| Abstract: | BACKGROUND: In a previous microarray expression analysis, the authors identified candidate genes that were expressed differentially between ovarian tumors with low malignant potential and invasive serous epithelial ovarian tumors. Among them, the apoptosis-related candidate genes tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), caspase 8 (CASP8), FLICE-inhibitory protein (FLIP), and cytochrome C (CYC) were identified. METHODS: For the current study, the authors conducted immunohistochemical analyses of a tissue array comprised of 235 serous tumors of different grades and stages to evaluate whether there was differential protein expression for these candidates and for the 4 death cell receptors of Trail: Dr4, Dr5, DcR1, and DcR2. RESULTS: All proteins except DcR1 and DcR2 had significantly differential expression levels between grade 0 tumors (low malignant potential) and grade 2 and 3 tumors. Trail also showed differential expression between grade 0 tumors and grade 1 tumors. When all tumors were compared, the expression levels of Trail, Dr4, Dr5, DcR1, and Flip differed significantly between early-stage and advanced-stage disease. High Dr5 expression was associated with a poor prognosis in patients who had invasive tumors and in the subgroup of patients who had grade 3 tumors. Furthermore, the combinations of 2 proteins (Trail and Dr5, DcR2 and Cyc, Flip and Dr5, Flip and DcR2, DcR1 and Dr5 or Dr4 and Flip) revealed an association with patient prognosis. CONCLUSIONS: The identification of new proteins in the initial diagnosis and prognosis of patients with epithelial ovarian cancer may lead to a better understanding of the disease, highlighting new potential therapeutic targets, and may be useful in patient management. |
