Manganese (III) meso-tetrakis N-ethylpyridinium-2-yl porphyrin acts as a pro-oxidant to inhibit electron transport chain proteins, modulate bioenergetics, and enhance the response to chemotherapy in lymphoma cells.
The manganese porphyrin, manganese (III) meso-tetrakis N-ethylpyridinium-2-yl porphyrin (MnTE-2-PyP(5+)), acts as a pro-oxidant in the presence of intracellular H2O2. Mitochondria are the most prominent source of intracellular ROS and important regulators of the intrinsic apoptotic pathway. Due to the increased oxidants near and within the mitochondria, we hypothesized that the mitochondria are a target of the pro-oxidative activity of MnTE-2-PyP(5+) and that we could exploit this effect to enhance the chemotherapeutic response in lymphoma. In this study, we demonstrate that MnTE-2-PyP(5+) modulates the mitochondrial redox environment and sensitizes lymphoma cells to antilymphoma chemotherapeutics. MnTE-2-PyP(5+) increased dexamethasone-induced mitochondrial ROS and oxidation of the mitochondrial glutathione pool in lymphoma cells. The combination treatment induced glutathionylation of Complexes I, III, and IV in the electron transport chain, and decreased the activity of Complexes I and III, but not the activity of Complex IV. Treatment with the porphyrin and dexamethasone also decreased cellular ATP levels. Rho(0) malignant T-cells with impaired mitochondrial electron transport chain function were less sensitive to the combination treatment than wild-type cells. These findings suggest that mitochondria are important for the porphyrin's ability to enhance cell death. MnTE-2-PyP(5+) also augmented the effects of 2-deoxy-D-glucose (2DG), an antiglycolytic agent. In combination with 2DG, MnTE-2-PyP(5+) increased protein glutathionylation, decreased ATP levels more than 2DG treatment alone, and enhanced 2DG-induced cell death in primary B-ALL cells. MnTE-2-PyP(5+) did not enhance dexamethasone- or 2DG-induced cell death in normal cells. Our findings suggest that MnTE-2-PyP(5+) has potential as an adjuvant for the treatment of hematologic malignancies.
Department of Pathology, University of Arizona, Tucson, AZ 85724, USA.
Melba C
MC
Jaramillo
Department of Pathology, University of Arizona, Tucson, AZ 85724, USA.
Margaret M
MM
Briehl
Department of Radiation Oncology, Duke University School of Medicine, Durham, NC 27710, USA.
Ines
I
Batinic-Haberle
Medical Pharmacology, University of Arizona, Tucson, AZ 85724, USA. Electronic address: mtome@email.arizona.edu.
Margaret E
ME
Tome
D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D019008:Drug Resistance, Neoplasm / Q000187:drug effects*; D004579:Electron Transport / Q000187:drug effects; D045222:Electron Transport Chain Complex Proteins / Q000378:metabolism*; D015180:Electrophoresis, Gel, Two-Dimensional; D004734:Energy Metabolism / Q000187:drug effects*; D005978:Glutathione / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008665:Metalloporphyrins / Q000494:pharmacology*; D051379:Mice; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D016877:Oxidants / Q000494:pharmacology*; D010084:Oxidation-Reduction; D015452:Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D040901:Proteomics; D017382:Reactive Oxygen Species / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013953:Thymus Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D014407:Tumor Cells, Cultured
D045222:Electron Transport Chain Complex Proteins; D008665:Metalloporphyrins; D016877:Oxidants; D017382:Reactive Oxygen Species; C431023:manganese (III) meso-tetrakis(N-ethylpyridinium-2-yl)porphyrin; D006861:Hydrogen Peroxide; D005978:Glutathione
Glutathionylation; Lymphoma; Mitochondria; MnTE-2-PyP(5+) (AEOL10113)