Abnormal expression of VEGF and its gene transcription status as diagnostic indicators in patients with non-small cell lung cancer

摘要

Objective Angiogenesis is known to be essential for the survival,growth,invasion,and metastasis of lung cancer cells. Vascular endothelial growth factor(VEGF) is an important factor regulating angiogenesis of non-small cell lung cancer(NSCLC); however,its pathologic features and significance are unclear. In this study,the tissue VEGF expression levels and its gene transcriptional status,as well as circulating VEGF levels,were investigated in patients with lung disease. Methods VEGF protein and m RNA expression levels in 38 lung tissue samples were analyzed by immunohistochemistry and reverse transcription-polymerase chain reaction(RT-PCR),respectively. Circulating VEGF levels were detected quantitatively by an enzyme linked immuno-sorbent assay. Results The level of VEGF expression was significantly higher in lung cancer tissue than in the corresponding paracancerous or non-cancerous tissues. The average level of VEGF-positive staining was 76% in tissue samples from NSCLC patients; the levels were 89% in tissue samples from stage III patients and 92% in stage IV patients. High VEGF expression was also evident in cases with lymph node metastasis(84%),distant metastasis(90%),and lower differentiation degree(89%). VEGF m RNA in cancerous tissues was represented predominantly by the VEGF121 and VEGF165 isoforms. Circulating VEGF levels were significantly higher in NSCLC patients [(840 ± 324) pg/m L] than in patients with benign lung diseases [(308 ± 96) pg/m L] or in healthy individuals serving as controls [(252 ± 108) pg/m L]. Conclusion The over-expression of lung VEGF and its gene transcription status should be useful molecular indicators for NSCLC diagnosis.