Hsa_circ_0087784 enhances non-small cell lung cancer progression via the miR-576-5p/CDCA4 axis

Background: Circular RNAs (circRNAs) belong to a family of covalently closed single-stranded RNAs that have been implicated in cancer progression. Previous studies have reported that hsa_circ_0087784 was abnormally expressed in breast cancer. However, the role of hsa_circ_0087784 in non-small cell lung cancer (NSCLC) is unknown. Methods: Here, we used RT-qPCR and FISH to examine hsa_circ_0087784 expression in NSCLC cells and tissue samples. The dual-luciferase reporter assay was used to identify downstream targets of hsa_circ_0087784. Transwell migration, 5-ethynyl-2<acute accent>-deoxyuridine, and CCK-8 assays were used to examine migration and proliferation. Tumorigenesis and metastasis assays were used to determine the role of hsa_circ_0087784 in NSCLC progression in a mouse tumor xenograft model in vivo. Results: We found that hsa_circ_0087784 was expressed at significantly high levels in NSCLC tissue samples and cell lines. Downregulation of hsa_circ_0087784 suppressed NSCLC cellular proliferation, as well as migration. Our dual-luciferase reporter assay revealed that miR-576-5p and CDCA4 were downstream targets of hsa_circ_0087784. CDCA4 overexpression or miR-576-5p suppression reversed the effects of hsa_circ_0087784 silencing on NSCLC cell migration, and EMT-related protein expression levels. Conclusion: Our findings suggested that downregulation of hsa_circ_0087784 inhibited NSCLC metastasis and progression through the regulation of CDCA4 expression and miR-576-5p sponging.