Increasing intracellular bioavailable copper selectively targets prostate cancer cells.

The therapeutic efficacy of two bis(thiosemicarbazonato) copper complexes, glyoxalbis[N4-methylthiosemicarbazonato]Cu(II) [Cu(II)(gtsm)] and diacetylbis[N4-methylthiosemicarbazonato]Cu(II) [Cu(II)(atsm)], for the treatment of prostate cancer was assessed in cell culture and animal models. Distinctively, copper dissociates intracellularly from Cu(II)(gtsm) but is retained by Cu(II)(atsm). We further demonstrated that intracellular H2gtsm [reduced Cu(II)(gtsm)] continues to redistribute copper into a bioavailable (exchangeable) pool. Both Cu(II)(gtsm) and Cu(II)(atsm) selectively kill transformed (hyperplastic and carcinoma) prostate cell lines but, importantly, do not affect the viability of primary prostate epithelial cells. Increasing extracellular copper concentrations enhanced the therapeutic capacity of both Cu(II)(gtsm) and Cu(II)(atsm), and their ligands (H2gtsm and H2atsm) were toxic only toward cancerous prostate cells when combined with copper. Treatment of the Transgenic Adenocarcinoma of Mouse Prostate (TRAMP) model with Cu(II)(gtsm) (2.5 mg/kg) significantly reduced prostate cancer burden (∼70%) and severity (grade), while treatment with Cu(II)(atsm) (30 mg/kg) was ineffective at the given dose. However, Cu(II)(gtsm) caused mild kidney toxicity in the mice, associated primarily with interstitial nephritis and luminal distention. Mechanistically, we demonstrated that Cu(II)(gtsm) inhibits proteasomal chymotrypsin-like activity, a feature further established as being common to copper-ionophores that increase intracellular bioavailable copper. We have demonstrated that increasing intracellular bioavailable copper can selectively kill cancerous prostate cells in vitro and in vivo and have revealed the potential for bis(thiosemicarbazone) copper complexes to be developed as therapeutics for prostate cancer.

[1]  Michael Hummel,et al.  Supplementary Figure 3 , 2010 .

[2]  Michael L. Wang,et al.  A phase 2 study of single-agent carfilzomib (PX-171-003-A1) in patients with relapsed and refractory multiple myeloma. , 2012, Blood.

[3]  M. Minden,et al.  A phase I study of the metal ionophore clioquinol in patients with advanced hematologic malignancies. , 2012, Clinical lymphoma, myeloma & leukemia.

[4]  Blaine R. Roberts,et al.  The hypoxia imaging agent CuII(atsm) is neuroprotective and improves motor and cognitive functions in multiple animal models of Parkinson’s disease , 2012, The Journal of experimental medicine.

[5]  Valeria Panebianco,et al.  Supplementary Figure 2 , 2012 .

[6]  P. Crouch,et al.  An impaired mitochondrial electron transport chain increases retention of the hypoxia imaging agent diacetylbis(4-methylthiosemicarbazonato)copperII , 2011, Proceedings of the National Academy of Sciences.

[7]  P. Crouch,et al.  Mechanisms controlling the cellular accumulation of copper bis(thiosemicarbazonato) complexes. , 2011, Inorganic chemistry.

[8]  D. Richardson,et al.  Antitumor activity of metal-chelating compound Dp44mT is mediated by formation of a redox-active copper complex that accumulates in lysosomes. , 2011, Cancer research.

[9]  Y. Haupt,et al.  Clioquinol induces cytoplasmic clearance of the X-linked inhibitor of apoptosis protein (XIAP): therapeutic indication for prostate cancer. , 2011, The Biochemical journal.

[10]  Jun O. Liu,et al.  Disulfiram is a DNA demethylating agent and inhibits prostate cancer cell growth , 2011, The Prostate.

[11]  S. Howell,et al.  Copper Transporters and the Cellular Pharmacology of the Platinum-Containing Cancer Drugs , 2010, Molecular Pharmacology.

[12]  J. White,et al.  Versatile new bis(thiosemicarbazone) bifunctional chelators: synthesis, conjugation to bombesin(7-14)-NH(2), and copper-64 radiolabeling. , 2010, Inorganic chemistry.

[13]  Ying Sun,et al.  Tumor cellular proteasome inhibition and growth suppression by 8-hydroxyquinoline and clioquinol requires their capabilities to bind copper and transport copper into cells , 2010, JBIC Journal of Biological Inorganic Chemistry.

[14]  J. Šmarda,et al.  Copper ions regulate cytotoxicity of disulfiram to myeloid leukemia cells. , 2009, International journal of molecular medicine.

[15]  Daniela Hoeller,et al.  Targeting the ubiquitin system in cancer therapy , 2009, Nature.

[16]  L. Kay,et al.  Clioquinol inhibits the proteasome and displays preclinical activity in leukemia and myeloma , 2009, Leukemia.

[17]  R. Mumper,et al.  Elevated copper and oxidative stress in cancer cells as a target for cancer treatment. , 2009, Cancer treatment reviews.

[18]  C. Masters,et al.  Increasing Cu bioavailability inhibits Aβ oligomers and tau phosphorylation , 2009, Proceedings of the National Academy of Sciences.

[19]  F. Arsenyan,et al.  Antitumor activity of substituted methylglyoxal bisthiosemicarbazones and their copper(II) chelates , 2008, Pharmaceutical Chemistry Journal.

[20]  C. Masters,et al.  Increasing Cu bioavailability inhibits A beta oligomers and tau phosphorylation , 2009 .

[21]  Yunfeng Zhou,et al.  Clioquinol targets zinc to lysosomes in human cancer cells. , 2009, The Biochemical journal.

[22]  X. Mao,et al.  The toxicology of Clioquinol. , 2008, Toxicology letters.

[23]  Z. Dvořák,et al.  The value of proteasome inhibition in cancer. Can the old drug, disulfiram, have a bright new future as a novel proteasome inhibitor? , 2008, Drug discovery today.

[24]  Di Chen,et al.  Disulfiram promotes the conversion of carcinogenic cadmium to a proteasome inhibitor with pro-apoptotic activity in human cancer cells. , 2008, Toxicology and applied pharmacology.

[25]  M. Merkx,et al.  Human copper transporter 2 is localized in late endosomes and lysosomes and facilitates cellular copper uptake. , 2007, The Biochemical journal.

[26]  F. Sarkar,et al.  Clioquinol, a therapeutic agent for Alzheimer's disease, has proteasome-inhibitory, androgen receptor-suppressing, apoptosis-inducing, and antitumor activities in human prostate cancer cells and xenografts. , 2007, Cancer research.

[27]  Q Ping Dou,et al.  Disulfiram, a clinically used anti-alcoholism drug and copper-binding agent, induces apoptotic cell death in breast cancer cultures and xenografts via inhibition of the proteasome activity. , 2006, Cancer research.

[28]  Markus J. Tamás,et al.  Molecular Biology of Metal Homeostasis and Detoxification , 2006 .

[29]  Bolin Liu,et al.  Anticancer activity of the antibiotic clioquinol. , 2005, Cancer research.

[30]  J. Mercer,et al.  Copper in mammals: mechanisms of homeostasis and pathophysiology , 2005 .

[31]  D. Dréau,et al.  Disulfiram inhibits activating transcription factor/cyclic AMP-responsive element binding protein and human melanoma growth in a metal-dependent manner in vitro, in mice and in a patient with metastatic disease. , 2004, Molecular cancer therapeutics.

[32]  Daniel F. Brayton,et al.  Disulfiram facilitates intracellular copper transport that causes Oxidative stress and cell death in human Melanoma cells. , 2004 .

[33]  W. Guida,et al.  Organic copper complexes as a new class of proteasome inhibitors and apoptosis inducers in human cancer cells. , 2004, Biochemical pharmacology.

[34]  Bart Barlogie,et al.  A phase 2 study of bortezomib in relapsed, refractory myeloma. , 2003, The New England journal of medicine.

[35]  J. Haseman,et al.  A Grading Scheme for the Assessment of Proliferative Lesions of the Mouse Prostate in the TRAMP Model , 2003, Toxicologic pathology.

[36]  I. Voskoboinik,et al.  Copper-regulated Trafficking of the Menkes Disease Copper ATPase Is Associated with Formation of a Phosphorylated Catalytic Intermediate* , 2002, The Journal of Biological Chemistry.

[37]  A. Tomida,et al.  Nuclear localization of proteasomes participates in stress-inducible resistance of solid tumor cells to topoisomerase II-directed drugs. , 2002, Cancer research.

[38]  B. Foster,et al.  The TRAMP Mouse as a Model for Prostate Cancer , 2001, Current protocols in immunology.

[39]  L. Szekely,et al.  Proteins associated with the promyelocytic leukemia gene product (PML)-containing nuclear body move to the nucleolus upon inhibition of proteasome-dependent protein degradation. , 2001, Proceedings of the National Academy of Sciences of the United States of America.

[40]  P. Zalewski,et al.  Cellular zinc fluxes and the regulation of apoptosis/gene-directed cell death. , 2000, The Journal of nutrition.

[41]  Sunderman Fw.  The influence of zinc on apoptosis , 1995 .

[42]  F. Sunderman.  The influence of zinc on apoptosis. , 1995, Annals of clinical and laboratory science.

[43]  J. A. Crim,et al.  The antitumor activity of Cu(II)KTS, the copper (II) chelate of 3-ethoxy-2-oxobutyraldehyde bis(thiosemicarbazone). , 1967, Cancer research.

[44]  V. Barry,et al.  Anticancer activity of bisthiosemicarbazones of methylglyoxal. , 1966, Cancer research.

[45]  E. Mihich,et al.  Kethoxal bis(thiosemicarbazone). II. Toxic and pathologic effects. , 1965, Cancer research.

[46]  H. Petering,et al.  THE ANTI-TUMOR ACTIVITY OF 2-KETO-3-ETHOXYBUTYRALDEHYDE BIS(THIOSEMICARBAZONE) AND RELATED COMPOUNDS. , 1964, Cancer research.

[47]  C. H. Bayley,et al.  THE PREPARATION OF SOME THIOSEMICARBAZONES AND THEIR COPPER COMPLEXES: PART III , 1960 .

[48]  B. L. Freedlander,et al.  Carcinostatic activity of some dicarbonyl compounds and their bis-hydrazones. , 1960, Acta - Unio Internationalis Contra Cancrum.

[49]  B. L. Freedlander,et al.  Carcinostatic action of polycarbonyl compounds and their derivatives. IV. Glyoxal bis (thiosemicarbazone) and derivatives. , 1958, Cancer research.

[50]  B. L. Freedlander,et al.  Carcinostatic action of polycarbonyl compounds and their derivatives. III. Hydroxymethylglyoxal bis (guanylhydrazone). , 1958, Cancer research.