circRNA Hsa_circ_0020850 Silence Represses the Development of Lung Adenocarcinoma via Regulating miR-195-5p/IRS2 Axis

BACKGROUND: The dysregulated circular RNAs (circRNAs) are relevant to lung adenocarcinoma development. Nevertheless, the function and mechanism of hsa_circ_0020850 (circ_0020850) in lung adenocarcinoma development are uncertain. METHODS: A total of 35 lung adenocarcinoma patients were recruited, and the tumor and normal tissue samples were harvested. A549 and PC-9 cells were exhibited for the experiments in vitro. circ_0020850, microRNA-195-5p (miR-195-5p) and insulin receptor substrate 2 (IRS2) abundances were detected via quantitative reverse transcription-polymerase chain reaction or Western blot. Cell proliferation, apoptosis, migration and invasion were measured via cell counting kit-8 (CCK8) assay, colony formation, flow cytometry, transwell and Western blot. The relationship between miR-195-5p and circ_0020850 or IRS2 was tested via dual-luciferase reporter analysis. The function of circ_0020850 on cell growth in vivo was measured via xenograft model. RESULTS: circ_0020850 expression was enhanced in lung adenocarcinoma tissues and cells. circ_0020850 silence suppressed cell proliferation, migration and invasion and facilitated apoptosis. miR-195-5p was targeted via circ_0020850, and its knockdown reversed the inhibitive effect of circ_0020850 silence on lung adenocarcinoma development. IRS2 was targeted via miR-195-5p, and miR-195-5p inhibited cell proliferation, migration and invasion and induced apoptosis via decreasing IRS2. circ_0020850 knockdown decreased IRS2 expression via regulating miR-195-5p. circ_0020850 down-regulation decreased lung adenocarcinoma xenograft tumor growth. CONCLUSION: circ_0020850 knockdown repressed lung adenocarcinoma cell proliferation, migration and invasion and promoted apoptosis via regulating miR-195-5p and IRS2.