Leukemia-Associated Cohesin Mutants Dominantly Enforce Stem Cell Programs and Impair Human Hematopoietic Progenitor Differentiation

• DOI: 10.1016/j.stem.2015.09.017
• Publication Date: 2015-10-25T10:31:23Z
• Authors: Claire Mazumdar; Ying Shen; Seethu Xavy; Feifei Zhao; Andreas Reinisch; Rui Li; M. Ryan Corces; Ryan A. Flynn; Jason D. Buenrostro; Steven M. Chan; Daniel Thomas; Julie L. Koenig; Wan-Jen Hong; Howard Y. Chang; Ravindra Majeti
• Keywords: 0301 basic medicine; Chromosomal Proteins, Non-Histone; Gene Expression Regulation, Leukemic; Stem Cells; Cell Cycle Proteins; Cell Differentiation; Cell Biology; Hematopoietic Stem Cells; Chromatin; Hematopoiesis; GATA2 Transcription Factor; Leukemia, Myeloid, Acute; 03 medical and health sciences; Transcriptional Regulator ERG; Core Binding Factor Alpha 2 Subunit; Mutation; Genetics; Molecular Medicine; Humans; Cohesins

Recurrent mutations in cohesin complex proteins have been identified in pre-leukemic hematopoietic stem cells and during the early development of acute myeloid leukemia and other myeloid malignancies. Although cohesins are involved in chromosome separation and DNA damage repair, cohesin complex functions during hematopoiesis and leukemic development are unclear. Here, we show that mutant cohesin proteins block differentiation of human hematopoietic stem and progenitor cells (HSPCs) in vitro and in vivo and enforce stem cell programs. These effects are restricted to immature HSPC populations, where cohesin mutants show increased chromatin accessibility and likelihood of transcription factor binding site occupancy by HSPC regulators including ERG, GATA2, and RUNX1, as measured by ATAC-seq and ChIP-seq. Epistasis experiments show that silencing these transcription factors rescues the differentiation block caused by cohesin mutants. Together, these results show that mutant cohesins impair HSPC differentiation by controlling chromatin accessibility and transcription factor activity, possibly contributing to leukemic disease.