A549 tumorigenic and BEAS-2B non-tumorigenic cell line derived small extracellular vesicles show distinct proteomic, N-glycoproteomic and chondroitin/dermatan sulfate profiles

Abstract

Extracellular vesicles (EVs) are critical mediators of intercellular communication and hold promise as biomarkers and therapeutic targets in cancer, but their molecular alterations remain poorly understood. Protein glycosylation is a frequent post-translational modification; however, most EV studies focus only on proteomics, while mapping glycosylation changes of proteins are still underrepresented. To address this shortcoming, we analyzed the proteomic, N-glycoproteomic, and chondroitin/dermatan sulfate (CS/DS) glycosaminoglycan (GAG) profiles of small EVs (sEVs) derived from A549 lung adenocarcinoma and BEAS-2B non-tumorigenic epithelial cell lines. Principal component analysis and hierarchical clustering revealed that all three profiles are highly dependent on the origin of sEV, highlighting fundamental differences not only at the proteomic but also at the N-glycopeptide and CS/DS levels. Protein expression differences were primarily associated with the upregulation of cell cycle regulation, DNA repair, metabolism, and protein synthesis, while immune-related processes were predominantly downregulated. Proteomics revealed differential expressions of 5 CS proteoglycans, anticipating that their CS profile may also change. N-glycoproteomics highlighted a shift from complex to hybrid N-glycans in cancer sEVs, alongside a significant decrease in fucosylation. Prominent glycoproteins characterized with multiple glycosylation sites included versican, galectin-3-binding protein and laminins. The total amount of CS/DS increased 3.4-fold in cancer sEVs, while the ratio of the two monosulfated disaccharides changed 2-fold, suggesting altered sulfation mechanisms. These findings highlight the potential of N-glycoproteomics and GAG profiling to enhance biomarker discovery and EV-based cancer diagnostics. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=121 SRC="FIGDIR/small/643059v1_ufig1.gif" ALT="Figure 1"> View larger version (23K): org.highwire.dtl.DTLVardef@c2dfdeorg.highwire.dtl.DTLVardef@1f79452org.highwire.dtl.DTLVardef@12a9dbborg.highwire.dtl.DTLVardef@d992da_HPS_FORMAT_FIGEXP M_FIG C_FIG Proteomic, N-glycoproteomic and chondroitin/dermatan sulfate disaccharide profiles differ between A549 lung adenocarcinoma and BEAS-2B non-tumorigenic epithelial cell derived small extracellular vesicles.