Circular RNA circSLC8A1 inhibits the proliferation and invasion of non-small cell lung cancer cells through targeting the miR-106b-5p /FOXJ3 axis.

Circular RNA derived from the SLC8A1 gene (circSLC8A1) has been implicated in the pathogenesis of several types of cancers. However, the role of circSLC8A1 in non-small cell lung cancer (NSCLC) remains unclear. In the present study, the expression levels of circSLC8A1 in NSCLC tissues and cell lines were determined by qRT-PCR analysis. Function-gain-assays were then carried out to further validate the role of circSLC8A1 in NSCLC in vitro. Online prediction software and the subsequent luciferase reporter assay were used to identify the target genes of circSLC8A1 and microRNA (miR)-106b-5p. CircSLC8A1 was found to be downregulated in NSCLC tissues and cell lines. Overexpression of circSLC8A1 significantly inhibited the proliferation and invasion of NSCLC cells. Further investigations shown that circSLC8A1 was able to bind to miR-106b-5p as well as inhibit the expression of miR-106b-5p in NSCLC cells. MiR-106b-5p mimics reversed the inhibitory effects of circSLC8A1 overexpression on cell proliferation and invasion. Furthermore, we found that forkhead box J3 (FOXJ3) to be a target gene of miR-106b-5p in NSCLC cells. Knockdown of FOXJ3 reversed the inhibitory effects of miR-106b-5p inhibitor on cell proliferation and invasion. Collectively, these findings indicate that circSLC8A1 exhibits anti-tumor activity in NSCLC, which might be mediated by the miR-106b-5p/FOXJ3 axis. The circSLC8A1/miR-106b-5p/FOXJ3 axis may thus represent a promising therapeutic target for the management of NSCLC.