title: Prevention of hematogenous metastasis by neutralizing mice and its chimeric anti-Aggrus/podoplanin antibodies.
abstract: The platelet aggregation-inducing factor, Aggrus (also known as podoplanin), is reported to contribute to cancer metastasis by mediating cancer cell-platelet interaction. Aggrus has been shown to be upregulated in many different types of cancers. Thus, not only the functional inhibition of Aggrus, but also its application as a cancer-specific antigen has therapeutic potential. Among a series of anti-Aggrus mAb established previously, no mouse anti-human Aggrus mAb exists that possesses the ability to neutralize platelet aggregation. For precise preclinical examinations of mouse and monkey models, the establishment of Aggrus-neutralizing mouse mAb and their chimeric Abs is needed. In this study, we established two mouse anti-human Aggrus mAb, P2-0 and HAG-3. A precise analysis of their epitopes revealed that P2-0 recognized the conformation near the bioactive O-glycosylation site at the Thr(52) residue. In contrast, HAG-3 recognized the amino-terminus side at a short distance from the conformation recognized by P2-0. We observed that only P2-0 attenuated Aggrus-induced platelet aggregation and Aggrus binding to its platelet receptor, that is, the C-type lectin-like receptor-2. Consistent with these data, only P2-0 prevented the experimental metastasis of human Aggrus-overexpressing CHO cells. Subsequently, we cloned the complementary determining region of P2-0 and produced the murine/human chimeric P2-0 antibody. This chimeric antibody maintained its inhibitory activity of Aggrus-induced platelet aggregation and experimental metastasis. Thus, P2-0 and its chimeric antibody are expected to aid the development of preclinical and clinical examinations of Aggrus-targeted cancer therapy.
authors.affiliation: The Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, Tokyo, Japan.
authors.forename: Youya
authors.initials: Y
authors.lastname: Nakazawa
authors.forename: Satoshi
authors.initials: S
authors.lastname: Takagi
authors.forename: Shigeo
authors.initials: S
authors.lastname: Sato
authors.forename: Tomoko
authors.initials: T
authors.lastname: Oh-hara
authors.forename: Sumie
authors.initials: S
authors.lastname: Koike
authors.forename: Miho
authors.initials: M
authors.lastname: Takami
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Arai
authors.forename: Naoya
authors.initials: N
authors.lastname: Fujita
mesh_terms: D000818:Animals; D058846:Antibodies, Monoclonal, Murine-Derived / Q000276:immunology*; D000912:Antibodies, Neoplasm / Q000276:immunology*; D057134:Antibodies, Neutralizing / Q000276:immunology*; D016466:CHO Cells / Q000473:pathology; D006224:Cricetinae; D003412:Cricetulus; D000939:Epitopes / Q000276:immunology*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000517:prevention & control / Q000556:secondary; D008562:Membrane Glycoproteins / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009362:Neoplasm Metastasis / Q000517:prevention & control*; D009363:Neoplasm Proteins / Q000276:immunology*; D009360:Neoplastic Cells, Circulating / Q000276:immunology*; D010974:Platelet Aggregation / Q000276:immunology*; D011487:Protein Conformation; D011993:Recombinant Fusion Proteins / Q000276:immunology; D013045:Species Specificity; D023041:Xenograft Model Antitumor Assays; D000098853:Podoplanin
chemical_list: D058846:Antibodies, Monoclonal, Murine-Derived; D000912:Antibodies, Neoplasm; D057134:Antibodies, Neutralizing; D000939:Epitopes; D008562:Membrane Glycoproteins; D009363:Neoplasm Proteins; D011993:Recombinant Fusion Proteins; C117468:PDPN protein, human; D000098853:Podoplanin