Amplified genes in cancer in upper digestive tract.

Gene amplification in stomach and oesophageal cancers was reviewed. In stomach cancers, two receptor type tyrosine kinases, c-erbB-2 and K-sam, are frequently amplified and overexpressed. c-erbB-2 seems to be preferentially amplified in well-differentiated, and K-sam in poorly-differentiated, gastric adenocarcinomas. 11q13 genes are amplified in about 50% of the oesophageal cancers. These genes include hst-1, int-2 and cyclin D/prad1, all of which are mapped to chromosome 11 at band q13. Although hst-1 and int-2 are usually not expressed despite amplification, elevated transcription of the cyclin D gene is accompanied by its amplification, suggesting a role of a G1 cyclin in oesophageal carcinogenesis.