The role of the P53-P21 pathway in metabolic stress-induced ferroptosis

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Abstract/Contents

Abstract
Ferroptosis is a form of iron-dependent, non-apoptotic cell death that occurs due to the collapse of the glutathione peroxidase antioxidant system and the lethal accumulation of lipid peroxides. Selectively inducing ferroptosis in cancer cells represents a promising therapeutic strategy. However, it remains unclear how canonical tumor suppressors and oncogenes influence cell susceptibility to ferroptosis. The p53 tumor suppressor gene is the most commonly mutated gene in human cancers and serves as a master regulator of cell stress responses, metabolic adaptation, DNA damage repair, and cell death. Using a time-lapse microscopy system to study cell death kinetics over time, I found that activation of wild-type p53 suppresses the onset of ferroptosis in human cancer cells, and that deletion of p53 results in heightened ferroptosis sensitivity. The transcriptional activity of p53 is required for this function, in part through transactivation of CDKN1A (encoding p21). Activation of the p53-p21 pathway suppresses the accumulation of lipid peroxides and promotes the conservation of glutathione, an essential antioxidant required for the reduction of lipid peroxides. p53-p21 pathway activation results in decreased expression of the enzyme ribonucleotide reductase (RNR), which uses glutathione as a cofactor in the reduction of ribonucleotides to deoxyribonucleotides. Genetic and chemical inhibition of RNR is sufficient to suppress ferroptosis and conserve glutathione similar to chemical activators of the p53-p21 pathway. These results suggest that the ability of the p53-p21 pathway to downregulate RNR may allow cells to conserve glutathione and direct it towards the management of lipid peroxides during ferroptosis. This work supports the known role for wild-type p53 in regulating cell survival under conditions of metabolic stress and identifies nucleotide metabolism as a new regulator of ferroptosis in cancer cells. These findings have important implications for the development of ferroptosis-based therapies for human disease

Description

Type of resource text
Form electronic resource; remote; computer; online resource
Extent 1 online resource
Place California
Place [Stanford, California]
Publisher [Stanford University]
Copyright date 2020; ©2020
Publication date 2020; 2020
Issuance monographic
Language English

Creators/Contributors

Author Tarangelo, Amy N
Degree supervisor Dixon, Scott James, 1977-
Thesis advisor Dixon, Scott James, 1977-
Thesis advisor Attardi, Laura
Thesis advisor Brandman, Onn
Thesis advisor Sage, Julien
Degree committee member Attardi, Laura
Degree committee member Brandman, Onn
Degree committee member Sage, Julien
Associated with Stanford University, Cancer Biology Program.

Subjects

Genre Theses
Genre Text

Bibliographic information

Statement of responsibility Amy Tarangelo
Note Submitted to the Cancer Biology Program
Thesis Thesis Ph.D. Stanford University 2020
Location electronic resource

Access conditions

Copyright
© 2020 by Amy N Tarangelo
License
This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).

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