Expression and amplification of the HER-2/neu (c-erbB-2) protooncogene in epithelial ovarian tumors and cell lines.

Abstract

Amplification of the c-erbB-2 protooncogene has been associated with a poor prognosis in human breast and ovarian cancers. Our study was undertaken to examine whether amplification, rearrangement, or overexpression of c-erbB-2 and other protooncogenes was frequently observed in epithelial ovarian cancers. c-erbB-2 was expressed in 87% of 22 ovarian cancers analyzed, but expression was significantly increased in only one of the 22 tumor specimens. In this case elevated c-erbB-2 expression was associated with dramatic amplification of the gene. In another tumor a 3.8 kb EcoRI fragment was found, in addition to the usual 4.4 and 6.0 kb fragments; this is consistent with a possible gene rearrangement or a restriction fragment length polymorphism. To place these results in perspective, expression of several other protooncogenes has been examined in ovarian carcinomas. The c-fos, c-myc, n-myc, c-fms, and c-Ha-ras protooncogenes were expressed in different fractions of tumors, but expression of l-myc, c-erbB, c-myb, c-sis, and c-mos was not detectable. Aside from c-erbB-2, neither amplification nor rearrangement was observed among the other protooncogenes studied. Expression of c-erbB-2, c-fms, c-myc, n-myc, c-fos, and c-Ha-ras deserves further evaluation as a prognostic factor in ovarian cancer.