Chen Qunbang, Gao Jian, Zhao Yingjia, Hou Ruizhe
Department of Neurosurgery, China-Japan Union Hospital of Jilin University, Changchun, 130033 Jilin China.
Department of Gynecology and Obstetric, The Second Hospital of Jilin University, Changchun, 130000 Jilin China.
Cancer Cell Int. 2020 Aug 26;20:411. doi: 10.1186/s12935-020-01433-2. eCollection 2020.
Dysregulation of lncRNAs is frequent in glioma and has emerged as an important mechanism involved in tumorigenesis. Previous analysis of Chinese Glioma Genome Atlas (CGGA) database indicated that LBX2-AS1 expression is one of differentially expression lncRNA between lower grade glioma (LGG) (grade II and III) and glioblastoma multiforme (GBM). However, the function and mechanism of LBX2-AS1 in glioma has not been evaluated yet.
Here, we analyzed the expression of LBX2-AS1 in GTEx data (normal brain), TCGA-LGG and TCGA-GBM. RT-PCR was performed to detect LBX2-AS1 in surgery obtained normal brain and glioma. CCK-8 kit and Annexin V-FITC-PI Apoptosis Detection Kit were used to study the function of LBX2-AS1 on glioma proliferation and apoptosis. Bioinformatic analysis, RNA immunoprecipitation, RT-PCR, western blotting and dual luciferase reporter assay were carried out to investigate the target miRNA of LBX2-AS1. The discovered mechanism was validated by the rescue assay.
Following study of GTEx and TCGA data, LBX2-AS1 was significantly elevated in glioma compared with normal brain and in GBM compared with LGG. Higher expression of LBX2-AS1 was associated with poor prognosis of patients with glioma. Expression of LBX2-AS1 was positively correlated with pathology classification of glioma. Knockdown of LBX2-AS1 inhibited cell proliferation and induced cell apoptosis in glioma. LBX2-AS1 have complimentary binding site for tumor suppressor miR-491-5p and we showed that LBX2-AS1 sponged miR-491-5p to upregulate TRIM28 expression in glioma cells. TRIM28 overexpression attenuated the effect of LBX2-AS1 knockdown on glioma cells.
In conclusion, LBX2-AS1 was an increased lncRNA in glioma. Mechanistically, LBX2-AS1 promoted glioma cell proliferation and resistance to cell apoptosis via sponging miR-491-5p.
lncRNAs的失调在胶质瘤中很常见，并已成为肿瘤发生的重要机制。先前对中国胶质瘤基因组图谱（CGGA）数据库的分析表明，LBX2-AS1表达是低级别胶质瘤（LGG，II级和III级）与多形性胶质母细胞瘤（GBM）之间差异表达的lncRNA之一。然而，LBX2-AS1在胶质瘤中的功能和机制尚未得到评估。
在此，我们分析了GTEx数据（正常脑）、TCGA-LGG和TCGA-GBM中LBX2-AS1的表达。采用RT-PCR检测手术获取的正常脑和胶质瘤中LBX2-AS1的表达。使用CCK-8试剂盒和Annexin V-FITC-PI凋亡检测试剂盒研究LBX2-AS1对胶质瘤增殖和凋亡的作用。进行生物信息学分析、RNA免疫沉淀、RT-PCR、蛋白质印迹和双荧光素酶报告基因检测以研究LBX2-AS1的靶标miRNA。通过拯救实验验证发现的机制。
在对GTEx和TCGA数据进行研究后，与正常脑相比，LBX2-AS1在胶质瘤中显著升高，与LGG相比，在GBM中显著升高。LBX2-AS1的高表达与胶质瘤患者的不良预后相关。LBX2-AS1的表达与胶质瘤的病理分级呈正相关。敲低LBX2-AS1可抑制胶质瘤细胞增殖并诱导细胞凋亡。LBX2-AS1具有与肿瘤抑制因子miR-491-5p的互补结合位点，并且我们表明LBX2-AS1通过海绵吸附miR-491-5p上调胶质瘤细胞中TRIM28的表达。TRIM28的过表达减弱了LBX2-AS1敲低对胶质瘤细胞的影响。
总之，LBX2-AS1是胶质瘤中一种上调的lncRNA。机制上，LBX2-AS1通过海绵吸附miR-491-5p促进胶质瘤细胞增殖并抵抗细胞凋亡。
