Conformation-Dependent Reversible Interaction of Ca/Calmodulin-Dependent Protein Kinase Kinase with an Inhibitor, TIM-063.

Ca/calmodulin-dependent protein kinase kinase (CaMKK), a Ca/CaM-dependent enzyme that phosphorylates and activates multifunctional kinases, including CaMKI, CaMKIV, protein kinase B/Akt, and 5'AMP-activated protein kinase, is involved in various Ca-signaling pathways in cells. Recently, we developed an ATP-competitive CaMKK inhibitor, TIM-063 (2-hydroxy-3-nitro-7-benzo[de]benzo[4,5]imidazo[2,1-a]isoquinolin-7-one, Ohtsuka et al. Biochemistry 2020, 59, 1701-1710).

Development and Characterization of Novel Molecular Probes for Ca/Calmodulin-Dependent Protein Kinase Kinase, Derived from STO-609.

Ca/calmodulin-dependent protein kinase kinase (CaMKK) activates particular multifunctional kinases, including CaMKI, CaMKIV, and 5'AMP-activated protein kinase (AMPK), resulting in the regulation of various Ca-dependent cellular processes, including neuronal, metabolic, and pathophysiological pathways. We developed and characterized a novel pan-CaMKK inhibitor, TIM-063 (2-hydroxy-3-nitro-7-benzo[de]benzo[4,5]imidazo[2,1-]isoquinolin-7-one) derived from STO-609 (7-benzimidazo[2,1-]benz[de]isoquinoline-7-one-3-carboxylic acid), and an inactive analogue (TIM-062) as molecular probes for the analysis of CaMKK-mediated cellular responses. Unlike STO-609, TIM-063 had an inhibitory activity against CaMKK isoforms (CaMKKα and CaMKKβ) with a similar potency ( = 0.

Inhibition of Hsp90 and 70 sensitizes melanoma cells to hyperthermia using ferromagnetic particles with a low Curie temperature.

Background: Heat shock protein (Hsp) 90 is a key regulator of various oncogene products and cell-signaling molecules, while Hsp70 protects against heat-induced apoptosis. We previously described a system in which hyperthermia was produced using thermosensitive ferromagnetic particles (FMPs) with a Curie temperature (T c) of 43 °C to mediate automatic temperature control, and demonstrated its antitumor effect in a mouse melanoma model. In the present study, the antitumor effects of combining Hsp90 inhibitor (17DMAG) and Hsp70 inhibitor (quercetin) with FMP-mediated hyperthermia were examined.