Objective  To investigate the effect of circSKA3 on the malignant behaviors of ovarian cancer cells and its potential mechanism.

Methods  Human ovarian cancer SK-OV-3 cells were cultured in vitro and randomly divided into si-NC group, si-circSKA3 group, miR-NC group, miR-532-5p group and si-circSKA3+anti-miR-NC and si-circSKA3+anti-miR-532-5p group. The expression levels of circSKA3 and miR-532-5p were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation, apoptosis and migration were detected by CCK-8 assay, plate clone formation assay, flow cytometry and Transwell assay. The targeting relationship between circSKA3 and miR-532-5p was evaluated using dual-luciferase reporter assays. Protein expression of Cleaved-caspase3 was measured by Western blotting.

Results  The expression level of circSKA3 in ovarian cancer tissues was significantly higher than that in adjacent normal ovarian tissues (P < 0.05). The expression of miR-532-5p in the ovarian cancer tissues was significantly lower than that in the adjacent normal ovarian tissues (P < 0.05). Compared with the si-NC group, the si-circSKA3 group showed significantly reduced circSKA3 expression, increased miR-532-5p expression, elevated cell proliferation inhibition rates and apoptosis rates, decreased colony formation numbers and migrating cell counts, and significantly higher Cleaved-caspase3 protein expression (P < 0.05). CircSKA3 was found to target miR-532-5p. After transfection with miR-532-5p mimictors, cell proliferation and cell migration were inhibited, and the inhibition rate of cell proliferation, the apoptosis rate, and the protein level of Cleaved-caspase3 were significantly increased (P < 0.05). Compared with transfection with circSKA3 small interfering RNA alone, co-transfection with circSKA3 small interfering RNA and miR-532-5p inhibitor promoted cell proliferation and migration, inhibited apoptosis rates, and reduced Cleaved-caspase3 protein expression (P < 0.05).

Conclusion  Silencing circSKA3 upregulates miR-532-5p expression, thereby inhibiting the malignant development of ovarian cancer cells.