Trapoxin A is a cyclotetrapeptide and an HDAC (histone deacetylase) inhibitor. Trapoxin increases the level of chromatin acetylation associated with histone H3 at low nanomolar concentrations. Unlike the reversible HDAC inhibition induced by TCA, Trapoxin irreversibly inhibits HDAC activity in crude cell lysates and induces the accumulation of hyperacetylated core histones in a number of mammalian cell lines and tissues. Histone acetylation and methylation have been studied extensively for their anti-tumor activities in carcinogenesis and Trapoxin has been suggested as a potential anticancer agent for pre-clinical trials.
