Characteristics of angioarchitecture in thyroid tumors in associated with expression of vascular endothelial growth factor (VEGF)

共聚焦激光扫描显微镜（CLSM）观察结合免疫组化IV型胶原清晰可视化的微血管结构的三维图像。这种方法显示，基本的血管模式与生长模式相关，这表明甲状腺肿瘤的实质和间质特征之间的相互依赖性。在这方面，我们决定研究血管内皮生长因子（VEGF）在甲状腺肿瘤。RT-PCR分析显示，所有甲状腺肿瘤标本均表达VEGF的-121、-165和189-氨基酸形式的条带。北方印迹分析显示，与正常甲状腺样本相比，肿瘤组织中VEGF mRNA水平增加。通过非同位素原位杂交和免疫组化，大多数的肿瘤细胞表达VEGF的mRNA和蛋白，而VEGF的表达被确定只在上皮细胞的孤立的滤泡在正常甲状腺组织。VEGF在乳头状癌瘤性乳头上的肿瘤细胞和未分化癌坏死周围的肿瘤细胞中有强表达。我们的研究结果表明，甲状腺肿瘤的组织学类型可能决定了血管模式，通过旁分泌机制，涉及VEGF。

Confocal laser scanning microscopy (CLSM) observation combined with immunohistochemistry for type IV collagen clearly visualized 3-dimensional images of the microvascular structures. This method revealed that the fundamental vascular pattern correlates well with the growth pattern, suggesting an interdependence between parenchyma and stroma characteristic for thyroid tumors. In this respect, we determined to study vascular endothelial growth factor (VEGF) in thyroid tumors. RT-PCR analysis showed that all specimens of thyroid tumors expressed bands corresponding to -121, -165, and 189-amino acid forms of VEGF. Northern blot analysis showed an increase in VEGF mRNA levels in neoplastic tissues in comparison with normal thyroid samples. By nonisotopic in situ hybridization and immunohistochemistry, most of the tumor cells expressed VEGF mRNA and protein, whereas VEGF expression was identified only in epithelium of isolated follicles in normal thyroid tissues. Intense expression of VEGF was observed in overlying tumor cells of neoplastic papillae of papillary carcinoma and in tumor cells surrounding necrosis in undifferentiated carcinoma. Our results suggest that the histological types of thyroid tumor may determine the vascular pattern through a paracrine mechanism involving VEGF.