Fig. 4

miR-148a-3p activates the EGFR/MAPK signaling pathway through inhibiting ERRFI1 expression. a Heat maps of target genes that down-regulated in GSE79097. The abscissa represents the sample number, the ordinate represents the gene names, the tree diagram on the left represents the clustering of gene expression, and the box plot on the upper right represents the scale. b Intersection of the miR-148a-3p target genes predicted by miRDB, miDIP, miRSearch, and TargetScan databases with the down-regulated genes in the GSE79097 microarray. The five ellipses in the Figure represent the number of predicted target genes from the four databases and the number of down-regulated genes in the GSE79097 microarray and the intersection represents intersected genes in five sets of data. c The binding sites between ERRFI1 and miR-148a-3p were predicted by the TargetScan database (https://www.targetscan.org/vert_71/). d Dual-luciferase reporter gene assay validation on the relationship between ERRFI1 and miR-148a-3p in HEK293T cells. e Expression of ERRFI1 was determined by RT-qPCR in non-neoplastic brain tissues of control group (n = 20), and neoplastic brain tissues of glioma patients (n = 45) including anaplastic astrocytoma, anaplastic oligodendroglioma, oligodendroglioma, astrocytoma, and glioblastoma (GAPDH was used as internal control). f Western blot analysis to detect ERRFI1 expression in the non-neoplastic brain tissues of control group (n = 20), and neoplastic brain tissues of glioma patients (n = 45) including anaplastic astrocytoma, anaplastic oligodendroglioma, oligodendroglioma, astrocytoma, and glioblastoma (GAPDH was used as internal control). g Pearson correlation analysis of ERRFI1 expression and miR-148a-3p expression in tumor tissues (n = 45). h Expression of ERRFI1 was determined by RT-qPCR in HUVECs transiently transfected with miR-148a-3p mimic or inhibitor (GAPDH was used as internal control). i Western blot analysis to analyze ERRFI1 expression in HUVECs transiently transfected with miR-148a-3p mimic or inhibitor. j Western blot analysis to detect ratios of p-EGFR/EGFR and p-ERK1/2/ERK1/2 in HUVECs transiently transfected with miR-148a-3p mimic or inhibitor. k Expression of miR-148a-3p and ERRFI1 was determined by RT-qPCR in HUVECs transfected with oe-ERRFI1/oe-NC and miR-148a-3p mimic/mimic NC (GAPDH was used as internal control). l Western blot analysis of ERRFI1, extent of EGFR and ERK1/2 phosphorylation, and ratios of p-EGFR/EGFR and p-ERK1/2/ERK1/2 in HUVECs transfected with oe-ERRFI1/oe-NC and miR-148a-3p mimic/mimic NC. * p < 0.05, ** p < 0.01, *** p < 0.001, and **** p < 0.0001. NS indicated no significant difference. Data are shown as mean ± SEM. The cell experiments were performed in 3 repeats and each repeat was performed in technical replicate (triplicate). Unpaired t test was used for comparison between the two groups