Aim: Tumor-derived extracellular vesicles play a crucial role in oncogenic processes. Current methods for isolating extracellular vesicles (EVs) do not distinguish between tumor- and non-tumor-derived EVs. The aim of this study was to evaluate the efficacy of TEXO-NET, a novel approach utilizing SubB2M, a genetically engineered lectin, immobilized on nanoparticles, for the selective enrichment of tumor-derived EVs. SubB2M specifically recognizes N-glycolylneuraminic acid (Neu5Gc), a sialic acid that is preferentially incorporated into glycoconjugates synthesized by cancer cells.
Method: EVs were isolated from the plasma/serum of breast and ovarian cancer patients using TEXO-NET and commercially available pan EV isolation kits. Captured EVs were quantified using Nanoparticle Tracking Analysis (NTA, ZetaView) to determine their size and concentration. EV-associated protein and RNA were quantified by ELISA, RT-PCR and Western blot.
Results: NTA established that TEXO-NET captured a significantly greater number of nanoparticles from breast cancer plasma compared to pan EV isolation kits. TEXO-NET captured EVs were released from the beads by Neu5Gc competitive displacement. CA125 expression in EVs isolated from pooled ovarian cancer serum was greater than matched controls. Similarly, higher amounts CA 15-3 were detected in EVs isolated from pooled breast cancer serum compared to matched controls.
Conclusion: The data obtained in this study establishes the effectiveness of TEXO-NET in selectively capturing a subpopulation of EVs enriched with tumor-specific biomarkers. This innovative approach could significantly contribute to the development of improved diagnostic tools in the field of oncology, facilitating the identification and utilization of diagnostic biomarkers for early detection and monitoring of cancer.