A Repurposing Strategy for Hsp90 Inhibitors Demonstrates Their Potency against Filarial Nematodes

作者:Gillan Victoria*; O'Neill Kerry; Maitland Kirsty; Sverdrup Francis M; Devaney Eileen
来源:PLoS Neglected Tropical Diseases, 2014, 8(2): e2699.
DOI:10.1371/journal.pntd.0002699

摘要

Novel drugs are required for the elimination of infections caused by filarial worms, as most commonly used drugs largely target the microfilariae or first stage larvae of these infections. Previous studies, conducted in vitro, have shown that inhibition of Hsp90 kills adult Brugia pahangi. As numerous small molecule inhibitors of Hsp90 have been developed for use in cancer chemotherapy, we tested the activity of several novel Hsp90 inhibitors in a fluorescence polarization assay and against microfilariae and adult worms of Brugia in vitro. The results from all three assays correlated reasonably well and one particular compound, NVP-AUY922, was shown to be particularly active, inhibiting Mf output from female worms at concentrations as low as 5.0 nanomolar after 6 days exposure to drug. NVP-AUY922 was also active on adult worms after a short 24 h exposure to drug. Based on these in vitro data, NVP-AUY922 was tested in vivo in a mouse model and was shown to significantly reduce the recovery of both adult worms and microfilariae. These studies provide proof of principle that the repurposing of currently available Hsp90 inhibitors may have potential for the development of novel agents with macrofilaricidal properties. Author Summary Adult filarial worms are long-lived nematode parasites that have proved very difficult to kill with existing drugs. Current campaigns for the control or elimination of these parasites are largely based on treatment with drugs such as diethylcarbamazine or ivermectin, that preferentially kill the first stage larvae of the parasite, the microfilariae. As microfilariae repopulate the body from unaffected adult worms, repeated dosing with these drugs is required over the long reproductive life span of the worm. The availability of compounds with macrofilaricidal activity would help facilitate the goal of controlling filarial infections. Hsp90 is a recognized target in tumor cells: consequently many oncology programs have developed small molecule inhibitors of Hsp90, several of which are commercially available. Here we provide proof of principle that inhibition of Hsp90 is lethal to adult Brugia worms in vivo, as well as in vitro, suggesting that these compounds may have potential for further development as macrofilaricidal drugs.

  • 出版日期2014-2