title: Novel Clostridium perfringens enterotoxin suicide gene therapy for selective treatment of claudin-3- and -4-overexpressing tumors.
abstract: Bacterial toxins are known to be effective for cancer therapy. Clostridium perfringens enterotoxin (CPE) is produced by the bacterial Clostridium type A strain. The transmembrane proteins claudin-3 and -4, often overexpressed in numerous human epithelial tumors (for example, colon, breast, pancreas, prostate and ovarian), are the targeted receptors for CPE. CPE binding to them triggers formation of membrane pore complexes leading to rapid cell death. In this study, we aimed at selective tumor cell killing by CPE gene transfer. We generated expression vectors bearing the bacterial wild-type CPE cDNA (wtCPE) or translation-optimized CPE (optCPE) cDNA for in vitro and in vivo gene therapy of claudin-3- and -4-overexpressing tumors. The CPE expression analysis at messenger RNA and protein level revealed more efficient expression of optCPE compared with wtCPE. Expression of optCPE showed rapid cytotoxic activity, hightened by CPE release as bystander effect. Cytotoxicity of up to 100% was observed 72 h after gene transfer and is restricted to claudin-3-and -4-expressing tumor lines. MCF-7 and HCT116 cells with high claudin-4 expression showed dramatic sensitivity toward CPE toxicity. The claudin-negative melanoma line SKMel-5, however, was insensitive toward CPE gene transfer. The non-viral intratumoral in vivo gene transfer of optCPE led to reduced tumor growth in MCF-7 and HCT116 tumor-bearing mice compared with the vector-transfected control groups. This novel approach demonstrates that CPE gene transfer can be employed for a targeted suicide gene therapy of claudin-3- and -4-overexpressing tumors, leading to the rapid and efficient tumor cell killing in vitro and in vivo.
authors: Experimental and Clinical Research Center, Charité University Medicine Berlin, Berlin, Germany. wowalt@mdc-berlin.de
authors: W
authors: W
authors: Walther
authors: S
authors: S
authors: Petkov
authors: O N
authors: ON
authors: Kuvardina
authors: J
authors: J
authors: Aumann
authors: D
authors: D
authors: Kobelt
authors: I
authors: I
authors: Fichtner
authors: M
authors: M
authors: Lemm
authors: J
authors: J
authors: Piontek
authors: I E
authors: IE
authors: Blasig
authors: U
authors: U
authors: Stein
authors: P M
authors: PM
authors: Schlag
mesh_terms: D000818:Animals; D024201:Bystander Effect; D045744:Cell Line, Tumor; D062465:Claudin-3; D062506:Claudin-4; D057167:Claudins / Q000235:genetics / Q000378:metabolism*; D004768:Enterotoxins / Q000235:genetics*; D041722:Genes, Transgenic, Suicide; D015316:Genetic Therapy / Q000379:methods*; D045325:HCT116 Cells; D006801:Humans; D008297:Male; D051379:Mice; D009369:Neoplasms / Q000628:therapy*; D023041:Xenograft Model Antitumor Assays
chemical_list: C568122:CLDN3 protein, human; C568157:CLDN4 protein, human; D062465:Claudin-3; D062506:Claudin-4; D057167:Claudins; C568123:Cldn3 protein, mouse; C568158:Cldn4 protein, mouse; D004768:Enterotoxins; C035598:enterotoxin, Clostridium