Abstract
Nuclear receptor coactivator 5 (NCOA5) specifically enhances estrogen receptor α-modulated transcriptional activity. As a novel tumor suppressor, depletion of NCOA5 is associated with the development of a variety of tumors, but its function in cervical cancer is currently unclear. In this study, we addressed how expression of NCOA5 changed in the development of human cervical cancer and its association with clinicopathological features, prognosis, and biology characteristics of cervical cancer. Analysis of the microarrays in the Oncomine database indicated that NCOA5 expression was lower in human cervical squamous cell carcinoma tissues than that in normal cervical tissues. That was corroborated by our experiments using fresh tissues: the expression levels of NCOA5 messenger RNA and protein were both significantly decreased in cervical cancer tissues compared with paired adjacent nontumor tissues (P < 0.01). Low expression of NCOA5 is associated with the International Federation of Gynecology and Obstetrics stage ( P = 0.043) and histological grade ( P = 0.018) of human cervical cancer. In addition, patients possessing low NCOA5 expression had poorer prognosis. Univariate and multivariate Cox regression analyses indicated that low NCOA5 expression may be an independent prognostic factor for poorer overall survival in cervical cancer. Further, downregulation of NCOA5 expression results in a significant increase in proliferation, migration, and invasion of HeLa cells. Data of xenograft tumor on BALB/c nude mice manifested that HeLa cells with low NCOA5 expression tend to form larger tumors than negative control ones. In contrast, overexpression of NCOA5 expression leads to the opposite results. Finally, we found that NCOA5 might affect the biological function of human cervical cancer cells by mediating the notch3 signaling pathway. These findings suggest that NCOA5 acts as a tumor suppressor to inhibit tumorigenicity, migration, and invasion, and thus represents a potential novel prognostic marker for overall survival in cervical cancer.