Circpkd2 Inhibits the Glioma Cell Proliferation, Invasion and Glycolytic Metabolism Through Regulating the Mir-1278/Lats2 Axis.

Glioma is the most prevalent brain tumor with a poor prognosis. Circular RNA (circ) (PKD2) has been identified as a potential tumor suppressor. However, the effect of circPKD2 on glioma has been unknown. circPKD2 expression in glioma and its potential targets were analyzed by bioinformatics methods, qRT-PCR, dual luciferase reporter, RNA-pull down and RNA immunoprecipitation assays. Overall survival was analyzed by Kaplan-Meier method. The correlation of circPKD2 expression with patient's clinical characteristics was assessed by Chi-square test. Glioma cell invasion was detected by Transwell invasion assay, and cell proliferation was determined by CCK8 and EdU assays. ATP level, Lactate production, and glucose consumption were measured by commercial assay kits, and glycolysis-related protein (Ki-67, VEGF, HK2, LDHA) levels were evaluated by western blot. circPKD2 expression was downregulated in glioma, but circPKD2 overexpression inhibited the cell proliferation, invasion, and glycolytic metabolism. Besides, patients with low circPKD2 expression had a worse prognosis. circPKD2 level was correlated with distant metastasis, WHO grade, and Karnofsky, KPS score. circPKD2 acted as a sponge of miR-1278, and LATS2 was a target gene of miR-1278. Moreover, circPKD2 could target miR-1278 to up-regulate LATS2 expression to suppress the cell proliferation, invasion, and glycolytic metabolism. These findings display that circPKD2 can function as a tumor suppressor in glioma by controlling the miR-1278/LATS2 axis and provide the potential biomarkers for glioma treatment.