Downregulation of ARID1A is correlated with poor prognosis in non-small cell lung cancer

Background: Non-small cell lung cancer (NSCLC) is the main type of lung cancer and NSCLC patients always have a low 5-year survival rate. It is vital to identify a biomarker for the prognosis of NSCLC patients. AT-rich interaction domain la (ARID1A) is a tumor suppressor that is involved in the progression of a variety of tumors. Methods: The ARID1A protein level in NSCLC tissues and paracancerous normal lung (PCNL) tissues were detected with immunohistochemistry (INC) and western blotting (WE). The chi(2) test and Spearman's rank correlation analysis were carried out to examine the association between ARID1A expression and the clinicopathological features of NSCLC. The Kaplan-Meier method and log-rank test were used to compare overall survival (OS) in the ARID1A low expression group and the ARID1A high expression group. Results: The results of WB and IHC demonstrated that the ARID1A protein level was significantly reduced in NSCLC tissues compared with PCNL tissues (P<0.05). The low expression of ARID1A in NSCLC tissues was significantly associated with poor differentiation (P=0.005), smoking (P<0.001), lymphatic invasion (P=0.013), distant metastasis (P=0.010), and high TNM stage (P=0.001). The overall five-year survival rate of NSCLC patients was lower in the ARID1A low expression group than in the ARID1A high expression group. Multivariate analysis showed that the expression of ARID1A had an independent prognostic impact on OS (P=0.024). Conclusions: ARID1A may be a novel biomarker for predicting the prognosis of NSCLC patients.