Knockdown of circ0082374 inhibits cell viability, migration, invasion and glycolysis in glioma cells by miR-326/SIRT1

•Circ0082374 expression is increased in glioma tissues and cells.•Circ0082374 silence inhibits cell viability, migration, invasion and glycolysis.•Circ0082374 regulates SIRT1 expression by sponging miR-326.•Circ0082374 knockdown decreases xenograft tumor growth. Circular RNAs (circRNAs) play important roles in the development and treatment of glioma. However, the role and mechanism of circRNA carboxypeptidase A4 (circ0082374) in glioma are largely unknown. Forty-two glioma patients and 28 normal patients were recruited. Glioma cell lines A172 and U251 were used for functional assays. The expression levels of circ0082374, microRNA-326 (miR-326) and sirtuin 1 (SIRT1) were examined via quantitative real-time polymerase chain reaction or western blot. Cell viability, migration, invasion and glycolysis were measured via cell counting kit-8, trans-well, oxygen consumption rate and western blot, respectively. The target correlation of circ0082374/miR-326 or miR-326/SIRT1 was explored via dual-luciferase reporter, RNA immunoprecipitation and pull-down assays. The role of circ0082374 in vivo was investigated via xenograft model. We found circ0082374 expression was elevated in glioma tissues and cells. Knockdown of circ0082374 suppressed the viability, migration, invasion and glycolysis in glioma cells. miR-326 was a target of circ0082374 and miR-326 knockdown attenuated the inhibitive role of circ0082374 silence in glioma progression. SIRT1 was a target of miR-326 and circ0082374 could promote SIRT1 expression by sponging miR-326. Silence of SIRT1 reversed the promoting effect of circ0082374 on glioma progression. Knockdown of circ0082374 reduced xenograft tumor growth by miR-326/SIRT1 in vivo. Collectively, silence of circ0082374 repressed the viability, migration, invasion and glycolysis in glioma cells by regulating miR-326 and SIRT1 in a ceRNA mechanism, providing a new mechanism for the pathogenesis of glioma.