Therapeutic antitumor efficacy of monoclonal antibody against Claudin‐4 for pancreatic and ovarian cancers

• Published in: Cancer science 2009-09, Vol.100 (9), p.1623-1630
• Main Authors: Suzuki, Masayo, Kato‐Nakano, Mariko, Kawamoto, Shinobu, Furuya, Akiko, Abe, Yuzuru, Misaka, Hirofumi, Kimoto, Naoya, Nakamura, Kazuyasu, Ohta, So, Ando, Hiroshi
• Format: Article
• Language: English
• Subjects: Animals; Antibodies, Monoclonal - therapeutic use; Antibody-Dependent Cell Cytotoxicity; Biological and medical sciences; Blotting, Western; Cells, Cultured; CHO Cells; Claudin-4; Complement System Proteins - immunology; Cricetinae; Cricetulus; Cytotoxicity, Immunologic - immunology; Female; Flow Cytometry; Gastroenterology. Liver. Pancreas. Abdomen; Humans; Immunoglobulin G - immunology; Immunoglobulin G - metabolism; Immunoprecipitation; Liver. Biliary tract. Portal circulation. Exocrine pancreas; Medical sciences; Membrane Proteins - immunology; Mice; Mice, SCID; Original; Ovarian Neoplasms - immunology; Ovarian Neoplasms - pathology; Ovarian Neoplasms - therapy; Pancreatic Neoplasms - immunology; Pancreatic Neoplasms - pathology; Pancreatic Neoplasms - therapy; Recombinant Fusion Proteins - genetics; Recombinant Fusion Proteins - immunology; Recombinant Fusion Proteins - metabolism; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - genetics; RNA, Messenger - metabolism; Tumors
• ISSN: 1347-9032; 1349-7006; 1349-7006
• DOI: 10.1111/j.1349-7006.2009.01239.x

Claudin‐4 (CLDN4) is a tetraspanin transmembrane protein of tight junction structure and is highly expressed in pancreatic and ovarian cancers. In this study, we aimed to generate an anti‐Claudin‐4 monoclonal antibody (mAb) and evaluate its antitumor efficacy in vitro and in vivo. To isolate specific mAb, we generated CLDN3, 4, 5, 6, and 9, expressing Chinese hamster ovary (CHO) cells, and then used them as positive and negative targets through cell‐based screening. As a result, we succeeded in isolating KM3900 (IgG2a), which specifically bound to CLDN4, from BXSB mice immunized with pancreatic cancer cells. Immunoprecipitation and flow cytometry analysis revealed that KM3900 recognized the conformational structure and bound to extracellular loop 2 of CLDN4. Furthermore, binding of KM3900 was detected on CLDN4‐expressing pancreatic and ovarian cancer cells, but not on negative cells. Next, we made the mouse–human chimeric IgG1 (KM3934) and evaluated its antitumor efficacy. KM3934 induced dose‐dependent antibody‐dependent cellular cytotoxicity and complement‐dependent cytotoxicity in vitro, and significantly inhibited tumor growth in MCAS or CFPAC‐1 xenograft SCID mice in vivo (P