RESUMO
The vascular endothelial growth factor (VEGF) is a major mediator of angiogenesis involving tumor growth and metastasis. Polymorphisms in the VEGF gene may regulate VEGF production. In this case-control study, we investigated whether functional polymorphisms (+405 C > G and +936 C > T) in the VEGF gene are associated with the risk of lung cancer. Genomic DNA was isolated from the blood of 100 lung cancer patients and 150 healthy controls, and total RNA was isolated from 48 tumor tissues and adjacent normal lung tissues. Two DNA polymorphisms (+405 C > G and +936 C > T) in the 3'-untranslated regions (3'-UTR) and 5'-untranslated regions (5'-UTR) of vascular endothelial growth factor A (VEGFA) were studied using PCR-RFLP method, and mRNA expression of VEGFA was studied by quantitative real-time PCR. Polymorphisms in the 5'-UTR (+405 C > G) and 3'-UTR (+936 C > T) did not show significant difference between lung cancer cases and control samples (P = 0.11 and P = 0.09, respectively). VEGF +405 CG and GG are significantly more in age group >50 years old, in all grades, and in early pathological stages (P = 0.04, P = 0.03, and P = 0.006, respectively). Also, increased expression of VEGFA mRNA was noted in tumorous compared to non-tumorous tissue (P < 0.0001). Overexpression of the gene was considered at ΔC (T) > 6.0. Within the group of patients with conventional tumor, those with histology other than squamous cell carcinoma (SCC) had a higher level of VEGFA mRNA expression than SCC patients (P = 0.04). Overexpression of VEGFA mRNA was noted in lung cancer and more so in lung cancer with adenocarcinoma and large cell carcinoma histology and in pathological stages III and IV. VEGFA +405 C > G SNP showed an association with age, pathological grade, and stage.
