期刊
CELL DEATH AND DIFFERENTIATION
卷 23, 期 4, 页码 640-653出版社
NATURE PUBLISHING GROUP
DOI: 10.1038/cdd.2015.131
关键词
-
资金
- University of Strasbourg
- Ligue Contre le Cancer (Comite du Grand Est)
- Fondation ARC pour la Recherche sur le Cancer
- Canceropole Grand Est
- Region Alsace
- French Ministere de l'Enseignement Superieur et de la Recherche
Integrin alpha 5 beta 1 expression is correlated with a worse prognosis in high-grade glioma. We previously unraveled a negative crosstalk between integrin alpha 5 beta 1 and p53 pathway, which was proposed to be part of the resistance of glioblastoma to chemotherapies. The restoration of p53 tumor-suppressor function is under intensive investigations for cancer therapy. However, p53-dependent apoptosis is not always achieved by p53-reactivating compounds such as Nutlin-3a, although full transcriptional activity of p53 could be obtained. Here we investigated whether integrin alpha 5 beta 1 functional inhibition or repression could sensitize glioma cells to Nutlin-3a-induced p53-dependent apoptosis. We discovered that alpha 5 beta 1 integrin-specific blocking antibodies or small RGD-like antagonists in association with Nutlin-3a triggered a caspase (Casp) 8/Casp 3-dependent strong apoptosis in glioma cells expressing a functional p53. We deciphered the molecular mechanisms involved and we showed the crucial role of two anti-apoptotic proteins, phosphoprotein enriched in astrocytes 15 (PEA-15) and survivin in glioma cell apoptotic outcome. PEA-15 is under alpha 5 beta 1 integrin/AKT (protein kinase B) control and survivin is a p53-repressed target. Moreover, interconnections between integrin and p53 pathways were revealed. Indeed PEA-15 repression by specific small-interfering RNA (siRNA)-activated p53 pathway to repress survivin and conversely survivin repression by specific siRNA decreased alpha 5 beta 1 integrin expression. This pro-apoptotic loop could be generalized to several glioma cell lines, whatever their p53 status, inasmuch PEA-15 and survivin protein levels were decreased. Our findings identify a novel mechanism whereby inhibition of alpha 5 beta 1 integrin and activation of p53 modulates two anti-apoptotic proteins crucially involved in the apoptotic answer of glioma cells. Importantly, our results suggest that high-grade glioma expressing high level of alpha 5 beta 1 integrin may benefit from associated therapies including integrin antagonists and repressors of survivin expression.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据