Molecular Weight (MW)

356.17

Formula

C16H10BrN3O2

CAS No.

667463-62-9

Storage

-20℃ for 3 years in powder form

-80℃ for 2 years in solvent

Solubility (In vitro)

DMSO: 71 mg/mL (199.3 mM)

Water: <1 mg/mL

Ethanol: 21 mg/mL (59.0 mM)

Solubility (In vivo)

30% PEG400+0.5% Tween80+5% propylene glycol: 30 mg/mL

Synonyms

GSK-3 Inhibitor IX, 6-bromoindirubin-3-oxime; BIO; GSK 3 Inhibitor IX; MLS 2052; MLS-2052; MLS2052.

In Vitro

In vitro activity: BIO (6-bromoindirubin-3'-oxime) is a specific inhibitor of glycogen synthase kinase-3 (GSK-3), with IC50 of 5 nM for GSK-3α/β, shows>16-fold selectivity over CDK5. BIO interacts within the ATP binding pocket of these kinases, reduces β-catenin phosphorylation on a GSK-3-specific site in cellular models, closely mimicks Wnt signaling in Xenopus embryos. In human and mouse embryonic stem cells, BIO maintains the undifferentiated phenotype and sustains expression of the pluripotent state-specific transcription factors Oct-3/4, Rex-1 and Nanog. BIO-mediated Wnt activation is functionally reversible, as withdrawal of the compound leads to normal multidifferentiation programs in both human and mouse embryonic stem cells. BIO promotes proliferation in mammalian cardiomyocytes. 6BIO is also a pan-JAK inhibitor, with IC50 values of 0.03, 1.5, 8.0, 0.5 μM for TYK2, JAK1, JAK2 and JAK3. BIO selectively inhibits phosphorylation of STAT3 and induces apoptosis of human melanoma cells

Kinase Assay: Kinase activities are assayed in Buffer A or C at 30°C, at a final ATP concentration of 15 μM. Blank values are subtracted and activities calculated as pmoles of phosphate incorporated during a 10 min incubation. Controls are performed with appropriate dilutions of dimethylsulfoxide. In a few cases phosphorylation of the substrate is assessed by autoradiography after SDS-PAGE. GSK-3α/β is purified from porcine brain by affinity chromatography on immobilized axin. It is assayed, following a 1/100 dilution in 1 mg BSA/ml 10 mM DTT, with 5 μl 40 μM GS-1 peptide, a specific GSK-3 substrate, (YRRAAVPPSPSLSRHSSPHQSpEDEEE), in buffer A, in the presence of 15 μM [γ-32P] ATP (3,000 Ci/mmol; 1 mCi/ml) in a final volume of 30 μl. After 30 min incubation at 30°C, 25 μl aliquots of supernatant are spotted onto 2.5 × 3 cm pieces of Whatman P81 phosphocellulose paper, and 20 seconds later, the filters are washed five times (for at least 5 min each time) in a solution of 10 ml phosphoric acid/liter of water. The wet filters are counted in the presence of 1 ml ACS scintillation fluid.

Cell Assay: COS1, Hepa (wild-type, CEM/LM AhR deficient and ELB1 ARNT deficient), or SH-SY5Y cells are grown in 6 cm culture dishes in Dulbecco's Modified Medium (DMEM) containing 10% fetal bovine serum. For treatment, IO (5 μM), BIO (5 or 10 μM), MeBIO (5 or 50 μM), LiCl (20 or 40 mM), or mock solution (DMSO, 0.5% final concentration) is added to medium when cell density reaches ~70% confluence. After 12 (SH-SY5Y) or 24 hours, the cells, while still in plate, are lysed with lysis buffer (1% SDS, 1 mM sodium orthovanadate, 10 mM Tris [pH 7.4]). The lysate is passed several times through a 26G needle, centrifuged at 10,000 × g for 5 min, and adjusted to equal protein concentration. About 8 μg of each sample is loaded for immunoblotting. Enhanced chemiluminescence is used for detection. The following primary antibodies are used: mouse anti-β-catenin CT (Upstate Biotechnolgies, Clone 7D8, recognizes total β-catenin), mouse anti-phospho-β-catenin (Upstate Biotechnologies, Clone 8E7, recognizes dephosphorylated β-catenin), mouse anti-GSK-3 β, mouse anti-GSK-3 phosphoTyr216, rabbit anti-AhR (Aryl hydrocarbon receptor), and rabbit anti-actin.

In Vivo

BIO suppresses melanoma tumor growth in a mouse xenograft model.

Animal model

Xenopus laevis embryos model

Formulation & Dosage

Dissolved in 30% Solutol (Basf) at a concentration of 10 mg/mL; 50 mg/kg; Oral gavage

References

Chem Biol. 2003 Dec;10(12):1255-66; Nat Med. 2004 Jan;10(1):55-63; Cancer Res. 2011 Jun 1;71(11):3972-9.