Alvespimycin (17-DMAG) is a potent inhibitor of Hsp90, binding to Hsp90 with an EC50 of 62 ± 29 nM.
Alvespimycin (17-DMAG) is a potent inhibitor of Hsp90, binding to Hsp90 with an EC50 of 62 nM. Alvespimycin (17-DMAG) inhibits the growth of the human cancer cell lines SKBR3 and SKOV3, which overexpress Hsp90 client protein Her2, and causes down-regulation of Her2 as well as induction of Hsp70 consistent with Hsp90 inhibition, for Her2 degradation with EC50 of 8 ± 4 nM and 46 ± 24 nM in SKBR3 and SKOV3 cells, respectively; for Hsp70 induction with EC50 of 4 ± 2 nM and 14 ± 7 nM in SKBR3 and SKOV3 cells, respectively[1]. Compared with the vehicle control, Alvespimycin (17-DMAG) dose-dependent apoptosis (P<0.001 averaged across 24- and 48-hour time points) at concentrations of 50 nM to 500 nM, which represent pharmacologically attainable doses. Similar to many other agents, Alvespimycin (17-DMAG) also demonstrates time-dependent apoptosis (P <0.001, averaged across all doses) in chronic lymphocytic leukemia (CLL) cells with extended exposure from 24 to 48 hours. In addition,Alvespimycin (17-DMAG) is much more potent after 24 and 48 hours of treatment than 17-AAG[2].
The tumors are grown for two months before the start of i.p. injections every four days over one month with 0, 50, 100 and 200 mg/kg dipalmitoyl-radicicol or 0, 5, 10 and 20 mg/kg Alvespimycin (17-DMAG). Despite sample heterogeneity, the HSP90 inhibitor-treated animals have significantly lower tumour volumes than the vehicle control-treated animals. HSP90 inhibitors have been shown to cause liver toxicity in an animal model of gastrointestinal cancer. Nevertheless, the reduction in tumor size using dipalmitoyl-radicicol is statistically significant at 100 mg/kg, while Alvespimycin (17-DMAG) at either 10 or 20 mg/kg elicits a significant reduction in tumor size[3].
References:
[1]. Ge J, et al. Design, synthesis, and biological evaluation of hydroquinone derivatives of 17-amino-17-demethoxygeldanamycin as potent, water-soluble inhibitors of Hsp90. J Med Chem. 2006 Jul 27;49(15):4606-15.
[2]. Hertlein E, et al. 17-DMAG targets the nuclear factor-kappaB family of proteins to induce apoptosis in chronic lymphocytic leukemia: clinical implications of HSP90 inhibition. Blood. 2010 Jul 8;116(1):45-53.
[3]. Henke A, et al. Reduced Contractility and Motility of Prostatic Cancer-Associated Fibroblasts after Inhibition of Heat Shock Protein 90. Cancers (Basel). 2016 Aug 24;8(9). pii: E77.