Circular RNA circASS1 is down-regulated in breast cancer cells MDA-MB-231 and suppressed invasion and migration.

Aim: The study aimed to investigate the role of circular RNA circASS1 in breast cancer cells. Materials & methods: Circular RNAs microarray expression profile were analyzed in MCF-7, MDA-MB-231, and qRT-PCR and western blotting were used to quantify expression of circASS1 and its parental gene ASS1. Wound healing, migration and invasion assay were performed. Luciferase assay system was used to detect harbored miRNA. Results: CircASS1 in MDA-MB-231 is downregulated comparing to MCF-7, and overexpression of circASS1 could suppress invasion and migration. While silence, it could promote invasion and migration. MiR-4443 functioning as a tumor promoter gene could be captured by circASS1. ASS1 is upregulated in loss-of-function experiments, while downregulated in gain-of-function experiments. Conclusion: CircASS1 suppresses invasion and migration capacity of breast cancer cells and harbored miR-4443.