Role of glutathione in apoptosis induced by radiation as determined by 1H MR spectra of cultured tumor cells.
Radiat Res
; 167(3): 268-82, 2007 Mar.
Article
em En
| MEDLINE
| ID: mdl-17316070
ABSTRACT
The relationship between apoptosis induced by gamma radiation and glutathione in cells of two human cancer cell lines, HeLa from cervix carcinoma and MCF-7 from mammary carcinoma, was examined. MCF-7 cells appeared to be more radioresistant than HeLa cells, and radiation-induced apoptosis, which was monitored by assessing phosphatidylserine externalization, was observed in HeLa cells but not in MCF-7 cells. Glutathione levels monitored by (1)H MRS were higher in MCF-7 cells than in HeLa cells, while the opposite was true for the free glu signals. MCF-7 cells became more radiosensitive when treated with 0.1 mM buthionine sulfoximine, which inhibits GSH synthesis through inactivation of gamma-glutamylcysteine synthetase, with the concomitant appearance of radiation-induced apoptosis. We can thus reasonably associate, at least in part, the resistance of MCF-7 cells to apoptosis with a high level of glutathione and probably with a high activity of gamma-glutamylcysteine synthetase. A late decrease in glutathione concentration after irradiation was observed in MCF-7 cells, but not in HeLa cells and to a lesser degree in buthionine sulfoximine-treated MCF-7 cells. This would indicate that the radiation-induced decrease in glutathione concentration is not related to the onset of apoptosis, but it is more likely related to glutathione consumption as a result of detoxification reactions.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Apoptose
/
Glutationa
Limite:
Humans
Idioma:
En
Revista:
Radiat Res
Ano de publicação:
2007
Tipo de documento:
Article
País de afiliação:
Itália