title: Inhibitors of the immunoproteasome: current status and future directions.
abstract: The ubiquitin-proteasome system (UPS) plays a vital role in maintaining protein homeostasis and regulating numerous cellular processes. The proteasome, a multi-protease complex, is the key component of the UPS and has been validated as a therapeutic target by the FDA's approval of bortezomib and carfilzomib. These proteasome inhibitor drugs have substantially improved outcomes in patients with hematological malignancies and are currently being investigated for other types of cancer as well as several other diseases. These approved proteasome inhibitors target the catalytic activity of both the constitutive proteasome and the immunoproteasome indiscriminately, and their inhibitory effects on the constitutive proteasome in normal cells are believed to contribute to unwanted side effects. In addition, selective immunoproteasome inhibition has been proposed to have unique effects on other diseases, including those involving aberrant immune function. Initially recognized for its role in the adaptive immune response, the immunoproteasome is often upregulated in disease states such as inflammatory diseases and cancer, suggesting functions beyond antigen presentation. In an effort to explore the immunoproteasome as a potential therapeutic target in these diseases, the development of immunoproteasome-specific inhibitors has become the focus of recent studies. Owing to considerable efforts by both academic and industry groups, immunoproteasome-selective inhibitors have now been identified and tested against several disease models. These inhibitors also provide a valuable set of chemical tools for investigating the biological function of the immunoproteasome. In this review, we will focus on the recent efforts towards the development of immunoproteasome-selective inhibitors.
authors.affiliation: Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone, Lexington, Kentucky 40536-0596, USA.
authors.forename: Zachary
authors.initials: Z
authors.lastname: Miller
authors.forename: Lin
authors.initials: L
authors.lastname: Ao
authors.forename: Kyung Bo
authors.initials: KB
authors.lastname: Kim
authors.forename: Wooin
authors.initials: W
authors.lastname: Lee
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D006801:Humans; D009369:Neoplasms / Q000188:drug therapy* / Q000276:immunology* / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D061988:Proteasome Inhibitors / Q000627:therapeutic use*
chemical_list: D000970:Antineoplastic Agents; D061988:Proteasome Inhibitors; D046988:Proteasome Endopeptidase Complex