Joseph Ischia1, Fred Saad, Martin Gleave. 1. Vancouver Prostate Centre and Department of Urologic Sciences, University of British Columbia, Vancouver, British Columbia bThe Division of Urology, University of Montreal Hospital Center (CHUM), University of Montreal, Montreal, Quebec, Canada.
Abstract
PURPOSE OF REVIEW: To present the recent advances in novel agents that target heat shock proteins (Hsps) to treat or delay the development of castration resistant prostate cancer (CRPC). RECENT FINDINGS: Multiple preclinical studies have shown that silencing Hsp27, Hsp90, or clusterin sensitizes prostate cancer cells to modern chemotherapy and radiation treatments; and overexpression of these chaperones confers resistance to these therapies. Antisense oligonucleotides targeting Hsp27 and clusterin have shown good biological activity in human phase II trials and phase III studies are ongoing. Despite promising preclinical efficacy, a number of phase I/II human trials with various Hsp90 inhibitors have been disappointing with negligible anticancer activity and dose-limiting toxicity profiles. Newer Hsp90 inhibitors with better toxicity profiles, and inhibitors that target Hsp90 cofactors, such as FKBP52, are currently being investigated in human studies. SUMMARY: Many Hsp chaperone client proteins are key components of alternative growth factor pathways upregulated in CRPC and are involved in key resistance pathways to current chemotherapy and radiotherapy regimes. New treatments that inhibit Hsps are attractive anticancer strategies as they have the ability to simultaneously target multiple pathways involved in CRPC.
PURPOSE OF REVIEW: To present the recent advances in novel agents that target heat shock proteins (Hsps) to treat or delay the development of castration resistant prostate cancer (CRPC). RECENT FINDINGS: Multiple preclinical studies have shown that silencing Hsp27, Hsp90, or clusterin sensitizes prostate cancer cells to modern chemotherapy and radiation treatments; and overexpression of these chaperones confers resistance to these therapies. Antisense oligonucleotides targeting Hsp27 and clusterin have shown good biological activity in human phase II trials and phase III studies are ongoing. Despite promising preclinical efficacy, a number of phase I/II human trials with various Hsp90 inhibitors have been disappointing with negligible anticancer activity and dose-limiting toxicity profiles. Newer Hsp90 inhibitors with better toxicity profiles, and inhibitors that target Hsp90 cofactors, such as FKBP52, are currently being investigated in human studies. SUMMARY: Many Hsp chaperone client proteins are key components of alternative growth factor pathways upregulated in CRPC and are involved in key resistance pathways to current chemotherapy and radiotherapy regimes. New treatments that inhibit Hsps are attractive anticancer strategies as they have the ability to simultaneously target multiple pathways involved in CRPC.
Authors: Laia Querol Cano; Derek N Lavery; Soraya Sin; Emma Spanjaard; Greg N Brooke; Jessica D Tilman; Ahmed Abroaf; Luke Gaughan; Craig N Robson; Rakesh Heer; Francesco Mauri; Johan de Rooij; Keltouma Driouch; Charlotte L Bevan Journal: Mol Oncol Date: 2014-09-06 Impact factor: 6.603