Mutational analysis of the beta-catenin gene in gastric carcinomas

Previous studies reported that mutation of the adenomatous polyposis coli ( APC) gene was not observed in the majority of gastric cancers. To evaluate the role of the APC/beta -catenin/Tcf pathway, we analyzed mutations in the beta -catenin gene and the accumulation of beta -catenin protein in gastri c carcinomas. An interstitial deletion spanning exon 3 of the beta -catenin gene was observed in 1 of 13 gastric cancer cell lines. No missense mutati on was found in these 13 cell lines. Nuclear and/or cytoplasmic localizatio n of beta -catenin was observed in 16 of 70 primary gastric carcinomas by i mmunohistochemistry, while we found no mutations in exon 3 in 35 carcinoma tissues available for PCR amplification. Our findings suggest that somatic mutations of the beta -catenin gene are rare in human gastric carcinomas an d that accumulation of normal beta -catenin protein in a subset of gastric cancers may be due to other mechanisms of its activation. Copyright (C) 200 1 S. Karger AG, Basel.