Circ_0011385 increases cisplatin resistance in breast cancer via miR-615-5p suppression.

Purpose: Circular RNAs (circRNAs) participate in chemo-resistance among different cancers, containing breast cancer (BC). Herein, this project aimed to investigate the role of circ_0011385 on cisplatin (DDP) resistance in BC cells. Methods: circ_0011385 and microRNA (miR)-615-5p content in DDP-resistant BC cells and their parent cells (MCF-7) was calculated by RT-qPCR. CCK-8 assessed inhibition rate, and further to calculate half inhibitory concentration (IC50). Clone formation and flow cytometry experiments detected clone numbers and apoptosis rate. Dual-luciferase reporter system validated targeting between circ_0011385 and miR-615-5p. Results: circ_0011385 was upregulated, whereas miR-615-5p was decreased in MCF-7/DDP cells. Silencing circ_0011385 or miR-615-5p overexpression enhanced BC cell sensitivity to DDP, repress proliferation, and expedite apoptosis rate. Circ_0011385 directly targeted miR-615-5p. CONCLUSION: Silencing circ_0011385 increases DDP sensitivity by targeting and up-regulating miR-615-5p expression in MCF-7/DDP. [ABSTRACT FROM AUTHOR]