Cohesin Mutations in Acute Myelogenous Leukemia

A. Background Information: This subcontract is related to Aim 2 of the grant proposal and more specifically on the role of cohesin haploinsufficency on the repertoire of distal cis-¬regulatory elements regulating HoxA9 expression. This stems from the observation by the Rao laboratory that Cohesin loss causes increased HoxA9 expression through altered targeting of the PRC2 complex. We hypothesize here that cohesin facilitates interactions between the HoxA9 locus and distal cis-regulatory elements (CREs) responsible for recruiting the PRC2 complex to induce gene silencing. B. Phase II Technical Objectives: To determine if cohesin loss alters the repertoire of distal CREs regulating HoxA9 expression we plan to employ circular chromatin conformation capture (4C) to identify changes in the distal CREs interacting with the HoxA9 promoter after cohesin loss. These experiments will identify a novel mechanism for PRC2 recruitment in mammals. This model, where distal CREs mediate PRC2 recruitment is well established in Drosophila but not in mammals.