Fig. 2
Periostin (POSTN) was markedly upregulated in GBM samples and cell lines, and increased expression of POSTN was strongly linked to unfavorable outcomes in GBM patients. A and B, Volcano plots depicting DEGs identified in patients with different prognoses using the datasets from TCGA (A) and CGGA (B). C, Venn diagram showing intersection analysis of upregulated genes from TCGA and CGGA datasets to identify common candidate genes. D and G, POSTN mRNA expression in gliomas categorized by WHO grade using the CGGA database (D) and TCGA database (G) (***P < 0.001, **P < 0.01, *P < 0.05, one-way ANOVA followed by Tukey’s Honest Significant Difference (HSD) test). E and H, Analysis of POSTN mRNA expression levels across different glioma subtypes (classical, mesenchymal, proneural) using data from the CGGA database (E) and TCGA database (H) (***P < 0.001, one-way ANOVA followed by Tukey’s HSD post-test). F and I, Kaplan-Meier survival analysis of POSTN expression in IDH-wt GBM samples across all subtypes from the CGGA (F) and TCGA datasets (I) (CGGA: P = 0.012, TCGA: P = 0.0002, log-rank test). J, IHC images showing POSTN distribution in gliomas of different WHO grades, including oligodendrogliomas (grade II), astrocytomas (grade III), and glioblastomas (grade IV), respectively. K, Western blot assays of POSTN expression in four glioma tissues compared to matched peritumoral infiltration tissues, using GAPDH as the reference control. qRT-PCR assays of POSTN mRNA levels in four gliomas tumor tissues versus matched peritumoral infiltration tissues (****P < 0.0001, **P < 0.01, Student’s t-test). Upper: Western blot analysis. Lower: qRT-PCR analysis. L, Western blot assays of POSTN expression in U87, LN229, and U251 GBM cells relative to normal human astrocytes (NHA), using GAPDH as the reference control. qRT-PCR assays for detecting POSTN mRNA levels in U87, LN229, and U251 GBM cell lines versus NHA (****P < 0.0001, Student’s t-test). Upper: Western blot analysis. Lower: qRT-PCR analysis.
