Overexpression of astrocyte-elevated gene-1 is associated with ovarian cancer development and progression.

It has previously been reported that astrocyte-elevated gene-1 (AEG-1) has a critical role in the regulation of tumor development, and/or progression. However, the functional significance of AEG-1 in human ovarian cancer remains unclear. The present study conducted an immunohistochemical analysis of ovarian tissues, and the association between AEG-1 protein expression, clinicopathological features and outcomes were investigated. The gain or loss of AEG-1 function was also examined, through exogenous overexpression or knockdown of expression by small interfering RNA, in ovarian cancer cells. Normal ovarian tissue exhibited very little or no AEG-1 immunoreactivity, whereas high expression levels of AEG-1 were detected in 12.7% of cystadenomas, 30.0% of borderline tumors, and 71.2% of ovarian carcinomas, respectively, as determined by immunohistochemistry. Statistical analyses demonstrated a significant correlation of AEG-1 expression with differentiation (P=0.001), lymph node metastasis (P=0.008) and clinical staging (P=0.002). In addition, the overall survival time of patients with higher AEG-1 expression levels was markedly shorter, as compared with patients with lower expression levels of AEG-1 (P=0.001). Multivariate analysis indicated that AEG-1 expression was an independent prognostic indicator of the survival of patients with ovarian cancer. Furthermore, exogenous overexpression of AEG-1 in ovarian cancer cells was shown to significantly enhance cell proliferation, adhesion and invasion. Conversely, silencing AEG-1 expression caused an inhibition of cell growth, adhesion and invasion. The results of the present study indicate that AEG-1 is a valuable biomarker for the prediction of ovarian cancer prognosis, and AEG-1 inhibition may be a potential therapeutic strategy for ovarian cancer treatment.