"Abstract The cancer epigenome is markedly aberrant, and chromatin factors are commonly mutated in many malignancies. Recent functional studies suggest that chromatin mis-regulation can promote de-differentiation and self-renewal of cancer cells. However, the epigenetic mechanisms by which cancer cell fate programs are impaired are poorly understood. Here, I aim to address this question in two cancers that are clearly driven by chromatin mis-regulation: acute myeloid leukemia (AML) and pediatric high grade gliomas (HGGs) such as diffuse intrinsic pontine glioma (DIPG). AML driver mutations commonly involve translocations of chromatin regulatory genes, and DIPG driver mutations occur in histone H3 in 80% of cases. Both AML and HGGs arise in poorly-differentiated cells, and I hypothesize that chromatin factors help sustain these improper differentiation programs. ?Differentiation therapy? aims to treat such cancers by inducing cellular maturation to disable self-renewal and halt proliferation. While differentiation therapy has only been used in the promyelocytic subtype of AML (APL), my preliminary data suggest that this approach may be successful in non-APL AMLs and HGGs if the critical epigenetic programs regulating cell fate can be identified and manipulated. Indeed, we have already obtained leads on promising small molecule inhibitors and genetic targets that promote differentiation. In this proposal, I will take similar strategies to interrogate the epigenetic basis of AML and HGG cancer cell fate. My approach will involve (1) Integrative epigenomic profiling of induced differentiation programs in genetically-defined or patient-derived cancer cell line models with relevant drivers to identify a ?roadmap? to cancer cell differentiation, (2) High throughput CRISPR-Cas9-based screening of these cellular models to identify chromatin factors that regulate differentiation, (3) Biochemical analyses to identify the molecular mechanisms by which existing screen hits and those found in future screens manipulate chromatin to influence cancer cell fate, and (4) Validation of findings in pre-clinical animal models and in clinical sample analyses. While I will lead all aspects of this investigation, I will have direct support from several world authorities in AML and HGG. Ultimately, the goal of this project is to identify novel therapeutic targets and approaches for AML and HGG. In the future, my aim is for this work to open the door to the generalizable concept of using epigenetic manipulation to therapeutically target cancer cell identity programs. " |