Circular RNA circACTN4 promotes proliferation, invasion and metastasis of breast cancer cells

Abstract

Objective To investigate the expression of circular RNA circACTN4 (also called hsa_circ_0050900) in breast cancer (BC) and its effect on the proliferation, invasion and metastasis of BC cells. Methods The circRNA expression profiles of 4 pairs of BC tissues and adjacent tissues were analyzed by circRNA chip analysis, and the relative expression level of circACTN4 was detected by qRT-PCR. After BC cell lines MCF-7/MDA-MB-231 were transfected with circACTN4 overexpression plasmid and control plasmid, respectively, the effects of circACTN4 on cell proliferation, migration and invasion were tested by Cell Counting Kit-8 (CCK-8), EdU assay, colony formation, scratching assay, and Transwell migration and invasion assay. Western blotting was executed to determine the protein expression of CCND1, CCND2 and CDK4. The effects of circACTN4 on the growth and metastasis of transplanted tumors were also observed in nude mice. Results The expression of circACTN4 was significantly higher in BC tissues and cells than in the paired adjacent tissues and normal breast epithelial cells (P < 0.01). Up-regulation of circACTN4 enhanced the proliferation, migration and invasion of BC cells (P < 0.05), and facilitated the expression of CCND1, CCND2 and CDK4 (P < 0.01). The results of in vivo experiments also showed that up-regulation of circACTN4 promoted the growth and metastasis of transplanted tumors, with the tumor microvascular density and the number of lung metastatic nodules significantly increased in the circACTN4 group, as compared with the control group (P < 0.05). Conclusion circACTN4 is highly expressed in BC tissues and cells. It can promote the proliferation, migration and invasion of BC cells, and facilitate the growth and metastasis of transplanted tumors in vivo.

Keywords

• circular rna
• circactn4
• breast cancer
• transplanted tumor