AMPLIFICATION OF THE C-ERBB-2 GENE DETECTED BY FISH IN GASTRIC CANCERS

The amplification and overexpression of the c-erbB-2 gene are consider ed to be implicated in the process of carcinogenesis of a variety of h uman tumors. The amplification and overexpression of c-erbB-2 were inv estigated in 48 surgically resected human gastric cancers by means of fluorescence in situ hybridization and immunohistochemistry. DNA ploid y was determined by flow cytometry. The c-erbB-2 amplification was dem onstrated as a cluster of signals, suggesting homogeneously staining r egion (HSR), in three tumors (6.3%) accompanied by the overexpression of its protein. Such overexpression was detected in another tumor with out amplification of the c-erbB-2 gene. All tumors with amplification and overexpression of c-erbB-2 were differentiated adenocarcinoma hist ologically, but only 10.3 and 13.8% of differentiated carcinomas showe d amplification and overexpression of the c-erbB-2 gene, respectively. There was no relationship between the amplification and overexpressio n of c-erbB-2 and the depth of tumor invasion and lymph node involveme nt. Three of four cases with overexpression of cerbB-2 were classified into DNA aneuploid tumor.