Circ_0001666 affects miR-620/WNK2 axis to inhibit breast cancer progression

Background: Circular RNAs (circRNAs) play important roles in the progression of various cancers, including breast Cancer (BC). However, the role of circ_0001666 in BC remains unclear.

Objective: To explore the role of circ_0001666 in the progression of BC and reveal its potential molecular mechanism.

Methods: Real-time polymerase chain reaction was conducted to determine the expression of circ_0001666, miR-620 and with-no-lysine kinase 2 (WNK2). Cell counting kit 8 assay, flow cytometry and transwell assay were used to measure cell proliferation, Apoptosis, migration and invasion. Western blot was utilized to examine the level of protein. Dual-luciferase reporter assay and RNA immunoprecipitation assay were used to verify the interaction between miR-620 and circ_0001666 or WNK2. Mice xenotransplantation models were built to explore the effect of circ_0001666 on BC tumor growth in vivo.

Results: Circ_0001666 was downregulated in BC tumor tissues and cells. Overexpressed circ_0001666 inhibited the proliferation, migration, invasion, while promoted Apoptosis and tumor growth of BC in vitro or in vivo. Furthermore, circ_0001666 could serve as a Sponge of miR-620. MiR-620 inhibitor hindered BC cell progression, which was similar to the effect of circ_0001666 overexpression. WNK2 was a target of miR-620, and circ_0001666 could Sponge miR-620 to positive regulate WNK2. The knockdown of WNK2 reversed the effect of circ_0001666 overexpression on BC progression.

Conclusion: Circ_0001666 hindered the progression of BC via miR-620/WNK2 axis.