MiR-4443 promotes migration and invasion of breast cancer cells by inhibiting PEBP1 expression

• Published in: Nan fang yi ke da xue xue bao = Journal of Southern Medical University 2020-12, Vol.40 (12), p.1712-1719
• Main Authors: Wang, Jinyan, Wang, Jinqiu, Gu, Quan, Yang, Yan, Ma, Yajun, Zhu, Jing, Zhang, Quanan
• Format: Article
• Language: Chinese
• Subjects: Breast Neoplasms - genetics; Cell Line, Tumor; Cell Movement; Cell Proliferation; Gene Expression Regulation, Neoplastic; Humans; MCF-7 Cells; MicroRNAs - genetics; Neoplasm Invasiveness - genetics; Phosphatidylethanolamine Binding Protein
• ISSN: 1673-4254
• DOI: 10.12122/j.issn.1673-4254.2020.12.03

To investigate the effect of miR-4443 expression on migration and invasion of breast cancer. We examined the expression of miR-4443 in breast carcinoma in situ and paired adjacent tissues from 3 breast cancer patients with high-throughput sequencing and verified the results using TCGA database. We also detected miR-4443 expressions using real-time quantitative PCR (RT-qPCR) in low invasive and highly invasive breast cancer cells (MCF-7 and MDA-MB-231 cells, respectively). The changes in apoptosis, migration and invasion of MCF-7 and MDA-MB-231 cells after transfection with miR-4443 mimics, mimics-NC, miR-4443 inhibitor or inhibitor-NC were analyzed using flow cytometry, wound healing assay and Transwell invasion assay. The target gene of miR-4443 was predicted by bioinformatics software and validated by a dual luciferase reporter gene system. RT-qPCR and Western blotting were performed to detect the expression of recombinant human phosphatidyl ethanolamine binding protein 1 (PEBP1) in the transfected cells. The expression of miR-4443 was significantly higher in the breast cancer tissues than in the adjacent tissues ( < 0.01), and was significantly up-regulated in MDA-MB-231 cells as compared with MCF-7 cells ( < 0.01). Transfection with miR-4443 mimics or inhibitors did not obviously affect apoptosis rate of the breast cancer cells ( >0.05), but significantly enhanced or weakened the migration and invasion abilities of the cells, respectively ( < 0.01). Bioinformatic analysis identified PEBP1 as the target gene of miR-4443 with a close correlation with metastasis of breast cancer ( < 0.01), and the result was confirmed by double luciferase reporter gene assay. The mRNA and protein expression of PEBP1 were significantly lower in MDA-MB-231 cells than in MCF-7 cells ( < 0.01), and miR-4443 over-expression or knockdown significantly down-regulated or up-regulated PEBP1 expressions in the cells, respectively ( < 0.01). MiR-4443 promotes the migration and invasion of breast cancer cells by inhibiting the expression of PEBP1, suggesting the possibility of suppressing miR-4443 expression as a potential therapeutic strategy for breast cancer.