Circular RNA hsa-circ-000881 suppresses the progression of lung adenocarcinoma in vitro via a miR-665/PRICKLE2 axis

Background Circular RNA (circRNA) has become a new focus in the field of tumor biology research in recent years. Many circRNAs have been showed to play an important role in the progression of lung adenocarcinoma (LUAD). In this work, we studied the oncological role of hsa-circ-000881 in LUAD and attempted to explore the related mechanism. Methods The relative expressions of hsa-circ-000881, miR-665, and PRICKLE2 were detected by RT-qPCR or western blot. Functional assays were conducted to analyze the role of hsa-circ-000881 in the proliferation, migration, and invasion of LUAD cells. A luciferase reporter assay was performed to verify whether hsa-circ-000881, miR-665, and PRICKLE2 interact with each other. Results Circ-000881 was remarkably downregulated in LUAD. Overexpression of circ-000881 attenuated cell growth, migration, and invasion, whereas its knockdown enhanced the malignancy of LUAD cells. The results of luciferase reporter assay and bioinformatics analysis confirmed that circ-000881 served as a sponge for miR-665, and PRICKLE2 was a direct target of miR-665.Overexpression of miR-665 or silencing of PRICKLE2 abolished circ-000881-mediated inhibition of malignant tumor behavior in LUAD cells. Conclusions Circ-000881 has inhibitory effects on LUAD via a miR-665/PRICKLE2 axis, suggesting that circ-000881 may be an underlying therapeutic target for LUAD.