Integrative Identification and Validation of Exosome-Related Genes as Diagnostic Biomarkers and Potential Therapeutic Targets in Cholangiocarcinoma

Cholangiocarcinoma (CCA) is an aggressive biliary malignancy with limited diagnostic tools and poor prognosis. Early detection remains challenging due to nonspecific symptoms and a lack of reliable biomarkers. Exosomes, as stable carriers of molecular cargos, have emerged as promising sources for non-invasive cancer biomarkers. Here, we integrated multiple GEO datasets to identify exosome-related differentially expressed genes (ERDEGs) associated with CCA. Through differential expression analysis, machine-learning feature selection, and immune infiltration profiling, we identified two key exosome-related genes, WNT5A and PFN2 , as potential diagnostic biomarkers. Both genes showed robust diagnostic performance across internal and external validation cohorts. Functional enrichment revealed strong associations with extracellular matrix organization, EMT activation, and immune regulation pathways. Molecular docking suggested potential therapeutic compounds targeting these genes. Immunohistochemistry further confirmed significant overexpression of WNT5A and PFN2 in CCA tissues compared with adjacent controls. Collectively, our findings highlight WNT5A and PFN2 as promising exosome-related biomarkers that may improve early diagnosis and offer new therapeutic opportunities for cholangiocarcinoma.