Expression and significance of vascular endothelial cadherin in non-small cell lung cancer

Abstract:

Objective：To investigate the expression of vascular endothelial cadherin（VE-cadherin） in non-small cell lung cancer（NSCLC） and its association with the clinicopathological characteristics and vascular endothelial grow factor（VEGF）. Methods：Expression of VE-cadherin was examined at protein level by immunohistochemical staining in 72 cases of NSCLC tissues and their adjacent non-neoplastic tissues；34 of which were measured at mRNA level by qRT-PCR and VEGF was taken as positive reference. Expression of VE-cadherin in lung cancer cell line A549 and normal human bronchial epithelial cells（NHBEC） was detected by Western blot and VE-cadherin gene expression was inhibited with siRNA in A549 cells. Results：Positive rates of VE-cadherin in cancer cells and vascular endothelial cells were 69.4% and 52.8%，which were higher than those in alveolar epithelial cells（0%） and vascular endothelial cells（20.8%） in adjacent non-neoplastic tissues（P<0.05）. Positive rates of VE-cadherin were higher in cases with lymph node metastasis than in cases without lymph node metastasis（P<0.05）. Positive rates of VE-cadherin were higher at Ⅲ and Ⅳ stage than atⅠand Ⅱstage（P<0.05）. Positive rates of VEGF in cancer cells and vascular endothelial cells were 84.7% and 62.5%，which were higher than those in alveolar epithelial cells（16.7%） and vascular endothelial cells（29.2%） in adjacent non-neo－plastic tissues（P<0.05）. qRT-PCR results demonstrated that relative expression of VE-cadherin mRNA in NSCLC tissues and adjacent non-neoplastic tissues were 1.15±0.87 and 0.70±0.57；relative expression of VEGF mRNA were 1.39±1.17 and 0.79±0.65（P<0.05）. VEGF and VE-cadherin were positive correlated at both protein and mRNA levels（P=0.001，P=0.008）. Western blot demon－strated that VE-cadherin expression could be detected in the A549 cells，but not in NHBEC and sequence-specific siRNA can significantly decreased expression of VE-cadherin in A549 cells. Conclusions：VE-cadherin may play an important role in angiogene－sis and act in a synergistic manner with VEGF in NSCLC. siRNA can effectively inhibit the expression of VE-cadherin in A549 cells.