Tabriz University of Medical Sciences Advanced Pharmaceutical Bulletin 2228-5881 16 2 2026 06 15 Effect of Exosome-loaded hsa-miR-203a-3p on Triple Negative Breast Cancer Cell Viability, Migration, and Gene Targets: In Silico and In Vitro Study 352 362 10.34172/apb.45269 EN Syamsul Arif Ardiansyah https://orcid.org/0000-0001-8277-3266 Habibullah Noficandra https://orcid.org/0009-0000-9634-5641 Pamungkas Bagus Satriyo https://orcid.org/0000-0001-9544-3119 Dwi Aris Agung Nugrahaningsih https://orcid.org/0000-0002-1616-3053 Sofia Mubarika Haryana https://orcid.org/0000-0001-7205-652X Journal Article 10.34172/apb.45269 2025 02 25 2026 05 07 Introduction: Triple-negative breast cancer (TNBC) is an aggressive breast cancer subtype lacking targeted therapy options. MicroRNA-based therapy, particularly hsa-miR-203a-3p, has shown tumor-suppressive potential; however, an effective delivery system is required to enhance its stability and cellular uptake. Exosomes represent a promising natural carrier for miRNA delivery. Methods: Exosomes derived from UC-MSCS secretome were isolated and characterized using Nanoparticle Tracking Analysis (NTA). Exosome-loaded hsa-miR-203a-3p (ExomiR) was generated using the Exo-Fect transfection system. Functional assays, including MTT and wound-healing assays, were performed on TNBC Hs578T cells. qRT-PCR was used to measure miRNA uptake. In silico analysis utilizing TargetScan, TarBase, DAVID, and the TNBC dataset GSE65194 was performed to identify target genes and pathways. Results: ExomiR significantly reduced TNBC cell viability in a dose-dependent manner, with viability dropping below 50% at the 2×dose. Migration assays showed the strongest inhibition at 1×dose at 12 hours (37.4±13%, P<0.01) and at 2×dose at 24 hours (32.3±6.18%, P<0.0001). ExomiR treatment yielded an 87-fold increase in intracellular hsa-miR-203a-3p expression. In silico analysis identified 23 upregulated TNBC-related target genes, including CCNB1 and CDK1, which regulate cell cycle, p53 signaling, and cellular senescence pathways. Conclusion: Exosome-mediated delivery enhances hsa-miR-203a-3p uptake and effectively suppresses cell viability and migration in TNBC cells. Computational analysis further indicates that hsa-miR-203a-3p regulates key oncogenic pathways, supporting its potential as a therapeutic agent.