ABSTRACT
Objective To explore the effect of microRNAs 224 and 21 on human glioma stem cells survival and the possible molecular mechanisms.Methods qPCR was used to detect the dysregulated expression of microRNAs in malignant glioma samples, human GBM stem cells, artificially established GBM stem cell lines and human tissues.Caspase 3/7 assay, Annexin V apoptosis/fluorescence assay were performed to determine the effect of miR-21 or miR-224 mimics and inhibitor on cell apoptosis.Living cells count was used to assess miR-21 or miR-224 mimics and inhibitor on cell growth.TargetScan was used to explore potential targets of miR-21 and miR-224, and dual luciferase reporter assay was used to identify whether the 3’UTR of Caspase 3, Caspase 9 and Bim mRNA was a binding target of miR-21 or miR-224.Western blot was used to detect the expression of Caspase 3, Caspase 9 and Bim protein after transfection of miR-21 or miR-224 mimics or inhibitors.Results miR-21 and miR-224 are strongly upregulated in GSC samples, multiple GBM human tumor specimens, and GBM neurosphere stem cell lines ( P<0.05 ) .Caspase 3/7 assay and Annexin V apoptosis/fluorescence assay results showed that miR-224 and miR-21 regulated GSC apoptosis.Living cells count results demonstrated that miR-224 and miR-21 regulated GSC growth.miR-224 and miR-21 regulate pro-apoptotic gene expression by directly targeting Caspase 3, Caspase 9, and Bim 3’-UTRs. Conclusion These results indicate that miR-224 and miR-21 are important physiologic drivers of GSC resistance to apoptosis, providing new points of therapeutic leverage against these treatment-resistant cells.