title: The oncology drug elesclomol selectively transports copper to the mitochondria to induce oxidative stress in cancer cells.
abstract: Elesclomol is an investigational drug that exerts potent anticancer activity through the elevation of reactive oxygen species (ROS) levels and is currently under clinical evaluation as a novel anticancer therapeutic. Here we report the first description of selective mitochondrial ROS induction by elesclomol in cancer cells based on the unique physicochemical properties of the compound. Elesclomol preferentially chelates copper (Cu) outside of cells and enters as elesclomol-Cu(II). The elesclomol-Cu(II) complex then rapidly and selectively transports the copper to mitochondria. In this organelle Cu(II) is reduced to Cu(I), followed by subsequent ROS generation. Upon dissociation from the complex, elesclomol is effluxed from cells and repeats shuttling elesclomol-Cu complexes from the extracellular to the intracellular compartments, leading to continued copper accumulation within mitochondria. An optimal range of redox potentials exhibited by copper chelates of elesclomol and its analogs correlated with the elevation of mitochondrial Cu(I) levels and cytotoxic activity, suggesting that redox reduction of the copper triggers mitochondrial ROS induction. Importantly the mitochondrial selectivity exhibited by elesclomol is a distinct characteristic of the compound that is not shared by other chelators, including disulfiram. Together these findings highlight a unique mechanism of action with important implications for cancer therapy.
authors.affiliation: Synta Pharmaceuticals Corp., Lexington, MA 02421, USA.
authors.forename: Masazumi
authors.initials: M
authors.lastname: Nagai
authors.forename: Nha H
authors.initials: NH
authors.lastname: Vo
authors.forename: Luisa
authors.initials: L
authors.lastname: Shin Ogawa
authors.forename: Dinesh
authors.initials: D
authors.lastname: Chimmanamada
authors.forename: Takayo
authors.initials: T
authors.lastname: Inoue
authors.forename: John
authors.initials: J
authors.lastname: Chu
authors.forename: Britte C
authors.initials: BC
authors.lastname: Beaudette-Zlatanova
authors.forename: Rongzhen
authors.initials: R
authors.lastname: Lu
authors.forename: Ronald K
authors.initials: RK
authors.lastname: Blackman
authors.forename: James
authors.initials: J
authors.lastname: Barsoum
authors.forename: Keizo
authors.initials: K
authors.lastname: Koya
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Wada
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D001692:Biological Transport / Q000187:drug effects; D045744:Cell Line, Tumor; D003300:Copper / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D006834:Hydrazines / Q000494:pharmacology*; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism*; D009369:Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D010084:Oxidation-Reduction / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects*; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; D006834:Hydrazines; D017382:Reactive Oxygen Species; C512195:elesclomol; D003300:Copper