O2⋅- and H2O2-Mediated Disruption of Fe Metabolism Causes the Differential Susceptibility of NSCLC and GBM Cancer Cells to Pharmacological Ascorbate
Joshua D Schoenfeld, Zita A Sibenaller, Kranti A Mapuskar, Brett A Wagner, Kimberly L Cramer-Morales, Muhammad Furqan, Sonia Sandhu, Thomas L Carlisle, Mark C Smith, Taher Abu Hejleh, Daniel J Berg, Jun Zhang, John Keech, Kalpaj R Parekh, Sudershan Bhatia, Varun Monga, Kellie L Bodeker, Logan Ahmann, Sandy Vollstedt, Heather Brown, Erin P Shanahan Kauffman, Mary E Schall, Ray J Hohl, Gerald H Clamon, Jeremy D Greenlee, Matthew A Howard, Michael K Schultz, Brian J Smith, Dennis P Riley, Frederick E Domann, Joseph J Cullen, Garry R Buettner, John M Buatti, Douglas R Spitz, Bryan G Allen, Joshua D Schoenfeld, Zita A Sibenaller, Kranti A Mapuskar, Brett A Wagner, Kimberly L Cramer-Morales, Muhammad Furqan, Sonia Sandhu, Thomas L Carlisle, Mark C Smith, Taher Abu Hejleh, Daniel J Berg, Jun Zhang, John Keech, Kalpaj R Parekh, Sudershan Bhatia, Varun Monga, Kellie L Bodeker, Logan Ahmann, Sandy Vollstedt, Heather Brown, Erin P Shanahan Kauffman, Mary E Schall, Ray J Hohl, Gerald H Clamon, Jeremy D Greenlee, Matthew A Howard, Michael K Schultz, Brian J Smith, Dennis P Riley, Frederick E Domann, Joseph J Cullen, Garry R Buettner, John M Buatti, Douglas R Spitz, Bryan G Allen
Abstract
Pharmacological ascorbate has been proposed as a potential anti-cancer agent when combined with radiation and chemotherapy. The anti-cancer effects of ascorbate are hypothesized to involve the autoxidation of ascorbate leading to increased steady-state levels of H2O2; however, the mechanism(s) for cancer cell-selective toxicity remain unknown. The current study shows that alterations in cancer cell mitochondrial oxidative metabolism resulting in increased levels of O2⋅- and H2O2 are capable of disrupting intracellular iron metabolism, thereby selectively sensitizing non-small-cell lung cancer (NSCLC) and glioblastoma (GBM) cells to ascorbate through pro-oxidant chemistry involving redox-active labile iron and H2O2. In addition, preclinical studies and clinical trials demonstrate the feasibility, selective toxicity, tolerability, and potential efficacy of pharmacological ascorbate in GBM and NSCLC therapy.
Keywords: ferritin; glioblastoma multiforme; hydrogen peroxide; labile iron metabolism; non-small cell lung cancer; oxidative stress; pharmacological ascorbate; superoxide; superoxide dismutase; transferrin receptor.
Copyright © 2017 Elsevier Inc. All rights reserved.
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Source: PubMed