Fig. 1

EGF contributes to NTN4 expression in GBM cells. a On the basis of RNA sequencing data from 934 NIH cell lines, we calculated the Spearman product-moment correlation coefficient. The co-expression analysis revealed that the expression of EGFR correlates with NTN4 (R_value = 0.573) and ITGB4 (R_value = 0.539). b & c According to scRNA sequencing data of glioblastoma, 191 genes co-expressed with EGFR were enriched by overlapping Spearman product-moment correlation coefficient and distant correlation analysis. These 191 genes were further used for signaling pathway enrichment and GO bioprocess enrichment. ECM organization and Caspase-related signaling pathways were enriched by signaling pathway analysis (b). Nervous system development and glial cell differentiation were enriched by GO bioprocess analysis (c). d Using Q-RT-PCR, the mRNA levels of NTN4 and EGFR were determined in two primary glioblastoma cell lines: GBM-14042 and GBM-112D. e-f EGF treatment was performed at the concentration of 20 ng/ml and was re-applied every 48 h. 24 h, 48 h, and 96 h after EGF treatment, the mRNA levels of NTN4 were determined in U251MG, GBM-14042 and GBM-112D cells by Q-RT-PCR (e). After treatment for 48 h and 96 h, the expression of NTN4 was 2 to 3-fold higher than control group. The enhancing effects of EGF on NTN4 expression (green) were also detected by immunofluorescence in U251MG at 48 h and 72 h, and the Dapi staining was shown in blue (f)