Potential biological roles of exosomal non-coding RNAs in breast cancer.

Breast cancer (BC) is one of the most common malignant tumors among women, accounting for 24.5% of all cancer cases and leading to 15.5% of cancer-related mortality. The treatment of BC patients remains a significant challenge due to the disease's high invasiveness, elevated metastatic potential, substantial drug resistance, and high recurrence rate. Exosomes, which are lipid-bilayer extracellular vesicles ranging in size from 30 to 150 nm, mediate intercellular communication between tumor cells and surrounding cells in the tumor microenvironment by transferring various bioactive substances, such as proteins, lipids, and nucleic acids. Recently, growing evidence has demonstrated that non-coding RNAs (ncRNAs) are enriched in exosomes and play a critical role in regulating cell proliferation, metastasis, drug resistance, and angiogenesis in BC. Consequently, exosomal ncRNAs have emerged as a promising therapeutic target for BC treatment, given their involvement in multiple processes of cancer progression. This review provides a comprehensive and in-depth analysis of emerging exosomal ncRNAs in BC, highlighting their potential biological mechanisms and advanced applications in BC treatment.