An Ezh2 and Ezh1 dual inhibitor, UNC1999, re-shapes the landscape of H3K27me3 versus H3K27ac in MLL-AF9-transformed murine leukemia

Ezh2 and EZH1 are histone H3 lysine 27 (H3K27)-specific methyltransferases. Their hyperactive mutations and overexpression were found in cancer including various hematological malignancies. UNC1999 is a highly selective inhibitor for both enzymes. It suppresses H3K27 tri- and di-methylation globally and inhibits growth of MLL-rearranged acute leukemia. Here we performed ChIP-Seq to profile how UNC1999 affects distribution of H3K27me3 and its antagonizing H3K27ac in MLL-AF9-immortalized leukemia cells. We also performed ChIP-seq of SUZ12, an essential common cofactor of EZH2 and EZH1 following compound treatments. We treated MLL-AF9 transformed murine leukemia cells with DMSO, UNC1999 or UNC2400 (an inactive analog compound of UNC1999). Cells were then collected and used for ChIP-Sequencing of Input, H3K27me3, SUZ12, and H3K27ac.