Optimization of rVAR2-Based Isolation of Cancer Cells in Blood for Building a Robust Assay for Clinical Detection of Circulating Tumor Cells

• Main Authors: Nicolai T. Sand, Tobias B. Petersen, Sara R. Bang-Christensen, Theresa D. Ahrens, Caroline Løppke, Amalie M. Jørgensen, Tobias Gustavsson, Swati Choudhary, Thor G. Theander, Ali Salanti, Mette Ø. Agerbæk
• Format: Article
• Language: English
• Published: MDPI AG 2020-03-01
• Series: International Journal of Molecular Sciences
• Subjects: Circulating tumor cells (CTCs); rVAR2; enrichment technologies; cancer; diagnostics; rare cell isolation
• Online Access: https://www.mdpi.com/1422-0067/21/7/2401
• ISSN: 1661-6596; 1422-0067

Early detection and monitoring of cancer progression is key to successful treatment. Therefore, much research is invested in developing technologies, enabling effective and valuable use of non-invasive liquid biopsies. This includes the detection and analysis of circulating tumor cells (CTCs) from blood samples. Recombinant malaria protein VAR2CSA (rVAR2) binds a unique chondroitin sulfate modification present on the vast majority of cancers and thereby holds promise as a near-universal tumor cell-targeting reagent to isolate CTCs from complex blood samples. This study describes a technical approach for optimizing the coupling of rVAR2 to magnetic beads and the development of a CTC isolation platform targeting a range of different cancer cell lines. We investigate both direct and indirect approaches for rVAR2-mediated bead retrieval of cancer cells and conclude that an indirect capture approach is most effective for rVAR2-based cancer cell retrieval.