Zabel M, Seidel J, Kaczmarek A, Surdyk-Zasada J, Grzeszkowiak J, Górny A
Department of Histology and Embryology, Medical Academy, Poznań, Poland.
Histochem J. 1995 Nov;27(11):859-68.
The immunocytochemical characterization of cell lines originating from thyroid medullary carcinoma, i.e. human TT cells and rat rMTC 6-23 cells, was undertaken. The immunocytochemical studies were supplemented by ultrastructural studies, including ultrastructural immunocytochemistry, and by radioimmunological estimation of calcitonin secretion to the medium. In rMTC 6-23 cells (subcultures 24 to 30), no hormone presence was demonstrated immunocytochemically, which corresponded to the absence of secretory granules at the ultrastructural level. Of various proteins sought, only neuron-specific enolase could be demonstrated. Nevertheless, the cells secreted calcitonin into the medium. TT cells (passages 145 to 160) produced secretory granules. The granules contained calcitonin, calcitonin gene-related peptide, somatostatin, neurotensin, met-enkephalin, leu-enkephalin, gastrin releasing peptide, parathyroid hormone-related protein, functional proteins of the chromogranin group and synaptophysin. Other functional proteins found in the cytosol of TT cells included non-specific enolase, calbindin and tyrosine hydroxylase. Receptor for calcitriol was localized in the cell nucleus. Marker proteins were localized in the cytosol (carcinoembryonic antigen) and in the cell skeleton (alpha-tubulin, cytokeratin). Following changes in ionized calcium levels in the medium, changes in calcitonin secretion and in immunocytochemical detectability of some hormones and functional proteins were observed. TT cells demonstrated the expression of numerous hormones and functional proteins associated with calcitonin secretion. Further, the cells in their ultrastructure, immunocytochemical and secretory characteristics, resemble more closely normal parafollicular cells of the thyroid and, in our opinion, represent a more appropriate model for functional studies.
对源自甲状腺髓样癌的细胞系，即人TT细胞和大鼠rMTC 6 - 23细胞进行了免疫细胞化学特性分析。免疫细胞化学研究辅以超微结构研究，包括超微结构免疫细胞化学，并通过对培养基中降钙素分泌的放射免疫测定进行补充。在rMTC 6 - 23细胞（传代培养24至30代）中，免疫细胞化学未显示激素存在，这与超微结构水平上分泌颗粒的缺失相对应。在所寻找的各种蛋白质中，仅能证明神经元特异性烯醇化酶的存在。然而，这些细胞向培养基中分泌降钙素。TT细胞（传代145至160代）产生分泌颗粒。这些颗粒含有降钙素、降钙素基因相关肽、生长抑素、神经降压素、甲硫氨酸脑啡肽、亮氨酸脑啡肽、胃泌素释放肽、甲状旁腺激素相关蛋白、嗜铬粒蛋白组的功能蛋白和突触素。在TT细胞胞质溶胶中发现的其他功能蛋白包括非特异性烯醇化酶、钙结合蛋白和酪氨酸羟化酶。维生素D3受体定位于细胞核。标记蛋白定位于胞质溶胶（癌胚抗原）和细胞骨架（α - 微管蛋白、细胞角蛋白）。随着培养基中离子钙水平的变化，观察到降钙素分泌以及一些激素和功能蛋白的免疫细胞化学可检测性的变化。TT细胞显示出与降钙素分泌相关的多种激素和功能蛋白的表达。此外，这些细胞在超微结构、免疫细胞化学和分泌特性方面更类似于甲状腺正常滤泡旁细胞，并且在我们看来，代表了更适合功能研究的模型。
