A role of metallothionein-3 in radiation-induced autophagy in glioma cells.
Sci Rep
; 10(1): 2015, 2020 02 06.
Article
en En
| MEDLINE
| ID: mdl-32029749
Although metallothionein-3 (MT3), a brain-enriched form of metallothioneins, has been linked to Alzheimer's disease, little is known regarding the role of MT3 in glioma. As MT3 plays a role in autophagy in astrocytes, here, we investigated its role in irradiated glioma cells. Irradiation increased autophagy flux in GL261 glioma cells as evidenced by increased levels of LC3-II but decreased levels of p62 (SQSTM1). Indicating that autophagy plays a cytoprotective role in glioma cell survival following irradiation, measures inhibiting autophagy flux at various steps decreased their clonogenic survival of irradiated GL261 as well as SF295 and U251 glioma cells. Knockdown of MT3 with siRNA in irradiated glioma cells induced arrested autophagy, and decreased cell survival. At the same time, the accumulation of labile zinc in lysosomes was markedly attenuated by MT3 knockdown. Indicating that such zinc accumulation was important in autophagy flux, chelation of zinc with tetrakis-(2-pyridylmethyl)ethylenediamine (TPEN), induced arrested autophagy in and reduced survival of GL261 cells following irradiation. Suggesting a possible mechanism for arrested autophagy, MT3 knockdown and zinc chelation were found to impair lysosomal acidification. Since autophagy flux plays a cytoprotective role in irradiated glioma cells, present results suggest that MT3 and zinc may be regarded as possible therapeutic targets to sensitize glioma cells to ionizing radiation therapy.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Autofagia
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Neoplasias Encefálicas
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Fotones
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Glioma
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Metalotioneína
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Proteínas del Tejido Nervioso
Límite:
Animals
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Humans
Idioma:
En
Revista:
Sci Rep
Año:
2020
Tipo del documento:
Article
Pais de publicación:
Reino Unido