Comparative hybridization of an array of 21 500 ovarian cDNAs for the discovery of genes overexpressed in ovarian carcinomas

Comparative hybridization of cDNA arrays is a powerful tool for the measure ment of differences in gene expression between two or more tissues. We opti mized this technique and employed it to discover genes with potential for t he diagnosis of ovarian cancer. This cancer is rarely identified in time fo r a good prognosis after diagnosis. An array of 21 500 unknown ovarian cDNA s was hybridized with labeled first-strand cDNA from 10 ovarian tumors and six normal tissues. One hundred and thirty-four clones are overexpressed in at least five of the 10 tumors. These cDNAs were sequenced and compared to public sequence databases. One of these, the gene HE4, was found to be exp ressed primarily in some ovarian cancers, and is thus a potential marker of ovarian carcinoma. (C) 1999 Elsevier Science B.V. All rights reserved.