Elevated expression of Cripto-1 correlates with poor prognosis in non-small cell lung cancer

Human Cripto-1 (CR-1) plays an important oncogenic role during tumorigenesis and is overexpressed in a wide range of carcinomas, yet little is known about CR-1 in non-small cell lung cancer (NSCLC). The aims of this study were to detect CR-1 expression in NSCLC and to analyze its association with prognosis of NSCLC patients. The expression of CR-1 messenger RNA (mRNA) and protein in 35 cases of NSCLC and corresponding noncancerous tissue samples was examined by quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR) and Western blotting. Immunohistochemistry was performed to detect the expression of CR-1 in 128 NSCLC tissues. The expression levels of CR-1 mRNA and protein in NSCLC tissues were significantly higher than those in corresponding noncancerous tissues (P < 0.001). A high level of CR-1 expression was correlated with poor tumor differentiation (P = 0.002), tumor-node-metastasis (TNM) stage (P = 0.004), and lymph node metastasis (P = 0.001). The results of the Kaplan-Meier analysis indicated that a high expression level of CR-1 resulted in a significantly poor prognosis of NSCLC patients. Multivariate Cox regression analysis revealed that CR-1 expression level was an independent prognostic parameter for the overall survival rate of NSCLC patients. Our data suggest that the high expression of CR-1 may play an important role in the progression of NSCLC, and CR-1 expression may offer a valuable marker for predicting the outcome of patients with NSCLC.