MicroRNAs are single-stranded small non-coding RNA molecules which regulate mammalian cell growth, differentiation, and apoptosis by altering the expression of other genes and play a role in tumor genesis and progression. MiR-106a is upregulated in several types of malignancies and provides a pro-tumorigenic effect. However, its role in glioma is largely unknown. Our findings demonstrate that the low expression of miR-106a in human glioma specimens is significantly correlated with high levels of E2F1 protein and high-grade glioma. Here, we present the first evidence that miR-106a provides a tumor-suppressive effect via suppressing proliferation of and inducing apoptosis in human glioma cells. We further show that E2F1 is a direct functional target of miR-106a, suggesting that the effect of miR-106a on the glioma suppressive effect may result from inhibition of E2F1 via post-transcriptional regulation. In addition, our results reveal that miR-106a can increase p53 expression via E2F1 inhibition, whereas the effect of miR-106a on the proliferation of glioma cells is independent of p53 status. Further investigations will focus on the therapeutic use of miR-106a-mediated antitumor effects in glioma.
Glioblastoma multiforme (GBM) is lethal brain tumor thought to arise from GBM stem cells (GBM-SCs). MicroRNAs carry out post-transcriptional regulation of various cellular processes that modulate the stemness properties of GBM-SCs. Here, we investigated the critical role of miR-153 in GBM-SCs. First, GBM-SCs were isolated from six GBM specimens. These GBM-SCs formed GBM spheres, expressed markers associated with neural stem cells, and possessed the capacity for self-renewal and multilineage differentiation. Then qRT-PCR analysis showed that miR-153 expression was down-regulated in GBM tissues relative to normal brain tissues, and in CD133 positive cells relative to CD133 negative cells. This project demonstrates for the first time that transient transfection of miR-153 into GBM-SCs can inhibit their stemness properties, such as impairing self-renewal ability and inducing differentiation. Meanwhile, miR-153 can also repress GBM-SCs growth and induce apoptosis. Altogether, these results indicate that reactivation of miR-153 expression suggests novel therapeutic strategies for GBM-SCs.
MiR-106a expression was relatively abundant and stable in a large cohort of archival FFPE GBM specimens and could be used as an independent prognostic biomarker in those patients. Thus, miR-106a can be used to predict prognosis and treatment response in individual GBM patients.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.