Oncogenic gene expression and epigenetic remodeling of cis-regulatory elements in ASXL1-mutant chronic myelomonocytic leukemia

Myeloid neoplasms are clonal hematopoietic stem cell disorders driven by the sequential acquisition of recurrent genetic lesions. Truncating mutations in the chromatin remodeler ASXL1 (ASXL1 MT ) are associated with a high-risk disease phenotype with increased proliferation, epigenetic therapeutic resistance, and poor survival outcomes. We performed a multi-omics interrogation to define gene expression and chromatin remodeling associated with ASXL1 MT in chronic myelomonocytic leukemia (CMML). ASXL1 MT are associated with a loss of repressive histone methylation and increase in permissive histone methylation and acetylation in promoter regions. ASXL1 MT are further associated with de novo accessibility of distal enhancers binding ETS transcription factors, targeting important leukemogenic driver genes. Chromatin remodeling of promoters and enhancers is strongly associated with gene expression and heterogenous among overexpressed genes. These results provide a comprehensive map of the transcriptome and chromatin landscape of ASXL1 MT CMML, forming an important framework for the development of novel therapeutic strategies targeting oncogenic cis interactions. ‘Mutations in the chromatin remodeler ASXL1 (ASXL1 MT ) are associated with poor clinical outcome, however, their impact on chromatin dynamics remains unexplored. Here the authors use a multi-omics approach for chronic myelomonocytic leukemia (CMML) and investigate the transcriptome and chromatin landscape of ASXL1 MT CMML.