RUNX1 Control of the CEBPA enhancer as a Target of Myeloid Transformation

Background

Development of novel therapies is essential in acute myeloid leukemia (AML), as it has an approximately 50% mortality rate in pediatrics. One model of AML suggests two categories of mutations: type I mutations, which cause the cells to uncontrollably divide, and type II mutations, that inhibit the cells' maturation. Two genetic targets of interest that are widely affected by type II mutations in AML are RUNX1 and C/EBPa. The reduction of RUNX1 activity, which results in a significant decrease in C/EBPa expression, is found in 30% of AMLs. Furthermore, C/EBPa is decreased in half of all cases of AML. The Friedman Lab has identified a highly conserved CEBPA enhancer which largely impacts the expression of C/EBPa and is highly regulated by RUNX1 through four binding sites.

Project Goal

We believe that the regulation of this enhancer important in AML and thus, we desire to understand the regulatory pathway of the enhancer. Using the CRISPR technique, we will replace the wild type (WT) CEBPA enhancer with a mutant enhancer containing mutated RUNX1 binding sites in murine myeloid cells. Additionally, we will use multiple cell lines with common AML mutations to determine how these mutations affect the C/EBPa protein and enhancer. In both the CRISPR mutated line as well as the lines with AML translocations, we will assess for changes in epigenetic marks using Chromatin Immunoprecipitation (ChIP). Ultimately, we hope that agents affecting cell methylation could be used to target these epigenetic aberrations at the CEBPA enhancer, allowing for differentiation therapy to allow normal maturation.