Claudin-4-targeting of diphtheria toxin fragment A using a C-terminal fragment of Clostridium perfringens enterotoxin.
Claudin (CL)-4, a tight junction protein, is overexpressed in some human neoplasias, including ovarian, breast, pancreatic and prostate cancers. The targeting of CL-4 is a novel strategy for tumor therapy. We previously found that the C-terminal fragment of Clostridium perfringens enterotoxin (C-CPE) binds to CL-4. In the present study, we genetically prepared a novel CL-4-targeting molecule (DTA-C-CPE) by fusion of C-CPE and diphtheria toxin fragment A (DTA). Although DTA is not toxic to CL-4-expressing L cells, even at 20 microg/ml, DTA-C-CPE is toxic to CL-4-expressing L cells at 1 microg/ml. DTA-C-CPE-induced cytotoxicity was attenuated by pretreatment of the cells with C-CPE but not bovine serum albumin, indicating that DTA-C-CPE may bind to CL-4-expressing L cells through its C-CPE domain. To evaluate the specificity of DTA-C-CPE, we examined its cytotoxic effects in L cells that express CL-1, -2, -4 or -5. We found that DTA-C-CPE was toxic to only CL-4-expressing L cells. Thus, C-CPE may be a promising ligand for the development of cancer-targeting systems.
Laboratory of Bio-Functional Molecular Chemistry, Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan.
Hideki
H
Kakutani
Masuo
M
Kondoh
Rie
R
Saeki
Makiko
M
Fujii
Yoshiteru
Y
Watanabe
Hiroyuki
H
Mizuguchi
Kiyohito
K
Yagi
D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000494:pharmacology; D002417:Cattle; D002460:Cell Line; D062506:Claudin-4; D004167:Diphtheria Toxin / Q000008:administration & dosage* / Q000737:chemistry / Q000494:pharmacology; D016503:Drug Delivery Systems; D004768:Enterotoxins / Q000737:chemistry*; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D008024:Ligands; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D009369:Neoplasms / Q000188:drug therapy / Q000503:physiopathology; D010446:Peptide Fragments / Q000008:administration & dosage* / Q000737:chemistry / Q000494:pharmacology; D011485:Protein Binding; D012710:Serum Albumin, Bovine / Q000494:pharmacology
D000970:Antineoplastic Agents; C568157:CLDN4 protein, human; D062506:Claudin-4; C568158:Cldn4 protein, mouse; D004167:Diphtheria Toxin; D004768:Enterotoxins; D008024:Ligands; D008565:Membrane Proteins; D010446:Peptide Fragments; C029795:diphtheria toxin fragment A; C035598:enterotoxin, Clostridium; D012710:Serum Albumin, Bovine