Effects of Clostridium perfringens enterotoxin via claudin-4 on normal human pancreatic duct epithelial cells and cancer cells.

Abstract

The tight junction protein claudin-4 is frequently overexpressed in pancreatic cancer, and is also a receptor for Clostridium perfringens enterotoxin (CPE). The cytotoxic effects of CPE are thought to be useful as a novel therapeutic tool for pancreatic cancer. However, the responses to CPE via claudin-4 remain unknown in normal human pancreatic duct epithelial (HPDE) cells. We introduced the human telomerase reverse transcriptase (hTERT) gene into HPDE cells in primary culture as a model of normal HPDE cells in vitro. hTERT-HPDE cells treated with or without 10% FBS and pancreatic cancer cell lines PANC-1, BXPC3, HPAF-II and HPAC were treated with CPE. In Western blotting, the expression of claudin-4 protein in hTERT-HPDE cells treated with 10% FBS was as high as it was in all of the pancreatic cancer cell lines. In hTERT-HPDE cells with or without 10% FBS, cytotoxicity was not observed at any concentration of CPE, whereas in all pancreatic cancer cell lines, CPE had a dose-dependent cytotoxic effect. In hTERT-HPDE cells with 10% FBS, claudin-4 was localized in the apical-most regions, where there are tight junction areas, in which in all pancreatic cancer cell lines claudin-4 was found not only in the apical-most regions but also at basolateral membranes. In hTERT-HPDE cells with 10% FBS after treatment with CPE, downregulation of barrier function and claudin-4 expression at the membranes was observed. In HPAC cells, the sensitivity to CPE was significantly decreased by knockdown of claudin-4 expression using siRNA compared to the control. These findings suggest that, in normal HPDE cells, the lack of toxicity of CPE was probably due to the localization of claudin-4, which is different from that of pancreatic cancer cells. hTERT-HPDE cells in this culture system may be a useful model of normal HPDE cells not only for physiological regulation of claudin-4 expression but also for developing safer and more effective therapeutic methods targeting claudin-4 in pancreatic cancer.

• Authors: Hiroshi Yamaguchi, Takashi Kojima, Tatsuya Ito, Daisuke Kyuno, Yasutoshi Kimura, Masafumi Imamura, Koichi Hirata, Norimasa Sawada
• Journal: Cellular & molecular biology letters (Cell Mol Biol Lett) Vol. 16 Issue 3 Pg. 385-97 (Sep 2011) ISSN: 1689-1392 [Electronic] England
• PMID: 21573709 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• CLDN1 protein, human
• CLDN4 protein, human
• CLDN7 protein, human
• Claudin-1
• Claudin-4
• Claudins
• Enterotoxins
• Membrane Proteins
• OCLN protein, human
• Occludin
• RNA, Small Interfering
• enterotoxin, Clostridium
• TERT protein, human
• Telomerase

Topics

• Blotting, Western
• Carcinoma, Pancreatic Ductal (metabolism, pathology)
• Cell Death (drug effects)
• Cell Line, Tumor
• Claudin-1
• Claudin-4
• Claudins (metabolism)
• Electric Impedance
• Enterotoxins (pharmacology)
• Epithelial Cells (drug effects, metabolism, pathology)
• Humans
• Immunohistochemistry
• Membrane Proteins (metabolism)
• Occludin
• Pancreatic Ducts (pathology)
• Pancreatic Neoplasms (metabolism, pathology)
• Protein Transport (drug effects)
• RNA, Small Interfering (metabolism)
• Telomerase (metabolism)