NSC95397 (2,3-bis-[(2-hydroxyethyl)thio]-1,4-
naphthoquinone) is a CDC25 inhibitor with anti-
cancer properties. Since the anti-inflammatory activity of this compound has not yet been explored, the aim of this study was to examine whether this compound is able to modulate the inflammatory process.
Toll like receptor (TLR)-mediated inflammatory responses were induced by
lipopolysaccharide (LPS), a TLR4
ligand, and pam3CSK, a TLR2
ligand, in peritoneal macrophages and RAW264.7. The molecular mechanism of
NSC95397's anti-inflammatory activity was studied using immunoblotting analysis, nuclear fractionation, immunoprecipitation, overexpression strategies,
luciferase reporter gene assays, and
kinase assays.
NSC95397 dose-dependently suppressed the production of
nitric oxide (NO),
tumor necrosis factor (TNF)-α, and
prostaglandin (PG)E2, and diminished the
mRNA expression of inflammatory genes such as inducible
NO synthase (iNOS),
cyclooxygenase (COX)-2,
interferon (IFN)-β, and TNF-α in peritoneal macrophages and RAW264.7 cells that were stimulated by LPS and pam3CSK. This compound also clearly blocked the activation of NF-κB (p65),
AP-1 (c-Fos/c-Jun), and IRF-3 in LPS-treated RAW264.7 cells and TRIF- and MyD88-overexpressing HEK293 cells. In addition, biochemical and molecular approaches revealed that this compound targeted AKT, IKKα/β, MKK7, and TBK1. Therefore, these results suggest that the anti-inflammatory function of
NSC95397 can be attributed to its inhibition of multiple targets such as AKT, IKKα/β, MKK7, and TBK1.