MiR-146a Restoration Suppresses Triple-Negative Breast Cancer Cell Migration: A Bioinformatic and In Vitro Study

Purpose: Breast cancer is one of the most commonly diagnosed types of cancer worldwide. This cancer is treated with various methods like mastectomy, chemotherapy, hormone therapy, and radiotherapy. Among them, targeted therapy, like microRNA (miRNA) replacement therapy, is considered a new approach to treating breast cancer. Methods: Data analysis from TCGA datasets were used to investigate the expression of hsamiR- 146a-5p in breast cancer. MTT assay was used to evaluate the viability of MDA-MB-231 cells after hsa-miR-146a-5p ectopic expression. A wound-healing assay was used to observe migration in the MDA-MB-231 cell line and the effect of the hsa-miR-146a-5p ectopic expression on migration. Finally, quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used as a method to determine the effect of the hsa-miR-146a-5p ectopic expression on the expression of CXCR4, β-catenin, MMP2, MMP9, and Vimentin genes known to be involved in invasion and migration of MDA-MB-231 cells. Results: Our results indicated that hsa-miR-146a-5p is not involved in apoptosis in the MDAMB- 231 cells, while it is highly effective in migration inhibition. MMP9, MMP2, CXCR4, and Vimentin expressions were suppressed by hsa-miR-146a-5p induction; however, it induced the expression of β-catenin. Conclusion: Some non-coding RNAs, such as hsa-miR-146a-5p, are effective in breast cancer targeted therapy. As cancer is a complicated disorder, therefore the combination of therapies might lead to novel therapeutic strategies.