Shang Chao, Hong Yang, Guo Yan, Xue Yi-xue
Department of Neurobiology, College of Basic Medicine, China Medical University, Shenyang, Liaoning, China (mainland).
Department of Neurosurgery, Shengjing Hospital, China Medical University, Shenyang, Liaoning, China (mainland).
Med Sci Monit. 2016 Mar 3;22:710-6. doi: 10.12659/msm.897055.
BACKGROUND Human brain glioma is the most common endocranial tumor; its mortality and morbidity are very high. The objective of this study was to determine whether miR-338-3p can regulate malignant biological behaviors of glioma cells by targeted silencing of MACC1. MATERIAL AND METHODS The expression of miR-338-3p was detected by quantitative real-time PCR in brain glioma tissues and cell lines. Bioinformatics software was used to predict some potential target genes of miR-338-3p. Luciferase activities assay was used to verify the combination between target genes and miR-338-3p. And MACC1 protein expression was detected by Western blot. The apoptosis and proliferation ability were analyzed by MTT and flow cytometry assay. RESULTS Compared with normal brain tissues and cells, miR-338-3p in glioma tissues and cell lines was confirmed to be expressed at low levels, and down-regulation of miR-338-3p tended to be correlated with worse histological grade. Up-regulation of miR-338-3p promoted apoptosis and sharply inhibited cell proliferation ability of U251 and U87 cells. The luciferase activities assay, biotin-avidin pull-down assay, and western blot analysis verified that MACC1 was a specific target gene of miR-338-3p. Subsequent experiments found that up-regulation of MACC1 significantly inhibited the apoptosis and increased the cell proliferation ability of U251 and U87 cells. The regulation effects of miR-338-3p on malignant biological behaviors of glioma cells can be partly reversed by up-regulation of MACC1. CONCLUSIONS Down-regulation of miR-338-3p was an independent prognostic biomarker associated with poor prognosis in glioma patients; miR-338-3p acted as a tumor-suppressing gene whose silencing can inhibit malignant biological behaviors of glioma cells. MACC1 was a specific target gene of miR-338-3p, which regulates malignant biological behaviors of glioma cells partly through directly silencing MACC1 expression.
背景 人脑胶质瘤是最常见的颅内肿瘤，其死亡率和发病率都非常高。本研究的目的是确定miR-338-3p是否能通过靶向沉默MACC1来调节胶质瘤细胞的恶性生物学行为。
材料与方法 采用定量实时PCR检测脑胶质瘤组织和细胞系中miR-338-3p的表达。利用生物信息学软件预测miR-338-3p的一些潜在靶基因。采用荧光素酶活性测定法验证靶基因与miR-338-3p之间的结合。通过蛋白质免疫印迹法检测MACC1蛋白表达。采用MTT法和流式细胞术分析细胞凋亡和增殖能力。
结果 与正常脑组织和细胞相比，胶质瘤组织和细胞系中的miR-338-3p表达水平较低,且miR-338-3p的下调往往与较差的组织学分级相关。上调miR-338-3p可促进U251和U87细胞凋亡并显著抑制其细胞增殖能力。荧光素酶活性测定、生物素-抗生物素蛋白下拉分析和蛋白质免疫印迹分析证实MACC1是miR-338-3p的特异性靶基因。随后实验发现,上调MACC1可显著抑制U251和U87细胞凋亡并提高其细胞增殖能力。上调MACC1可部分逆转miR-338-3p对胶质瘤细胞恶性生物学行为的调节作用。
结论 miR-338-3p下调是胶质瘤患者预后不良的独立预后生物标志物；miR-338-3p作为一种肿瘤抑制基因，其沉默可抑制胶质瘤细胞的恶性生物学行为。MACC1是miR-338-3p的特异性靶基因，其通过直接沉默MACC1表达部分调节胶质瘤细胞的恶性生物学行为。
