Exosomal Proteome from Hepatocellular Carcinoma Patient-Derived Xenograft Mice Serves as Identity of Liver Cancer

Hepatocellular carcinoma (HCC) constitutes approximately 90% of liver cancers, yet its early detection remains challenging due to the low sensitivity of current diagnostic methods and the difficulty in identifying minimal cancer cells within the body. This study employed a patient-derived xenograft (PDX) mouse model to screen for biomarkers, leveraging its advantage of low background interference compared to human serum exosome studies. Using a novel microextraction technique, exosomes were isolated from just one microliter of serum from HCC PDX mice, followed by proteomic profiling. Analysis revealed that serum exosomal proteins from PDX mice were enriched in cancer-related pathways. The exosomal proteome not only distinguished PDX mice from controls but also differentiated between individual PDX groups, supporting its use as a tumor-specific identifier (tumor ID) and a noninvasive tool for monitoring tumors. Bioinformatics identified a panel of serum exosomal protein biomarkers predictive of HCC patient outcomes, which were validated via targeted proteomics and array-based high-throughput detection. These upregulated biomarkers in HCC patients positively correlate with disease severity and poor prognosis, underscoring their clinical potential.