Objective: To study the relationship between expression of caveolin-1 (Cav-1) and pERK1/2 and prognosis in non-small cell lung cancer (NSCLC).
Methods: Cav-1 and pERK1/2 protein expression was assessed by immunohistochemistry in samples obtained from 160 patients with NSCLC and 20 patients with normal lung tissue.
Results: Normal bronchial and alveolar epithelial cells were positive for Cav-1 (membranous and cytoplasmic staining patterns). The expression rate of Cav-1 in NSCLC was 65.6% (105/160), which was significantly lower than that in normal lung tissue (P = 0.002). The Cav-1-positive rates in well to moderately differentiated tumors and poorly differentiated tumors were 56.8% (46/81) and 75.7% (53/70), respectively (P = 0.015). The expression of Cav-1 was much higher in patients with lymph node metastasis (77.8%, compared with 55.7% in lymph node-negative group, P = 0.003). The expression was also higher in stage III to IV than in stage I to II disease (75.4%, compared with 58.2%, P = 0.024). The overall survival of patients with Cav-1-positive tumors (71.4%, 37.1% and 17.1% 1-, 3- and 5-year survival, respectively) was lower than those with Cav-1-negative tumors (89.1%, 69.1% and 43.6% 1-, 3- and 5-year survival, respectively, P = 0.000). On the other hand, normal bronchial and alveolar epithelial cells were negative for pERK1/2. The expression rate of pERK1/2 in NSCLC was 61.3%, which was significantly higher than that in normal lung tissues (P = 0.000). The pERK1/2-positive rates in well to moderately differentiated tumors and poorly differentiated tumors was 53.1% and 71.4%, respectively (P = 0.021). The expression of pERK1/2 was much higher in patients with lymph node metastasis (80.6%, compared with 45.5% in lymph node-negative group, P = 0.000). The expression of pERK1/2 was also higher in stage III to IV than in stage I to II disease (76.8%, compared with 49.5%, P = 0.426). The overall survival of patients with pERK1/2-positive tumors (74.5%, 42.9% and 19.4% 1-, 3- and 5-year survival, respectively) was lower than those with pERK1/2-negative tumors (82.3%, 56.5% and 37.1% 1-, 3- and 5-year survival, respectively, P = 0.002). Cav-1 and pERK1/2 expression showed negative correlation (P = 0.000).
Conclusions: Cav-1 expression is lower in NSCLC than in normal lung tissue, whereas pERK1/2 expression is higher in NSCLC. Positive expression of Cav-1 and overexpression of pERK1/2 correlates with tumorigenesis and tumor progression of NSCLC. Cav-1 and pERK1/2 may serve as potential markers for predicting prognosis in NSCLC.