title: Construction, expression, and characterization of an anti-tumor immunotoxin containing the human anti-c-Met single-chain antibody and PE38KDEL.
abstract: Recombinant immunotoxins consisting of small antibody fragments fused to cytotoxic moieties are being evaluated for use in prospective antibody-targeted cancer therapies. A receptor tyrosine kinase known as c-Met is overexpressed in a vast range of human malignancies, making it an ideal target for antibody-mediated delivery of numerous cytotoxic agents. A single Fab molecule capable of binding to human c-Met with high affinity and specificity was previously identified using antibody phage-display technology. In order to develop a molecule to increase both the cytotoxicity and anti-tumor activity of the anti-c-Met molecule, a recombinant immunotoxin anti-c-Met/PE38KDEL was constructed and expressed by fusing the human anti-c-Met single-chain variable fragment (ScFv) with a modified Pseudomonas exotoxin A (PE38KDEL). Purified anti-c-Met/PE38KDEL was demonstrated to specifically bind to cells of c-Met-positive human hepatoma cell lines, causing a proliferation defect by inducing caspase-3/8-mediated apoptosis, as observed by in vitro assays. Furthermore, anti-c-Met/PE38KDEL administration was shown to inhibit the growth of hepatocellular carcinoma xenografts in vivo through suppression of Ki-67 expression and enhancement of tumor cell apoptosis rates. Cumulatively, the current findings demonstrate the successful construction of a recombinant immunotoxin capable of accurately targeting c-Met-positive human hepatoma cell lines both in vitro and in vivo, providing a novel compound with potential for applications as an alternative therapy for c-Met-positive cancer management.
authors.affiliation: Department of Gastroenterology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing 210011, China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Liu
authors.forename: Zhenqing
authors.initials: Z
authors.lastname: Feng
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Zhu
authors.forename: Wei
authors.initials: W
authors.lastname: Xu
authors.forename: Jin
authors.initials: J
authors.lastname: Zhu
authors.forename: Xiuhuang
authors.initials: X
authors.lastname: Zhang
authors.forename: Zhining
authors.initials: Z
authors.lastname: Fan
authors.forename: Guozhong
authors.initials: G
authors.lastname: Ji
mesh_terms: D036002:ADP Ribose Transferases / Q000235:genetics / Q000276:immunology / Q000494:pharmacology*; D001427:Bacterial Toxins / Q000235:genetics / Q000276:immunology / Q000494:pharmacology*; D001666:Binding Sites, Antibody; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy* / Q000276:immunology / Q000473:pathology; D045744:Cell Line, Tumor; D005098:Exotoxins / Q000235:genetics / Q000276:immunology / Q000494:pharmacology*; D006801:Humans; D000922:Immunotoxins / Q000235:genetics / Q000276:immunology / Q000494:pharmacology*; D008113:Liver Neoplasms / Q000188:drug therapy* / Q000276:immunology / Q000473:pathology; D019859:Proto-Oncogene Proteins c-met / Q000235:genetics / Q000276:immunology; D057127:Single-Chain Antibodies / Q000235:genetics / Q000276:immunology / Q000494:pharmacology*; D037521:Virulence Factors / Q000235:genetics / Q000276:immunology / Q000494:pharmacology*; D023041:Xenograft Model Antitumor Assays; D000097668:Pseudomonas aeruginosa Exotoxin A
chemical_list: D036002:ADP Ribose Transferases; D001427:Bacterial Toxins; D005098:Exotoxins; D000922:Immunotoxins; D019859:Proto-Oncogene Proteins c-met; D057127:Single-Chain Antibodies; D037521:Virulence Factors; D000097668:Pseudomonas aeruginosa Exotoxin A