various beneficial bacteria. The challenge is that each patient has different microbiota and therefore may respond differently to the same prebiotic therapy. They are developing approaches for personalizing prebiotic treatments for hematopoietic stem cell transplant (HCT) patients based on their individual gut microbiota. After validating their prebiotic personalization with a mouse model, they will test the safety and feasibility of this treatment in a Phase 1 clinical trial with HCT patients.

Kaposi's sarcoma herpesvirus (KSHV) is a human oncogenic virus and the causative agent of cancers including Kaposi’s sarcoma, primary effusion lymphoma, and Multicentric Castleman disease. The related human herpesvirus Epstein-Barr Virus (EBV) is even more prevalent than KSHV, and is linked to cancers including Burkitt’s lymphoma, Hodgkin’s lymphoma, and nasopharyngeal carcinoma. Dr. Didychuk is investigating the mechanisms by which KSHV co-opts the cellular host machinery to produce its own gene products in a manner distinct from other viruses and host cells. A molecular understanding of how herpesviruses hijack the late gene transcription machinery will reveal new therapeutic weaknesses in the viral lifecycle and allow for structure-guided design of novel anti-viral drug targets.

Dr. Didychuk is investigating the mechanism by which the Kaposi’s sarcoma herpesvirus (KSHV) co-opts the cellular host machinery to produce its own gene products in a manner distinct from other viruses and host cells. This research should reveal insights into this unique mode of transcriptional control. KHSV is an oncogenic virus that causes various cancers including, Kaposi’s sarcoma, primary effusion lymphoma, and multicentric Castleman’s disease, in immunocompromised individuals.

Mutations in the cancer-causing oncogene JAK2 are a hallmark of myeloproliferative neoplasms (MPNs), a blood disorder characterized by over-production of mature blood cells. While currently available JAK2 inhibitors improve symptoms, they are unsuccessful at completely eradicating diseased cells, so remissions are rare. Using genetically engineered mice, Dr. Dunbar will investigate how MPN cells remain dependent on JAK2 signaling for cell growth, and how additional mutations in the epigenome (the proteins involved in regulating gene expression) might contribute to drug resistance. His research aims to identify improved JAK2 inhibitors and lend insight into whether targeting both oncogenic drivers and epigenetic defects could be required for effective therapy. Ultimately, he hopes these findings will translate into better treatments for patients with these cancers.

Dr. Eisen studies how a class of enzymes known as the Tec kinases help to activate the immune response. Two of these kinases, Itk and Btk, are remarkably similar in sequence composition and structure but play distinct roles in immune cells. Dr. Eisen is using high-throughput methods to understand the differences between these enzymes. This work will also aid in the overall molecular understanding of Btk, which is a therapeutic target of B-cell lymphoma and is inhibited by the chemotherapeutic ibrutinib.
Christopher’s research centers on the earliest steps whereby normal cells transform into abnormal cells with the potential to become cancer. He will focus on better understanding the first steps of the process by which normal blood cells become lymphomas, cancers that are generally thought to arise from blood cells that have already committed to becoming lymphocytes, an important component of the immune system. He hypothesizes, however, that some lymphomas actually arise from earlier hematopoietic stem cells (HSCs). He will interrogate this hypothesis by studying a cohort of lymphoma patients who also have detectable genetic mutations in HSCs that are known to be associated with blood cancers – a condition known as clonal hematopoiesis of indeterminate potential, or CHIP – to determine whether the mutations in the HSCs were the earliest events in the development of the patients’ lymphomas. Having a better understanding of lymphomas’ cellular basis will hopefully allow new insights into their clinical behavior and therapeutic vulnerabilities.

New drugs that target metabolic pathways have shown promise for the treatment of cancer, but the benefits of these drugs have been restricted to rare patients whose cancers have mutations in specific metabolic enzymes. Dr. Intlekofer identified a metabolic pathway whereby subpopulations of genetically identical cancer cells produce a metabolite called L-2-hydroxyglutarate (L-2HG) that induces stem cell-like properties associated with resistance to anti-cancer therapies. He is investigating the mechanisms by which L-2HG regulates the identity and function of cancer stem cells in order to determine whether targeting the L-2HG pathway represents a broadly applicable strategy for treating cancer.