Accumulating studies authenticate that circular RNAs (circRNAs) are involved in the progression of cancers. However, their role in breast cancer (BC) remains largely unknown. In this study, real-time polymerase chain reaction was employed to detect the circ_0000291 and miR-326 expressions in BC tissues and cells. The correlation between the expression level of circ_0000291 and clinicopathological parameters of BC patients was analyzed. Western blot was used to detect the expression of E26 transformation-specific sequence-1 (ETS1), E-cadherin, N-cadherin and Vimentin in BC cells. Cell proliferation was measured using the cell counting kit-8 assay and the bromodeoxyuridine assay. Cell migration and invasion were detected by Transwell assay. The interactions between circ_0000291 and miR-326, miR-326 and ETS1 were verified using bioinformatics prediction, the dual-luciferase reporter gene assay or/and RNA binding protein immunoprecipitation assay. We demonstrated that circ_0000291 was significantly upregulated in BC, and its high expression was positively correlated with T stage and local lymph node metastasis. Functional assays validated that circ_0000291 promoted BC cell proliferation, migration and invasion. The mechanism studies indicated that circ_0000291 could decoy miR-326 and in turn upregulate the expression of ETS1. In conclusion, circ_0000291 is the novel oncogenic circRNA and promotes BC progression via modulating the miR-326/ETS1 axis.
Keywords: BC; ETS1; circ_0000291; miR-326.
© 2020 Japanese Society of Pathology and John Wiley & Sons Australia, Ltd.