کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1981711 1539420 2014 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Tumor suppressive miRNA-34a suppresses cell proliferation and tumor growth of glioma stem cells by targeting Akt and Wnt signaling pathways
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Tumor suppressive miRNA-34a suppresses cell proliferation and tumor growth of glioma stem cells by targeting Akt and Wnt signaling pathways
چکیده انگلیسی


• miR-34a was decreased in both glioma and glioma stem cell-lines as compared to normal brain tissues.
• Glioma stem cell-lines HNGC-2 and NSG-K16 possess the mesenchymal glioblastoma phenotype.
• miR-34a over-expression in these cell lines decreased their proliferative and migratory potential, and induced apoptosis.
• Rictor, a part of the mTORC2 complex, is a novel target for miR-34a in glioma stem cells.
• The tumor suppressive function of miR-34a is mediated via Rictor and affects the AKT/mTOR pathway and Wnt signaling.

MiRNA-34a is considered as a potential prognostic marker for glioma, as studies suggest that its expression negatively correlates with patient survival in grade III and IV glial tumors. Here, we show that expression of miR-34a was decreased in a graded manner in glioma and glioma stem cell-lines as compared to normal brain tissues. Ectopic expression of miR-34a in glioma stem cell-lines HNGC-2 and NSG-K16 decreased the proliferative and migratory potential of these cells, induced cell cycle arrest and caused apoptosis. Notably, the miR-34a glioma cells formed significantly smaller xenografts in immuno-deficient mice as compared with control glioma stem cell-lines. Here, using a bioinformatics approach and various biological assays, we identify Rictor, as a novel target for miR-34a in glioma stem cells. Rictor, a defining component of mTORC2 complex, is involved in cell survival signaling. mTORC2 lays downstream of Akt, and thus is a direct activator of Akt. Our earlier studies have elaborated on role of Rictor in glioma invasion (Das et al., 2011). Here, we demonstrate that miR34a over-expression in glioma stem cells profoundly decreased levels of p-AKT (Ser473), increased GSK-3β levels and targeted for degradation β-catenin, an important mediator of Wnt signaling pathway. This led to diminished levels of the Wnt effectors cyclin D1 and c-myc. Collectively, we show that the tumor suppressive function of miR-34a in glioblastoma is mediated via Rictor, which through its effects on AKT/mTOR pathway and Wnt signaling causes pronounced effects on glioma malignancy.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: FEBS Open Bio - Volume 4, 2014, Pages 485–495
نویسندگان
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