Isolation of the Epstein-Barr virus in scirrhous gastric cancer by efficiency-monitored representational difference analysis

We applied an improved representational difference analysis (RDA), efficien cy-monitored RDA (EM-RDA), to analyze the genetic alterations of scirrhous gastric cancer. Clinical samples of this cancer are difficult to analyze ge netically because of the large number of normal cells in the stroma, The en tire 3rd difference product obtained from EM-RDA was subcloned. This is equ ivalent to the scirrhous gastric cancer DNA with the normal gastric tissue DNA subtracted from it. The difference clones, which were confirmed by Sout hern blot as being derived from the cancer, were sequenced. As a result, tw o difference clones were identified as DNA fragments of the Epstein-Barr vi rus (EBV). The existence of EBV in the scirrhous gastric cancer cells was p roved by EBV-encoded small RNA 1 in situ hybridization, EM-RDA made it poss ible to detect the first case of EBV-related gastric cancer in a young woma n. Copyright (C) 2000 S. Karger AG, Basel.