Jiang Kuan, Zhi Tongle, Xu Wenhui, Xu Xiupeng, Wu Weining, Yu Tianfu, Nie Er, Zhou Xu, Bao Zhongyuan, Jin Xin, Zhang Junxia, Wang Yingyi, Liu Ning
Department of Neurosurgery, The First Affiliated Hospital of Nanjing Medical UniversityNanjing 210000, Jiangsu Province, China.
Department of Neurosurgery, Yixing People's HospitalYixing 214200, Jiangsu Province, China.
Am J Cancer Res. 2017 Apr 1;7(4):784-800. eCollection 2017.
MicroRNAs are associated with different types of cancers. In this study, we found that miR-1468-5p could inhibit growth and cell cycle progression in glioma by targeting ribonucleotide reductase large subunit M1 (RRM1). First, we analyzed miR-1468-5p expression in different glioma grades and the prognostic significance of its expression in glioblastoma multiform patients from the Chinese Glioma Genome Atlas. Then, we expressed miR-1468-5p in U87 and U251 cells and assessed the effects on proliferation and cell cycle progression using cell counting kit-8, colony formation, EdU and flow cytometry assays. Western blotting and luciferase reporter assays identified RRM1 as a novel direct target of miR-1468-5p. Experiments to determine the role of RRM1 in glioma showed that RRM1 expression was significantly higher in glioma than in normal brain tissues, and silencing RRM1 with small-interfering RNAs decreased proliferation and suppressed cell cycle progression, which indicated that RRM1 had pro-tumor functions. miR-1468-5p overexpression suppressed RRM1 expression, reduced glioma cell proliferation and induced cell cycle arrest, which was partially rescued by forced RRM1 expression. In summary, our study revealed that the regulatory mechanism of miR-1468-5p in glioma cell cycle progression involved direct regulation of RRM1 expression, suggesting that RRM1 may be a potential therapeutic target for glioma.
微小RNA与不同类型的癌症相关。在本研究中，我们发现miR-1468-5p可通过靶向核糖核苷酸还原酶大亚基M1（RRM1）抑制胶质瘤的生长和细胞周期进程。首先，我们分析了中国胶质瘤基因组图谱中不同级别胶质瘤中miR-1468-5p的表达及其在多形性胶质母细胞瘤患者中的预后意义。然后，我们在U87和U251细胞中表达miR-1468-5p，并使用细胞计数试剂盒-8、集落形成、EdU和流式细胞术检测评估其对增殖和细胞周期进程的影响。蛋白质印迹法和荧光素酶报告基因检测确定RRM1是miR-1468-5p的一个新的直接靶点。确定RRM1在胶质瘤中作用的实验表明，RRM1在胶质瘤中的表达显著高于正常脑组织，用小干扰RNA沉默RRM1可降低增殖并抑制细胞周期进程，这表明RRM1具有促肿瘤功能。miR-1468-5p过表达抑制RRM1表达，减少胶质瘤细胞增殖并诱导细胞周期停滞，而强制表达RRM1可部分挽救这种作用。总之，我们的研究揭示了miR-1468-5p在胶质瘤细胞周期进程中的调控机制涉及对RRM1表达的直接调节，提示RRM1可能是胶质瘤的一个潜在治疗靶点。
