PEG3 is differentially expressed in high-grade serous ovarian cancers.
Ovarian cancer is the most lethal gynecologic cancer (1-3). We sought to identify genes associated with high-grade serous ovarian cancer (HGSC) by comparing global gene expression profiles of normal ovary with that of primary tumors from women diagnosed with HGSC using published microarray data (4, 5). We identified paternally expressed gene 3 (PEG3) (6) as among the genes whose expression was most different in HGSC ovarian tumors. PEG3 expression was significantly lower in ovarian tumors relative to normal ovary. In one dataset, an anti-sense transcript produced at the PEG3 locus was among those most differentially expressed between HGSC tumors and benign ovarial tissue. These data indicate that significant changes in expression at the PEG3 imprinted locus could be a feature of high-grade serous ovarian cancers.