{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,16]],"date-time":"2026-10-16T20:48:57Z","timestamp":1792183737104,"version":"4.4.0"},"reference-count":34,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2019,7,24]],"date-time":"2019-07-24T00:00:00Z","timestamp":1563926400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Biomolecules"],"abstract":"<jats:p>Elesclomol ((N-malonyl-bis(N\u2032-methyl-N\u2032-thiobenzoylhydrazide)); formerly STA-4783) is a mitochondria-targeted chemotherapeutic agent that has demonstrated efficacy in selective cancer cell killing in pre-clinical and clinical testing. The biologically active form of elesclomol is a deprotonated copper chelate (elesclomol:copper; E:C), which has been shown to enhance reactive oxygen species (ROS) production and induce a transcriptional gene profile characteristic of an oxidative stress response in vitro. Previous studies suggest that E:C interacts with the electron transport chain (ETC) to generate high levels of ROS within the organelle and ultimately induce cell death. The purpose of this study was to further explore the mechanism of cellular and mitochondrial toxicity of E:C by examining its direct effect on mitochondrial bioenergetic function. The results obtained indicate that E:C treatment in whole cells of non-tumorigenic origin at high concentrations (40 \u03bcM and higher) induces a rapid and substantial increase in mitochondrial superoxide levels and dissipation of mitochondrial membrane potential. Furthermore, similar higher concentrations of E:C act as a direct uncoupler of oxidative phosphorylation and generalized inhibitor of electron transport activity in isolated, intact mitochondria, and induce a dose-dependent inhibition of mitochondrial NADH-ubiquinone oxidoreductase activity in freeze-thawed mitochondrial preparations. The results of this study are important in that they are the first to demonstrate a direct effect of the E:C chelate on bioenergetic function in isolated mammalian mitochondria, and suggest the possibility that the increase in ROS production and cytotoxicity induced by E:C may in part be due to uncoupling of mitochondrial oxidative phosphorylation and\/or inhibition of electron transport activity. These results also provide important information about the mechanisms of mitochondrial and cellular toxicity induced by E:C and will ultimately contribute to a better understanding of the therapeutic potential of elesclomol as an anticancer compound.<\/jats:p>","DOI":"10.3390\/biom9080298","type":"journal-article","created":{"date-parts":[[2019,7,24]],"date-time":"2019-07-24T10:48:19Z","timestamp":1563965299000},"page":"298","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":47,"title":["The Anticancer Agent Elesclomol Has Direct Effects on Mitochondrial Bioenergetic Function in Isolated Mammalian Mitochondria"],"prefix":"10.3390","volume":"9","author":[{"given":"Josephine S.","family":"Modica-Napolitano","sequence":"first","affiliation":[{"name":"Department of Biology, Merrimack College, North Andover, MA 01845, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Leena P.","family":"Bharath","sequence":"additional","affiliation":[{"name":"Department of Health Sciences, Merrimack College, North Andover, MA 01845, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alison J.","family":"Hanlon","sequence":"additional","affiliation":[{"name":"Department of Biology, Merrimack College, North Andover, MA 01845, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Liam D.","family":"Hurley","sequence":"additional","affiliation":[{"name":"Department of Biology, Merrimack College, North Andover, MA 01845, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2019,7,24]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"23","DOI":"10.3390\/cancers1010023","article-title":"N\u20321,N\u20323-Dimethyl-N\u20321,N\u20323-bis(phenylcarbonothioyl) Propanedihydrazide (Elesclomol) Selectively Kills Cisplatin Resistant Lung Cancer Cells through Reactive Oxygen Species (ROS)","volume":"1","author":"Wangpaichitr","year":"2009","journal-title":"Cancers"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"5070","DOI":"10.1016\/j.bmcl.2013.07.032","article-title":"Syntheses and antitumor activities of N\u2019(1), N\u2019(3)-dialkyl-N\u2019(1), N\u2019(3)-di-(alkylcarbonothioyl) malonohydrazide: The discovery of elesclomol","volume":"23","author":"Chen","year":"2013","journal-title":"Bioorg. Med. Chem. Lett."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"2437","DOI":"10.3109\/10428194.2016.1138293","article-title":"A phase I study of elesclomol sodium in patients with acute myeloid leukemia","volume":"57","author":"Hedley","year":"2016","journal-title":"Leuk. Lymphoma"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"584","DOI":"10.1158\/1078-0432.CCR-06-0964","article-title":"Phase I Clinical Trial of STA- 4783 in Combination with Paclitaxel in Patients with Refractory Solid Tumors","volume":"13","author":"Berkenblit","year":"2007","journal-title":"Clin. Cancer Res."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"527","DOI":"10.1200\/JCO.2007.12.7837","article-title":"Meta-analysis of Phase II Cooperative Group Trials in Metastatic Stage IV Melanoma to Determine Progression-free and Overall Survival Benchmarks for Future Phase II Trials","volume":"26","author":"Korn","year":"2008","journal-title":"J. Clin. Oncol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1211","DOI":"10.1200\/JCO.2012.44.5585","article-title":"Final Results of Phase III SYMMETRY Study: Randomized, Double-Blind Trial of Elesclomol Plus Paclitaxel versus Paclitaxel Alone as Treatment for Chemotherapy-Naive Patients with Advanced Melanoma","volume":"31","author":"Eggermont","year":"2013","journal-title":"J. Clin. Oncol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"2319","DOI":"10.1158\/1535-7163.MCT-08-0298","article-title":"Elesclomol Induces Cancer Cell Apoptosis Through Oxidative Stress","volume":"7","author":"Kirshner","year":"2008","journal-title":"Mol. Cancer Ther."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"2142","DOI":"10.1016\/j.freeradbiomed.2012.03.017","article-title":"The Oncology Drug Elesclomol Selectively Transports Copper to the Mitochondria to Induce Oxidative Stress in Cancer Cells","volume":"52","author":"Nagai","year":"2012","journal-title":"Free Radic. Biol. Med."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Blackman, R.K., Cheung-Ong, K., Gebbia, M., Proia, D.A., He, S., Kepros, J., Jonneaux, A., Marchetti, P., Kluza, J., and Rao, P.E. (2012). Mitochondrial Electron Transport is the Cellular Target of the Oncology Drug Elesclomol. PLoS ONE, 7.","DOI":"10.1371\/journal.pone.0029798"},{"key":"ref_10","first-page":"7876","article-title":"Mitochondrial Toxicity of Cationic Photosensitizers for Photochemotherapy","volume":"50","author":"Joyal","year":"1990","journal-title":"Cancer Res."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"265","DOI":"10.1016\/S0021-9258(19)52451-6","article-title":"Protein Measurement with the Folin Phenol Reagent","volume":"193","author":"Lowry","year":"1951","journal-title":"J. Biol. Chem."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1235","DOI":"10.1038\/nprot.2012.058","article-title":"Assessment of Mitochondrial Respiratory Chain Enzymatic Activities on Tissues and Cultured Cells","volume":"7","author":"Spinazzi","year":"2012","journal-title":"Nat. Protoc."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"913","DOI":"10.1007\/s10495-007-0756-2","article-title":"Mitochondria, oxidative stress and cell death","volume":"12","author":"Ott","year":"2007","journal-title":"Apoptosis"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"3663","DOI":"10.1007\/s00018-009-0099-y","article-title":"Reactive oxygen species-dependent signaling regulates cancer","volume":"66","author":"Weinberg","year":"2009","journal-title":"Cell Mol. Life Sci."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"789","DOI":"10.1158\/1078-0432.CCR-06-2082","article-title":"Reactive oxygen species: A breath of life or death?","volume":"13","author":"Fruehauf","year":"2007","journal-title":"Clin. Cancer Res."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"19792","DOI":"10.1074\/jbc.274.28.19792","article-title":"Oxidative stress inhibits apoptosis in human lymphoma cells","volume":"274","author":"Lee","year":"1999","journal-title":"J. Biol. Chem."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"241","DOI":"10.1016\/j.ccr.2006.08.009","article-title":"Selective killing of oncogenically transformed cells through a ROS-mediated mechanism by h-phenylethyl isothiocyanate","volume":"10","author":"Trachootham","year":"2006","journal-title":"Cancer Cell"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"175","DOI":"10.1016\/j.ccr.2006.08.015","article-title":"Reactive oxygen species in cancer cells: Live by the sword, die by the sword","volume":"10","author":"Schumacker","year":"2006","journal-title":"Cancer Cell"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"17394","DOI":"10.3390\/ijms160817394","article-title":"Treatment Strategies that Enhance the Efficacy and Selectivity of Mitochondria-Targeted Anticancer Agents","volume":"16","author":"Weissig","year":"2015","journal-title":"Int. J. Mol. Sci."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"118","DOI":"10.3389\/fonc.2017.00118","article-title":"The Mitochondrial Complex(I)ty of Cancer","volume":"7","author":"Urra","year":"2017","journal-title":"Front. Oncol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"668","DOI":"10.1007\/s12011-011-9039-4","article-title":"In Vitro Effect of Copper Chloride Exposure on Reactive Oxygen Species Generation and Respiratory Chain Complex Activities of Mitochondria Isolated from Broiler Liver","volume":"144","author":"Su","year":"2011","journal-title":"Biol. Trace Elem. Res."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"545","DOI":"10.18388\/abp.2004_3590","article-title":"Cd2+-promoted mitochondrial permeability transition: A comparison with other heavy metals","volume":"51","author":"Belyaeva","year":"2004","journal-title":"Acta Biocim Pol"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"384","DOI":"10.1016\/j.bbabio.2008.11.003","article-title":"Differential effects of mitochondrial Complex I inhibitors on production of reactive oxygen species","volume":"1787","author":"Fato","year":"2009","journal-title":"Biochim. Biophys. Acta"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"8516","DOI":"10.1074\/jbc.M210432200","article-title":"Mitochondrial Complex I Inhibitor Rotenone Induces Apoptosis through Enhancing Mitochondrial Reactive Oxygen Species Production","volume":"278","author":"Li","year":"2003","journal-title":"J. Biol. Chem."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1016\/S0014-5793(97)01159-9","article-title":"High protonic potential actuates a mechanism of production of reactive oxygen species in mitochondria","volume":"416","author":"Korshunov","year":"1997","journal-title":"FEBS Lett."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"37","DOI":"10.1196\/annals.1427.015","article-title":"The Role of Mitochondria in Reactive Oxygen Species Metabolism and Signaling","volume":"1147","author":"Starkov","year":"2008","journal-title":"Ann. N. Y. Acad. Sci."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"313","DOI":"10.1016\/j.cardiores.2006.07.019","article-title":"Mitochondrial uncoupling, with low concentration FCCP, induces ROS-dependent cardioprotection independent of KATP channel activation","volume":"72","author":"Brennan","year":"2006","journal-title":"Cardiovasc. Res."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"150","DOI":"10.1016\/0014-5793(95)01449-7","article-title":"Opening of the mitochondrial permeability transition pore by uncoupling or inorganic phosphate in the presence of Ca2+ is dependent on mitochondrial-generated reactive oxygen species","volume":"378","author":"Kowaltowski","year":"1996","journal-title":"FEBS Lett."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"100","DOI":"10.1016\/j.yjmcc.2014.09.023","article-title":"The mitochondrial permeability transition pore: Molecular nature and role as a target in cardioprotection","volume":"78","author":"Bernardi","year":"2015","journal-title":"J. Mol. Cell Cardiol."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1001","DOI":"10.1084\/jem.192.7.1001","article-title":"Reactive Oxygen Species (ROS)-induced ROS Release: A New Phenomenon Accompanying Induction of the Mitochondrial Permeability Transition in Cardiac Myocytes","volume":"192","author":"Zorov","year":"2000","journal-title":"J. Exp. Med."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"8161","DOI":"10.1073\/pnas.1806296115","article-title":"Elesclomol restores mitochondrial function in genetic models of copper deficiency","volume":"115","author":"Soma","year":"2018","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"532","DOI":"10.1002\/iub.2002","article-title":"The Evaluation of the Anti-Cancer Drug Elesclomol that Forms a Redox-Active Copper Chelate as a Potential Anti-Tubercular Drug","volume":"71","author":"Ngwane","year":"2019","journal-title":"IUBMB Life"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"681","DOI":"10.1038\/s41589-019-0291-9","article-title":"Mitochondrial metabolism promotes adaptation to proteotoxic stress","volume":"15","author":"Tsvetkov","year":"2019","journal-title":"Nat. Chem. Biol."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"121","DOI":"10.2174\/156652407779940495","article-title":"Mitochondria and human cancer","volume":"7","author":"Kulawiec","year":"2007","journal-title":"Curr. Mol. Med."}],"container-title":["Biomolecules"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2218-273X\/9\/8\/298\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T13:09:10Z","timestamp":1760188150000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2218-273X\/9\/8\/298"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,7,24]]},"references-count":34,"journal-issue":{"issue":"8","published-online":{"date-parts":[[2019,8]]}},"alternative-id":["biom9080298"],"URL":"https:\/\/doi.org\/10.3390\/biom9080298","relation":{},"ISSN":["2218-273X"],"issn-type":[{"value":"2218-273X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2019,7,24]]}}}