MiRNA-329 targeting E2F1 inhibits cell proliferation in glioma cells

Bingxiang Xiao,Ruxiang Xu,Benfu He,Zhiliang Liu,Li Tan

doi:10.1186/1479-5876-11-172

Abstract

BackgroundMicroRNAs have recently emerged as key regulators of cancers, miR-329 located on 14q32.31 is one of down-regulated miRNAs in glioma, but the function and molecular mechanisms of miR-329 in determining the malignant phenotype of human glioma are elusive. This study therefore was conducted to investigate the role of miR-329 in biological behaviors of human glioma LN18 and T98G cell lines and its molecular mechanisms.MethodsNine patients with GBM were analyzed for the expression of miR-329 by quantitative RT–PCR. MiR-329 overexpression was established by transfecting miR-329 precursor into LN18 and T98G cells, and its effects on cell proliferation were studied using MTT assay, anchorage-independent growth ability assay, colony formation assays, Bromodeoxyuridine labeling and immunofluorescence.The effects of miR-329 on cell cycle were studied by flow cytometry. The target of miR-329 was determined by luciferase assays. The regulation of miR-329 on Akt pathway was determined by western blot.ResultsThe E2F1 was identified as the target of miR-329. Overexpression of miR-329 blocked G1/S transition in LN18 and T98G cell lines, dramatically suppressed cell proliferation and the ability of colony formation. MiR-329 significantly decreased the phosphorylation levels of intracellular kinases Akt and expression of cyclin D1, but the expression of p21 was upregulated, cell growth was suppressed by inhibiting E2F1-mediated Akt pathway.ConclusionsMiR-329 may inhibit cell proliferation in human glioma cells through regulating E2F1-mediated suppression of Akt pathway.

Highlights

MicroRNAs have recently emerged as key regulators of cancers, miR-329 located on 14q32.31 is one of down-regulated miRNAs in glioma, but the function and molecular mechanisms of miR-329 in determining the malignant phenotype of human glioma are elusive
MiR-329 overexpression reduces cell proliferation in glioma To explore the role of miR-329 downregulation in the development and progression of glioma, we examined its effect on cell proliferation
A MTT assay showed that miR-329 upregulation significantly inhibited the proliferation rate of LN18 and T98G glioma cells (Figure 2A), and this was further confirmed by a colony formation assay (Figure 2B)

Summary

Introduction

MicroRNAs have recently emerged as key regulators of cancers, miR-329 located on 14q32.31 is one of down-regulated miRNAs in glioma, but the function and molecular mechanisms of miR-329 in determining the malignant phenotype of human glioma are elusive. Recent advances have implicated a defined set of oncogenic pathways in the underlying biology of this tumor group [2]. Among these crucial signaling networks, the Akt pathway and E2F1 have emerged as being important in glioma pathogenesis, which is correlated with poor prognosis in multiple glioma subtypes [3,4]. The function and molecular mechanism of miR-329 in determining the malignant phenotype of human glioma are elusive. MiR-329 may act as the role of tumor suppressor in glioma cells

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