Hsa_circ_0008035 Knockdown Inhibits Bladder Cancer Progression through miR-1184/RAP2B Axis.

INTRODUCTION: Circular RNAs (circRNAs) are related to the pathogenesis and progression of bladder cancer (BC). This research aimed to investigate the role and mechanism of hsa_circ_0008035 (circ_0008035) in BC progression.

METHODS: Circ_0008035, microRNA (miR)-1,184, and Ras-related protein 2B (RAP2B) levels were examined in BC via quantitative real-time polymerase chain reaction and Western blotting. Cell Counting Kit-8, colony formation, 5-ethynyl-2'-deoxyuridine staining, flow cytometry, caspase-3 assay kit, transwell, and tube formation assays were conducted to estimate the effects of circ_0008035 on the malignant phenotypes of BC tumors. The interaction between RNAs and genes was evaluated via a dual-luciferase reporter and RNA immunoprecipitation assays. A xenograft model of BC in nude mice was established to estimate the effect of circ_0008035 in BC in vivo.

RESULTS: Circ_0008035 and RAP2B levels were upregulated, while miR-1184 abundance was downregulated in BC tissues and cells. Circ_0008035 knockdown constrained cell proliferation, migration, invasion and angiogenesis but promoted apoptosis in vitro. And circ_0008035 silencing curbed xenograft tumor growth in vivo. Circ_0008035 acted as a miRNA sponge for miR-1184. Circ_0008035 increased RAP2B expression by sponging miR-1184. MiR-1184 downregulation relieved the effects of circ_0008035 knockdown on BC progression. And RAP2B knockdown partly reversed the effects of miR-1184 overexpression on BC progression.

CONCLUSION: Circ_0008035-mediated BC progression via regulating the miR-1184/RAP2B axis, providing a potential target for BC treatment.