Discovery of Potent and Selective Covalent Inhibitors of JNK

Abstract

The mitogen activated kinases JNK1/2/3 are key enzymes in signaling modules that transduce and integrate extracellular stimuli into coordinated cellular response. Here we report the discovery of the first irreversible inhibitors of JNK1/2/3. We describe two JNK3 co-crystal structures at 2.60 and 2.97 Å resolutions that show the compounds form covalent bonds with a conserved cysteine residue. JNK-IN-8 is a selective JNK inhibitor that inhibits phosphorylation of c-Jun, a direct substrate of JNK kinase, in cells exposed to sub-micromolar drug in a manner that depends on covalent modification of the conserved cysteine residue. Extensive biochemical, cellular and pathway-based profiling establish the selectivity of JNK-IN-8 for JNK and suggest that the compound will be broadly useful as a pharmacological probe of JNK-dependent signal transduction. Potential lead compounds have also been identified for kinases including IRAK1, PIK3C3, PIP4K2C, and PIP5K3.

An In Vivo Functional Screen Identifies JNK Signaling As a Modulator of Chemotherapeutic Response in Breast Cancer

“…To confirm that the effect of JNK downregulation was due to loss of JNK catalytic activity, 4T1-Luc cells were treated with increasing concentrations of three chemically distinct pan-JNK small-molecule inhibitors, SP600125 (28), JNK inhibitor VIII (29,30), and JNK-IN-8 (13). JNK inhibition was monitored by a decrease in Ser63 phosphorylation of the JNK downstream target c-Jun (Fig.…”

“…The JNK family of mitogen-activated protein kinases (MAPK) has been implicated in the pathogenesis of a number of tumor types, plus in other pathologies such as autoimmune disease (12,13). However, multiple roles have been proposed for these kinases, on one hand preventing malignant transformation via induction of apoptosis and on the other promoting cell survival in established tumors.…”

JNK1 stress signaling is hyper-activated in high breast density and the tumor stroma: Connecting fibrosis, inflammation, and stemness for cancer prevention

“…40 Thus, several JNK1 inhibitors (e.g., Leflunomide, CC-401, CC-930, XG-102, Bentamapimod) 41 are being developed clinically for the treatment and prevention of various fibrotic and inflammatory disorders, such as idiopathic pulmonary fibrosis (IPF), and dermal scarring (keloids), as well as cardiac fibrosis/heart failure and inflammatory bowel disease (IBD). 42 Other clinical uses for JNK1 inhibitors include the treatment of many other stress-related, aging-associated, and degenerative diseases, 43 such as hearing loss, ischemic brain disease (stroke), retinal neo-vascularization, uveitis, and metabolic syndrome, as well as diabetes. 44 Matrix stiffness has been implicated in the disease pathogenesis underlying high mammographic density.…”

Role of the MAPK/cJun NH 2 -terminal kinase signaling pathway in starvation-induced autophagy

“…To confirm the conclusion that MAPK8/9 suppresses autophagic flux in primary hepatocytes, we examined wild-type (WT) hepatocytes treated with JNK-IN-8, a potent and selective small molecule inhibitor of MAPK8/9 [41]. We found that treatment with JNK-IN-8 caused increased accumulation of LC3B-II following lysosomal inhibition (Figure.…”