Isolation and characterization of fucosylated extracellular vesicles based on a novel GlyExo-Capture technique

Owing to their diagnostic and therapeutic potential, extracellular vesicles (EVs) derived from tumour cells have recently garnered great interest. The presence of different glycosylation sites at the EV surface supports the need for efficient glycosylated EV isolation. Here, we developed a GlyExo-Capture technique for robustly capturing fucosylated EVs from sera and cell supernatants. Lens culinaris lectin (LCA)-immobilized magnetic complexes were found to capture approximately 60% of the total EVs from HepG2 cells. The capture efficiency was reduced to less than 40% in nontumorigenic MIHA cells. Notably, the cellular uptake pattern of highly fucosylated EVs was markedly different from that of EVs with low fucosylation. The unearthing of enriched fucosylated EV miRNA cargos by next-generation deep sequencing (NGS) revealed 75 differentially expressed miRNAs (DEMs) in hepatocellular carcinoma (HCC). Among them, a 4-miRNA panel was chosen and yielded an area under the ROC curve (AUC) of 0.86 and 0.84 for the detection of HCC from non-HCC controls in testing samples and independent validation samples, respectively. The 4-miRNA signature was independent of alpha-fetoprotein (AFP), and a combined model with AFP yielded an increased AUC of 0.92. In conclusion, we developed a high-throughput method for capturing fucosylated EVs efficiently and shed light on the use of fucosylated EVs as potential sources of miRNAs for cancer biomarker detection.