Fig. 6

BBOX1-AS1 regulates MELK expression through sponging miR-27a-5p in NSCLC cells. a Venn diagram exhibited 180 up-regulated genes in NSCLC according to 4 different GEO datasets (GSE19188, GSE18842, GSE29250, GSE33532) following the criteria of log2 fold change ≥1. b Intersection of these 180 up-regulated genes and miR-27a-5p targets predicted by TargetScan and miRDB. c GEPIA was utilized to evaluate the expression of MELK in LUAD and LUSC. d Kaplan-Meier plotter database was used to analyze the prognostic significance of MELK in NSCLC patients. e Schematic diagram of the binding sites between miR-27a-5p and MELK-3’UTR. f Luciferase activity assays in A549 and SK-MES-1 cells transfected with miR-NC or miR-27a-5p and MELK-wt or MELK-mut reporter. g RNA pull-down assays were utilized to determine the enrichment of MELK mRNA in NSCLC cells after being precipitated by Biotin-miR-27a-5p. h Western blot assays were performed to determine the effect of miR-27a-5p mimic or inhibitor on MELK protein level in NSCLC cells. i Bioinformatics tool GEPIA showed a positive correlation between MELK and BBOX1-AS1 expression in lung cancer tissues. j qRT-PCR analysis of MELK expression in 76 NSCLC tumor tissues and adjacent normal samples. k Expression correlation between MELK and BBOX1-AS1 or miR-27a-5p in NSCLC tumor tissues. l The protein levels of MELK, p-FAK and FAK were determined by western blot assays in A549 cells transfected with Vector, BBOX1-AS1 or BBOX1-AS1 + miR-27a-5p and SK-MES-1 cells transfected with si-NC, si-BBOX1-AS1 or si-BBOX1-AS1 + inh-miR-27a-5p. ***P < 0.001