Abstract
Background
Breast cancer (BC) is the most common malignancy in women, posing a serious health risk. Exosomal microRNA (miRNA) has emerged as a promising cancer biomarker. Despite its potential, research on exosomal miRNA in BC remains limited. This study aims to identify plasma exosomal miRNAs for diagnosing BC.
Methods
Firstly, plasma exosomal miRNA sequencing was conducted on 45 BC patients and 5 healthy controls, followed by Differential Expression Analysis to screen for differentially expressed miRNAs. The diagnostic value of these miRNAs was assessed using receiver operating characteristic (ROC) curves. Subsequent analysis of candidate miRNAs was carried out in the TCGA database. Target genes of differentially expressed miRNAs were predicted using online databases, and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed. Finally, a ceRNA network was constructed using Cytoscape.
Results
Our analysis indicates that, compared to normal controls, plasma exosomal miR-125b-5p and miR-143-3p are significantly downregulated in BC patients. The area under the curve (AUC) for exosomal miR-125b-5p is 0.951 (sensitivity 91.1%, specificity 100%), and the AUC for exosomal miR-143-3p is 0.924 (sensitivity 86.7%, specificity 100%). In the TCGA database, the expression of miR-125b-5p and miR-143-3p is downregulated in BC tissues compared to adjacent normal tissues. Target gene prediction and enrichment analyses reveal pathways closely associated with BC occurrence.
Conclusions
Our results demonstrate that plasma exosomal miR-125b-5p and miR-143-3p can distinguish between BC patients and normal controls. The downregulation of plasma exosomal miR-125b-5p and miR-143-3p may potentially serve as a marker for the occurrence of BC.