Chromatin dynamics and gene regulation in normal and malignant hematopoiesis
Acute myeloid leukemia (AML) and several hematological malignancies arise from acquisition of multiple stepwise genetic and epigenetic changes in hematopoietic stem and progenitor cells. Understanding the regulatory pathways that are deregulated in hematopoietic stem and progenitor cells is important to better understand the development of leukemia and to design novel therapeutic strategies for the treatment of leukemia. With that broad focus in mind, our lab applies genetic, epigenetic and biochemical approaches in genetically modified mouse models, humanized mouse models and human primary leukemic cells. Our research focuses on three areas:
1. Interplay between transcription factors and chromatin dynamics in normal and malignant hematopoietic stem cells (HSC)
The development of chromosome conformation capture technology has revolutionized our understanding of long-range enhancer-promoter interactions and how these interactions are deregulated in multiple diseases. However, our understanding of chromatin structure and how transcription factors regulate higher-order genome architecture is limited. We are exploring the mechanisms by which transcription factors regulate chromatin dynamics in normal and malignant HSCs, and the implications of chromosomal rearrangements observed in hematological malignancies in topologically associated domains (TAD) architecture and gene expression.
2. Transcriptional deregulation in AML
Mutations in transcription factors have long been shown to be central in tumorigenesis. Our lab is interested in understanding transcriptional regulation of myeloid differentiation and how this is altered in AML. In particular, we are studying deregulation of transcription factors C/EBPα and core-binding factors, CBFs (consisting of RUNX and CBFβ proteins) in AML. We are investigating the preleukemic molecular events in AML with CEBPA mutations and chromosomally rearranged RUNX1/ CBFβ.
3. Development and optimization of AML PDX models
Patient-derived xenotransplantation (PDX) models represent a great tool for understanding disease biology, clonal evolution, and pre-clinical drug testing. PDX models utilizing human primary AML samples have provided novel insights into functional heterogeneity across patients, including the identification of phenotypes associated with leukemia-initiating cell populations. Even though there has been great progress in modeling human AML in PDX models (NSG, NSGS, NSGW41, NOG-EXL, etc.), many human primary AML samples fail to engraft in various PDX models. We are in the process of developing novel PDX models for studying human hematopoiesis and AML. In addition, we are actively involved in optimizing the transplantation regimens to improve the engraftment efficiency of human hematopoietic stem and myeloid progenitors in various PDX models.