ABSTRACT
Promiscuous inhibitors of tyrosine protein kinases, proteases and phosphatases are useful reagents for probing regulatory pathways and stabilizing lysates as well as starting points for the design of more selective agents. Ubiquitination regulates many critical cellular processes, and promiscuous inhibitors of deubiquitinases (DUBs) would be similarly valuable. The currently available promiscuous DUB inhibitors are highly reactive electrophilic compounds that can crosslink proteins. Herein we introduce diarylcarbonate esters as a novel class of promiscuous DUB inhibitors that do not have the liabilities associated with the previously reported compounds. Diarylcarbonates stabilize the high molecular weight ubiquitin pools in cells and lysates. They also elicit cellular phenotypes associated with DUB inhibition, demonstrating their utility in ubiquitin discovery. Diarylcarbonates may also be a useful scaffold for the development of specific DUB inhibitors.
Subject(s)
Carbonates/pharmacology , Deubiquitinating Enzymes/antagonists & inhibitors , Enzyme Inhibitors/pharmacology , Carbonates/chemical synthesis , Carbonates/chemistry , Deubiquitinating Enzymes/metabolism , Dose-Response Relationship, Drug , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/chemistry , Humans , Molecular Structure , Structure-Activity Relationship , Ubiquitination/drug effectsABSTRACT
Although the roles of mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K) signaling in KRAS-driven tumorigenesis are well established, KRAS activates additional pathways required for tumor maintenance, the inhibition of which are likely to be necessary for effective KRAS-directed therapy. Here, we show that the IκB kinase (IKK)-related kinases Tank-binding kinase-1 (TBK1) and IKKε promote KRAS-driven tumorigenesis by regulating autocrine CCL5 and interleukin (IL)-6 and identify CYT387 as a potent JAK/TBK1/IKKε inhibitor. CYT387 treatment ablates RAS-associated cytokine signaling and impairs Kras-driven murine lung cancer growth. Combined CYT387 treatment and MAPK pathway inhibition induces regression of aggressive murine lung adenocarcinomas driven by Kras mutation and p53 loss. These observations reveal that TBK1/IKKε promote tumor survival by activating CCL5 and IL-6 and identify concurrent inhibition of TBK1/IKKε, Janus-activated kinase (JAK), and MEK signaling as an effective approach to inhibit the actions of oncogenic KRAS.
