Activation of WEE1 confers resistance to PI3K inhibition in glioblastoma.
Neuro Oncol
; 20(1): 78-91, 2018 01 10.
Article
em En
| MEDLINE
| ID: mdl-29016926
ABSTRACT
Background:
Oncogenic activation of phosphatidylinositol-3 kinase (PI3K) signaling plays a pivotal role in the development of glioblastoma (GBM). However, pharmacological inhibition of PI3K has so far not been therapeutically successful due to adaptive resistance through a rapid rewiring of cancer cell signaling. Here we identified that WEE1 is activated after transient exposure to PI3K inhibition and confers resistance to PI3K inhibition in GBM.Methods:
Patient-derived glioma-initiating cells and established GBM cells were treated with PI3K inhibitor or WEE1 inhibitor alone or in combination, and cell proliferation was evaluated by CellTiter-Blue assay. Cell apoptosis was analyzed by TUNEL, annexin V staining, and blotting of cleaved caspase-3 and cleaved poly(ADP-ribose) polymerase. Both subcutaneous xenograft and orthotropic xenograft studies were conducted to evaluate the effects of the combination on tumorigenesis; the tumor growth was monitored by bioluminescence imaging, and tumor tissue was analyzed by immunohistochemistry to validate signaling changes.Results:
PI3K inhibition activates WEE1 kinase, which in turn phosphorylates cell division control protein 2 homolog (Cdc2) at Tyr15 and inhibits Cdc2 activity, leading to G2/M arrest in a p53-independent manner. WEE1 inhibition abrogated the G2/M arrest and propelled cells to prematurely enter into mitosis and consequent cell death through mitotic catastrophe and apoptosis. Additionally, combination treatment significantly suppressed tumor growth in a subcutaneous model but not in an intracranial model due to limited blood-brain barrier penetration.Conclusions:
Our findings highlight WEE1 as an adaptive resistant gene activated after PI3K inhibition, and inhibition of WEE1 potentiated the effectiveness of PI3K targeted inhibition, suggesting that a combinational inhibition of WEE1 and PI3K might allow successful targeted therapy in GBM.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Neoplasias Encefálicas
/
Proteínas Tirosina Quinases
/
Proteínas Nucleares
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Glioblastoma
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Proteínas de Ciclo Celular
/
Inibidores de Fosfoinositídeo-3 Quinase
Tipo de estudo:
Prognostic_studies
Limite:
Animals
/
Humans
Idioma:
En
Revista:
Neuro Oncol
Assunto da revista:
NEOPLASIAS
/
NEUROLOGIA
Ano de publicação:
2018
Tipo de documento:
Article