title: Copper as a target for prostate cancer therapeutics: copper-ionophore pharmacology and altering systemic copper distribution.
abstract: Copper-ionophores that elevate intracellular bioavailable copper display significant therapeutic utility against prostate cancer cells in vitro and in TRAMP (Transgenic Adenocarcinoma of Mouse Prostate) mice. However, the pharmacological basis for their anticancer activity remains unclear, despite impending clinical trails. Herein we show that intracellular copper levels in prostate cancer, evaluated in vitro and across disease progression in TRAMP mice, were not correlative with copper-ionophore activity and mirrored the normal levels observed in patient prostatectomy tissues (Gleason Score 7 & 9). TRAMP adenocarcinoma cells harbored markedly elevated oxidative stress and diminished glutathione (GSH)-mediated antioxidant capacity, which together conferred selective sensitivity to prooxidant ionophoric copper. Copper-ionophore treatments [CuII(gtsm), disulfiram & clioquinol] generated toxic levels of reactive oxygen species (ROS) in TRAMP adenocarcinoma cells, but not in normal mouse prostate epithelial cells (PrECs). Our results provide a basis for the pharmacological activity of copper-ionophores and suggest they are amendable for treatment of patients with prostate cancer. Additionally, recent in vitro and mouse xenograft studies have suggested an increased copper requirement by prostate cancer cells. We demonstrated that prostate adenocarcinoma development in TRAMP mice requires a functional supply of copper and is significantly impeded by altered systemic copper distribution. The presence of a mutant copper-transporting Atp7b protein (tx mutation: A4066G/Met1356Val) in TRAMP mice changed copper-integration into serum and caused a remarkable reduction in prostate cancer burden (64% reduction) and disease severity (grade), abrogating adenocarcinoma development. Implications for current clinical trials are discussed.
authors.affiliation: Centre for Cellular and Molecular Biology, School of Life and Environmental Sciences, Deakin University, Burwood, Victoria, Australia.
authors.forename: Delphine
authors.initials: D
authors.lastname: Denoyer
authors.affiliation: Research Division, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia.|Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, Victoria, Australia.
authors.forename: Helen B
authors.initials: HB
authors.lastname: Pearson
authors.affiliation: Centre for Cellular and Molecular Biology, School of Life and Environmental Sciences, Deakin University, Burwood, Victoria, Australia.
authors.forename: Sharnel A S
authors.initials: SA
authors.lastname: Clatworthy
authors.affiliation: Centre for Chemistry and Biotechnology, School of Life and Environmental Sciences, Deakin University, Waurn Ponds, Victoria, Australia.
authors.forename: Zoe M
authors.initials: ZM
authors.lastname: Smith
authors.affiliation: Centre for Chemistry and Biotechnology, School of Life and Environmental Sciences, Deakin University, Waurn Ponds, Victoria, Australia.
authors.forename: Paul S
authors.initials: PS
authors.lastname: Francis
authors.affiliation: Centre for Cellular and Molecular Biology, School of Life and Environmental Sciences, Deakin University, Burwood, Victoria, Australia.
authors.forename: Roxana M
authors.initials: RM
authors.lastname: Llanos
authors.affiliation: The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, Australia.
authors.forename: Irene
authors.initials: I
authors.lastname: Volitakis
authors.affiliation: Research Division, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia.|Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, Victoria, Australia.
authors.forename: Wayne A
authors.initials: WA
authors.lastname: Phillips
authors.affiliation: Centre for Cellular and Molecular Biology, School of Life and Environmental Sciences, Deakin University, Burwood, Victoria, Australia.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Meggyesy
authors.affiliation: Centre for Cellular and Molecular Biology, School of Life and Environmental Sciences, Deakin University, Burwood, Victoria, Australia.
authors.forename: Shashank
authors.initials: S
authors.lastname: Masaldan
authors.affiliation: Centre for Cellular and Molecular Biology, School of Life and Environmental Sciences, Deakin University, Burwood, Victoria, Australia.|Department of Pathology, The University of Melbourne, Parkville, Victoria, Australia.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Cater
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism*; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D003300:Copper / Q000378:metabolism*; D000073840:Copper-Transporting ATPases / Q000235:genetics; D007476:Ionophores / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D011471:Prostatic Neoplasms / Q000378:metabolism*
chemical_list: D000970:Antineoplastic Agents; D007476:Ionophores; D003300:Copper; C000612461:Atp7b protein, mouse; D000073840:Copper-Transporting ATPases
keywords: Atp7b; TRAMP; copper; ionophore; prostate cancer