Mutations of the de novo DNA methyltransferase 3A (DNMT3A) are associated with multiple hematologic malignancies, including both myeloid and lymphoid leukemias; however, the mechanisms through which such mutations contribute to their development is obscure. Loss of Dnmt3a function in murine hematopoietic stem cells (HSCs) led to dramatic HSC expansion and inhibited differentiation without frank leukemia suggesting the importance of co-occurring mutations in other genes for leukemia development. Here, our overarching goal is to gain insight into the underlying pathophysiologic mechanisms through which DNMT3A mutations alter the course of disease given an otherwise similar mutational profile. We hypothesize that Dnmt3a loss primes stem cells and/or early progenitors for transformation by preventing the repression of stem cell self-renewal genes, inhibiting differentiation, and expanding a target cell population that is then sensitized to the impact of secondary oncogenic hits. We expect that the cellular milieu, in terms of cell type, age, and degree of methylation loss influences the type of leukemia that develops. By investigating the role of Dnmt3a mutations using our mouse model, we hope to elucidate how DNMT3A mutations contribute to an array of malignancies. Toward this goal, we will examine the influence of the mutation type on the generation of myeloid versus lymphoid malignancies using a Dnmt3a-FLT3-ITD model. FLT3-ITD will be introduced into Dnmt3a-mutant HSCs and progenitors and the type and latency of disease generated will be examined. We will also examine the role of the organismal milieu in terms of aging. In addition, we will examine the influence of the target cell type of cooperating FLT3 mutations on the disease outcome. Finally, the mechanism through which Dnmt3a mutation accelerates and alters the impact of FLT3-ITD expression will be examined. Specifically, the whole genome methylation profile and gene expression patterns of similar malignancies with and without Dnmt3a mutations will be compared. Methylation alterations will also be compared with those found in similar human leukemias harboring DNMT3A mutations. Ultimately, these data will allow us to identify the role of DNA methylation broadly, and at specific loci in human leukemia development. Together, these approaches will lend insight into the manner in which DNMT3A mutations promote a variety of human hematologic malignancies and lead to development of new therapeutic approaches for DNMT3A-associated malignancies.

Public Health Relevance

Mutations in a DNA methyltransferase, DNMT3A, are frequently found in a variety of types of leukemias. Here, we have generated a mouse model with which we can study the way in which DNMT3A can participate in such diverse activities, with the long-term goal of developing novel therapeutic strategies.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA183252-05
Application #
9544059
Study Section
Cancer Molecular Pathobiology Study Section (CAMP)
Program Officer
Jhappan, Chamelli
Project Start
2014-09-11
Project End
2019-08-31
Budget Start
2018-09-01
Budget End
2019-08-31
Support Year
5
Fiscal Year
2018
Total Cost
Indirect Cost
Name
Baylor College of Medicine
Department
Pediatrics
Type
Schools of Medicine
DUNS #
051113330
City
Houston
State
TX
Country
United States
Zip Code
77030
Jeong, Mira; Park, Hyun Jung; Celik, Hamza et al. (2018) Loss of Dnmt3a Immortalizes Hematopoietic Stem Cells In Vivo. Cell Rep 23:1-10
Brunetti, Lorenzo; Gundry, Michael C; Sorcini, Daniele et al. (2018) Mutant NPM1 Maintains the Leukemic State through HOX Expression. Cancer Cell 34:499-512.e9
Su, Jianzhong; Huang, Yung-Hsin; Cui, Xiaodong et al. (2018) Homeobox oncogene activation by pan-cancer DNA hypermethylation. Genome Biol 19:108
Tan, Qiumin; Brunetti, Lorenzo; Rousseaux, Maxime W C et al. (2018) Loss of Capicua alters early T cell development and predisposes mice to T cell lymphoblastic leukemia/lymphoma. Proc Natl Acad Sci U S A 115:E1511-E1519
Jeong, Mira; Guzman, Anna G; Goodell, Margaret A (2017) Genome-Wide Analysis of DNA Methylation in Hematopoietic Cells: DNA Methylation Analysis by WGBS. Methods Mol Biol 1633:137-149
Huang, Yung-Hsin; Su, Jianzhong; Lei, Yong et al. (2017) DNA epigenome editing using CRISPR-Cas SunTag-directed DNMT3A. Genome Biol 18:176
Lei, Yong; Zhang, Xiaotian; Su, Jianzhong et al. (2017) Targeted DNA methylation in vivo using an engineered dCas9-MQ1 fusion protein. Nat Commun 8:16026
Brunetti, Lorenzo; Gundry, Michael C; Goodell, Margaret A (2017) DNMT3A in Leukemia. Cold Spring Harb Perspect Med 7:
Yang, Liubin; Rodriguez, Benjamin; Mayle, Allison et al. (2016) DNMT3A Loss Drives Enhancer Hypomethylation in FLT3-ITD-Associated Leukemias. Cancer Cell 30:363-365
Eckstein, Olive S; Wang, Linghua; Punia, Jyotinder N et al. (2016) Mixed-phenotype acute leukemia (MPAL) exhibits frequent mutations in DNMT3A and activated signaling genes. Exp Hematol 44:740-4

Showing the most recent 10 out of 21 publications