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Pharmacological ascorbate induces sustained mitochondrial dysfunction

delete2023-08-01
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OA
AI
R
Rory S. Carroll
J
Juan Du
B
Brianne R. O’Leary
G
Garett J. Steers
P
Prabhat C. Goswami
G
Garry R. Buettner
J
Joseph J. Cullen *
DOI:10.1016/j.freeradbiomed.2023.04.023delete
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Abstract

Abstract

En 中文
Pharmacological ascorbate (P-AscH-; high dose given intravenously) generates H2O2 that is selectively cytotoxic to cancer compared to normal cells. The RAS-RAF-ERK1/2 is a major signaling pathway in cancers carrying RAS mutations and is known to be activated by H2O2. Activated ERK1/2 also phosphorylates the GTPase dynamin-related protein (Drp1), which then stimulates mitochondrial fission. Although early generation of H2O2 leads to cytotoxicity of cancer cells, we hypothesized that sustained increases in H2O2 activate ERK-Drp1 signaling, leading to an adaptive response; inhibition of this pathway would enhance the toxicity of P-AscH-. Increases in phosphorylated ERK and Drp1 induced by P-AscH- were reversed with genetic and pharmacological inhibitors of ERK and Drp1, as well as in cells lacking functional mitochondria. P-AscH- increased Drp1 colocalization to mitochondria, decreased mitochondrial volume, increased disconnected components, and decreased mitochon-drial length, suggesting an increase in mitochondrial fission 48 h after treatment with P-AscH-. P-AscH- decreased clonogenic survival; this was enhanced by genetic and pharmacological inhibition of both ERK and Drp1. In murine tumor xenografts, the combination of P-AscH- and pharmacological inhibition of Drp1 increased overall survival. These results suggest that P-AscH- induces sustained changes in mitochondria, through activation of the ERK/Drp1 signaling pathway, an adaptive response. Inhibition of this pathway enhanced the toxicity P-AscH- to cancer cells.
Keywords:
Oxidative stress
Pharmacological ascorbate
Mitochondrial dynamics
Mitochondrial fission
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Journal

Free Radical Biology and Medicine cover
Free Radical Biology and Medicine
IF:
8.2
Papers:
2.1W
Citations:
5.4W

Organization

U
University of Iowa
Scholars:
2.8W
Papers: 2.3W
Citations: 600