The nuclear receptor coactivator 5 (NCOA5) was a unique coactivator independent of AF2 that can modulate ERα-mediated transcription. Recent researches have indicated that its downregulation may participate in cancer development and progression. The aims of the present study were to investigate NCOA5 expression in esophageal squamous cell carcinoma (ESCC) and validate its possible influence on patients' prognosis. NCOA5 expression was examined by immunohistochemical staining in 119 ESCC patients' tissues. Ten paired tumor and adjacent normal specimens were examined by Western blot analysis. Statistical analysis was performed to assess its relevance with various clinicopathologic features and its influence on patients' survival. By immunohistochemistry analysis, NCOA5 expression was found to be significantly correlated with differentiation (P = 0.039), T status (P = 0.047) and stage (P = 0.036). Furthermore, we found NCOA5 higher expression in normal tissues than in tumor tissues by Western blot analysis. Univariate analysis showed that poor differentiation (P = 0.035, P = 0.027), lymph node metastasis (P < 0.001, P < 0.001), high T status (P = 0.010, P = 0.012), advanced stage (P < 0.001, P < 0.001) and NCOA5 low expression (P < 0.001, P < 0.001) were significantly correlated with poor prognosis of both disease-free survival (DFS) and overall survival (OS). Multivariate analysis showed that NCOA5 low expression (P = 0.019, P = 0.047), high T status (P = 0.015, P = 0.012), lymph node metastasis (P = 0.040, P = 0.021) and advanced stage (P = 0.017, P = 0.046) were independent prognostic factors of poor DFS and OS. Our findings suggest that NCOA5 low expression is associated with ESCC progression and is a potential biomarker in predicting poor prognosis. Further studies of NCOA5 may help develop new therapeutic strategies against ESCC.

BackgroundSirtuin1 (SIRT1) is an NAD+-dependent type III histone deacetylase (HDAC). This research investigated the prevalence of SIRT1 protein expression and its prognostic influence with the aim of validating its potential role in lymphangiogenesis and lymphovascular invasion (LVI) in pN0 esophageal squamous cell carcinoma (ESCC).MethodsA total of 206 patients were enrolled in this retrospective study. SIRT1 and VEGF-C protein expression was detected by immunohistochemical staining. Peritumoral lymphatic microvessel density (LVD) and LVI were evaluated by immunostaining for D2-40. Statistical analysis was then preformed to investigate the relevance of SIRT1 expression and various clinicopathologic features and to examine the effect of SIRT1 on tumor-induced lymphangiogenesis, LVI and prognosis.ResultsSIRT1 positive expression was identified in 95 cases in the nucleus and was significantly correlated with T status (P < 0.001), disease stage (P = 0.001), VEGF-C positive expression (P = 0.015), high LVD (P = 0.013) and positive LVI (P = 0.015). Patients with SIRT1 positive expression, high LVD and positive LVI had a significantly unfavorable 5-year disease free survival (P < 0.001, P = 0.030, and P < 0.001, respectively) and overall survival (P < 0.001, P = 0.017, and P < 0.001, respectively). However, based on multivariate Cox regression analysis, only SIRT1 positive expression and positive LVI were significant independent prognosticators of poor disease-free survival (P = 0.029 and 0.018, respectively) and overall survival (P = 0.045 and 0.031, respectively).ConclusionsSIRT1 positive expression was significantly associated with tumor progression, lymphangiogenesis, LVI and poor survival in pN0 ESCC patients. Our research shows a utilization of SIRT1 in prognosing poor survival and providing possible target for ESCC patients through inhibiting its lymphangiogenesis activity.