Fig 2: Gene Set Enrichment Analysis between the four highest and four lowest GPNMB expression samples in GSE53733. (A-I) Enriched pathways of (A) ‘hypoxia’, (B) ‘angiogenesis’, (C) ‘epithelial mesenchymal transition’, (D) ‘focal adhesion’, (E) ‘chemokine receptors bind chemokines’, (F) ‘chemokine receptor binding’, (G) ‘extracellular matrix component’, (H) ‘extracellular matrix binding’ and (I) ‘extracellular matrix receptor interaction’. GPNMB, glycoprotein non-metastatic melanoma protein B.

Fig 3: Prognostic role of GPNMB in glioma confirmed in tissue microarrays. (A) Representative images of immunohistochemical staining against GPNMB with different intensity scores. (B) The immunohistochemical scores of GPNMB expression were higher in high-grade (WHO III and IV) compared with low-grade (WHO I and II) glioma. (C) The Renyi test demonstrated that high GPNMB expression was significantly associated with a lower survival rate compared with that in the low GPNMB expression group (P=0.002). GPNMB, glycoprotein non-metastatic melanoma protein B; WHO, World Health Organization.

Fig 4: Pearson correlation analysis between GPNMB and markers of angiogenesis, migration and invasion in GSE53733. (A-I) Correlations between GPNMB and (A) CD31, (B) ENG, (C) CXCR4, (D) TGFB1, (E) PLAU, (F) PLAUR, (G) MMP-2, (H) MMP-7 and (I) MMP-9. GPNMB, glycoprotein non-metastatic melanoma protein B; CD31, cluster of differentiation 31; ENG, endoglin; CXCR4, C-X-C motif chemokine receptor 4; TGFB1, transforming growth factor ß1; PLAU, urokinase; PLAUR, PLAU receptor; MMP, matrix metalloproteinase.

Fig 5: The association between GPNMB expression and clinicopathological characteristics of 220 patients with glioma from the Chinese Glioma Genome Atlas dataset explored using the mRNA microarray data and clinical information. (A) Compared with non-tumor brain tissues, higher levels of GPNMB expression were observed in glioma tissues. (B and C) The GPNMB expression levels were compared in the (B) four gene expression-based and (C) four histological subtypes. (D) The levels of GPNMB expression in different WHO grades were compared. (E) Lower KPS were identified in patients with high GPNMB expression. (F) Kaplan-Meier analysis with the log-rank test demonstrated that high GPNMB expression was associated with shorter survival time compared with that of patients with low GPNMB expression. (G and H) Survival differences were compared between patients with high and low GPNMB expression in sub-populations aged (G) 10–30, (H) 31–50 and (I) 51–70 years. *P<0.05, **P<0.01 and ***P<0.001. GPNMB, glycoprotein non-metastatic melanoma protein B; KPS, Karnofsky performance scores.