Circular RNA ABCB10 promotes cell proliferation and invasion, but inhibits apoptosis via regulating the microRNA-1271-mediated Capn4/Wnt/beta-catenin signaling pathway in epithelial ovarian cancer

Circular RNA ABCB10 (circ-ABCB10) modulates cellular functions and microRNA (miR)-1271 in epithelial ovarian cancer (EOC). The present study aimed to investigate the interaction between circ-ABCB10 and miR-1271 in regulating EOC cellular function and the calpain small subunit 1 (Capn4)/Wnt/beta-catenin signaling pathway. circ-ABCB10 and miR-1271 expression levels were detected in EOC cells (OVCAR3, UWB1.289, SKOV3 and CAOV3) and normal ovarian epithelial cells (IOSE80) via reverse-transcription quantitative PCR. SKOV3 cells were transfected with control short hairpin (sh)RNA plasmids, control inhibitor, circ-ABCB10 shRNA plasmids and miR-1271 inhibitor. UWB1.289 cells were transfected with control overexpression plasmids, control mimic, circ-ABCB10 overexpression plasmids and miR-1271 mimic. Subsequently, cell proliferation, apoptosis, invasion and the Capn4/Wnt/beta-catenin signaling pathway were assessed. In addition, a luciferase activity assay was performed. circ-ABCB10 expression was significantly increased in OVCAR3, SKOV3 and CAOV3 cells compared with IOSE80 cells, but was not significantly altered in UWB1.289 cells. miR-1271 expression was significantly decreased in OVCAR3, UWB1.289, SKOV3 and CAOV3 cells compared with IOSE80 cells. In both SKOV3 and UWB1.289 cells, circ-ABCB10 negatively regulated miR-1271, whereas miR-1271 did not affect circ-ABCB10. Furthermore, circ-ABCB10 enhanced cell proliferation, invasion and the Capn4/Wnt/beta-catenin signaling pathway, but inhibited cell apoptosis, whereas miR-1271 suppressed cell proliferation, invasion and the Capn4/Wnt/beta-catenin signaling pathway, but facilitated cell apoptosis. Moreover, miR-1271 attenuated the proproliferative, proinvasive and antiapoptotic effects of circ-ABCB10, and reversed the positive regulation of circ-ABCB10 on the Capn4/Wnt/beta-catenin signaling pathway. Besides, the luciferase activity assay indicated that circ-ABCB10 directly bound to miR-1271. In conclusion, the present study indicated that circ-ABCB10 promoted cell proliferation and invasion, and suppressed apoptosis by regulating the miR-1271-mediated Capn4/Wnt/beta-catenin signaling pathway in EOC.