Circular RNA KIF4A promotes cell migration, invasion and inhibits apoptosis through miR-152/ZEB1 axis in breast cancer

BACKGROUND: Circular RNAs (circRNAs) have been demonstrated to exert crucial mediators in tumor initiation and development. Nevertheless, the roles of circKIF4A in breast cancer (BC) are still not very clear. METHODS: Quantitative real-time polymerase chain reaction (qRT-PCR) was conducted to determine the expression of circKIF4A, miR-152, zinc finger E-box binding homeobox 1 (ZEB1) mRNA and caspase-3. Western blot assay was utilized to examine the protein level of ZEB1. Transwell assay and flow-cytometric analysis were adopted for the evaluation of cell migration, invasion and apoptosis, respectively. The associations among circKIF4A, miR-152 and ZEB1 were predicted by online websites and verified by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. RESULTS: CircKIF4A and ZEB1 were conspicuously upregulated and miR-152 was markedly reduced in BC tissues and cells. Deficiency of circKIF4A repressed migration, invasion and induced apoptosis of BC cells. Moreover, circKIF4A was confirmed to be a sponge of miR-152 and miR-152 could bind to ZEB1. MiR-152 inhibition or ZEB1 overexpression abolished the impacts of circKIF4A knockdown on cell migration, invasion and apoptosis in BC. CONCLUSION: Silencing of circKIF4A hampered cell metastasis and promoted apoptosis by regulating ZEB1 via sponging miR-152 in BC.