Differential expression of RAS-like estrogen regulated growth inhibitor in human epithelial ovarian cancer.
Epithelial ovarian cancer (EOC) is the most lethal gynecologic cancer (1). We performed discovery of genes associated with epithelial ovarian cancer and of the high-grade serous ovarian cancer (HGSC) subtype, using published and public microarray data (2, 3) to compare global gene expression profiles of normal ovary or fallopian tube with that of primary tumors from women diagnosed with epithelial ovarian cancer or HGSC. We identified the gene encoding RAS-like estrogen regulated growth inhibitor, RERG, as among the genes whose expression was most different in epithelial ovarian cancer as compared to the normal fallopian tube. RERG expression was significantly lower in high-grade serous ovarian tumors relative to normal fallopian tube. In a separate dataset, we discovered significant differential expression of a non-coding RNA transcribed from the RERG locus, RERG-AS1, in the tumors of patients with epithelial ovarian cancer when comparing tumors based on disease progression. RERG expression correlated with progression-free survival in patients with ovarian cancer. These data indicate that expression of RERG is perturbed in epithelial ovarian cancers broadly and in ovarian cancers of the HGSC subtype. RERG may be relevant to pathways underlying ovarian cancer initiation (transformation) or progression.