High DPP4 expression predicts poor prognosis in patients with low-grade glioma.

Dipeptidyl peptidase-IV (DPP4) plays a key role in tumor development; however, its role in glioma pathogenesis has not been determined. Here, we aimed to investigate the expression pattern of DPP4 and explore the association between expression and patient prognosis in glioma. DPP4 levels were investigated using qRT-PCR, immunohistochemistry and western blot in a rat model of glioma and also in patient samples. The relationship between DPP4 levels, WHO pathological grade gliomas, and isocitrate dehydrogenase 1 and 2 (IDH1/2) status was assessed in patient samples. Our data indicated that DPP4 levels were markedly increased in a rat model of glioma (p < 0.05, p < 0.01) and aslo in patient samples. Furthermore, the elevation of DPP4 levels in the samples obtained from pateints was associated with the pathogical grade of glioma and the IDH1/2 status (p < 0.01, p < 0.001). High DPP4 levels decreased the survival probability of patients with low-grade glioma (LGG). The data from patient samples showed that DPP4 expression increased with the pathological grade. Increased expression of DPP4 could be a promising index for determining the prognosis of glioma.