SIRT1 expression is associated with poor prognosis of lung adenocarcinoma.

Several studies have reported that the overexpression of Sirtuin 1 (SIRT1) was associated with poor prognosis in various human cancers. However, little is known regarding the prognostic value of SIRT1 in lung adenocarcinoma. Therefore, the aim of this study is to evaluate the role of SIRT1 in the prognosis of lung adenocarcinoma patients. Using a tissue microarray, we detected SIRT1 expression by immunohistochemistry in lung adenocarcinoma tissue, as well as in corresponding noncancerous tissues (NCTs). A high expression level of SIRT1 was observed in 74.7% (56/75) of patients with lung adenocarcinoma and 6.7% (5/75) of NCTs (P<0.001). SIRT1 expression was significantly associated with high pathological stage. Importantly, we found that SIRT1 expression was associated with worse overall survival in these lung adenocarcinoma patients (67.0 months vs 104.5 months; P=0.005). In addition, anaplastic lymphoma kinase, epidermal growth factor receptor, vascular endothelial growth factor (VEGF), and Survivin expression were evaluated by fluorescent in situ hybridization or immunohistochemistry, respectively. We found that VEGF and Survivin were both highly expressed in the lung adenocarcinoma tissues, as compared to NCTs. Moreover, the SIRT1 and VEGF expression statuses were significantly positively correlated (r=0.238, P=0.039), while SIRT1 and Survivin expression status were not significantly correlated (r=0.220, P=0.058). Correlation analysis showed a positive correlation between VEGF and Survivin expression (r=0.436, P<0.001). However, we found that VEGF and Survivin expression were not associated with the prognosis of lung adenocarcinoma patients (P=0.334; P=0.433, respectively). Taken together, our findings suggest that SIRT1 plays a role in the progression of lung adenocarcinoma and may be a significant prognostic indicator for lung adenocarcinoma patients.