Chromatin modifications as therapeutic targets in MLL-rearranged leukemia.

MLL-rearranged leukemias exemplify malignancies with perturbations of the epigenetic landscape. Specific chromatin modifications that aid in the perpetuation of MLL fusion gene driven oncogenic programs are being defined, presenting novel avenues for therapeutic intervention. Proof-of-concept studies have recently been reported, using small-molecule inhibitors targeting the histone methyltransferase disruptor of telomeric silencing 1-like (DOT1L), or the acetyl-histone binding protein bromodomain containing protein 4 (BRD4) showing potent activity against MLL-rearranged leukemias in preclinical models. It is apparent that intensive efforts will be made toward the further development of small-molecule inhibitors targeting these, and other chromatin-associated protein targets. These studies may lead to the advent of a new generation of much-needed therapeutic modalities in leukemia and other cancers.