Knockdown of circ_0102273 inhibits the proliferation, metastasis and glycolysis of breast cancer through miR-1236-3p/PFKFB3 axis.

The key regulatory roles of circular RNAs (circRNAs) in human diseases have been demonstrated, including breast cancer (BC). The purpose of this study is to explore the role of circ_0102273, a newly discovered circRNA, in BC progression. The expression levels of circ_0102273, microRNA (miR)-1236-3p and 6-phosphofructo-2-kinase/fructose-2, 6-biphosphatase 3 (PFKFB3) were determined by quantitative real-time PCR. Cell proliferation, migration and invasion were measured using colony formation assay, EdU staining, wound healing assay and transwell assay. Glucose consumption, lactate production and ATP level were detected to evaluate cell glycolysis. The interaction between miR-1236-3p and circ_0102273 or PFKFB3 was confirmed by dual-luciferase reporter assay and RIP assay. Additionally, western blot analysis was utilized for measuring PFKFB3 protein expression. In-vivo experiments were performed to further explore the function of circ_0102273 in BC tumorigenesis. Our data showed that circ_0102273 was highly expressed in BC tumor tissues and cells, and its downregulation could inhibit BC cell proliferation, metastasis and glycolysis. MiR-1236-3p was confirmed to be sponged by circ_0102273, and its inhibitor could reverse the negative regulation of sh-circ_0102273 on BC cell proliferation, metastasis and glycolysis. PFKFB3 could be targeted by miR-1236-3p, and its expression could be positively regulated by circ_0102273. In addition, miR-1236-3p could suppress BC cell proliferation, metastasis and glycolysis, while this effect could be abolished by PFKFB3. Furthermore, circ_0102273 knockdown also had been discovered to reduce BC tumorigenesis in vivo. In summary, our research proposed that circ_0102273 might be a potential target for BC treatment, which could inhibit BC proliferation, metastasis and glycolysis through the miR-1236-3p/PFKFB3 axis.