Acute myeloid leukemia (AML) is a genetically heterogeneous bone marrow cancer affecting at least 15,000 individuals per year in the US and causing significant morbidity and mortality. We identified BCOR loss of function mutations among a set of genes that is specifically mutated in AML that arises after myelodysplastic syndromes, is common among older patients, and is associated with poor clinical outcomes. The mechanisms by which BCOR mutations drive leukemogenesis are not understood. In preliminary studies, we showed that Bcor mutations promote increased hematopoietic stem cell self-renewal and sensitize primary cells to activating RAS mutations. These represent the first reported mouse models of Bcor-deficient myeloid disease. We also demonstrate for the first time that BCOR protein interacts in human AML cell lines with components of a variant polycomb repressive complex 1 (PRC1), suggesting a functional importance of ubiquinated histone 2A lysine 119 (H2AK119ub) in AML development. Our hypothesis is that somatic mutations affecting BCOR cause failure to recruit PRC2 to polycomb repressive targets via reduction of H2AK119ub. To define the molecular basis of BCOR function during initiation and progression of myeloid malignancies, we propose the following Specific Aims 1) Define the contribution of Bcor deletion to myeloid transformation in primary Tet2-/- hematopoietic cells. We will use CRISPR/Cas9 gene editing in primary mouse Tet2-/- cells in vitro and in vivo to define the functional impact of Bcor loss of function mutations on hematopoietic stem cell self-renewal and lineage-specific differentiation. 2) Identify the role of RAS mutations in promoting transformation of Bcor- deficient cells. We will take advantage of novel in vitro and in vivo models to identify the cooperative effects of activating RAS mutations during transformation of Bcor-deficient cells. 3) Define the impact of BCOR deficiency on histone epigenetic modifications during myeloid leukemogenesis. We will define the global and locus-specific effects of BCOR deletion on histone H3 epigenetic marks in a human AML cell line and assess whether genetic and chemical targeting of EZH2 attenuates BCOR-associated transformation. Collectively, the information learned in these studies will provide new insights into the biology o AML and lay the groundwork for developing novel targeted therapies. The applicant, Dr. Coleman Lindsley, has outlined a five-year career development plan to meet his goal of becoming an independent investigator in translational leukemia research. Dr. Lindsley has assembled an Advisory Committee of internationally recognized experts to provide scientific and career mentorship. He has established collaborations with experts in cancer epigenetics, leukemia genetics, and applied biostatistics to provide experimental advice and specific training in the field. Dana-Farber Cancer Institute is an optimal environment for completion of Dr. Lindsley's scientific and career goals, given its outstanding research community and long-standing record for training independent physician-scientist.

Public Health Relevance

Acute myeloid leukemia (AML) is the most common acute leukemia in adults and is associated with significant morbidity and mortality because of bone marrow failure and treatment resistance. This project will use state-of- the-art tools to identify and characterize the relationship between genetic changes in normal blood stem cells, specifically those affecting the BCOR gene, and development of leukemia. Understanding this fundamental relationship and how BCOR mutations cooperate with other AML mutations could lead to improved treatments for AML and related disorders.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Clinical Investigator Award (CIA) (K08)
Project #
1K08CA204734-01
Application #
9088831
Study Section
Subcommittee I - Transistion to Independence (NCI)
Program Officer
Lim, Susan E
Project Start
2016-04-15
Project End
2021-03-31
Budget Start
2016-04-15
Budget End
2017-03-31
Support Year
1
Fiscal Year
2016
Total Cost
Indirect Cost
Name
Dana-Farber Cancer Institute
Department
Type
DUNS #
076580745
City
Boston
State
MA
Country
United States
Zip Code
Schaefer, Eva J; Lindsley, R Coleman (2018) Significance of Clonal Mutations in Bone Marrow Failure and Inherited Myelodysplastic Syndrome/Acute Myeloid Leukemia Predisposition Syndromes. Hematol Oncol Clin North Am 32:643-655
Gibson, Christopher J; Kennedy, James A; Nikiforow, Sarah et al. (2017) Donor-engrafted CHIP is common among stem cell transplant recipients with unexplained cytopenias. Blood 130:91-94
Morgan, Elizabeth A; Lee, Mark N; DeAngelo, Daniel J et al. (2017) Systematic STAT3 sequencing in patients with unexplained cytopenias identifies unsuspected large granular lymphocytic leukemia. Blood Adv 1:1786-1789
Kuo, Frank C; Mar, Brenton G; Lindsley, R Coleman et al. (2017) The relative utilities of genome-wide, gene panel, and individual gene sequencing in clinical practice. Blood 130:433-439
Lindsley, R Coleman; Saber, Wael; Mar, Brenton G et al. (2017) Prognostic Mutations in Myelodysplastic Syndrome after Stem-Cell Transplantation. N Engl J Med 376:536-547
Lindsley, R Coleman (2017) Now I cuss less about ICUS. Blood 129:3282-3283
Vedula, Rahul S; Lindsley, R Coleman (2017) Measurement of Residual Disease in Acute Myeloid Leukemia. Curr Hematol Malig Rep 12:574-581
Gibson, Christopher J; Lindsley, R Coleman; Tchekmedyian, Vatche et al. (2017) Clonal Hematopoiesis Associated With Adverse Outcomes After Autologous Stem-Cell Transplantation for Lymphoma. J Clin Oncol 35:1598-1605
Lindsley, R Coleman (2017) Uncoding the genetic heterogeneity of myelodysplastic syndrome. Hematology Am Soc Hematol Educ Program 2017:447-452
Lindsley, R Coleman (2017) Mutational complexity in myelodysplasia. Best Pract Res Clin Haematol 30:290-294

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