Histone deacetylases (HDAC) are a family of 11 enzymes that are involved in the regulation of gene activation and silencing by regulating chromatin structure. HDAC11 is responsible for the deacetylation of lysine residues on the N-terminal part of the core histones (H2A, H2B, H3 and H4). Deacetylation of histones is associated with the condensation of chromatin to a compact structure (heterochromatin) in which the genes are silenced. Each member of the HDAC family exhibits a different, individual substrate specificity and function in vivo.
HDACs are known to be associated with a number of well characterized cellular oncogenes and tumour- suppressor genes and inhibitors of HDACs induce growth arrest, differentiation or apoptosis of cancer cells in vitro and in vivo.