Major determinants of photoinduced cell death: Subcellular localization versus photosensitization efficiency


Autoria(s): OLIVEIRA, Carla S.; TURCHIELLO, Rozane; KOWALTOWSKI, Alicia J.; INDIG, Guilherme L.; BAPTISTA, Mauricio S.
Contribuinte(s)

UNIVERSIDADE DE SÃO PAULO

Data(s)

20/10/2012

20/10/2012

2011

Resumo

We present a study on whether and to what extent subcellular localization may compete favorably with photosensitization efficiency with respect to the overall efficiency of photoinduced cell death. We have compared the efficiency with which two cationic photosensitizers, namely methylene blue (MB) and crystal violet (CV), induce the photoinduced death of human cervical adenocarcinoma (HeLa) cells. Whereas MB is well known to generate singlet oxygen and related triplet excited species with high quantum yields in a variety of biological and chemical environments (i.e., acting as a typical type II photosensitizer), the highly mitochondria-specific CV produces triplet species and singlet oxygen with low yields, acting mostly via the classical type I mechanism (e.g., via free radicals). The findings described here indicate that the presumably more phototoxic type II photosensitizer (MB) does not lead to higher degrees of cell death compared to the type I (CV) photosensitizer. In fact, CV kills cells with the same efficiency as MB, generating at least 10 times fewer photoinduced reactive species. Therefore, subcellular localization is indeed more important than photochemical reactivity in terms of overall cell killing, with mitochondrial localization representing a highly desirable property for the development of more specific/efficient photosensitizers for photodynamic therapy applications. (C) 2011 Elsevier Inc. All rights reserved.

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

FAPESP

CNPq

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

American Cancer Society

American Cancer Society[RSG-02-026-01-CDD]

Identificador

FREE RADICAL BIOLOGY AND MEDICINE, v.51, n.4, p.824-833, 2011

0891-5849

http://producao.usp.br/handle/BDPI/30955

10.1016/j.freeradbiomed.2011.05.023

http://dx.doi.org/10.1016/j.freeradbiomed.2011.05.023

Idioma(s)

eng

Publicador

ELSEVIER SCIENCE INC

Relação

Free Radical Biology and Medicine

Direitos

restrictedAccess

Copyright ELSEVIER SCIENCE INC

Palavras-Chave #Photosensitization #Intracellular localization #Methylene blue #Crystal violet #Photodynamic therapy #Singlet oxygen #ROS #Free radicals #METHYLENE-BLUE #SINGLET OXYGEN #PHOTODYNAMIC THERAPY #TRIARYLMETHANE DYES #PHOTOCHEMICAL PROPERTIES #OXIDATIVE STRESS #MOLECULAR-OXYGEN #CRYSTAL VIOLET #TUMOR-CELLS #IN-VITRO #Biochemistry & Molecular Biology #Endocrinology & Metabolism
Tipo

article

original article

publishedVersion