You have accessJournal of UrologyProstate Cancer: Basic Research1 Apr 2011404 A NOVEL TARGETED THERAPY FOR PROSTATE CANCER USING CLOSTRIDIUM PERFRINGENS ENTEROTOXIN Toshihiro Maeda, Masaki Murata, Hideki Chiba, Hiroshi Kitamura, Naoya Masumori, Norimasa Sawada, and Taiji Tsukamoto Toshihiro MaedaToshihiro Maeda Sapporo, Japan More articles by this author , Masaki MurataMasaki Murata Sapporo, Japan More articles by this author , Hideki ChibaHideki Chiba Fukushima, Japan More articles by this author , Hiroshi KitamuraHiroshi Kitamura Sapporo, Japan More articles by this author , Naoya MasumoriNaoya Masumori Sapporo, Japan More articles by this author , Norimasa SawadaNorimasa Sawada Sapporo, Japan More articles by this author , and Taiji TsukamotoTaiji Tsukamoto Sapporo, Japan More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2011.02.493AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Clostridium perfringens enterotoxin (CPE), a major cause of food poisoning, triggers lysis of epithelial cells through binding to tight-junction proteins claudin-3 (Cldn3) and Cldn4. Considering that Cldn3 and Cldn4 are overexpressed in various cancers, including prostate, breast and ovarian cancers, they are expected to be promising candidates for targeted therapy against chemotherapy-resistant cancers. In this study, we investigated the cytotoxic effects of CPE on prostate cancer cells in vitro and in vivo. METHODS By Western blot and immunohistochemical analyses, we determined the expression levels and subcellular localization of both Cldn3 and Cldn4 proteins in three androgen-independent human prostate cancer cell lines (22Rv1, DU145 and PC3) and normal human prostate epithelial cells (PrEC). These cells were treated with CPE (0, 0.1, 0.3, 0.5 and 1.0 μg/ml), and the cytotoxicity was examined under a phase-contrast microscope and by colorimetric assay. PC3 cells were also analyzed under a transmission electron microscope and subjected to terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Furthermore, we studied whether knockdown of Cldn3 and/or Cldn4 expression using RNA interference influenced CPE-mediated cytotoxicity in PC3 and 22Rv1 cells. The therapeutic effect of CPE was evaluated in PC3 xenografts in athymic mice (Balb/c). RESULTS Cldn4 protein was strongly expressed in PC3 and PrEC, but less and only weakly observed in 22Rv1 and DU145, respectively. In contrast, Cldn3 protein was expressed in 22Rv1 and DU145 at higher levels than in PC3, but not detected in PrEC. Cldn4 and Cldn3 were distributed along whole cell membranes of PC3, 22Rv1 and DU145, whereas Cldn4 was localized at tight junctions in PrEC. CPE-mediated cytotoxicity was greatly detected in PC3 and moderately and weakly observed in 22Rv1 and DU145, respectively, but was hardly detectable in PrEC. Necrosis but not apoptosis was observed in CPE-treated PC3. Reduced expression of Cldn4, but not Cldn3, led to remarkable decreases of the cytotoxicity in both PC3 and 22Rv1. The injection of CPE around PC3 xenografts significantly suppressed tumor growth. CONCLUSIONS CPE-mediated cytotoxicity was observed in three androgen-independent human prostate cancer cell lines, but barely detected in normal human prostate epithelial cells. In addition, the cytotoxic effect depended not only on the expression level of Cldn4 protein but also on its subcellular localization. These results suggest that Cldn4-targeted therapy using CPE may be a new treatment for prostate cancer. © 2011 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 185Issue 4SApril 2011Page: e163 Advertisement Copyright & Permissions© 2011 by American Urological Association Education and Research, Inc.MetricsAuthor Information Toshihiro Maeda Sapporo, Japan More articles by this author Masaki Murata Sapporo, Japan More articles by this author Hideki Chiba Fukushima, Japan More articles by this author Hiroshi Kitamura Sapporo, Japan More articles by this author Naoya Masumori Sapporo, Japan More articles by this author Norimasa Sawada Sapporo, Japan More articles by this author Taiji Tsukamoto Sapporo, Japan More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...