Definition

A bicyclic depsipeptide antibiotic isolated from the bacterium Chromobacterium violaceum with antineoplastic activity. After intracellular activation, romidepsin binds to and inhibits histone deacetylase (HDAC), resulting in alterations in gene expression and the induction of cell differentiation, cell cycle arrest, and apoptosis. This agent also inhibits hypoxia-induced angiogenesis and depletes several heat shock protein 90 (Hsp90)-dependent oncoproteins.