Abnormal expression of vascular endothelial growth factor (VEGF) and its clinical features in tissues of human lung cancer

摘要

Objective: Angiogennesis, the formation of new blood vessels from the existing vascular bed, is essential step for growth and invasion of primary tumor. Vascular endothelial growth factor (VEGF) is known to play crucial role in tumor angiogenesis. In the present study, we investigate the expression of VEGF and VEGF-mRNA in the angiogennesis, metastasis and prognosis of lung cancer. Methods: The VEGF cellular distributions and expression in 38 specimens of patients with lung cancer were investigated with immunohistochemistry stain technology. The total RNAs in 38 tissues of lung cancer was measured, then the levels of VEGF-mRNA expression were analyzed by a reverse-transcription polymerase chain reaction (RT-PCR) assay. The levels of VEGF in sera of patients with lung cancer, benign lung diseases and healthy controls were detected through Enzyme linked immunosorbent assay (ELISA) method. Results: The VEGF positive stain was 76% in 38 cases of lung cancer specimens. The 89% rate of VEGF stain was found for clinical stage Ⅲ cases and 92% for stage Ⅳ lung cancers. The significantly higher expression of VEGF was evidenced in patients with lymph node metastasis (84 %), distant metastasis (90%), and lung cancers with lower histological differentiation (89%), respectively. The expression level of total RNA was significantly higher in patients with lung cancers than that in their paracancerous or distant lung tissues. The VEGF expressions were tightly correlated with total RNA concentration of lung carcinoma ( P < 0.01). The predominant expressions of VEGF121 and VEGF165 gene fragments were found in lung cancer specimens by RT-PCR analysis. No significant difference of serum VEGF levels was detected between cases with lung cancer and patients with benign diseases. However, the VEGF level of cases with benign diseases was decreased significantly after patients with anti-inflammation medication. Conclusion: The present data suggested that the tumor tissue VEGF expression and VEGF-mRNA analysis in patients with lung cancer be a useful indicator for angiogenesis and metastasis of lung cancer.