title: Rapid eradication of colon carcinoma by Clostridium perfringens Enterotoxin suicidal gene therapy.
abstract: Bacterial toxins have evolved to an effective therapeutic option for cancer therapy. The Clostridium perfringens enterotoxin (CPE) is a pore-forming toxin with selective cytotoxicity. The transmembrane tight junction proteins claudin-3 and -4 are known high affinity CPE receptors. Their expression is highly upregulated in human cancers, including breast, ovarian and colon carcinoma. CPE binding to claudins triggers membrane pore complex formation, which leads to rapid cell death. Previous studies demonstrated the anti-tumoral effect of treatment with recombinant CPE-protein. Our approach aimed at evaluation of a selective and targeted cancer gene therapy of claudin-3- and/or claudin-4- expressing colon carcinoma in vitro and in vivo by using translation optimized CPE expressing vector.
  
  
  
  In this study the recombinant CPE and a translation optimized CPE expressing vector (optCPE) was used for targeted gene therapy of claudin-3 and/or -4 overexpressing colon cancer cell lines. All experiments were performed in the human SW480, SW620, HCT116, CaCo-2 and HT-29 colon cancer and the isogenic Sk-Mel5 and Sk-Mel5 Cldn-3-YFP melanoma cell lines. Claudin expression analysis was done at protein and mRNA level, which was confirmed by immunohistochemistry. The CPE induced cytotoxicity was analyzed by the MTT cytotoxicity assay. In addition patient derived colon carcinoma xenografts (PDX) were characterized and used for the intratumoral in vivo gene transfer of the optCPE expressing vector in PDX bearing nude mice.
  
  
  
  Claudin-3 and -4 overexpressing colon carcinoma lines showed high sensitivity towards both recCPE application and optCPE gene transfer. The positive correlation between CPE cytotoxicity and level of claudin expression was demonstrated. Transfection of optCPE led to targeted, rapid cytotoxic effects such as membrane disruption and necrosis in claudin overexpressing cells. The intratumoral optCPE in vivo gene transfer led to tumor growth inhibition in colon carcinoma PDX bearing mice in association with massive necrosis due to the intratumoral optCPE expression.
  
  
  
  This novel approach demonstrates that optCPE gene transfer represents a promising and efficient therapeutic option for a targeted suicide gene therapy of claudin-3 and/or claudin-4 overexpressing colon carcinomas, leading to rapid and effective tumor cell killing in vitro and in vivo.
authors.affiliation: Experimental and Clinical Research Center, Charité University Medicine, Lindenberger Weg 80, 13125, Berlin, Germany.
authors.forename: Jessica
authors.initials: J
authors.lastname: Pahle
authors.affiliation: Max-Delbrück-Center for Molecular Medicine, Rober-Rössle-Str.10, 13125, Berlin, Germany.
authors.forename: Lutz
authors.initials: L
authors.lastname: Menzel
authors.affiliation: Max-Delbrück-Center for Molecular Medicine, Rober-Rössle-Str.10, 13125, Berlin, Germany.
authors.forename: Nicole
authors.initials: N
authors.lastname: Niesler
authors.affiliation: Max-Delbrück-Center for Molecular Medicine, Rober-Rössle-Str.10, 13125, Berlin, Germany.
authors.forename: Dennis
authors.initials: D
authors.lastname: Kobelt
authors.affiliation: Experimental and Clinical Research Center, Charité University Medicine, Lindenberger Weg 80, 13125, Berlin, Germany.
authors.forename: Jutta
authors.initials: J
authors.lastname: Aumann
authors.affiliation: Experimental Pharmacology & Oncology (EPO) GmbH Berlin, Rober-Rössle-Str. 10, 13125, Berlin, Germany.
authors.forename: Maria
authors.initials: M
authors.lastname: Rivera
authors.affiliation: Experimental and Clinical Research Center, Charité University Medicine, Lindenberger Weg 80, 13125, Berlin, Germany. wowalt@mdc-berlin.de.|Max-Delbrück-Center for Molecular Medicine, Rober-Rössle-Str.10, 13125, Berlin, Germany. wowalt@mdc-berlin.de.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Walther
mesh_terms: D000818:Animals; D024201:Bystander Effect; D062465:Claudin-3 / Q000235:genetics*; D062506:Claudin-4 / Q000235:genetics*; D003016:Clostridium perfringens; D003110:Colonic Neoplasms / Q000235:genetics / Q000473:pathology / Q000628:therapy*; D004768:Enterotoxins / Q000627:therapeutic use*; D005260:Female; D041722:Genes, Transgenic, Suicide; D015316:Genetic Therapy; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D023041:Xenograft Model Antitumor Assays
chemical_list: C568122:CLDN3 protein, human; C568157:CLDN4 protein, human; D062465:Claudin-3; D062506:Claudin-4; D004768:Enterotoxins; C035598:enterotoxin, Clostridium
keywords: Clostridium perfringens enterotoxin (CPE); Colon cancer; Gene therapy; Suicide gene