Bromodomains as therapeutic targets in cancer

The malleability of the epigenome has long been recognized as a unique opportunity for therapeutic intervention. Interest in targeting components of the epigenetic machinery for therapeutic gain had initially been aimed at chromatin modifying enzymes. However, advances in medicinal chemistry have now made it possible to exploit protein-protein interactions at the chromatin interface. Bromodomains (BRD) are a conserved motif used by a large number of chromatin-associated proteins to recognize and bind acetylated histone tails. Small molecules with high specificity for the Bromodomain and Extra Terminal family of proteins (BRD2, BRD3, BRD4 and BRDT) have recently been shown to have remarkable pre-clinical efficacy in various malignancies. These findings have provided the impetus for exploring other BRD proteins as novel targets in cancer therapy.