Association of PDIA4 with clinicopathological characters in gliomas
According to the hypothesis that PDIA4 plays a critical role in glioma aggressiveness, we first measured the expression of PDIA4 in glioma tissues compared with normal brain tissues. The remarkably increased expression of PDIA4 was observed in both GBM samples and Low-Grade glioma (LGG) samples (Figure 1A, p<0.001). To further validate this result, we performed Q-PCR in glioma cell lines. The results documented that the mRNA expression of PDIA4 was elevated in glioma cell lines when compared with normal glial cell line (Figure 1B). Moreover, PDIA4 expression was positively correlated with glioma histological grade in both TCGA and CGGA cohort (Figure 1C). It’s widely recognized mutations in isocitrate dehydrogenase genes (IDH1 and IDH2) have strong connections with tumor behaviors in gliomas. Patients with IDH-mutant (IDH-Mut) histology exhibited better prognosis than IDH-wildtype (IDH-Wt). Intriguingly, we also observed the elevated expression level of PDIA4 in IDH-Wt subtype of glioma when compared with IDH-Mut tumors (Figure 1D). Additionally, we evaluated the expression of PDIA4 in different patterns of glioma. The results showed higher expression of PDIA4 in mesenchymal and classical subtypes rather than neural and proneural subtypes (Figure 1E).