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 characterized by poor prognosis and limited therapeutic options. Exosomal microRNAs (miRNAs), enclosed within secretory vesicles, have emerged as promising non-invasive biomarkers for cancer detection and disease monitoring. In this study, we identify a panel of five 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 meta-analysis of public datasets combined with in-vitro validation revealed that elevated expression of these miRNAs correlates with poor overall survival. Functional assays further demonstrated that hsa-miR-1180 and hsa-miR-4728 enhance TNBC cell migration and invasion, implicating them in key oncogenic pathways such as Wnt, Notch, and EGFR. The consistent enrichment of these miRNAs in exosomes underscores their potential as exploratory biomarkers for future liquid-biopsy-based applications. To our knowledge, this discovery-phase investigation is the first to associate this exosomal miRNA panel with TNBC and its stem-like subpopulations, providing a preliminary framework for subsequent mechanistic and translational validation.