STAT3 Inhibitor VIII, 5,15-DPP

A cell-permeable porphyrin compound that binds STAT3 (K_D = 880 nM by SPR) and prevents STAT3 SH2 domain-mediated ligand binding (IC₅₀ = 280 nM) and dimerization (~60% inhibition at 50 µM in HEK293), while exhibiting much reduced activity against STAT1 ligand binding (IC₅₀ = 10 µM) and no activity againt Grb2 ligand binding even at concentrations as high as 20 µM. One day 5,15-DPP pre-treatment (50 µM) of MDA-MB-468 cultures is shown to greatly inhibit IL-6-induced STAT3, but not STAT1/5a/5b, nuclear translocation (by >90%) and nuclear STAT3 c-myc promoter binding activity, resulting in a more than 90% reduction in cellular c-myc protein level.

A cell-permeable porphyrin compound that directly binds to STAT3, prevents STAT3 dimerization and acts as a STAT3-SH2 domain antagonist with selectivity over STAT1 and Grb2 (IC₅₀ = 0.28, 10 and >20 µM, respectively). Shown to preferentially suppress STAT3 nuclear translocation and subsequent DNA binding in MDA-MB-468 cells with negligible effect on STAT1, STAT5a and STAT5b; further, reduce c-myc promoter binding and c-myc protein expression in IL-6 induced HEK-293-STAT3 cells. Does neither affect JAK kinase activity nor lower the expression or the phosphorylation levels of STAT3.

Packaged under inert gas

Following reconstitution, aliquot and freeze (-20°C). Stock solutions are stable for up to 6 months at -20°C.

Uehara, Y., et al. 2009. Biochem. Biophys. Res. Commun.380, 627.

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

Toxicity: Standard Handling (A)