Abstract 23: Sanguinarine suppresses survivin expression and inhibits the growth of prostate cancer cells

Abstract

Abstract Background: Prostate cancer is a frequently occurring disease and is the second leading cause of cancer related deaths of men in the United States. Current treatments have proved inadequate in curing or controlling prostate cancer and a search for agents for the management of this disease is urgently needed. Survivin plays an important role in both progression of castration-resistant prostate cancer and resistance to chemotherapy. Altered expression of survivin in prostate cancer cells is associated with cancer progression, drug/radiation resistance, poor prognosis and short patient survival. Methods: We performed a cell based rapid screen of the Prestwick Chemical Library consisting of 1120 FDA-approved compounds with known safety and bioavailability in humans to identify potential inhibitors of survivin and anti-cancer agents for prostate cancer. Results: Sanguinarine, a benzophenanthridine alkaloid derived primarily from the bloodroot plant, was identified as a novel inhibitor of survivin that selectively kills prostate cancer cells over “normal” prostate epithelial cells. We found that sanguinarine inhibits survivin protein expression through protein degradation via the ubiquitin-proteasome system. Sanguinarine induces apoptosis and inhibits tumor formation and growth of human prostate cancer cells. Administration of sanguinarine, beginning 3 days post ectopic implantation of DU145 human prostate cancer cells, reduces both tumor weight and volume by more than 70% compared to the control treated mice with no apparent toxicity. In addition, sanguinarine sensitized prostate cancer cells to paclitaxel-mediated growth inhibition and apoptosis, offering a potential therapeutic strategy for overcoming taxol resistance. Conclusions: These results suggest that sanguinarine may be developed as an agent either alone or in combination with taxol for treatment of castration-resistant prostate cancer overexpressing survivin. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 23.