Elevated FUS/TLS expression is negatively associated with E-cadherin expression and prognosis of patients with non-small cell lung cancer.

Abstract

Fused in sarcoma/translocated in liposarcoma (FUS/TLS), a ubiquitous and multifunctional DNA and RNA-binding protein, contributes an important function in cancer and neurodegenerative disease; however, its role in lung cancer remains unclear. In the present study, the expression of FUS/TLS in non-small cell lung cancer (NSCLC) and the significance of FUS/TLS for predicting the clinical outcome of patients with NSCLC, was examined. FUS/TLS expression was investigated in NSCLC tissues and their matched adjacent non-tumorous tissues by reverse transcription-quantitative polymerase chain reaction, western blotting, and immunohistochemistry. Tissue microarrays representing 208 patients with NSCLC were used to determine the expression pattern and associations with FUS/TLS using immunohistochemistry. Prognostic significance was assessed by Kaplan-Meier survival estimates and log-rank tests. Data revealed that FUS/TLS expression was elevated in NSCLC tissues compared with corresponding normal tissue mRNA (9.27±0.73 vs. 6.15±0.60) and protein (3.32±0.75 vs. 0.30±0.07) levels. In tissue microarrays, FUS/TLS was highly expressed in 103 (49.5%, 103/208) NSCLC tissues compared with adjacent normal lung tissues (28.4%, 59/208). Overexpression of FUS/TLS was associated with higher tumor node metastasis stage (P=0.016), poorer differentiation (P=0.008), large tumor size (P=0.019) and predicted poor prognosis (P=0.005) in patients with NSCLC. Notably, correlation analysis revealed a significant inverse association between the expression of FUS/TLS and E-cadherin (r2=0.51; P=0.036). Furthermore, patients with NSCLC with high FUS/TLS and impaired E-cadherin expression had a notably poor prognosis (P=4.01×10-4). Thus, the results from the present study indicate that elevated FUS/TLS expression promotes NSCLC progression. FUS/TLS, alone or in combination with E-cadherin, is a novel prognostic predictor for patients with NSCLC.