Gramicidin A Induces Metabolic Dysfunction and Energy Depletion Leading to Cell Death in Renal Cell Carcinoma Cells

作者:David Justin M; Owens Tori A; Barwe Sonali P; Rajasekaran Ayyappan K*
来源:Molecular Cancer Therapeutics, 2013, 12(11): 2296-2307.
DOI:10.1158/1535-7163.MCT-13-0445

摘要

Ionophores are lipid-soluble organic molecules that disrupt cellular transmembrane potential by rendering biologic membranes permeable to specific ions. They include mobile-carriers that complex with metal cations and channel-formers that insert into the membrane to form hydrophilic pores. Although mobile-carriers possess anticancer properties, investigations on channel-formers are limited. Here, we used the channel-forming ionophore gramicidin A to study its effects on the growth and survival of renal cell carcinoma (RCC) cells. RCC is a histologically heterogeneous malignancy that is highly resistant to conventional treatments. We found that gramicidin A reduced the in vitro viability of several RCC cell lines at submicromolar concentrations (all IC50 %26lt;1.0 mu mol/L). Gramicidin A exhibited similar toxicity in RCC cells regardless of histologic subtype or the expression of either the von Hippel-Lindau tumor suppressor gene or its downstream target, hypoxia-inducible factor-1 alpha. Gramicidin A decreased cell viability equal to or greater than the mobile-carrier monensin depending on the cell line. Mechanistic examination revealed that gramicidin A blocks ATP generation by inhibiting oxidative phosphorylation and glycolysis, leading to cellular energy depletion and nonapoptotic cell death. Finally, gramicidin A effectively reduced the growth of RCC tumor xenografts in vivo. These results show a novel application of gramicidin A as a potential therapeutic agent for RCC therapy.

  • 出版日期2013-11