WITHDRAWN: Circular RNA CircRNA-0000520 promotes non-small cell lung cancer progression through sponging microRNA-521

Abstract

The non-small cell lung cancer (NSCLC) accounts for 85 % of all lung cancers. This study investigated how the circular RNA (circRNA)-0000520 affected NSCLC and the underlying mechanisms, providing potential target for developing effective treatments of NSCLC. Firstly, circRNA-0000520 expression in tissues and cells were explored by the GEO2R online tool analyzing the public dataset obtained from the Gene Expression Omnibus (GEO) database and real-time reverse transcriptase-polymerase chain reaction (RT-qPCR). CircRNA-0000520 was upregulated in NSCLC (P < 0.05). Knockdown of circRNA-0000520 decreased the proliferation, migration and invasion of NSCLC cells, while increased the apoptosis and G0/G1 arrest of NSCLC cells (P < 0.05). Next, the downstream miRNAs of circRNA-0000520 were detected. By using RT-qPCR, the miR-521 was found to be downregulated in both NSCLC tissues and cell lines. And circRNA-0000520 knockdown obviously led to an increase of miR-521 in NSCLC cells. Circinteractome database was used to predict the binding sites of miR-521 in circRNA-0000520. And the interaction between circRNA-0000520 and miR-521 were verified by dual-luciferase reporter assay and RNA immunoprecipitation verified the interaction between circRNA-0000520 and miR-521. Furthermore, miR-521 depletion reversed the decreased levels of proliferation, migration and invasion of NSCLC cells, and the increased levels of apoptosis and G0/G1 arrest of NSCLC cells (P < 0.05) induced by circRNA-0000520 knockdown. In general, this study further verified that circRNA-0000520 played oncogenic roles in NSCLC and promoted the malignant behavior of NSCLC, and firstly proved that circRNA-0000520 acted as a sponge of miR-521, suggesting the potential of circRNA-0000520/miR-521 axis as the promising therapeutic targets for patients with NSCLC.