Cancer-Specific, Intracellular, Reductive Activation of Anticancer PtIV Prodrugs

Chemistry. 2017 Apr 27;23(24):5678-5681. doi: 10.1002/chem.201701192. Epub 2017 Apr 5.

Abstract

Because cellular uptake of anticancer PtII and PtIV drugs occurs by different mechanisms, the latter ones can exhibit substantial activity towards cells, which have either intrinsic or acquired resistance towards PtII drugs. However, this positive effect is diminished due to reductive activation of PtIV drugs in extracellular space that can be one of the reasons why they have not yet been approved for clinical use despite over 60 clinical trials conducted worldwide. Herein, we suggest a solution to this problem by achieving highly specific intracellular versus extracellular prodrug reduction. In particular, we prepared a hybrid PtIV prodrug containing two pro-reductants. This hybrid was uptaken by cells, the pro-reductants were activated in the cancer-specific microenvironment (high H2 O2 ), and reduced PtIV by two one-electron transfers. The drug formed in this way induced cell death both in cisplatin-sensitive and resistant cell lines, but remained nontoxic to normal cells.

Keywords: aminoferrocenes; cancer; electron transfer; platinum(IV) prodrugs; reactive oxygen species.

MeSH terms

  • Antineoplastic Agents / chemical synthesis
  • Antineoplastic Agents / chemistry*
  • Antineoplastic Agents / toxicity
  • Cell Cycle Checkpoints / drug effects
  • Cell Line, Tumor
  • Cell Proliferation
  • Coordination Complexes / chemical synthesis
  • Coordination Complexes / chemistry
  • Coordination Complexes / toxicity
  • Ferrous Compounds / chemistry
  • Humans
  • Hydrogen Peroxide / chemistry
  • Metallocenes / chemistry
  • Platinum / chemistry*
  • Prodrugs / chemical synthesis
  • Prodrugs / chemistry*
  • Prodrugs / toxicity

Substances

  • Antineoplastic Agents
  • Coordination Complexes
  • Ferrous Compounds
  • Metallocenes
  • Prodrugs
  • Platinum
  • Hydrogen Peroxide
  • ferrocene