No involvement of beta-catenin gene mutation in gastric carcinomas induced by N-methyl-N-nitrosourea in male F344 rats.

Abstract

The agent N-methyl-N-nitrosourea (MNU) is a direct acting carcinogen and induces well-differentiated adenocarcinoma on the rat gastric mucosa. In this study, 27 histopathologically verified gastric carcinomas induced in male F344 rats were analyzed for mutations in the N-terminal phosphorylation sites (codons 1-51) of the beta-catenin gene by using polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) assays. In parallel studies, the specific localization of the beta-catenin protein was also examined by immunohistochemical analysis. No mutations in the beta-catenin gene were found in any of 27 gastric carcinomas induced by MNU. Immunohistochemical analysis resulted in the beta-catenin protein to be localized in the plasma membrane but cytoplasmic and/or nuclear accumulation of beta-catenin was not identified in any of these carcinomas. These results suggest that mutations in the beta-catenin gene are less contributory to the development of rat gastric carcinomas induced by MNU. This animal model may provide a system for evaluating the mechanism of human gastric carcinogenesis that is not associated with beta-catenin gene mutations.

• Authors: Masahito Shimizu, Masumi Suzui, Hisataka Moriwaki, Hideki Mori, Naoki Yoshimi
• Journal: Cancer letters (Cancer Lett) Vol. 195 Issue 2 Pg. 147-52 (Jun 10 2003) ISSN: 0304-3835 [Print] Ireland
• PMID: 12767522 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Carcinogens
• Codon
• Ctnnb1 protein, rat
• Cytoskeletal Proteins
• DNA, Neoplasm
• Membrane Proteins
• Trans-Activators
• beta Catenin
• Methylnitrosourea

Topics

• Adenocarcinoma (chemically induced, genetics)
• Adenocarcinoma, Papillary (chemically induced, genetics)
• Animals
• Carcinogens
• Cell Membrane (chemistry)
• Cell Nucleus (chemistry)
• Codon
• Cytoplasm (chemistry)
• Cytoskeletal Proteins (analysis, genetics, physiology)
• DNA Mutational Analysis
• DNA, Neoplasm (genetics)
• Male
• Membrane Proteins (analysis, genetics)
• Methylnitrosourea
• Phosphorylation
• Polymerase Chain Reaction
• Polymorphism, Single-Stranded Conformational
• Rats
• Rats, Inbred F344
• Stomach Neoplasms (chemically induced, genetics)
• Trans-Activators (analysis, genetics, physiology)
• beta Catenin