A copper chelate of thiosemicarbazone NSC 689534 induces oxidative/ER stress and inhibits tumor growth in vitro and in vivo

Free Radic Biol Med. 2011 Jan 1;50(1):110-21. doi: 10.1016/j.freeradbiomed.2010.10.696. Epub 2010 Nov 4.


In this study, a Cu(2+) chelate of the novel thiosemicarbazone NSC 689534 was evaluated for in vitro and in vivo anti-cancer activity. Results demonstrated that NSC 689534 activity (low micromolar range) was enhanced four- to fivefold by copper chelation and completely attenuated by iron. Importantly, once formed, the NSC 689534/Cu(2+) complex retained activity in the presence of additional iron or iron-containing biomolecules. NSC 689534/Cu(2+) mediated its effects primarily through the induction of ROS, with depletion of cellular glutathione and protein thiols. Pretreatment of cells with the antioxidant N-acetyl-l-cysteine impaired activity, whereas NSC 689534/Cu(2+) effectively synergized with the glutathione biosynthesis inhibitor buthionine sulfoximine. Microarray analysis of NSC 689534/Cu(2+)-treated cells highlighted activation of pathways involved in oxidative and ER stress/UPR, autophagy, and metal metabolism. Further scrutiny of the role of ER stress and autophagy indicated that NSC 689534/Cu(2+)-induced cell death was ER-stress dependent and autophagy independent. Last, NSC 689534/Cu(2+) was shown to have activity in an HL60 xenograft model. These data suggest that NSC 689534/Cu(2+) is a potent oxidative stress inducer worthy of further preclinical investigation.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Antineoplastic Agents / pharmacology
  • Antineoplastic Agents / therapeutic use
  • Cell Proliferation / drug effects*
  • Chelating Agents / metabolism
  • Chelating Agents / pharmacology
  • Copper / metabolism
  • Down-Regulation / drug effects
  • Endoplasmic Reticulum / drug effects
  • Endoplasmic Reticulum / metabolism
  • Female
  • HL-60 Cells
  • Humans
  • Mice
  • Mice, Nude
  • Neoplasms / metabolism
  • Neoplasms / pathology*
  • Organometallic Compounds / pharmacology
  • Organometallic Compounds / therapeutic use
  • Oxidants / pharmacology
  • Oxidants / therapeutic use
  • Oxidative Stress / drug effects*
  • Thiosemicarbazones / pharmacology*
  • Thiosemicarbazones / therapeutic use
  • Tumor Cells, Cultured
  • Unfolded Protein Response / drug effects
  • Up-Regulation / drug effects
  • Xenograft Model Antitumor Assays


  • Antineoplastic Agents
  • Chelating Agents
  • NSC 689534
  • Organometallic Compounds
  • Oxidants
  • Thiosemicarbazones
  • Copper