Dichloroacetate enhances apoptotic cell death via oxidative damage and attenuates lactate production in metformin-treated breast cancer cells
Autor: | Yongxian Zhuang, Allison B. Haugrud, W. Keith Miskimins, Joseph D. Coppock |
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Rok vydání: | 2014 |
Předmět: |
Cancer Research
Programmed cell death medicine.medical_specialty Pyruvate dehydrogenase kinase Apoptosis Breast Neoplasms Protein Serine-Threonine Kinases Biology Article Oxidative Phosphorylation Cell Line Tumor Internal medicine Antineoplastic Combined Chemotherapy Protocols medicine Humans chemistry.chemical_classification Reactive oxygen species Dichloroacetic Acid Pyruvate Dehydrogenase Acetyl-Transferring Kinase Cancer Drug Synergism medicine.disease Metformin Endocrinology Oncology chemistry Lactic acidosis Cancer cell Lactates MCF-7 Cells Cancer research Female Reactive Oxygen Species medicine.drug |
Zdroj: | Breast Cancer Research and Treatment. 147:539-550 |
ISSN: | 1573-7217 0167-6806 |
Popis: | The unique metabolism of breast cancer cells provides interest in exploiting this phenomenon therapeutically. Metformin, a promising breast cancer therapeutic, targets complex I of the electron transport chain leading to an accumulation of reactive oxygen species (ROS) that eventually lead to cell death. Inhibition of complex I leads to lactate production, a metabolic byproduct already highly produced by reprogrammed cancer cells and associated with a poor prognosis. While metformin remains a promising cancer therapeutic, we sought a complementary agent to increase apoptotic promoting effects of metformin while attenuating lactate production possibly leading to greatly improved efficacy. Dichloroacetate (DCA) is a well-established drug used in the treatment of lactic acidosis which functions through inhibition of pyruvate dehydrogenase kinase (PDK) promoting mitochondrial metabolism. Our purpose was to examine the synergy and mechanisms by which these two drugs kill breast cancer cells. Cell lines were subjected to the indicated treatments and analyzed for cell death and various aspects of metabolism. Cell death and ROS production were analyzed using flow cytometry, Western blot analysis, and cell counting methods. Images of cells were taken with phase contrast microscopy or confocal microscopy. Metabolism of cells was analyzed using the Seahorse XF24 analyzer, lactate assays, and pH analysis. We show that when DCA and metformin are used in combination, synergistic induction of apoptosis of breast cancer cells occurs. Metformin-induced oxidative damage is enhanced by DCA through PDK1 inhibition which also diminishes metformin promoted lactate production. We demonstrate that DCA and metformin combine to synergistically induce caspase-dependent apoptosis involving oxidative damage with simultaneous attenuation of metformin promoted lactate production. Innovative combinations such as metformin and DCA show promise in expanding breast cancer therapies. |
Databáze: | OpenAIRE |
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