The Chromatin Regulator CHD8 Is a Context-Dependent Mediator of Cell Survival in Murine Hematopoietic Malignancies

Abstract

Aberrant chromatin regulation is a frequent driver of leukemogenesis. Mutations in chromatin regulators often result in more stem-like cells that seed a bulk leukemic population. Inhibitors targeting these proteins represent an emerging class of therapeutics, and identifying further chromatin regulators that promote disease progression may result in additional drug targets. We identified the chromatin-modifying protein CHD8 as necessary for cell survival in a mouse model of BCR-Abl+ B-cell acute lymphoblastic leukemia. This disease has a poor prognosis despite treatment with kinase inhibitors targeting BCR-Abl. Although implicated as a risk factor in autism spectrum disorder and a tumor suppressor in prostate and lung cancer, the mechanism of CHD8’s activity is still unclear and has never been studied in the context of hematopoietic malignancies. Here we demonstrate that depletion of CHD8 in B-ALL cells leads to cell death. While multiple B cell malignancies were dependent on CHD8 expression for survival, T cell malignancies displayed milder phenotypes upon CHD8 knockdown. In addition, ectopic expression of the Notch1 intracellular domain in a T cell malignancy partially alleviated the detrimental effect of CHD8 depletion. Our results demonstrate that CHD8 has a context-dependent role in cell survival, and its inhibition may be an effective treatment for B lymphoid malignancies.