Ubiquitin-specific proteases as targets for anticancer drug therapies

Abstract Ubiquitination is an essential posttranslational modification that has emerged as a key regulator of multiple cellular processes in multiple manners. Different enzymes are involved in the control of ubiquitin homeostasis, being deubiquitinases (DUBs) responsible for cleaving the linkage between ubiquitin and target proteins. DUBs can be classified into seven families, among which ubiquitin-specific proteases (USPs) stand out due to their wide functional diversity. USPs are involved in a plethora of cellular processes, several of which are frequently altered in cancer. Consistent with this, altered USP function has been related to different human tumor types, and in recent years, the knowledge about pro- and antitumorigenic roles played by USPs has grown considerably. This fact has turned USPs into attractive targets for anticancer drug therapies. In this chapter we attempt to summarize the involvement of USPs in a variety of cellular processes and highlight their critical implications in different types of human cancer. Finally, we discuss the growing relevance of using USPs as targets in cancer therapy and the current status of small inhibitory molecules against USP functions.