The circ-VCAN with radioresistance contributes to the carcinogenesis of glioma by regulating microRNA-1183

Abstract

Circular RNAs (circRNAs), a widespread type of noncoding RNA, are produced by reverse splicing with a circular loop structure. Circ-VCAN (hsa-circ-0073237) acts as a novel circRNA, although its roles in the progression and radioresistance of glioma remain unknown.Expressions of circ-VCAN and microRNA-1183 (miR-1183) were analyzed by quantitative real-time PCR, and the functions of circ-VCAN and irradiate in glioma cell proliferation, apoptosis, migration, and invasion were assessed using cell counting kit-8, flow cytometry, Wound healing, and Transwell assays. The interaction between circ-VCAN and miR-1183 was validated dual-luciferase reporter assay.Our results revealed that circ-VCAN was significantly upregulated in radioresistant glioma tissues compared with radiosensitive tissues, and that circ-VCAN expression was negatively correlated with miR-1183 expression in glioma tissues. We also determined that circ-VCAN expression was decreased and miR-1183 expression was increased in U87 and U251 cells after irradiation. Both knockdown of circ-VCAN and treatment with miR-1183 mimics inhibited proliferation, migration, and invasion, and accelerated apoptosis of the irradiated U87 and U251 cells. In addition, luciferase reporter assays revealed that circ-VCAN might function as a sponge for miR-1183. Finally, overexpression of circ-VCAN expedited carcinogenesis and reduced glioma radiosensitivity by regulating miR-1183.Circ-VCAN serves as a potential oncogene of glioma by regulating miR-1183, and plays an essential role in the radioresistance of glioma.