Circ_0000877 accelerates proliferation and immune escape of non-small cell lung cancer cells by regulating microRNA-637/E2F2 axis.

BACKGROUND: Recently, circular RNA (circRNA) has become a vital targeted therapy gene for non-small-cell lung cancer (NSCLC) cells. CircRNA_0000877 (Circ_0000877) has been researched in diffuse large B-cell lymphoma (DLBCL). However, whether circ_0000877 regulated NSCLC cell progression is still poorly investigated. The research attempted to investigate the influence of circ_0000877 in NSCLC.

METHODS: Circ_0000877 levels in NSCLC tissues and cell lines were determined applying RT-qPCR. Cell functions were evaluated by CCK-8, EdU, flow cytometry, ELISA, and western blot. Gene interactions were predicted by Cirular RNA interactome database and Target Scan website and certified by dual-luciferase reporter, RIP, and RNA pull-down assays. Finally, mice experimental model was established to explore the effects of circ_0000877 on tumor growth in vivo.

RESULTS: The elevated trend of circ_0000877 expression was discovered in NSCLC tissues compared to para-carcinoma tissues. The clinicopathological data uncovered that up-regulated circ_0000877 was linked to tumor size, differentiation, and TNM stages of NSCLC patients. Knockdown of circ_0000877 inhibited the proliferation, triggered apoptosis, and prohibited immune escape in NSCLC cells. It was certified that miR-637 was directly interacted with circ_0000877 and targeted by E2F2. Overexpressed E2F2 strongly overturned the functions of circ_0000877 knockdown in NSCLC cells. Mice experimental data demonstrated that circ_0000877 knockdown suppressed tumor growth in vivo.

CONCLUSION: The research demonstrated that circ_0000877 exhibited the promotive effect on NSCLC cells proliferation and immune escape by regulating miR-637/E2F2 axis.