Geldanamycin (GA) is a benzoquinone-containing ansamycin that inhibits heat shock protein 90. GA derivatives are being evaluated as anti-neoplastic agents, but their utility against parasites whose heat shock proteins (Hsps) have homology with human Hsp90 is unknown. The activities of four synthetic GA derivatives were tested in vitro using adult Brugia malayi and Schistosoma japonicum. Two of the derivatives, 17-N-allyl-17-demethoxygeldanamycin (17-AAG) and 17-N-(2-dimethylaminoethylamino)-17-demethoxygeldanamycin (DMAG), are currently in human clinical trials as anticancer drugs. Using concentrations considered safe peak plasma concentrations for these two derivatives, all four derivatives were active against both parasites. The less toxic derivative 17-AAG was as effective as GA in killing S. japonicum, and both DMAG and 5′-bromogeldanoxazinone were more active than 17-AAG against B. malayi. This work supports continued evaluation of ansamycin derivatives as broad spectrum antiparasitic agents. 1. Introduction Heat shock proteins (Hsps) play critical roles in diverse biological processes including cellular development and homeostasis. Heat shock protein 90 (Hsp90) is an abundant and important eukaryotic cytosolic ATP-binding protein that serves as a chaperone in cellular processes including apoptosis and proliferation [1, 2]. Geldanamycin (GA; 1 in Figure 1) is a naturally occurring benzoquinone ansamycin, originally isolated from Streptomyces hygroscopicus [3]. GA binds to the ATP-binding pocket of Hsp90, specifically inhibiting ATPase activity [4, 5] and therefore it has been evaluated for its antiproliferative effects in oncogenesis in vitro and in vivo with promising application as a novel anti-cancer therapy [6, 7].Several laboratories have reported activity of GA against the Hsp of Plasmodium falciparum and Brugia pahangi; however other nematodes with conserved Hsp such as Caenorhabditis elegans are not affected by GA, suggesting possible conformational heterogeneity of Hsp between species [8, 9]. A less toxic derivative of geldanamycin, 17-N-allyl-17-demethoxygeldanamycin [10] (17-AAG; 2 in Figure 1), is now in phase II clinical trials [11, 12] in humans with neoplastic disorders. Phase I trials with 17-AAG showed safety profiles for dosing schedules with peak plasma concentrations of ca. 10？μM [13–15]. A second 17-amino-substituted geldanamycin derivative, 17-N-(2-dimethylaminoethylamino)-17-demethoxygeldanamycin (DMAG; 3 in Figure 1), is now undergoing phase I clinical trials [16]. However, neither of these compounds is currently widely
References
[1]
L. H. Pearl and C. Prodromou, “Structure and mechanism of the Hsp90 molecular chaperone machinery,” Annual Review of Biochemistry, vol. 75, pp. 271–294, 2006.
[2]
R. Zhao and W. A. Houry, “Hsp90: a chaperone for protein folding and gene regulation,” Biochemistry and Cell Biology, vol. 83, no. 6, pp. 703–710, 2005.
[3]
C. DeBoer, P. A. Meulman, R. J. Wnuk, and D. H. Peterson, “Geldanamycin, a new antibiotic,” Journal of Antibiotics, vol. 23, no. 9, pp. 442–447, 1970.
[4]
C. E. Stebbins, A. A. Russo, C. Schneider, N. Rosen, F. U. Hartl, and N. P. Pavletich, “Crystal structure of an Hsp90-geldanamycin complex: targeting of a protein chaperone by an antitumor agent,” Cell, vol. 89, no. 2, pp. 239–250, 1997.
[5]
J. P. Grenert, W. P. Sullivan, P. Fadden et al., “The amino-terminal domain of heat shock protein 90 (hsp90) that binds geldanamycin is an ATP/ADP switch domain that regulates hsp90 conformation,” Journal of Biological Chemistry, vol. 272, no. 38, pp. 23843–23850, 1997.
[6]
U. Banerji, I. Judson, and P. Workman, “The clinical applications of heat shock protein inhibitors in cancer—present and future,” Current Cancer Drug Targets, vol. 3, no. 5, pp. 385–390, 2003.
[7]
P. Workman, “Combinatorial attack on multistep oncogenesis by inhibiting the Hsp90 molecular chaperone,” Cancer Letters, vol. 206, no. 2, pp. 149–157, 2004.
[8]
C. L. David, H. E. Smith, D. A. Raynes, E. J. Pulcini, and L. Whitesell, “Expression of a unique drug-resistant Hsp90 ortholog by the nematode Caenorhabditis elegans,” Cell Stress and Chaperones, vol. 8, no. 1, pp. 93–104, 2003.
[9]
N. A. Him, V. Gillan, R. D. Emes, K. Maitland, and E. Devaney, “Hsp-90 and the biology of nematodes,” BMC Evolutionary Biology, vol. 9, no. 1, article no. 254, 2009.
[10]
E. A. Sausville, J. E. Tomaszewski, and P. Ivy, “Clinical development of 17-allylamino, 17-demethoxygeldanamycin,” Current Cancer Drug Targets, vol. 3, no. 5, pp. 377–383, 2003.
[11]
E. I. Heath, M. Gaskins, H. C. Pitot et al., “A phase II trial of 17-allylamino-17-demethoxygeldanamycin in patients with hormone-refractory metastatic prostate cancer,” Clinical Prostate Cancer, vol. 4, no. 2, pp. 138–141, 2005.
[12]
E. A. Ronnen, G. V. Kondagunta, N. Ishill et al., “A phase II trial of 17-(Allylamino)-17-demethoxygeldanamycin in patients with papillary and clear cell renal cell carcinoma,” Investigational New Drugs, vol. 24, no. 6, pp. 543–546, 2006.
[13]
R. K. Ramanathan, M. J. Egorin, J. L. Eiseman et al., “Phase I and pharmacodynamic study of 17-(allylamino)-17- demethoxygeldanamycin in adult patients with refractory advanced cancers,” Clinical Cancer Research, vol. 13, no. 6, pp. 1769–1774, 2007.
[14]
R. Bagatell, L. Gore, M. J. Egorin et al., “Phase I pharmacokinetic and pharmacodynamic study of 17-N-allylamino-17- demethoxygeldanamycinin pediatric patients with recurrent or refractory solid tumors: a pediatric oncology experimental therapeutics investigators consortium study,” Clinical Cancer Research, vol. 13, no. 6, pp. 1783–1788, 2007.
[15]
B. J. Weigel, S. M. Blaney, J. M. Reid et al., “A phase I study of 17-allylaminogeldanamycin in relapsed/refractory pediatric patients with solid tumors: a children's oncology group study,” Clinical Cancer Research, vol. 13, no. 6, pp. 1789–1793, 2007.
[16]
A. J. Murgo, S. Kummar, E. R. Gardner, et al., “Phase I trial of 17-dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG) administered twice weekly,” Journal of Clinical Oncology, vol. 25, p. 3566, 2007.
[17]
R. C. Schnur and M. L. Corman, “Tandem [3,3]-sigmatropic rearrangements in an ansamycin: stereospecific conversion of an (S)-allylic alcohol to an (S)-allylic amine derivative,” Journal of Organic Chemistry, vol. 59, no. 9, pp. 2581–2584, 1994.
[18]
Y. Shen, Q. Xie, M. Norberg, E. Sausville, G. Vande Woude, and D. Wenkert, “Geldanamycin derivative inhibition of HGF/SF-mediated Met tyrosine kinase receptor-dependent urokinase-plasminogen activation,” Bioorganic and Medicinal Chemistry, vol. 13, no. 16, pp. 4960–4971, 2005.
[19]
K. L. Rinehart Jr., M. W. McMillan, and T. R. Witty, “Synthesis of phenazine and phenoxazinone derivatives of geldanamycin as potential polymerase inhibitors,” Bioorganic Chemistry, vol. 6, no. 3, pp. 353–369, 1977.
[20]
R. C. Schnur, M. L. Corman, R. J. Gallaschun et al., “erbB-2 oncogene inhibition by geldanamycin derivatives: synthesis, mechanism of action, and structure-activity relationships,” Journal of Medicinal Chemistry, vol. 38, no. 19, pp. 3813–3820, 1995.
[21]
B. Chen, D. Zhong, and A. Monteiro, “Comparative genomics and evolution of the HSP90 family of genes across all kingdoms of organisms,” BMC Genomics, vol. 7, article no. 156, 2006.
[22]
P. Chène, “ATPases as drug targets: learning from their structure,” Nature Reviews Drug Discovery, vol. 1, no. 9, pp. 665–673, 2002.
[23]
E. Devaney, K. O'Neill, W. Harnett, L. Whitesell, and J. H. Kinnaird, “Hsp90 is essential in the filarial nematode Brugia pahangi,” International Journal for Parasitology, vol. 35, no. 6, pp. 627–636, 2005.
[24]
S. R. Pavithra, R. Kumar, and U. Tatu, “Systems analysis of chaperone networks in the malarial parasite Plasmodium falciparum,” PLoS Computational Biology, vol. 3, no. 9, pp. 1701–1715, 2007.
[25]
R. Kumar, A. Musiyenko, and S. Barik, “The heat shock protein 90 of Plasmodium falciparum and antimalarial activity of its inhibitor, geldanamycin,” Malaria Journal, vol. 2, no. 1, article 30, 2003.
[26]
G. Banumathy, V. Singh, S. R. Pavithra, and U. Tatu, “Heat shock protein 90 function is essential for Plasmodium falciparum growth in human erythrocytes,” Journal of Biological Chemistry, vol. 278, no. 20, pp. 18336–18345, 2003.
[27]
S. Townson, B. Ramirez, F. Fakorede, M. A. Mouries, and S. Nwaka, “Challenges in drug discovery for novel antifilarials,” Expert Opinion on Drug Discovery, vol. 2, no. 1, pp. S63–S73, 2007.
[28]
M. Kron, F. Yousif, and B. Ramirez, “Capacity building in anthelmintic drug discovery,” Expert Opinion on Drug Discovery, vol. 2, no. 1, pp. S75–S82, 2007.
[29]
K. M. Wasan, D. R. Brocks, S. D. Lee, K. Sachs-Barrable, and S. J. Thornton, “Impact of lipoproteins on the biological activity and disposition of hydrophobic drugs: implications for drug discovery,” Nature Reviews Drug Discovery, vol. 7, no. 1, pp. 84–99, 2008.
[30]
B. Ramirez, Q. Bickle, F. Yousif, F. Fakorede, M. A. Mouries, and S. Nwaka, “Schistosomes: challenges in compound screening,” Expert Opinion on Drug Discovery, vol. 2, no. 1, pp. S53–S61, 2007.
[31]
I. Saenger, G. Laemmler, and P. Kimmig, “Filarial infections of Mastomys natalensis and their relevance for experimental chemotherapy,” Acta Tropica, vol. 38, no. 3, pp. 277–288, 1981.
[32]
K. E. Kinnamon, R. R. Engle, B. T. Poon, W. Y. Ellis, J. W. McCall, and M. T. Dzimianski, “Anticancer agents suppressive for adult parasites of filariasis in mongolian jirds,” Experimental Biology and Medicine, vol. 224, no. 1, pp. 45–49, 2000.
[33]
L. Pica-Mattoccia, M. J. Doenhoff, C. Valle et al., “Genetic analysis of decreased praziquantel sensitivity in a laboratory strain of Schistosoma mansoni,” Acta Tropica, vol. 111, no. 1, pp. 82–85, 2009.
[34]
T. Taldone, V. Gillan, W. Sun et al., “Assay strategies for the discovery and validation of therapeutics targeting Brugia pahangi Hsp90,” PLoS Neglected Tropical Diseases, vol. 4, no. 6, article e714, 2010.
[35]
J. R. Sydor, E. Normant, C. S. Pien et al., “Development of 17-allylamino-17-demethoxygeldanamycin hydroquinone hydrochloride (IPI-504), an anti-cancer agent directed against Hsp90,” Proceedings of the National Academy of Sciences of the United States of America, vol. 103, no. 46, pp. 17408–17413, 2006.
[36]
C. S？ti, E. Nagy, Z. Giricz, L. Vígh, P. Csermely, and P. Ferdinandy, “Heat shock proteins as emerging therapeutic targets,” British Journal of Pharmacology, vol. 146, no. 6, pp. 769–780, 2005.
