Abstract:
Objective : To investigate the expression of pERK and MMP-9 in non-small cell lung cancer (NSCLC) andits clinical significance.
Methods : The expression of pERK and MMP-9 protein was assessed with immunohistochemistry in lung tissues from 160 patients with NSCLC collected from October 1999 to December 2002and 20 samples of normal lung tissue. We analyzed the correlation of the expression of pERK and MMP-9 inNSCLC with clinicopathologic parameters.
Results : Normal bronchial and alveolar epithelium were negativefor pERK expression. The expression rate of pERK in NSCLC samples was 61.3%, significantly higher thanthat in normal lung tissues (
P<0.05). The expression of pERK was higher in poorly differentiated NSCLC tissues (74.3%) than in well-differentiated (49.1%) and moderately differentiated (54.3%) tumor tissues (
P=0.039 and
P=0.004). The expression of pERK was much higher in patients with lymph node metastasis(80.6%:45.5%) (
P=0.000). The expression of pERK was also higher in stage Ⅲ and Ⅳ than in stage Ⅰ andⅡ (76.8%:49.5%) (
P=0.000). The overall 1-, 3-, and 5-year survival rates of patients with pERK expression(74.5%, 42.9%, and 19.4%, respectively) were lower than those without pERK expression (82.3%, 56.5%,and 37.1%, respectively) (
P=0.002). The expression rates of MMP-9 in normal bronchial and alveolar epithelium in NSCLC samples were 15% and 65.0%, respectively (
P<0.05). The expression of MMP-9 was higher inpoorly differentiated NSCLC tissues (80.0%) than in well-differentiated and moderately differentiated NSCLCtissues (54.5% and 51.4%, respectively) (
P=0.002 and
P=0.002). The expression of MMP-9 was much higherin patients with lymph node metastasis (80.6%:52.3%) (
P=0.000). The expression of MMP-9 was also higherin stage III and IV tissues than in stage I and II tissues (79.7% :53.8%) (
P=0.001). The overall 1-, 3-, and5-year survival rates in patients with MMP-9 expression (72.1%, 37.5%, and 18.3%) were lower than in patients without MMP-9 expression (87.5%, 67.9%, and 41.1%) (
P=0.002). There was a positive correlation between pERK expression and MMP-9 expression, with a Pearson correlation value of 0.438.
Conclusion : Compared with normal lung tissues, tissues from NSCLC show an upregulation of pERK and MMP-9, and the expression of these 2 genes enhances tumor progression. Overexpression of pERK and MMP-9 is significantlycorrelated with poor prognosis in patients with NSCLC.