Identification of novel exosomal miRNAs and their role in diagnosis and prognosis of Triple Negative Breast Cancer

Triple-negative breast cancer (TNBC) is a clinically aggressive subtype with poor prognosis and limited treatment options. Exosomal microRNAs (miRNAs), encapsulated within secretory vesicles, have emerged as promising biomarkers for cancer detection and monitoring. In this study, we identify five novel exosomal miRNAs—hsa-miR-6803, hsa-miR-1180, hsa-miR-4728, hsa-miR-1915, and hsa-miR-940—that are consistently overexpressed in TNBC cells, stem-like subpopulations, and patient tumor tissues. Integrated analysis of public datasets and in vitro validation revealed that elevated expression of these miRNAs correlates with poor overall survival. Functional assays demonstrated that miR-1180 and miR-4728 significantly promote TNBC cell migration and invasion. These miRNAs also target critical oncogenic pathways, including Wnt, Notch, and EGFR. Their enrichment in exosomes highlights their translational potential as liquid biopsy-based biomarkers and therapeutic targets. This work is the first to link this miRNA panel to both TNBC tumorigenesis and stem-like cell biology, offering new insights into disease progression and potential strategies for personalized care.