Zheng Yungui, Lu Xiaowen, Xu Liepeng, Chen Zhe, Li Qinxi, Yuan Jun
Department of Neurosurgery, The First Affiliated Hospital of Medical College, Shantou University, Shantou, Guangdong 515041, PR China.
Department of Neurosurgery, The First Affiliated Hospital of Medical College, Shantou University, Shantou, Guangdong 515041, PR China.
Hum Pathol. 2017 Nov;69:63-71. doi: 10.1016/j.humpath.2017.09.006. Epub 2017 Sep 29.
Previous studies indicated that microRNA (miR)-675 and its precursor lncRNA H19 were both overexpressed in glioma tissues, and H19 might play an oncogenic role. To investigate the involvement of miR-675 in gliomas and its underlying mechanisms, we here collected candidate target genes of miR-675-5p from miRTarBase (http://mirtarbase.mbc.nctu.edu.tw/, Release 6.0), which contains the experimentally validated microRNA-target interactions. Then, regulatory effects of miR-675 on its target genes were validated using clinical samples and glioma cell lines. Involvement of the miR-675-target axis deregulation in cell proliferation, migration and invasion of glioma was demonstrated by both gain- and loss-of-function experiments. As a result, retinoblastoma 1 (RB1) was identified as a candidate target gene of miR-675-5p. Expression levels of miR-675-5p in glioma tissues and cells were negatively correlated with RB1 expression at both mRNA and protein levels. Importantly, deregulation of the miR-675-5p-RB1 axis was significantly associated with advanced World Health Organization (WHO) grade and low Karnofsky performance score (KPS) score of glioma patients. Luciferase reporter assay verified that RB1 was a direct target gene of miR-675 in glioma cells. Functionally, miR-675 promoted glioma cell proliferation, migration and invasion. Notably, simulation of RB1 antagonized the effects induced by miR-675 up-regulation in glioma cells. In conclusion, our data suggest that miR-675 may be a key negative regulator of RB1 and the imbalance of the miR-675-RB1 axis may be clinically associated with aggressive progression of glioma patients. In addition, miR-675 may act as an oncogenic miRNA in glioma cells via regulating its target gene RB1.
先前的研究表明，微小RNA（miR）-675及其前体长链非编码RNA H19在胶质瘤组织中均呈过表达，且H19可能发挥致癌作用。为了研究miR-675在胶质瘤中的作用及其潜在机制，我们从miRTarBase（http://mirtarbase.mbc.nctu.edu.tw/，版本6.0）收集了miR-675-5p的候选靶基因，该数据库包含经过实验验证的微小RNA-靶标相互作用。然后，使用临床样本和胶质瘤细胞系验证了miR-675对其靶基因的调控作用。功能获得和功能缺失实验均证明了miR-675-靶标轴失调参与了胶质瘤细胞的增殖、迁移和侵袭。结果，视网膜母细胞瘤1（RB1）被鉴定为miR-675-5p的候选靶基因。胶质瘤组织和细胞中miR-675-5p的表达水平在mRNA和蛋白质水平上均与RB1表达呈负相关。重要的是，miR-675-5p-RB1轴的失调与胶质瘤患者的世界卫生组织（WHO）高级别分级和低卡诺夫斯基功能状态评分（KPS）显著相关。荧光素酶报告基因检测证实RB1是胶质瘤细胞中miR-675的直接靶基因。在功能上，miR-675促进了胶质瘤细胞的增殖、迁移和侵袭。值得注意的是，模拟RB1可拮抗miR-675上调在胶质瘤细胞中诱导的效应。总之，我们的数据表明，miR-675可能是RB1的关键负调节因子，miR-675-RB1轴的失衡可能在临床上与胶质瘤患者的侵袭性进展相关。此外，miR-675可能通过调节其靶基因RB1在胶质瘤细胞中作为致癌微小RNA发挥作用。
