{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T14:06:06Z","timestamp":1785420366411,"version":"3.56.0"},"reference-count":32,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2020,3,31]],"date-time":"2020-03-31T00:00:00Z","timestamp":1585612800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004836","name":"Independent Research Fund Denmark","doi-asserted-by":"publisher","award":["8020-00446A"],"award-info":[{"award-number":["8020-00446A"]}],"id":[{"id":"10.13039\/501100004836","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100012774","name":"Innovation Fund Denmark","doi-asserted-by":"publisher","award":["7038-00212B"],"award-info":[{"award-number":["7038-00212B"]}],"id":[{"id":"10.13039\/100012774","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100009708","name":"Novo Nordisk Foundation","doi-asserted-by":"publisher","award":["NNF18SA0034956"],"award-info":[{"award-number":["NNF18SA0034956"]}],"id":[{"id":"10.13039\/501100009708","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Holms Mindelegat","award":["20006-1982"],"award-info":[{"award-number":["20006-1982"]}]},{"DOI":"10.13039\/100012774","name":"Innovationsfonden","doi-asserted-by":"publisher","award":["9090-00024B"],"award-info":[{"award-number":["9090-00024B"]}],"id":[{"id":"10.13039\/100012774","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>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.<\/jats:p>","DOI":"10.3390\/ijms21072401","type":"journal-article","created":{"date-parts":[[2020,4,1]],"date-time":"2020-04-01T03:44:13Z","timestamp":1585712653000},"page":"2401","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":17,"title":["Optimization of rVAR2-Based Isolation of Cancer Cells in Blood for Building a Robust Assay for Clinical Detection of Circulating Tumor Cells"],"prefix":"10.3390","volume":"21","author":[{"given":"Nicolai T.","family":"Sand","sequence":"first","affiliation":[{"name":"Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, 2200 Copenhagen, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tobias B.","family":"Petersen","sequence":"additional","affiliation":[{"name":"Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, 2200 Copenhagen, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3927-4861","authenticated-orcid":false,"given":"Sara R.","family":"Bang-Christensen","sequence":"additional","affiliation":[{"name":"Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, 2200 Copenhagen, Denmark"},{"name":"VarCT Diagnostics, 2200 Copenhagen, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Theresa D.","family":"Ahrens","sequence":"additional","affiliation":[{"name":"Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, 2200 Copenhagen, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0679-5118","authenticated-orcid":false,"given":"Caroline","family":"L\u00f8ppke","sequence":"additional","affiliation":[{"name":"Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, 2200 Copenhagen, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8554-7261","authenticated-orcid":false,"given":"Amalie M.","family":"J\u00f8rgensen","sequence":"additional","affiliation":[{"name":"VarCT Diagnostics, 2200 Copenhagen, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tobias","family":"Gustavsson","sequence":"additional","affiliation":[{"name":"Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, 2200 Copenhagen, Denmark"},{"name":"VarCT Diagnostics, 2200 Copenhagen, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Swati","family":"Choudhary","sequence":"additional","affiliation":[{"name":"Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, 2200 Copenhagen, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Thor G.","family":"Theander","sequence":"additional","affiliation":[{"name":"Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, 2200 Copenhagen, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ali","family":"Salanti","sequence":"additional","affiliation":[{"name":"Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, 2200 Copenhagen, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5865-2034","authenticated-orcid":false,"given":"Mette \u00d8.","family":"Agerb\u00e6k","sequence":"additional","affiliation":[{"name":"Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, 2200 Copenhagen, Denmark"},{"name":"VarCT Diagnostics, 2200 Copenhagen, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,3,31]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1559","DOI":"10.1126\/science.1203543","article-title":"A Perspective on Cancer Cell Metastasis","volume":"331","author":"Chaffer","year":"2011","journal-title":"Science"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"216","DOI":"10.1186\/bcr616","article-title":"Expert Group: IARC Handbooks of Cancer Prevention. Vol.7: Breast Cancer Screening. Lyon, France: IARC; 2002. 248pp","volume":"5","author":"Smith","year":"2003","journal-title":"Breast Cancer Res."},{"key":"ref_3","first-page":"51","article-title":"European guidelines for quality assurance in colorectal cancer screening and diagnosis: Overview and introduction to the full supplement publication","volume":"45","author":"Group","year":"2013","journal-title":"Endoscopy"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1556","DOI":"10.1200\/JCO.2010.28.7045","article-title":"Evaluation and Prognostic Significance of Circulating Tumor Cells in Patients With Non\u2013Small-Cell Lung Cancer","volume":"29","author":"Krebs","year":"2011","journal-title":"J. Clin. Oncol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"6302","DOI":"10.1158\/1078-0432.CCR-08-0872","article-title":"Circulating Tumor Cells Predict Survival Benefit from Treatment in Metastatic Castration-Resistant Prostate Cancer","volume":"14","author":"Scher","year":"2008","journal-title":"Clin. Cancer Res."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"781","DOI":"10.1056\/NEJMoa040766","article-title":"Circulating Tumor Cells, Disease Progression, and Survival in Metastatic Breast Cancer","volume":"351","author":"Cristofanilli","year":"2004","journal-title":"N. Engl. J. Med."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1223","DOI":"10.1093\/annonc\/mdn786","article-title":"Prognostic significance of circulating tumor cells in patients with metastatic colorectal cancer","volume":"20","author":"Cohen","year":"2009","journal-title":"Ann. Oncol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"58","DOI":"10.1016\/j.ccr.2007.12.003","article-title":"Systemic Spread Is an Early Step in Breast Cancer","volume":"13","author":"Geigl","year":"2008","journal-title":"Cancer Cell"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"349","DOI":"10.1016\/j.cell.2011.11.025","article-title":"EMT and Dissemination Precede Pancreatic Tumor Formation","volume":"148","author":"Rhim","year":"2012","journal-title":"Cell"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"24517","DOI":"10.1038\/srep24517","article-title":"Circulating Tumor Cell Count Correlates with Colorectal Neoplasm Progression and Is a Prognostic Marker for Distant Metastasis in Non-Metastatic Patients","volume":"6","author":"Tsai","year":"2016","journal-title":"Sci. Rep."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1597","DOI":"10.1002\/ijc.30575","article-title":"Burkitt lymphoma expresses oncofetal chondroitin sulfate without being a reservoir for placental malaria sequestration","volume":"140","author":"Pereira","year":"2017","journal-title":"Int. J. Cancer"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Bang-Christensen, S.R., Pedersen, R.S., Pereira, M.A., Clausen, T.M., L\u00f8ppke, C., Sand, N.T., Ahrens, T.D., J\u00f8rgensen, A.M., Lim, Y.C., and Goks\u00f8yr, L. (2019). Capture and Detection of Circulating Glioma Cells Using the Recombinant VAR2CSA Malaria Protein. Cells, 8.","DOI":"10.3390\/cells8090998"},{"key":"ref_13","unstructured":"Cummings, R.D., and Pierce, J.M. (2010). Chapter 3\u2014Glycosaminoglycans. Handbook of Glycomics, Academic Press."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"500","DOI":"10.1016\/j.ccell.2015.09.003","article-title":"Targeting Human Cancer by a Glycosaminoglycan Binding Malaria Protein","volume":"28","author":"Salanti","year":"2015","journal-title":"Cancer Cell"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"40344","DOI":"10.1074\/jbc.M006398200","article-title":"Characterization of Proteoglycans of Human Placenta and Identification of Unique Chondroitin Sulfate Proteoglycans of the Intervillous Spaces That Mediate the Adherence ofPlasmodium falciparum-infected Erythrocytes to the Placenta","volume":"275","author":"Achur","year":"2000","journal-title":"J. Biol. Chem."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1502","DOI":"10.1126\/science.272.5267.1502","article-title":"Adherence of Plasmodium falciparum to Chondroitin Sulfate A in the Human Placenta","volume":"272","author":"Fried","year":"1996","journal-title":"Science"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"179","DOI":"10.1046\/j.1365-2958.2003.03570.x","article-title":"Selective upregulation of a single distinctly structured var gene in chondroitin sulphate A-adhering Plasmodium falciparum involved in pregnancy-associated malaria","volume":"49","author":"Salanti","year":"2003","journal-title":"Mol. Microbiol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"359","DOI":"10.1016\/j.placenta.2003.10.019","article-title":"The Sick Placenta\u2014The Role of Malaria","volume":"25","author":"Brabin","year":"2004","journal-title":"Placenta"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"23332","DOI":"10.1074\/jbc.M112.348839","article-title":"Structural and functional insight into how the Plasmodium falciparum VAR2CSA protein mediates binding to chondroitin sulfate A in placental malaria","volume":"287","author":"Clausen","year":"2012","journal-title":"J. Biol. Chem."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"15908","DOI":"10.1074\/jbc.M110.191510","article-title":"The chondroitin sulfate A-binding site of the VAR2CSA protein involves multiple N-terminal domains","volume":"286","author":"Nielsen","year":"2011","journal-title":"J. Biol. Chem."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"178","DOI":"10.1016\/j.pt.2018.11.004","article-title":"Fighting Cancer Using an Oncofetal Glycosaminoglycan-Binding Protein from Malaria Parasites","volume":"35","author":"Salanti","year":"2019","journal-title":"Trends Parasitol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"133","DOI":"10.1186\/1477-7827-8-133","article-title":"Syndecan-1 knock-down in decidualized human endometrial stromal cells leads to significant changes in cytokine and angiogenic factor expression patterns","volume":"8","author":"Janni","year":"2010","journal-title":"Reprod. Biol. Endocrinol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"57","DOI":"10.1016\/S0092-8674(00)81683-9","article-title":"The Hallmarks of Cancer","volume":"100","author":"Hanahan","year":"2000","journal-title":"Cell"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"142","DOI":"10.1016\/j.eururo.2017.03.021","article-title":"An Oncofetal Glycosaminoglycan Modification Provides Therapeutic Access to Cisplatin-resistant Bladder Cancer","volume":"72","author":"Seiler","year":"2017","journal-title":"Eur. Urol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1288","DOI":"10.1158\/1541-7786.MCR-16-0103","article-title":"Oncofetal Chondroitin Sulfate Glycosaminoglycans Are Key Players in Integrin Signaling and Tumor Cell Motility","volume":"14","author":"Clausen","year":"2016","journal-title":"Mol. Cancer Res."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"3279","DOI":"10.1038\/s41467-018-05793-2","article-title":"The VAR2CSA malaria protein efficiently retrieves circulating tumor cells in an EpCAM-independent manner","volume":"9","author":"Yang","year":"2018","journal-title":"Nat. Commun."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"6897","DOI":"10.1158\/1078-0432.CCR-04-0378","article-title":"Tumor Cells Circulate in the Peripheral Blood of All Major Carcinomas but not in Healthy Subjects or Patients With Nonmalignant Diseases","volume":"10","author":"Allard","year":"2004","journal-title":"Clin. Cancer Res."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"e12517","DOI":"10.1371\/journal.pone.0012517","article-title":"Molecular biomarker analyses using circulating tumor cells","volume":"5","author":"Punnoose","year":"2010","journal-title":"PLoS ONE"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"E690","DOI":"10.1073\/pnas.1115485109","article-title":"Peptide tag forming a rapid covalent bond to a protein, through engineering a bacterial adhesin","volume":"109","author":"Zakeri","year":"2012","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"3908","DOI":"10.1021\/acsomega.7b01427","article-title":"Integration of Magnetic Bead-Based Cell Selection into Complex Isolations","volume":"3","author":"Pezzi","year":"2018","journal-title":"ACS omega"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"515","DOI":"10.1016\/j.ccr.2006.10.008","article-title":"A collection of breast cancer cell lines for the study of functionally distinct cancer subtypes","volume":"10","author":"Neve","year":"2006","journal-title":"Cancer Cell"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"757","DOI":"10.1373\/clinchem.2008.116467","article-title":"mRNA Expression and BRAF Mutation in Circulating Melanoma Cells Isolated from Peripheral Blood with High Molecular Weight Melanoma-Associated Antigen-Specific Monoclonal Antibody Beads","volume":"55","author":"Kitago","year":"2019","journal-title":"Clin. Chem."}],"container-title":["International Journal of Molecular Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1422-0067\/21\/7\/2401\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T09:13:42Z","timestamp":1760174022000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1422-0067\/21\/7\/2401"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,3,31]]},"references-count":32,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2020,4]]}},"alternative-id":["ijms21072401"],"URL":"https:\/\/doi.org\/10.3390\/ijms21072401","relation":{},"ISSN":["1422-0067"],"issn-type":[{"value":"1422-0067","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,3,31]]}}}