Investigation of VEGF and IL-8 Gene Polymorphisms in Patients with Differentiated Thyroid Cancer

Background: Differentiated thyroid carcinomas (DTC) account for most of the thyroid cancers. The emergence of DTC may be affected by various predisposing genetic alterations and environmental factors The aim of this study was to investigate the role of VEGF C936T and IL-8 A251T gene polymorphisms in the pathogenesis and metastasis of differentiated thyroid cancer. Methods: The study consisted of 101 patients DTC patients and 109 healthy controls. The parameters of the stage of cancer of the DTC patients at the time of diagnosis (TNM) were recorded. DNA was isolated from blood using a DNA isolation kit. VEGF C936T and IL-8 A251T gene polymorphisms were determined using the polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) methods. Distributions of gene polymorphisms were evaluated according to the Hardy-Weinberg principle. Results: The TT genotype from the VEGF C936T genotype distributions was higher in the control group than in the DTC group (p < 0.05). In contrast, the IL-8 A-251T genotype distributions were similar in both groups. No relationship was found between either cytokine gene polymorphism or the DTC stages. The frequency of IL-8 TT was higher in the DTC group with lymph gland metastasis (TT 92%) than in the group without lymph gland metastasis (TT 45.9%) (p < 0.05). Conclusions: We consider that the VEGF 936 TT genotype may play a protective role in the development of DTC and that the IL-8 A-251 TT genotype may contribute to the DTC lymph node metastasis. Therefore, these genotypes may hold a key to the evaluation of thyroid nodules and the metastasis of DTC.