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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

p53-Dependent and p53-Independent Responses of Cells Challenged by Photosensitization

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Abrantes, Aline B. de P. [1] ; Dias, Gustavo C. [1] ; Souza-Pinto, Nadja C. [1] ; Baptista, Mauricio S. [1]
Total Authors: 4
[1] Univ Sao Paulo, Inst Quim, Dept Bioquim, Sao Paulo - Brazil
Total Affiliations: 1
Document type: Journal article
Source: Photochemistry and Photobiology; v. 95, n. 1, p. 355-363, JAN 2019.
Web of Science Citations: 0

The p53 protein exerts fundamental roles in cell responses to a variety of stress stimuli. It has clear roles in controlling cell cycle, triggering apoptosis, activating autophagy and modulating DNA damage response. Little is known about the role of p53 in autophagy-associated cell death, which can be induced by photoactivation of photosensitizers within cells. The photosensitizer 1,9-dimethyl methylene blue (DMMB) within nanomolar concentration regimes has specific intracellular targets (mitochondria and lysosomes), photoinducing a typical scenario of cell death with autophagy. Importantly, in consequence of its subcellular localization, photoactive DMMB induces selective damage to mitochondrial DNA, saving nuclear DNA. By challenging cells having different p53 protein levels, we investigated whether p53 modulates DMMB/light-induced phototoxicity and cell cycle dynamics. Cells lacking p53 activity were slightly more resistant to photoactivated DMMB, which was correlated with a smaller sub-G1 population, indicative of a lower level of apoptosis. DMMB photosensitization seems to induce mostly autophagy-associated cell death and S-phase cell cycle arrest with replication stress. Remarkably, these responses were independent on the p53 status, indicating that p53 is not involved in either process. Despite describing some p53-related responses in cells challenged by photosensitization, our results also provide novel information on the consequences of DMMB phototoxicity. (AU)

FAPESP's process: 13/07937-8 - Redoxome - Redox Processes in Biomedicine
Grantee:Ohara Augusto
Support type: Research Grants - Research, Innovation and Dissemination Centers - RIDC
FAPESP's process: 12/50680-5 - Photosensitization in life sciences
Grantee:Mauricio da Silva Baptista
Support type: Research Projects - Thematic Grants
FAPESP's process: 17/04372-0 - Mitochondrial DNA: mechanisms for genome integrity maintenance and impact on disease
Grantee:Nadja Cristhina de Souza Pinto
Support type: Research Projects - Thematic Grants
FAPESP's process: 14/18123-4 - Protein p53 modulation of autophagic cell death induced by photodynamic therapy
Grantee:Aline Bianca de Paiva Abrantes
Support type: Scholarships in Brazil - Master
FAPESP's process: 10/51906-1 - Mitochondrial bioenergetics, ion transport, redox state and DNA metabolism
Grantee:Alicia Juliana Kowaltowski
Support type: Research Projects - Thematic Grants