Potent triazolothione inhibitor of heat-shock protein-90.
Feldman, R.I., Mintzer, B., Zhu, D., Wu, J.M., Biroc, S.L., Yuan, S., Emayan, K., Chang, Z., Chen, D., Arnaiz, D.O., Bryant, J., Ge, X.S., Whitlow, M., Adler, M., Polokoff, M.A., Li, W.W., Ferrer, M., Sato, T., Gu, J.M., Shen, J., Tseng, J.L., Dinter, H., Buckman, B.(2009) Chem Biol Drug Des 74: 43-50
- PubMed: 19519743 
- DOI: https://doi.org/10.1111/j.1747-0285.2009.00833.x
- Primary Citation of Related Structures:  
3HHU - PubMed Abstract: 
Heat-shock protein-90 is an attractive target for anticancer drugs, as heat-shock protein-90 blockers such as the ansamycin 17-(allylamino)-17-demethoxygeldanamycin greatly reduce the expression of many signaling molecules that are disregulated in cancer cells and are key drivers of tumor growth and metastasis. While 17-(allylamino)-17-demethoxygeldanamycin has shown promise in clinical trials, this compound class has significant template-related drawbacks. In this paper, we describe a new, potent non-ansamycin small-molecule inhibitor of heat-shock protein-90, BX-2819, containing resorcinol and triazolothione rings. Structural studies demonstrate binding of BX-2819 to the ADP/ATP-binding pocket of heat-shock protein-90. The compound blocked expression of heat-shock protein-90 client proteins in cancer cell lines and inhibited cell growth with a potency similar to 17-(allylamino)-17-demethoxygeldanamycin. In a panel of four cancer cell lines, BX-2819 blocked growth with an average IC(50) value of 32 nM (range of 7-72 nM). Efficacy studies demonstrated that treatment with BX-2819 significantly inhibited the growth of NCI-N87 and HT-29 tumors in nude mice, consistent with pharmacodynamic studies showing inhibition of heat-shock protein-90 client protein expression in tumors for greater than 16 h after dosing. These data support further studies to assess the potential of BX-2819 and related analogs for the treatment of cancer.
Organizational Affiliation: 
Bayer Healthcare, 2600 Hilltop Drive, Richmond, CA 94804, USA. rick.feldman@bayer.com