Exosomal miRNA Sequencing and Bioinformatics in Breast Cancer: A Case-Control Study in Baise, China

Breast carcinoma remains the most frequently diagnosed malignancy among women globally, carrying a substantial burden of incidence and fatality. Timely diagnosis and intervention are of utmost significance for improving patient prognosis. Accumulating evidence suggests that microRNAs (miRNAs) derived from plasma exosomes may serve as potential diagnostic biomarkers for mammary carcinoma. To conduct an exploratory analysis of the role of exosomal miRNAs, expression profiles were obtained from breast cancer patients and healthy controls recruited between February 20, 2025, and May 20, 2025 (a 3-month period), with written informed consent from all participants prior to enrollment, using high-throughput sequencing. Subsequently, differentially expressed miRNAs were analyzed through an integrated bioinformatics approach that included gene ontology (GO) term enrichment analysis, Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis, and target gene network analysis to predict their potential biological functions, involved pathways, and regulatory networks. An initial comparative analysis identified 265 miRNAs with modified expression profiles in breast cancer patients. Among them, 203 miRNAs were upregulated, and 62 miRNAs were downregulated. Notably, hsa-miR-6866-5p, hsa-miR-376c-3p, hsa-miR-656-3p, and hsa-miR-641 were significantly upregulated, whereas a cluster of miRNAs sharing a seed sequence, including hsa-miR-519a-5p, hsa-miR-519b-5p, hsa-miR-518e-5p, hsa-miR-522-5p, and hsa-miR-523-5p, were significantly downregulated. Moreover, functional analyses suggested that these miRNAs potentially participate in crucial signaling pathways, including Rap1, phospholipase D, oxytocin, and vascular endothelial growth factor. Predictions of the target gene network indicated their potential regulatory roles in the pathogenesis and progression of breast cancer. This exploratory study identified 9 miRNAs, including hsa-miR-6866-5p, hsa-miR-376c-3p, hsa-miR-656-3p, hsa-miR-641, hsa-miR-519a-5p, hsa-miR-519b-5p, hsa-miR-518e-5p, hsa-miR-522-5p, and hsa-miR-523-5p, that were dysregulated in plasma exosomes of breast cancer patients from Baize, China. Elucidating the precise regulatory functions of these candidate miRNAs in breast cancer development warrants extensive future empirical exploration.