N-glycome composition of extracellular vesicles released by urological cancer cells and reference non-malignant cells

Transport of bioactive molecules via extracellular vesicles (EVs) is one of the mechanisms of intercellular communication. EVs regulate a number of physiological processes in recipient cells, but also contribute to development and progression of many diseases, including cancer. Many glycoproteins are incorporated into EVs, but little is known about their biological significance. Glycosylation can affect sorting of protein into EVs and interaction of EVs with the target cell. Therefore, EV glycome is being investigated for possible diagnostic and therapeutic applications. The aim of this study was structural analysis and identification of N-glycans differentiating EVs from urological cancer cell lines (bladder - T24, prostate - PC-3, and renal - Caki-2) and their non-transformed counterparts (HCV-29, HPrEC and HREpC cells, respectively) using Matrix-Assisted Laser Desorption/Ionization Time-of-Flight mass spectrometry (MALDI-TOF). EVs derived from all cancerous cell lines showed increased abundance of oligomannose structures compared to EVs from non-transformed cells. Particularly, increased expression of H8N2, H9N2 and H10N2 structures was observed in EVs derived from all 3 cancer cell lines. Also, overall sialylation was decreased in cancer-derived EVs, with lower expression of H5N4E2, H6N5E1L2 and H6N5E2L1 structures. In addition, we identified structures/subgroups of structures that distinguish EVs from each individual urological cancer cell line from EVs from reference non-transformed cells. The results provide preliminary insight into the structural diversity and biological significance of N-glycans present in EVs derived from urological cancer cells. Identifying EV N-glycan enrichment or depletion patterns that are common to, or specific for studied urological cancers may contribute to development of new diagnostic approaches.