LncRNA HOXA‐AS3 promotes the malignancy of glioblastoma through regulating miR‐455‐5p/USP3 axis

Our objective was to determine the molecular mechanisms by which lncRNA HOXA‐AS3 regulates the biological behaviour of glioblastoma multiforme (GBM). We used an lncRNA microarray assay to identify GBM‐related lncRNA expression profiles. Qrt‐PCR was used to survey the levels of expression of long non‐coding RNA (lncRNA) HOXA‐AS3 and the target gene. Dual‐luciferase reporter assays were used to investigate the interaction of lncRNA HOXA‐AS3, the target gene and miRNA. Western blot analysis was used to examine the expression of USP3 and epithelial‐mesenchymal transition (EMT) genes. The MTT assay, transwell assay and wound healing assay were used to analyse the effects of lncRNA HOXA‐AS3 on GBM cell viability, mobility and invasiveness, respectively. Our results showed that lncRNA HOXA‐AS3 was significantly up‐regulated in GBM cells and could promote GBM cell proliferation, invasion and migration in vitro and in vivo. HOXA‐AS was found to be associated with poor survival prognosis in glioma patients. The dual‐luciferase reporter assay also revealed that lncRNA HOXA‐AS3 acts as a mir‐455‐5p sponge by up‐regulating USP3 expression to promote GBM progression. Western blot analysis showed that lncRNA HOXA‐AS3 could up‐regulate EMT‐related gene expression in GBM. Experiments showed mir‐455‐5p could rescue the effect of lncRNA HOXA‐AS3 on cell proliferation and invasion. The newly identified HOXA‐AS3/mir‐455‐5p/USP3 pathway offers important clues to understanding the key mechanisms underlying the action of lncRNA HOXA‐AS3 in glioblastoma.