Mitochondria-targeted nitroxides exacerbate fluvastatin-mediated cytostatic and cytotoxic effects in breast cancer cells

Cancer Biol Ther. 2011 Oct 15;12(8):707-17. doi: 10.4161/cbt.12.8.16441. Epub 2011 Oct 15.

Abstract

Mito-CP11, a mitochondria-targeted nitroxide formed by conjugating a triphenylphosphonium cation to a five-membered nitroxide, carboxy-proxyl (CP), has been used as a superoxide dismutase (SOD) mimetic. In this study, we investigated the antiproliferative and cytotoxic properties of submicromolar levels of Mito-CP11 alone and in combination with fluvastatin, a well known cholesterol lowering drug, in breast cancer cells. Mito-CP11, but not CP or CP plus the cationic ligand, methyl triphenylphosphonium (Me-TPP+), inhibited MCF-7 breast cancer cell proliferation. Mito-CP11 had only minimal effect on MCF-10A, non-tumorigenic mammary epithelial cells. Mito-CP11, however, significantly enhanced fluvastatin-mediated cytotoxicity in MCF-7 cells. Mito-CP11 alone and in combination with fluvastatin inhibited nuclear factor kappa-B activity mainly in MCF-7 cells. We conclude that mitochondria-targeted nitroxide antioxidant molecules (such as Mito-CP11) that are non-toxic to non-tumorigenic cells could enhance the cytostatic and cytotoxic effects of statins in breast cancer cells. This strategy of combining mitochondria-targeted non-toxic molecules with cytotoxic chemotherapeutic drugs may be successfully used to enhance the efficacy of antitumor therapies in breast cancer treatment.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Combined Chemotherapy Protocols / pharmacology*
  • Antioxidants / administration & dosage
  • Antioxidants / chemistry
  • Antioxidants / pharmacology
  • Breast Neoplasms / drug therapy*
  • Breast Neoplasms / pathology
  • Cell Line, Tumor
  • Drug Delivery Systems
  • Drug Synergism
  • Fatty Acids, Monounsaturated / administration & dosage
  • Fatty Acids, Monounsaturated / pharmacology*
  • Female
  • Fluvastatin
  • Humans
  • Hydroxymethylglutaryl-CoA Reductase Inhibitors / administration & dosage
  • Hydroxymethylglutaryl-CoA Reductase Inhibitors / pharmacology
  • Indoles / administration & dosage
  • Indoles / pharmacology*
  • Mevalonic Acid / administration & dosage
  • Mevalonic Acid / pharmacology
  • Mitochondria / drug effects*
  • Mitochondria / metabolism
  • Mitochondria / pathology
  • Nitrogen Oxides / administration & dosage
  • Nitrogen Oxides / chemistry
  • Nitrogen Oxides / pharmacology*
  • Organophosphorus Compounds / administration & dosage
  • Organophosphorus Compounds / chemistry
  • Organophosphorus Compounds / pharmacology
  • Reactive Oxygen Species / metabolism

Substances

  • Antioxidants
  • Fatty Acids, Monounsaturated
  • Hydroxymethylglutaryl-CoA Reductase Inhibitors
  • Indoles
  • Nitrogen Oxides
  • Organophosphorus Compounds
  • Reactive Oxygen Species
  • Fluvastatin
  • nitroxyl
  • Mevalonic Acid