Hinge Binder Scaffold Hopping Identifies Potent Calcium/Calmodulin-Dependent Protein Kinase Kinase 2 (CAMKK2) Inhibitor Chemotypes

Abstract

CAMKK2 is a serine/threonine kinase and an activator of AMPK whose dysregulation is linked with multiple diseases. Unfortunately, STO-609, the tool inhibitor commonly used to probe CAMKK2 signaling, has limitations. To identify promising scaffolds as starting points for the development of high-quality CAMKK2 chemical probes, we utilized a hinge-binding scaffold hopping strategy to design new CAMKK2 inhibitors. Starting from the potent but promiscuous disubstituted 7-azaindole GSK650934, a total of 32 compounds, composed of single-ring, 5,6-, and 6,6-fused heteroaromatic cores, were synthesized. The compound set was specifically designed to probe interactions with the kinase hinge-binding residues. Compared to GSK650394 and STO-609, 13 compounds displayed similar or better CAMKK2 inhibitory potency in vitro , while compounds 13g and 45 had improved selectivity for CAMKK2 across the kinome. Our systematic survey of hinge-binding chemotypes identified several potent and selective inhibitors of CAMKK2 to serve as starting points for medicinal chemistry programs.

Systemic ablation of Camkk2 impairs metastatic colonization and improves insulin sensitivity in TRAMP mice: Evidence for cancer cell-extrinsic CAMKK2 functions in prostate cancer

“…Efforts are ongoing by multiple groups to develop new potent and selective CAMKK2 inhibitors with the goal to create a clinical-grade drug for use in patient trials [24,34-38]. The data presented here indicate that CAMKK2 inhibitors may have additional benefits for patients beyond what was initially anticipated.…”

“…However, prior reports suggesting roles for CAMKK2 in an AR-cell line in culture [33] and here in vivo indicate roles for CAMKK2 even in AR-indifferent prostate cancers. Given the lack of effective treatments for this highly aggressive cancer subtype, it suggests that the use of CAMKK2 inhibitors, which are currently in development [24,34-38], warrant further investigation for the treatment of NEPC.…”

“…Protein concentrations were measured using Bradford’s reagent. Immunoblotting was conducted as before [24].…”

Systemic Ablation of Camkk2 Impairs Metastatic Colonization and Improves Insulin Sensitivity in TRAMP Mice: Evidence for Cancer Cell-Extrinsic CAMKK2 Functions in Prostate Cancer

“…Pieces of mouse brains (specifically cerebellum) were resected and homogenized using a handheld homogenizer in 1 mL ice-cold RIPA buffer and agitated at 4 °C for 1 h. Protein concentrations were measured using Bradford’s reagent (Protein Assay Dye Reagent Concentrate, Cat #5000006; Bio-Rad Laboratories, Hercules, CA, USA). Immunoblotting was conducted as before [ 27 ].…”

Unravelling the Role of Kinases That Underpin Androgen Signalling in Prostate Cancer

“…However, this potentially could be the accumulated effect of several inhibited kinases [122]. The process to develop small-molecule inhibitors is ongoing, with the hinge region of CAMKK2 as the main target for achieving CAMKK2 inhibition [122,125,126].…”