Induction of differentiation on the differentiation of human embryonal carcinoma

为了建立人生殖细胞肿瘤细胞的体外分化体系，我们从9个不同类型的人生殖细胞肿瘤细胞系中初步筛选出一株NEC-14细胞。从睾丸胚胎癌(EC)建立的NEC 14细胞系在裸鼠移植瘤中自发地表现出多向分化的能力，如腺体成分、软骨组织和胚外合体滋养细胞成分。作为体外分化诱导剂，我们使用了10M的N，N‘-六亚甲基双乙酰胺(HMBA)，因为该试剂在HMBA、维甲酸、孕酮、DMSO和DBC AMP之间具有最强的诱导分化活性。FACS分析表明，HMBA处理后降低了人EC抗原SSEA-3，并反向诱导了NEC 14细胞表面的SSEA-1和HLA-A、B、C抗原。此外，HMBA处理的NEC 14细胞对塑料基质的粘附性更强，并且含有更多的纤溶酶原激活剂(3倍于未处理的NEC 14细胞)。经过长时间的培养，角蛋白、结蛋白和波形蛋白在这些经HMBA处理的细胞亚群上可被免疫组织化学识别。在其他项目中，我们表征了F9胚胎多糖的分子特性，该分子特性被生殖细胞肿瘤患者血清中的一种独特抗体识别。我们还发现，神经元特异性烯醇化酶(NSE)的测定不仅对未成熟畸胎瘤有诊断价值，而且对无性细胞瘤也有诊断价值。

To establish an in vitro differentiation system of human germ cell tumor cells, we initially selected a cell line, NEC 14 from 9 cell lines derived from various types of human germ cell tumors. The NEC 14 line established from testicular embryonal carcinoma ( EC ) showed spontaneously a capacity for multiple differentiation in xenograft tumors in nude mice, such as glandular components, cartilagious tissue, and an extraembryonic syncytiotrophoblastic element. As a differentiation inducing reagent in vitro, we used 10 M of N,N'- hexamethylene bisacetamide ( HMBA ), since this reagent showed the most potent activity to induce apparently differentiated colonies among HMBA, retinoic acid, progesterone, DMSO, and dbc AMP.FACS analyses revealed that the HMBA treatment reduced human EC antigen, SSEA-3, and inversely induced SSEA-1 and HLA-A, B, C antigen on NEC 14 cells. Furthermore, these HMBA-treated NEC 14 cells showed higher adhesivity to plastic substrate, and contained larger amount ( 3X ) of plasminogen activator than untreated NEC 14 cells. After prolonged culture, keratin, desmin, and vimentin were immunohistochemically identifiable on a subpopulation of these HMBA-treated cells.In additional projects, we characterized the molecular properties of F9 embryoglycan recognized by a unique antibody in sera from patients with germ cell tumors. We also found that neuron-specific enolase ( NSE ) measurements are of diagnostic value not only for immature teratomas but also for dysgerminomas.