Circ_0020123 regulates autophagy, glycolysis, and malignancy by upregulating IRF4 through eliminating miR-193a-3p-mediated suppression of IRF4 in non-small cell lung cancer

Xing-Ping Yang, Yu-Zhen Zheng, Jian Tan, Ren-Jiang Tian, Piao Shen, Wei-Jie Cai,  Hong-Ying Liao

Abstract:

Circular RNA is related to the tumorigenesis of various cancers. Circular RNA hsa_circ_0020123 (circ_0020123) has been uncovered to promote non-small cell lung cancer (NSCLC) progression. However, the regulatory mechanism of circ_0020123 in NSCLC is unclear. The quantitative real-time polymerase chain reaction was employed to detect the levels of circ_0020123, microRNA (miR)-193a-3p, and IRF4 interferon regulatory factor 4 (IRF4) in NSCLC tissues and cells. Loss-of-function experiments were performed to analyze the impacts of circ_0020123 silencing on NSCLC cell malignancy, autophagy, and glycolysis. Protein levels were detected using western blotting. The regulatory mechanism of circ_0020123 was analyzed by bioinformatics analysis and validated by the dual-luciferase reporter, RNA immunoprecipitation assay, and RNA pull-down assay. Xenograft assay was performed to verify the biological function of circ_0020123. We observed an overt elevation in circ_0020123 expression in NSCLC samples and cells, and NSCLC patients with high circ_0020123 expression had a poor prognosis. Circ_0020123 knockdown constrained xenograft tumor growth in vivo and curbed cell proliferation, migration, and glycolysis, and accelerated cell apoptosis and autophagy in NSCLC cells in vitro. Circ_0020123 could absorb miR-193a-3p to regulate IRF4 expression. miR-193a-3p silencing overturned circ_0020123 knockdown-mediated impacts on NSCLC cell malignancy, autophagy, and glycolysis. And IRF4 overexpression reversed miR-193a-3p mimic-mediated effects on NSCLC cell malignancy, autophagy, and glycolysis. Circ_0020123 promoted glycolysis and tumor growth by upregulating IRF4 through sequestering miR-193a-3p in NSCLC, offering a novel mechanism by which circ_0020123 is responsible for the malignancy, autophagy, and glycolysis of NSCLC cells.