TY - JOUR
T1 - 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
AU - Jaramillo, Melba C.
AU - Briehl, Margaret M.
AU - Batinic-Haberle, Ines
AU - Tome, Margaret E.
N1 - Funding Information:
We thank Dr. David Elliot for technical advice and assistance with the DeltaVision Restoration Microscopy System; Dr. James E. Remington for the mito-roGFP2 plasmid; and David Stringer and Dr. Eugene Gerner for use of critical equipment. Funding for this study comes from the National Cancer Institute Grants CA-71768 (M.M.B) and CA-09213 (M.C.J), Arizona Cancer Support Grant CA-023074, Lymphoma SPORE CA-130805 (M.E.T., M.M.B.), and Small Faculty Grant (M.E.T). I.B.H. acknowledges her General Research Funds.
Publisher Copyright:
© 2015 Elsevier Inc.
PY - 2015/6/1
Y1 - 2015/6/1
N2 - The manganese porphyrin, manganese (III) meso-tetrakis N-ethylpyridinium-2-yl porphyrin (MnTE-2-PyP5+), 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-PyP5+ and that we could exploit this effect to enhance the chemotherapeutic response in lymphoma. In this study, we demonstrate that MnTE-2-PyP5+ modulates the mitochondrial redox environment and sensitizes lymphoma cells to antilymphoma chemotherapeutics. MnTE-2-PyP5+ 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-PyP5+ also augmented the effects of 2-deoxy-D-glucose (2DG), an antiglycolytic agent. In combination with 2DG, MnTE-2-PyP5+ increased protein glutathionylation, decreased ATP levels more than 2DG treatment alone, and enhanced 2DG-induced cell death in primary B-ALL cells. MnTE-2-PyP5+ did not enhance dexamethasone- or 2DG-induced cell death in normal cells. Our findings suggest that MnTE-2-PyP5+ has potential as an adjuvant for the treatment of hematologic malignancies.
AB - The manganese porphyrin, manganese (III) meso-tetrakis N-ethylpyridinium-2-yl porphyrin (MnTE-2-PyP5+), 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-PyP5+ and that we could exploit this effect to enhance the chemotherapeutic response in lymphoma. In this study, we demonstrate that MnTE-2-PyP5+ modulates the mitochondrial redox environment and sensitizes lymphoma cells to antilymphoma chemotherapeutics. MnTE-2-PyP5+ 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-PyP5+ also augmented the effects of 2-deoxy-D-glucose (2DG), an antiglycolytic agent. In combination with 2DG, MnTE-2-PyP5+ increased protein glutathionylation, decreased ATP levels more than 2DG treatment alone, and enhanced 2DG-induced cell death in primary B-ALL cells. MnTE-2-PyP5+ did not enhance dexamethasone- or 2DG-induced cell death in normal cells. Our findings suggest that MnTE-2-PyP5+ has potential as an adjuvant for the treatment of hematologic malignancies.
KW - Glutathionylation
KW - Lymphoma
KW - Mitochondria
KW - MnTE-2-PyP5 (AEOL10113)
UR - http://www.scopus.com/inward/record.url?scp=84926354552&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84926354552&partnerID=8YFLogxK
U2 - 10.1016/j.freeradbiomed.2015.01.031
DO - 10.1016/j.freeradbiomed.2015.01.031
M3 - Article
C2 - 25725417
AN - SCOPUS:84926354552
SN - 0891-5849
VL - 83
SP - 89
EP - 100
JO - Free Radical Biology and Medicine
JF - Free Radical Biology and Medicine
ER -