Identification of a dynamic core transcriptional network in t(8;21) AML regulating differentiation block and self-renewal [ChIP-Seq]. Homo sapiens

The leukemogenic fusion protein RUNX1/ETO impairs myeloid differentiation and drives malignant self-renewal. Here we use digital footprinting and ChIP-sequencing to identify the core RUNX1/ETO responsive transcriptional network of t(8;21) cells. We show that the transcriptional programme underlying leukemic propagation is regulated by a dynamic equilibrium between RUNX1/ETO and RUNX1 complexes, which bind in a mutually exclusive fashion to identical genomic sites. Perturbation of this equilibrium by RUNX1/ETO knockdown results in a global reassembly of transcription factor complexes within pre-existing open chromatin and the formation of a new C/EBP-alpha-dominated transcriptional network driving myeloid differentiation. Our work demonstrates that the block in myeloid differentiation in t(8;21) is caused by the dynamic balance between RUNX1/ETO and RUNX1 activities and the repression of C/EBP-alpha and highlights the core targets of epigenetic reprogramming in t(8;21) AML. Overall design: ChIP-sequencing and DNAse1-sequencing was used for the identification of a dynamic core transcriptional network in t(8;21) AML