Molecule

Description

Cancer

Description

CHIR-98014 is a potent and selective GSK-3 inhibitor for GSK-3ɑ and GSK-3β with IC50 of 0.65 nM and 0.58 nM, respectively.

Targets

IC₅₀

In Vitro

CHIR-98014 inhibits human GSK-3β with K_i of 0.87 nM. CHIR-98014 is very effective in preventing murine and rat GSK-3. Although CHIR-98014 acts as a simple competitive inhibitor of ATP binding, it displays from 500-fold to >1000-fold selectivity for GSK-3 versus 20 other protein kinases including Cdc2, ERK2, Tie-2 and KDR. CHIR-98014 prevents Cdc2 with IC50 of 3.7 μM. However, CHIR 98014 reveals similar ptoency against the highly homologous ɑ and β isoforms of GSK-3, it is noteworthy that it stronly discriminated between GSK-3 and its closest homologs CDC2 and ERK2. Exposure of insulin receptor-expressing CHO-IR cells or primary rat hepatocytes to increasing concentrations of inhibitor CHIR98014 results in a two- to three-fold stimulation of the GS activity ratio above basal. The concentrations of CHIR-98014 giving rise to half-maximal GS stimulation (EC50) is 106 nM and 107 nM for CHO-IR and rat hepatocytes, respectively. ^[1]

In Vivo

GSK-3 inhibitor CHIR-98014 activates the GS activity ratio in isolated type I skeletal muscle from insulin-sensitive lean Zucker and from insulin-ressitant ZDF rats. Soleus muscle isolated from ZDF rats shows significant resistance to insulin for activation of GS but responded to 500 nM CHIR-98014 to the same extent (40% increase) as muscle from lean Zucker rats. Notably, GS activation by insulin plus CHIR-98014 is additive in muscle from lean Zucker rats and greater than additive in muscle from the ZDF rats. Total GS activity is not altered by either CHIR-98014 or insulin in these cells and muscles. Meanwhile, CHIR-98014 does not influence the insulin dose-response in muscle from lean animals. The reduction in hyperglycemia and improved glucose disposal are not limited to db/db mice and ZDF rats, as similar results are observed with ob/ob mice, diet-induced diabetic C57BL/6 mice, and glucose-intolerant SHHF rats treated with CHIR-98014. ^[1] Additionally, CHIR-98014 decreases the phosphorylation (Ser396) of tau protein in the cortex and hippocampus of postnatal rats. ^[2]

Clinical Trials

Features

Kinase assays

Polypropylene 96-well plates are ?lled with 300 μL/well buffer (50 mM tris HCl, 10 mM MgCl₂, 1 mM EGTA, 1 mM dithiothreitol, 25 mM β-glycerophosphate, 1 mM NaF, 0.01% BSA, pH 7.5) containing kinase, peptide substrate, and any activators. CHIR-98014 or controls are added in 3.5 μL of DMSO, followed by 50 μL of ATP stock to yield a ?nal concentration of 1 μM ATP in all cell-free assays. After incubation, triplicate 100-μL aliquots are transferred to Combiplate eight plates containing 100 μL/well 50 μM ATP and 20 mM EDTA. After 1 hour, the wells are rinsed ?ve times with PBS, ?lled with 200 μL of scintillation ?uid, sealed, left 30 min, and counted in a scintillation counter. All steps are performed at room temperature.

Cell Lines

CHO-IR cells

Concentrations

0.01-10 μM

Incubation Time

30 min

Methods

Animal Models

db/db mice with 8-9 weeks

Formulation

15% Captisol/citrate vehicle

Doses

30 mg/kg

Administration

Subcutaneously