The Role of Exosomal MicroRNAs in the Tumor Microenvironment of Breast Cancer

Breast cancer, ranking first among women's cancers worldwide, develops from the breast tissue. Study of the breast tissue is, therefore of great significance to the diagnosis and treatment of breast cancer. Exosomes, acting as an effective communicator between cells, are in the ascendant in recent years. One of the most important cargoes contained in the exosomes is microRNAs, belonging to the non-coding RNA family. When the exosomal microRNAs are absorbed into the intracellular location, most of the microRNAs will act as tumor promoters or suppressors by inhibiting the translation process of the target mRNA, thus affecting the behavior of other stromal cells in the tumor microenvironment. At present, growing research focuses on the different types of donor cell sources, their contribution to cancer, miRNA profiling, their biomarker potential, etc. This review aims to state the function of diverse miRNAs in exosomes medicated cell-cell communication and the potency of some specific enriched miRNAs as molecular markers in clinical trials. We also describe the mechanism of anti-cancer compounds through exosomes and the exploration of artificially engineered techniques that lead miRNA-inhibitors into exosomes for therapeutic use.