Hsa_circ_0000520 is Involved in Breast Cancer Progression by Targeting miR-542-3p/S1PR1 Axis

Abstract

Background: CircRNAs feature prominently in breast cancer (BC) progression. This study was intended to investigate the role of hsa_circ_0000520 in BC progression.Methods: After the sample collection, quantitative real-time polymerase chain reaction (qRT-PCR) was conducted for quantifying the expressions of circ_0000520, miR-542-3p, and sphingosine-1-phosphate receptor 1 (S1PR1) mRNA. 5‐Ethynyl‐2′‐Deoxyuridine (EdU) and cell counting kit-8 (CCK-8) assays were used for measuring cell proliferation. Transwell assays were employed to detect cell migration and invasion. Western blotting was utilized for analyzing S1PR1 protein expression. Dual-luciferase reporter gene assay and RNA immunoprecipitation (RIP) assay were used to delve into the targeting relationship between circ_0000520 and miR-542-3p.Results: Circ_0000520 expression was markedly elevated in BC cell lines and tissues, and knockdown of circ_0000520 could inhibit BC cell multiplication, migration, and invasion. Circ_0000520 could target miR-542-3p to negatively regulate S1PR1 expression. S1PR1 overexpression plasmid could counteract the inhibitory effects of circ_0000520 knockdown on BC cell proliferation, migration, and invasion.Conclusion: Circ_0000520, as a cancer-promoting circRNA, participates in BC progression by regulating miR-542-3p/S1PR1 axis.