Overexpression of Nucleolin is a Potential Prognostic Marker in Endometrial Carcinoma

PURPOSE: Nucleolin (NCL) is a multifunctional protein with oncogenic properties. NCL expression levels have been linked to the outcomes of various malignancies, but the clinical value of NCL in patients with endometrial carcinoma (EC) remains unclear. Here, the expression of NCL in EC tissues and its associations with patient outcomes were assessed. PATIENTS AND METHODS: Data on NCL mRNA expression in EC and adjacent nonneoplastic tissues from The Cancer Genome Atlas (TCGA) were analyzed. In addition, NCL protein expression in 82 endometroid endometrial adenocarcinoma tissues and 15 non-malignant tissues was detected by immunohistochemistry. RESULTS: Elevated NCL expression was markedly correlated with serous endometrial carcinoma (P<0.001), advanced stage (P=0.029), and grade 3 (P<0.001). High NCL levels were associated with poorer overall survival (OS) and disease-free survival (DFS) compared with intermediate or low NCL levels (OS: P=0.001, DFS: P=0.006). The multivariate Cox proportional hazards model showed that NCL expression was an independent poor prognostic factor for DFS (HR=1.282, CI=1.027–1.601, P=0.028). A similar correlation between high expression levels of NCL and unfavorable DFS was found in endometrioid endometrial adenocarcinoma (HR=1.411, CI=1.083–1.840, P=0.011). Positive extra-nuclear NCL expression (HR=3.377, 95% CI=1.029–11.186, P=0.046) and low nuclear NCL expression (HR=0.233, 95% CI=0.068–0.796, P=0.020) were independent prognostic factors for DFS in endometrioid endometrial adenocarcinoma. CONCLUSION: Heterotopic NCL is a potential prognostic biomarker for EC. Inhibiting the distribution of NCL from the nucleus to the cytoplasm and membrane may be a promising therapeutic strategy to improve outcomes in patients with EC with high NCL expression.