PU-H71 (hydrate)

The heat shock protein 90 (HSP90) family of proteins are molecular chaperones involved in folding, activation, maturation, and assembly of different proteins, including the mediators of signal transduction and cell cycle progression. A class of inhibitors targeting HSP90 has emerged in anti-cancer therapy. PU-H71 (hydrate) is a purine scaffold HSP90 inhibitor that has potent in vitro anti-myeloma activity in both drug-sensitive (MM-1S, RPMI-8226/S, INA-6, NCI-H929, U266) and drug-resistant (MM-1R, RPMI-8226/Dox40, OMP-1) human myeloma cell lines (IC50s = 100-300 nM). It also demonstrates considerable efficacy inhibiting growth of triple-negative breast cancer tumor cell lines MDA-MB-468, MDA-MB-231, and HCC-1806 (IC50s = 65, 140, and 87 nM, respectively), diffuse large B-cell lymphomas (GI50 = 1.39 µM), and various hepatocellular carcinoma cell lines (GI50s < 3 µM).