Overexpression of Podoplanin Predicts Poor Prognosis in Patients With Glioma

High podoplanin (PDPN) expression correlates with poor prognosis in various cancers. However, the expression and clinical value of PDPN in glioma are unclear. In this study, PDPN expression was compared in 227 glioma tissues and 22 paired non-neoplastic tissues, and its association with prognostic factors was statistically analyzed. The effect of PDPN knockdown on the proliferation ability of glioma cells (U87MG and U118MG cell lines) was assessed along with the underlying molecular mechanism. Overexpression of PDPN was observed in the majority of glioma tissues compared with the expression in normal tissues. PDPN overexpression was positively correlated with IDH wild-type status, TERT promoter mutation status, and ATRX retention status, and was negatively correlated with 1p/19q codeletion status. The expression level of PDPN was positively correlated with the glioma grade in the diffuse astrocytoma, IDH wild-type. High PDPN expression was also negatively correlated with survival in astrocytoma patients with IDH mutation or wild-type and in glioblastoma patients with IDH wild-type. Grade, radiochemotherapy, and PDPN overexpression emerged as independent indicators for a poor prognosis of glioma patients. PDPN knockdown suppressed proliferation and reduced p-Akt and p-mTOR protein expression in glioma cells. PDPN is a potential biomarker or therapeutic target for glioma that is closely associated with tumor grade and poor prognosis, which may play a role in enhancing cell proliferation via Akt/mTOR signaling.