Vascular endothelial growth factor-C mRNA expression on lymphatic metastasis of thyroid papillary carcinoma

背景：已知血管内皮生长因子- c （VEGF-C）与淋巴管的发育有关。甲状腺乳头状癌的特征性转移到局部淋巴结，而滤泡性甲状腺癌通常是血源性扩散。本研究旨在确定VEGF-C基因的表达是否与这两种类型甲状腺癌的不同转移特征有关。方法：选取15例甲状腺乳头状癌和4例甲状腺滤泡癌的甲状腺癌标本。采用Northern印迹法和原位杂交法检测VEGF-C基因表达。采用免疫组化方法定位VEGF-C蛋白的沉积。结果：Northern blot检测VEGF-C基因在乳头状癌中的表达比例明显高于滤泡性癌。乳头状癌患者的非恶性甲状腺组织也比滤泡癌患者的组织表达更高水平的VEGF-C。原位杂交法在甲状腺乳头状癌细胞中观察到VEGF-C基因的表达，而在滤泡癌细胞中未见表达。乳头状癌细胞VEGF-C抗体染色阳性。结论：肿瘤细胞和周围组织同时表达VEGF-C基因可能与乳头状癌患者甲状腺内淋巴扩散和区域淋巴结转移的发生率有关。

Background :Vascular endothelial growth factor-C (VEGF-C) is known to be related to development of lymphatic vessels. Papillary thyroid carcinoma characteristically metastasizes to regional lymph nodes, whereas follicular thyroid carcinoma commonly spreads hematogenously. The present study was designed to determine whether expression of the VEGF-C gene is related to the different metastatic features of these 2 types of thyroid carcinoma.Methods :Tyroid carcinoma specimens were obtained from15 patients with papillary carcinoma and 4 patients with follicular carcinoma of the thyroid. VEGF-C gene expression was exmined by Northern blotting and in situ hybridization. Immunohistochemistry was performed to localize the deposition of VEGF-C protein.Results :The ratios of VEGF-C gene expression determined by Northern blot analysis were significantly higher in papillary than in follicular carcinoma. Nonmalignant thyroid tissue from patients with papillary carcinoma also expressed higher levels of VEGF-C than tissue from patients with follicular carcinoma. Expression of the VEGF-C gene was observed by in situ hybridization in cells of papillary thyroid carcinoma but not in those of follicular carcinoma. Positive staining with antibody against VEGF-C was detected in papillary cancer cells.Conclusions :Concurent overexpression of the VEGF-C gene by both tumor cells and the surrounding tissue may be related to the prevalence of intrathyroidal spread through lymphatics and regional lymph node metastasis in patients with papillary carcinoma.