Besides HDACs, multiple sirtuins (NAD+-dependent deacetylase sirtuin, SIRT; EC 3.5.1.98) are known to show deacetylase activity. They are considered class III histone deacetylases that deacetylate histones and transcription factors[1]. In turn, sirtuins can be inhibited by nicotinamide, which binds to a specific receptor site of the enzyme, so it is thought that drugs that interfere with this binding should increase sirtuin activity. Development of new agents that would specifically block the nicotinamide-binding site could provide an avenue for development of newer agents to treat degenerative diseases such as cancer, Alzheimer's, diabetes, atherosclerosis, and gout[2].
SIRT1 is involved in other signaling pathways as well, since it competes with HDAC1 in deacetylation of PTEN, an important phosphatase involved in cell signaling via phosphoinositols and the PI3K/AKT/mTOR signaling pathway. Aiming to keep up with these recent developments in oncology research,Axon Medchem recently added a significant number of HDAC inhibitors to its ever broadening range of products.