Circ_0057558 accelerates the development of prostate cancer through miR-1238-3p/SEPT2 axis

Background: Prostate cancer (PCa) is one of the most common malignant tumors in males with high morbidity and mortality. Existing studies have demonstrated that circ_0057558 may be a molecular marker affecting PCa. However, its detailed roles in PCa remain unclear.

Methods: The levels of circ_0057558, miR-1238-3p and Septin 2 (SEPT2) were measured by quantitative real-time polymerase chain reaction (qRT-PCR). Cell counting kit-8 (CCK-8) assay, colony formation assay, 5-Ethynyl-2'-deoxyuridine (EdU) assay, flow cytometry assay, wound healing assay, transwell assay and tube formation assay were conducted for cell function identification. Xenograft tumor experiment was used to test the effect of circ_0057558 in vivo. Dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were conducted to determine the relationships between miR-1238-3p and circ_0057558 or SEPT2.

Results: We identified that circ_0057558 level was elevated in PCa, and silencing circ_0057558 restrained PCa cell proliferation, survival, migration, invasion and angiogenesis. Circ_0057558 could sponge miR-1238-3p, and SEPT2 was the target of miR-1238-3p. Circ_0057558 promoted the expression of SEPT2 by negatively regulating miR-1238-3p, resulting in promotion of PCa progression. The effects of circ_0057558 knockdown in PCa development were overturned by the lack of miR-1238-3p. Also, overexpression of SEPT2 abolished the suppressive impacts of miR-1238-3p on PCa progression.

Conclusion: As a tumor promoter, circ_0057558 regulated the expression of miR-1238-3p and SEPT2 and facilitated PCa progression. These results indicated that circ_0057558 was a potential therapeutic marker of PCa.