Melanoma antigen genes 1 and 2 are differentially expressed in human gastric and cardial carcinomas

Background: MAGE genes encode for tumor-rejection antigens and are expresse d in tumors of different histologic types but not in normal tissues, with t he exception of testis and placenta. The aim of this study was to evaluate the frequency of MAGE-1 and -2 expression in gastric and in cardial carcino mas; these conditions have been described as two distinct diseases, having different etiologies, epidemiologic patterns, and gene mutations, Methods: Two groups of patients were studied: patients with distal gastric carcinoma and patients with carcinoma of the cardia. A group of patients with intest inal metaplasia in the gastric mucosa and controls were also included. All of them underwent upper GI endoscopy. Paired biopsy specimens were taken fo r routine histology and for RNA extraction, to study the expression of MAGE -1 and -2 genes. Results: None of the intestinal metaplastic samples or con trols expressed MAGE-1 and -2 at detectable levels. Whereas 40% of the gast ric cancer patients expressed either MAGE-1 or -2, 26.6% transcribed both. In the cardial cancer soup, 20% of the cases expressed at least one MAGE, a nd only 6.6% expressed both genes. These results might reinforce the concep t that cancer of the cardia is a distinct neoplastic disease with regard to esophageal and gastric (distal) carcinomas. Conclusions: Here we show that MAGE gene expression occurs in advanced stages of gastric and cardial canc er and therefore appears to be a late event. This might point to a reconsid eration of their potential role in cancer immunotherapy.