title: Bilateral ovarian carcinomas differ in the expression of metastasis-related genes.
abstract: The mechanisms behind bilaterality of ovarian carcinomas are not fully understood, as the two tumors could possibly represent two primary tumors, a primary tumor and a metastasis, or two metastases. The gene expression profiles from bilateral high-grade serous carcinomas (HGSCs) and clear cell carcinomas (CCCs) of the ovary were compared to study the association between the tumors of the two sides. A separate analysis of genes from chromosome 19 was also performed, since this chromosome is frequently rearranged in ovarian carcinomas. Tumors from four patients were included (three pairs of HGSC and one pair of CCC). The gene expression was analyzed at the exon level, and bilateral tumors were compared to identify within-pair differences. Gene expression data were also compared with genomic information on the same tumors. Similarities in gene expression were observed between the tumors within each pair, as expected if the two tumors were clonally related. However, certain genes exhibited differences in expression between the two sides, indicating metastasis involvement. Among the most differently expressed genes, one gene was common to all four pairs:Immunoglobulin J. In all HGSC pairs,serpin peptidase inhibitor, clade B (ovalbumin), member 2, serpin family E member 1andphospholipase A2, group IIA (platelets, synovial fluid) were also among the differentially expressed genes. The specific analysis of chromosome 19 highlighted expression differences in thezinc finger protein36 gene. These results indicate that bilateral ovarian tumors represent different stages during progression of a single clonal process. Several of the genes observed to be differently expressed are known to be metastasis-related, and are likely to be also involved in spreading from one side to the other in the bilateral cancer cases examined.
authors.affiliation: Section for Cancer Cytogenetics, Institute for Cancer Genetics and Informatics, The Norwegian Radium Hospital, Oslo University Hospital, NO-0424 Oslo, Norway; Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, NO-0316 Oslo, Norway.
authors.forename: Marianne Lislerud
authors.initials: ML
authors.lastname: Smebye
authors.affiliation: Section for Cancer Cytogenetics, Institute for Cancer Genetics and Informatics, The Norwegian Radium Hospital, Oslo University Hospital, NO-0424 Oslo, Norway; Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, NO-0316 Oslo, Norway.
authors.forename: Lisbeth
authors.initials: L
authors.lastname: Haugom
authors.affiliation: Department of Pathology, The Norwegian Radium Hospital, Oslo University Hospital, NO-0424 Oslo, Norway; Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, NO-0316 Oslo, Norway.
authors.forename: Ben
authors.initials: B
authors.lastname: Davidson
authors.affiliation: Department of Gynecology, The Norwegian Radium Hospital, Oslo University Hospital, NO-0424 Oslo, Norway.
authors.forename: Claes Göran
authors.initials: CG
authors.lastname: Trope
authors.affiliation: Section for Cancer Cytogenetics, Institute for Cancer Genetics and Informatics, The Norwegian Radium Hospital, Oslo University Hospital, NO-0424 Oslo, Norway; Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, NO-0316 Oslo, Norway; Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, NO-0316 Oslo, Norway.
authors.forename: Sverre
authors.initials: S
authors.lastname: Heim
authors.affiliation: Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, NO-0316 Oslo, Norway; Department of Molecular Oncology, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, NO-0424 Oslo, Norway.
authors.forename: Rolf Inge
authors.initials: RI
authors.lastname: Skotheim
authors.affiliation: Section for Cancer Cytogenetics, Institute for Cancer Genetics and Informatics, The Norwegian Radium Hospital, Oslo University Hospital, NO-0424 Oslo, Norway; Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, NO-0316 Oslo, Norway.
authors.forename: Francesca
authors.initials: F
authors.lastname: Micci
keywords: bilateral; gene expression; metastasis; ovarian carcinoma