Comparative evaluation of methods for isolating extracellular vesicles from ICC cell culture supernatants: Insights into proteomic and glycomic analysis
摘要
Extracellular vesicles (EVs) are nanoscale structures involved in intercellular communication and play a key role in cancer pathology. Intrahepatic cholangiocarcinoma (ICC) is a highly invasive malignancy marked by abnormal sialylated glycosylation. Analyzing proteins and glycans in EVs provides insights into ICC molecular subtyping and mechanisms. Optimizing EV isolation methods for ICC-derived EVs enables comprehensive proteomic and glycomic analysis.
MethodsWe systematically evaluated five EV isolation methods—Ultracentrifugation (UC), exoEasy, Total Exosome Isolation (TEI), EVtrap, and ÄKTA—by analyzing the biophysical properties, proteomic profiles, and glycomic structures of EVs. Subsequently, we applied TMT-based quantitative proteome and light/heavy methylamine labeling for the quantification of sialylated N-glycan linkage isomers to investigate alterations in proteins and N-glycans within EVs secreted by HuCCT1 and HCCC-9810 cells with overexpressing ST6 β‑galactoside α2,6‑sialyltransferase 1 (ST6GAL1).
ResultsBy evaluating the biophysical properties, proteome, and N-glycome of EVs extracted using five different methods, UC was identified as the optimal approach for this study, as it offered a balance between operational complexity, cost-effectiveness, and the preservation of EVs activity. In this study, a total of 1,928 high-confidence proteins and over 84 high-confidence glycans were quantified. EVs secreted by HuCCT1 and HCCC-9810 cells overexpressing ST6GAL1 exhibited consistent upregulation of 16 proteins, consistent downregulation of 10 proteins, as well as consistent upregulation of 3 glycans and consistent downregulation of 3 glycans.
ConclusionsQuantitative proteomic and glycomic analysis of ICC-derived EVs revealed that ST6GAL1 overexpression led to significant alterations in proteins involved in cancer cell adhesion and glycosylation pathways, along with specific changes in N-glycan structures. Notably, these modifications extended beyond α2,6-sialylation, suggesting that interactions between glycosyltransferases and glycans may drive these alterations.