NuRD subunit CHD4 regulates super-enhancer accessibility in Rhabdomyosarcoma and represents a general tumor dependency

ATP-dependent chromatin remodelers modulate gene expression by regulating genome accessibility and can contribute to tumorigenesis. In fusion-positive rhabdomyosarcoma (FP-RMS), we have previously identified the chromatin remodeler and NuRD subunit CHD4 as an essential gene for tumor survival. Here, we demonstrate that the FP-RMS vulnerability to CHD4 goes beyond its function as a NuRD member. Mechanistically, CHD4 interacts with BRD4 and co-localizes with the tumor driver and fusion protein PAX3-FOXO1 at super-enhancers where it generates a chromatin architecture permissive for the binding of the fusion protein. This allows the positioning of RNA polymerase 2 at promoters and the expression of the oncogenic program of PAX3-FOXO1. Additionally, analysis of genome-wide cancer dependency databases identifies CHD4 amongst the NuRD subunits as general novel cancer vulnerability. Our findings describe, for the first time, CHD4 as a regulator of super-enhancer-mediated gene expression and establish this chromatin remodeler as an unexpected broad tumor susceptibility. ChIP assays were performed using the iDeal ChIP-seq kit for Transcription Factors (Diagenode), and were performed once per target per cell line per condition.