CircVAPA exerts oncogenic property in non-small cell lung cancer by the miR-876-5p/WNT5A axis.

BACKGROUND Non-small cell lung cancer (NSCLC) is one of the most fatal malignant tumors. Emerging studies have clarified the crucial roles of circular RNAs (circRNAs) in the tumorigenesis of cancers. CircVAPA was demonstrated to function in some human cancers. The present study was designed to explore the role of circVAPA in NSCLC. METHODS RT-qPCR was used to measure the expression of genes. Actinomycin D and RNase R were employed to examine the stability of circVAPA. CCK-8, EdU, Transwell, sphere formation assay, and western blot analysis were conducted to examine the changes of NSCLC cells in response to circVAPA knockdown. Luciferase reporter assay was conducted for molecular mechanism. RESULTS Our findings demonstrated the high expression of circVAPA in tissues and cell lines of NSCLC. Knockdown of circVAPA had a suppressive effect on cell proliferation, migration, invasion and stemness, as well as inhibited tumor growth in vivo. Mechanistically, circVAPA acted as a ceRNA to upregulate WNT5A by sponging miR-876-5p. Moreover, circVAPA activated Wnt/β-catenin signaling by upregulation of WNT5A. Rescue assays showed that silencing of miR-876-5p or overexpression of WNT5A reversed the circVAPA knockdown-mediated inhibition on cellular processes in NSCLC. CONCLUSION CircVAPA promotes aggressive phenotypes of NSCLC cells by the miR-876-5p/WNT5A axis activating Wnt/β-catenin signaling.