ADAM-9 is a novel mediator of tenascin-C-stimulated invasiveness of brain tumor-initiating cells.
Neuro Oncol
; 17(8): 1095-105, 2015 Aug.
Article
em En
| MEDLINE
| ID: mdl-25646025
ABSTRACT
BACKGROUND:
Tenascin-C (TNC), an extracellular matrix protein overexpressed in malignant gliomas, stimulates invasion of conventional glioma cell lines (U251, U87). However, there is a dearth of such information on glioma stemlike cells. Here, we have addressed whether and how TNC may regulate the invasiveness of brain tumor-initiating cells (BTICs) that give rise to glioma progenies.METHODS:
Transwell inserts coated with extracellular matrix proteins were used to determine the role of TNC in BTIC invasion. Microarray analysis, lentiviral constructs, RNA interference-mediated knockdown, and activity assay ascertained the role of proteases in TNC-stimulated BTIC invasion in culture. Involvement of proteases was validated using orthotopic brain xenografts in mice.RESULTS:
TNC stimulated BTIC invasiveness in a metalloproteinase-dependent manner. A global gene expression screen identified the metalloproteinase ADAM-9 as a potential regulator of TNC-stimulated BTIC invasiveness, and this was corroborated by an increase of ADAM-9 protein in 4 glioma patient-derived BTIC lines. Notably, RNA interference to ADAM-9, as well as inhibition of mitogen-activated protein kinase 8 (c-Jun NH2-terminal kinase), attenuated TNC-stimulated ADAM-9 expression, proteolytic activity, and BTIC invasiveness. The relevance of ADAM-9 to tumor invasiveness was validated using resected human glioblastoma specimens and orthotopic xenografts where elevation of ADAM-9 and TNC expression was prominent at the invasive front of the tumor.CONCLUSIONS:
This study has identified TNC as a promoter of the invasiveness of BTICs through a mechanism involving ADAM-9 proteolysis via the c-Jun NH2-terminal kinase pathway.Palavras-chave
Texto completo:
1
Bases de dados:
MEDLINE
Assunto principal:
Células-Tronco Neoplásicas
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Neoplasias Encefálicas
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Glioblastoma
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Tenascina
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Proteínas ADAM
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Proteínas de Membrana
Limite:
Animals
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Humans
Idioma:
En
Revista:
Neuro Oncol
Assunto da revista:
NEOPLASIAS
/
NEUROLOGIA
Ano de publicação:
2015
Tipo de documento:
Article