Activation of mTOR in a subgroup of ovarian carcinomas: Correlation with p-eIF-4E and prognosis

作者:Noske Aurelia*; Lindenberg Juliane Lena; Darb Esfahani Silvia; Weichert Wilko; Buckendahl Ann Christin; Roeske Annika; Sehoui Jalid; Dietel Manfred; Denkert Carsten
来源:Oncology Reports, 2008, 20(6): 1409-1417.
DOI:10.3892/or_00000160

摘要

Ovarian carcinoma patients have an extremely poor prognosis; therefore, new molecular therapeutic approaches are urgently needed. The mTOR pathway, which may be targeted by substances such as Rapamycin or RAD001, is emerging as a promising target for anticancer therapy. So far, the expression and prognostic impact of mTOR signalling elements have not been completely studied in ovarian tumors. We analyzed p-mTOR, p-4E-BPI and p-elF-4E in 107 human ovarian lesions and observed an overexpression of p-mTOR (47%) and p-elF-4E (56%) protein in primary ovarian carcinomas as compared to borderline tumors. Phospho-mTOR expression was significantly related to p-eIF-4E (p <= 0.001) and serous histological type (p=0.03). Increased p-4E-BPI (31%) was associated with poor differentiation (p=0.04) and higher mitotic rate (p=0.004). In univariate analysis, increased expression of p-mTOR and p-eIF-4E was significantly associated with better overall Survival (p=0.003, p=0.029). To connect the expression data with mechanistic studies, a set of 10 ovarian cancer cell lines was used. Expression of p-mTOR was increased in all cancer cell lines as compared to ovarian surface epithelial (HOSE) cells. Rapamycin treatment revealed a reduction of p-mTOR and p-4E-BPI but increased p-AKT levels. We show for the first time an association of p-mTOR and p-eIF-4E with better overall survival for ovarian cancer patients. The combined results of our in vivo and cell culture studies suggest that a subpopulation of these patients may benefit from mTOR inhibition. The design of future clinical trials should incorporate biomarker testing to determine predictive markers for response to mTOR inhibitors.

  • 出版日期2008-12