Eilon G, Perkins J, Viola M V
Cancer Res. 1983 Aug;43(8):3763-9.
Although the primary cell type in human osteosarcoma is usually a neoplastic osteoblast, numerous other mesenchymal cell types may coexist in the same tumor. Previously described cloned, long-term osteosarcoma cell lines have had an osteoblastic phenotype. In this report, we describe a nonosteoblastic, long-term cell line derived from an osteosarcoma in a patient with Paget's disease. The cell line (FM-2) is nontransformed in having a low saturation density and anchorage-dependent growth, and it is nontumorigenic in nude mice. Important features of its fine structure include numerous elongated mitochondria, abundant Golgi and lysosomes, and a poorly developed rough endoplasmic reticulum. The line has high levels of lysosomal enzymes (acid phosphatase and N-acetylglucosaminidase) and low levels of alkaline phosphatase. It lacks numerous macrophage markers (lysozyme, C3, Fc receptors, and M1 antigen). The FM-2 line had a dose-dependent cyclic AMP response (7-fold increase) following treatment with calcitonin but not with parathormone. In 125I-calcitonin-binding experiments, we calculated approximately 5.3 +/- 0.2 X 10(3) receptor sites/cell with a kd of 1.8 +/- 0.1 X 10(-9) M. Conditioned medium from the FM-2 line was a potent stimulator of calcium release as assayed in a 45Ca-labeled fetal rat bone organ culture. This activity was not prostaglandin, vitamin D, parathormone, or epidermal growth factor, which are known stimulators of bone resorption. The FM-2 line does not appear to be derived from an osteoblast, macrophage, or fibroblast and may represent a calcitonin-responsive bone stem cell.
尽管人类骨肉瘤中的主要细胞类型通常是肿瘤性成骨细胞，但许多其他间充质细胞类型可能在同一肿瘤中共存。先前描述的克隆化长期骨肉瘤细胞系具有成骨细胞表型。在本报告中，我们描述了一种源自佩吉特病患者骨肉瘤的非成骨细胞长期细胞系。该细胞系（FM-2）未发生转化，具有低饱和密度和锚定依赖性生长，并且在裸鼠中不具有致瘤性。其精细结构的重要特征包括大量细长的线粒体、丰富的高尔基体和溶酶体，以及发育不良的粗面内质网。该细胞系具有高水平的溶酶体酶（酸性磷酸酶和N-乙酰葡糖胺酶）和低水平的碱性磷酸酶。它缺乏许多巨噬细胞标志物（溶菌酶、C3、Fc受体和M1抗原）。用降钙素处理后，FM-2细胞系具有剂量依赖性的环磷酸腺苷反应（增加7倍），但用甲状旁腺激素处理则无此反应。在125I-降钙素结合实验中，我们计算出约5.3±0.2×10³个受体位点/细胞，解离常数为1.8±0.1×10⁻⁹M。在45Ca标记的胎鼠骨器官培养中检测发现，FM-2细胞系的条件培养基是钙释放的有效刺激物。这种活性不是已知的骨吸收刺激物前列腺素、维生素D、甲状旁腺激素或表皮生长因子。FM-2细胞系似乎不是源自成骨细胞、巨噬细胞或成纤维细胞，可能代表一种降钙素反应性骨干细胞。
