Basic and clinical research on growth promoting factor for neurofibroma

神经纤维瘤病（NF）是一种最常见的遗传性疾病。近年来在第17和22号染色体上发现了nf相关基因。然而，神经纤维瘤发展的确切机制尚不清楚。我们以前从神经纤维瘤和患者血清中分离出这种物质，它能特异性地增强神经纤维瘤来源的成纤维细胞的增殖。这种物质是神经纤维瘤的一种神经纤维合成生长促进因子，在神经纤维瘤中含量很少，因此尚未应用生化分析。为了获得足量的神经纤维瘤源性生长促进因子，我们引入了三维培养体系，其中补充抗坏血酸2-磷酸。我们已经证实这种文化可以提供类似死亡的结构。与真皮层一样，成熟的胶原合成并积累了与真皮层成分相似的糖胺聚糖。在这个培养系统中，双糖分析显示，来自亨特综合征（粘多糖病II）的成纤维细胞比正常人产生更多的皮肤硫酸酯。这一结果可能表明，在该培养体系中，成纤维细胞可以维持其在体内的表型。利用该培养系统，我们发现从神经纤维瘤驱动的成纤维细胞的三维细胞层中提取的部分促进了神经纤维瘤来源的成纤维细胞的增殖。事实上，只有10-30%的患者通过NF基因分析显示出异常。此外，尚不清楚该基因产物如何参与神经纤维瘤的发展。神经纤维瘤病一定是由几种基因引起的。在后续的研究中，我们可以利用该系统获得足量的神经纤维瘤源性生长促进因子进行生化和分子生物学分析。

Neurofibromatosis (NF) is a most frequent hereditary disorder. Recent study disclosed NF-related gene (s) on chromosome 17 and 22. However, the precise mechanism of neurofibroma development is still unclear. We previously isolated the substance from neurofibroma and patient's sera, which specifically enhances neurofibroma-derived fibroblasts proliferation. This substance, a neurofibromaderived growth promoting factor for neurofibroma, is contained so little in neurofibroma that biochemical analysis has not been applied. To obtain a sufficient amount of neurofibroma-derived growth promoting factor, we introduced the three-dimensional culture system, in which ascorbic acid 2-phosphate was supplemented. We already confirmed this culture can provide the demis-like structure. Like the dermis, mature collagens synthesized and accumulated with glycosaminoglycans having the similar composition to the dermis. In this culture system, disaccharide analysis revealed that fibroblasts from Hunter syndrome (mucopolysaccharidosis II) produced a higher amount of dermatan sulfate than those from normal individuals. This result may suggest that in this culture system fibroblasts can maintain its phenotype as in vivo.Using this culture system, we found the fraction extracted from the three-dimensional cell layr of neurofibroma-driverd fibroblasts promoted the proliferation of neurofibroma-derived fibroblasts.In fact, only 10-30% of patients show the abnormality by the NF gene analysis. Furthermore, it is unknown how this gene product (s) is involved in the development of neurofibroma. There must be several genes responsible for neurofibromatosis. In the subsequent study, we can use this system to obtain the sufficient amount of neurofibroma-derived growth promoting factor for biochemical and molecular biological analysis.