Association of miR-326, SIRT1, and HMGA2 Expression in Breast Cancer Cells Exposed to Mesenchymal Stromal Cell-Derived Extracellular Vesicles

Abstract

Background: Breast cancer progression is influenced by tumor–microenvironment interactions mediated by Extracellular Vesicles (EVs), which transfer bioactive molecules such as microRNAs. This in vitro study investigated the role of miR-326 in modulating SIRT1 (Sirtuin 1) and HMGA2 (High-mobility group AT-hook 2) expression in breast cancer cells after treatment with EVs derived from Mesenchymal Stromal Cells (MSCs).  Methods: EVs were isolated from MSCs using the ExoQuick kit and characterized by Dynamic Light Scattering (DLS). EV internalization was confirmed by PKH26 fluorescent staining. After determining the appropriate dose by MTT assay, EVs were applied to MDA-MB-231 cells. Expression levels of miR-326, SIRT1, and HMGA2 were measured by Reverse Transcription quantitative Polymerase Chain Reaction (RT-qPCR). GAPDH and U6 snRNA were used as internal reference genes for mRNA and miRNA normalization, respectively. Data were analyzed using the unpaired Student’s t-test. Results: The mean size of EVs was approximately 120 nm. The highest viability of MDA-MB-231 cells was observed at an EV dose of 30 µg/ml. Treatment with EVs caused a significant decrease in miR-326 expression (p<0.05) and significant increases in the expression levels of SIRT1 (p<0.01) and HMGA2 (p<0.05). Conclusion: These findings suggest a potential association between miR-326 and its target genes, highlighting a possible therapeutic target within the tumor microenvironment.