STAT3 Inhibitor IX, Cpd188

A cell-permeable naphthol compound that inhibits IL-6-stimulated STAT3 Tyr⁷⁰⁵ phosphorylation and nuclear translocation in HepG2 cells (IC₅₀ = 73 and 39 µM, respectively) by targeting STAT3 SH2 domain peptide-binding pocket (IC₅₀ = 20 µM against EGFR-derived pY-peptide binding), while exhibiting little effect against IFN-γ-stimulated HepG2 cellular STAT1 phosphorylation even at concentrations as high as 300 µM. Shown to preferentially induce apoptosis in cultures expressing constitutively active STAT3 (EC₅₀ = 0.73, 3.96, and 7.01 µM in MDA-MB-468, MDA-MB-231, and MDA-MB-435 cultures, respectively), while being less effective against cells without constitutively active STAT3 (EC₅₀ = 15.5 and 17.19 µM in MDA-MB-453 and MCF7 cultures, respectively).

Packaged under inert gas

Toxicity: Standard Handling (A)

Following reconstitution, aliquot and freeze (-20°C). Stock solutions are stable for up to 3 months at -20°C.

Xu, X., et al. 2009. PLoS One4, e4783.

CALBIOCHEM is a registered trademark of Merck KGaA, Darmstadt, Germany