Recent progress in the development of histone deacetylase inhibitors as anti-cancer agents

Histone deacetylases (HDACs) regulate the expression and activity of many proteins in both cancer initiation and cancer progression. HDACs are now recognized as promising targets for anticancer agent development. HDAC inhibitors (HDACIs) are emerging as promising anticancer drugs which possess tumor-selective cytotoxicity. HDACIs could promote growth arrest, differentiation, and apoptosis of cancer cells, with minimal effects on normal tissue. Research of HDACIs is now becoming an interesting field. HDACIs comprise structurally diverse anticancer agents and have been widely used in the clinic. This review describes recent progress in the development of HDACIs, especially focusing on the design strategies, novel chemical structures, biological properties and structure-activity relationships (SARs) of HDACIs. We hope it will be helpful for medicinal chemists who are interested in the discovery of anticancer agents.