Expressions and clinical significances of TRAIL and its receptors in non-small cell lung cancer

Abstract

Objective To investigation the expressions of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and its receptors in non-small cell lung cancer (NSCLC) and their clinical significances. Methods The serum expression levels of TRAIL in 79 cases of NSCLC and 80 cases of normal subjects were detected by enzyme-linked immunosorbent assay (ELISA). The expressions of TRAIL-R2 and TRAIL-R4 in 42 cases of NSCLC and matched normal tissues were detected by immunohistochemistry. The relationships among TRAIL, TRAIL-R2, TRAIL-R4 and clinicopathologic features of NSCLC were analyzed. Results The expression of TRAIL in NSCLC patients was lower than that in normal human [(994.3±293.0)ng/ml vs. (1 141.7±266.1)ng/ml, t=3.29, P=0.00]. The expression of TRAIL was closely correlated with clinical stage (F=2.28, P=0.00) and differentiated degree(t=5.76, P=0.00). The positive expression rate of TRAIL-R2 in NSCLC was 73.8% (31/42), significantly lower than that in the normal tissue 100.0% (42/42) (χ2=3.88, P=0.05). The expression of TRAIL-R2 was closely correlated with clinical stage (χ2=27.89, P=0.00) and differentiated degree (χ2=9.50, P=0.00). The positive expression rate of TRAIL-R4 in NSCLC was 81.0% (34/42), significantly higher than that in the normal tissue 50.0% (21/42) (χ2=7.34, P=0.01). The expression of TRAIL-R4 was also closely correlated with clinical stage (χ2=17.82, P=0.00) and differentiated degree (χ2=4.47, P=0.03). There was a negative correlation between the expression of TRAIL-R2 and TRAIL-R4 in NSCLC (r=-0.67, P=0.01). Conclusion The decrease of TRAIL and TRAIL-R2 and increase of TRAIL-R4 expression may promote the occurrence and development of NSCLC, and they may provide targets for clinical treatment of NSCLC. Key words: Carcinoma, non-small-cell lung; TNF-related apoptosis-inducing ligand; Receptors, TNF-related apoptosis-inducing ligand