1. ¹Department of Obstetrics and Gynecology, Helsinki University Central Hospital, Helsinki, Finland
2. ²Department of Pathology, University of Helsinki, Helsinki, Finland
3. ³Children's Hospital, Helsinki University Central Hospital, Helsinki, Finland
4. ⁴Department of Pediatrics, Washington University, St. Louis, Missouri, Finland
5. ⁵Department of Medical Genetics, University of Helsinki, Helsinki, Finland
6. ⁶Department of Bacteriology and Immunology, University of Helsinki, Haartman Institute, Helsinki, Finland

Correspondence: Dr. Ralf Butzow, Department of Pathology, University of Helsinki, P.O. Box 21, FIN-00014 Helsinki, Finland. E-mail: ralf.butzow@hus.fi

Received 29 November 2000.

Abstract

Using comparative genomic hybridization (CGH), we have previously demonstrated frequent loss of 8p, especially its distal part, in ovarian carcinoma. To compare the deletion map of distal 8p in serous and mucinous ovarian carcinomas, we performed allelic analysis with 18 polymorphic microsatellite markers at 8p21–p23. In serous carcinoma, loss of heterozygosity (LOH) was detected in 67% of the samples, and the majority of the carcinomas showed loss of all or most of the informative markers. In contrast, only 21% of mucinous carcinomas showed allelic loss, with only one or two loci showing LOH in each sample. In serous carcinomas, LOH was associated with higher grade tumors. Three distinct minimal common regions of loss could be defined in serous carcinomas (at 8p21.1, 8p22–p23.1, and 8p23.1). Expression of a transcription factor gene, GATA4, located at one of these regions (8p23.1) was studied in serous and mucinous ovarian carcinomas by Northern blotting and immunohistochemical staining of tumor microarray. Expression was found to be lost in most serous carcinomas but retained in the majority of mucinous carcinomas. Our results suggest distinct pathogenetic pathways in serous and mucinous ovarian carcinomas and the presence of more than one tumor suppressor gene at 8p involved in the tumorigenesis of serous carcinoma.