title: Efficient cancer therapy with a nanobody-based conjugate.
abstract: Nanobodies are the smallest fragments of naturally occurring single-domain antibodies that have evolved to be fully functional in the absence of a light chain. Nanobodies are strictly monomeric, very stable, and highly soluble entities. We identified a nanobody with subnanomolar affinity for the human tumor-associated carcinoembryonic antigen. This nanobody was conjugated to Enterobacter cloacae beta-lactamase, and its site-selective anticancer prodrug activation capacity was evaluated. The conjugate was readily purified in high yields without aggregation or loss of functionality of the constituents. In vitro experiments showed that the nanobody-enzyme conjugate effectively activated the release of phenylenediamine mustard from the cephalosporin nitrogen mustard prodrug 7-(4-carboxybutanamido) cephalosporin mustard at the surface of carcinoembryonic antigen-expressing LS174T cancer cells. In vivo studies demonstrated that the conjugate had an excellent biodistribution profile and induced regressions and cures of established tumor xenografts. The easy generation and manufacturing yield of nanobody-based conjugates together with their potent antitumor activity make nanobodies promising vehicles for new generation cancer therapeutics.
authors.affiliation: Department of Molecular and Cellular Interactions, Flanders Interuniversity Institute for Biotechnology, Vrije Universiteit Brussel, Brussels, Belgium.
authors.forename: Virna
authors.initials: V
authors.lastname: Cortez-Retamozo
authors.forename: Natalija
authors.initials: N
authors.lastname: Backmann
authors.forename: Peter D
authors.initials: PD
authors.lastname: Senter
authors.forename: Ullrich
authors.initials: U
authors.lastname: Wernery
authors.forename: Patrick
authors.initials: P
authors.lastname: De Baetselier
authors.forename: Serge
authors.initials: S
authors.lastname: Muyldermans
authors.forename: Hilde
authors.initials: H
authors.lastname: Revets
mesh_terms: D000230:Adenocarcinoma / Q000276:immunology / Q000378:metabolism / Q000628:therapy*; D000818:Animals; D000906:Antibodies / Q000737:chemistry / Q000276:immunology / Q000378:metabolism / Q000627:therapeutic use*; D002272:Carcinoembryonic Antigen / Q000096:biosynthesis / Q000276:immunology*; D003110:Colonic Neoplasms / Q000276:immunology / Q000378:metabolism / Q000628:therapy*; D005260:Female; D006801:Humans; D007116:Immunization, Passive / Q000379:methods*; D018796:Immunoconjugates / Q000276:immunology / Q000493:pharmacokinetics / Q000627:therapeutic use*; D051379:Mice; D008819:Mice, Nude; D036103:Nanotechnology; D019151:Peptide Library; D014018:Tissue Distribution; D023041:Xenograft Model Antitumor Assays; D001618:beta-Lactamases / Q000378:metabolism / Q000493:pharmacokinetics / Q000494:pharmacology
chemical_list: D000906:Antibodies; D002272:Carcinoembryonic Antigen; D018796:Immunoconjugates; D019151:Peptide Library; D001618:beta-Lactamases