title: Development of a sensitive screening method for selecting monoclonal antibodies to be internalized by cells.
abstract: Antibody-drug conjugates (ADCs), drugs developed by conjugation of an anticancer agent to a monoclonal antibody (mAb), have lately attracted attention in cancer therapy because ADCs can directly bind cancer cells and kill them. Although mAbs for ADCs must be internalized by the target cells, few methods are available for screening mAbs for their ability to be internalized by cells. We have developed a recombinant protein, termed DT3C, which consists of diphtheria toxin (DT) lacking the receptor-binding domain but containing the C1, C2, and C3 domains of Streptococcus protein G (3C). When a mAb-DT3C conjugate, which functions in vitro like an ADC, reduces the viability of cancer cells, the mAb being tested must have been internalized by the target cells. DT3C can thus be a tool to identify efficiently and easily mAbs that can be internalized by cells, thereby enhancing the development of promising ADCs.
authors.affiliation: Department of Molecular Medicine, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo, Hokkaido 060-8556, Japan. Electronic address: mikiyama@sapmed.ac.jp.
authors.forename: Miki
authors.initials: M
authors.lastname: Yamaguchi
authors.affiliation: Department of Molecular Medicine, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo, Hokkaido 060-8556, Japan.
authors.forename: Yukari
authors.initials: Y
authors.lastname: Nishii
authors.affiliation: Department of Cell Biological Science, Faculty of Advanced Life Science, Graduate School of Life Science, Hokkaido University, Sapporo, Hokkaido 001-0021, Japan.
authors.forename: Kiminori
authors.initials: K
authors.lastname: Nakamura
authors.affiliation: Department of Molecular Medicine, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo, Hokkaido 060-8556, Japan.
authors.forename: Haruka
authors.initials: H
authors.lastname: Aoki
authors.affiliation: Department of Molecular Medicine, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo, Hokkaido 060-8556, Japan.
authors.forename: Sachie
authors.initials: S
authors.lastname: Hirai
authors.affiliation: Laboratory of Oncology, School of Life Science, Tokyo University of Pharmacy and Life Science, Hachioji, Tokyo 192-0392, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Uchida
authors.affiliation: Department of Molecular Medicine, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo, Hokkaido 060-8556, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Sakuma
authors.affiliation: Department of Molecular Medicine, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo, Hokkaido 060-8556, Japan; Laboratory of Oncology, School of Life Science, Tokyo University of Pharmacy and Life Science, Hachioji, Tokyo 192-0392, Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Hamada
mesh_terms: D000911:Antibodies, Monoclonal / Q000032:analysis* / Q000276:immunology / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry / Q000276:immunology; D002470:Cell Survival / Q000187:drug effects; D004167:Diphtheria Toxin / Q000737:chemistry / Q000276:immunology / Q000494:pharmacology / Q000627:therapeutic use; D004305:Dose-Response Relationship, Drug; D006801:Humans; D011994:Recombinant Proteins / Q000032:analysis / Q000276:immunology / Q000378:metabolism; D013329:Structure-Activity Relationship; D014407:Tumor Cells, Cultured
chemical_list: D000911:Antibodies, Monoclonal; D001426:Bacterial Proteins; D004167:Diphtheria Toxin; C034284:IgG Fc-binding protein, Streptococcus; D011994:Recombinant Proteins
keywords: Antibody–drug conjugate (ADC); Diphtheria toxin; Internalization; Streptococcal protein G