Over-expression ofbcl-xL gene in human gastric adenomas and carcinomas

Abstract

The present study was designed to clarify whether bel‐xL is involved in the development of carcinoma in the stomach. Levels of bel‐x_L and bc1‐2 mRNA were determined by a reverse‐transcription/polymerase‐chain reaction in endoscopic gastric biopsy specimens from 10 control subjects, 11 patients with adenomas and 14 patients with carcinomas. In 6 of 11 adenomas, 5 of 8 early carcinomas and 3 of 6 advanced carcinomas, the bel‐x_L gene was over‐expressed. In carcinomas, overexpression of the bel‐x_L gene was observed in 6 of 9 intestinaltype carcinomas and 2 of 5 diffuse‐type carcinomas. No correlation was observed between bel‐x_L and bc1‐2 gene expression. In cases in which the bel‐x_L gene was over‐expressed, an apparent increase in the protein level of Bcl‐x_L was observed by immunoblot analysis and intense Bcl‐x immunoreactivity was detected immunohistochemically within the tumor cells. In conclusion, we showed that bel‐x_L is over‐expressed in gastric carcinomas at both the RNA and protein levels, suggesting that overexpression of bel‐x_L may play a role in gastric carcinogenesis. © 1996 Wiley‐Liss, Inc.