Long non-coding RNA LBX2-AS1 enhances glioma proliferation through downregulating microRNA-491-5p

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.