Pera M F, Blasco-Lafita M J, Cooper S, Mason M, Mills J, Monaghan P
Radiotherapy Section, Royal Cancer Hospital, Sutton, Surrey, UK.
Differentiation. 1988 Dec;39(2):139-49. doi: 10.1111/j.1432-0436.1988.tb00089.x.
Human embryonal carcinoma cells sometimes display the developmental potential of early embryonic stem cells. While available data do not clearly identify a counterpart of these tumor cells in normal development, previous comparisons of human embryonal carcinoma and yolk sac carcinomas indicated that these cell types are closely related, and suggested that embryonal carcinoma cells might resemble the progenitors of extraembryonic endoderm. To analyse further cell-differentiation lineage in these tumors, we produced monoclonal antibodies to cytostructurally associated antigens of human embryonal carcinoma cells. Spleen cells from mice immunized with a detergent-insoluble extract of cultured human embryonal carcinoma cells were fused to NS-1 myeloma cells, and hybridoma supernatants were screened by indirect immunofluorescence on the immunizing cell line, then on a panel of cell lines derived from human embryonal carcinomas, yolk sac carcinomas, and a range of neoplastic and normal tissues. Monoclonal antibody GCTM-1 stained the nuclei of all human cells tested and served as a positive control; this antibody immunoprecipitated proteins of 85 and 66 k Da from human embryonal carcinoma cells. GCTM-2 recognized an epitope on a 200-k Da extracellular protein present on the surface of embryonal carcinoma cells, and stained the surface of visceral yolk sac-type carcinoma and colorectal carcinoma cells as well. Enzymatic analysis of carbohydrate residues on the GCTM-2 antigen revealed that it was a keratan sulphate proteoglycan, and suggested that the epitope recognized by the antibody lies on the core protein. In immunoblots, antibody GCTM-3 bound to a 57-k Da cytoskeletal protein expressed in human embryonal carcinoma. This antibody decorated filamentous arrays in cell lines from human embryonal carcinoma, visceral yolk sac carcinoma, parietal yolk sac carcinoma (endodermal sinus tumour), and adenocarcinoma and large cell carcinoma of the lung. Antibody GCTM-4 recognized a determinant present on a 69-k Da polypeptide, associated with a component of the lysosomal compartment, which was expressed in embryonal carcinoma cells, but no other cell type tested. The results with this antibody panel thus allow distinction between human embryonal carcinoma and yolk sac carcinoma, but provide further evidence of a close relationship between these cell types.
人胚胎癌细胞有时会表现出早期胚胎干细胞的发育潜能。虽然现有数据并未明确在正常发育过程中这些肿瘤细胞的对应物，但先前对人胚胎癌和卵黄囊癌的比较表明，这些细胞类型密切相关，并提示胚胎癌细胞可能类似于胚外内胚层的祖细胞。为了进一步分析这些肿瘤中的细胞分化谱系，我们制备了针对人胚胎癌细胞细胞结构相关抗原的单克隆抗体。用培养的人胚胎癌细胞的去污剂不溶性提取物免疫的小鼠脾细胞与NS-1骨髓瘤细胞融合，杂交瘤上清液通过间接免疫荧光在免疫细胞系上进行筛选，然后在一系列源自人胚胎癌、卵黄囊癌以及一系列肿瘤性和正常组织的细胞系上进行筛选。单克隆抗体GCTM-1对所有测试的人细胞的细胞核进行染色，并用作阳性对照；该抗体从人胚胎癌细胞中免疫沉淀出85 kDa和66 kDa的蛋白质。GCTM-2识别胚胎癌细胞表面存在的一种200 kDa细胞外蛋白上的一个表位，并且也对内脏卵黄囊型癌和结肠癌细胞的表面进行染色。对GCTM-2抗原上碳水化合物残基的酶促分析表明它是一种硫酸角质素蛋白聚糖，并提示该抗体识别的表位位于核心蛋白上。在免疫印迹中，抗体GCTM-3与在人胚胎癌中表达的一种57 kDa细胞骨架蛋白结合。该抗体在源自人胚胎癌、内脏卵黄囊癌、壁层卵黄囊癌（内胚窦瘤）以及肺腺癌和大细胞癌的细胞系中对丝状阵列进行装饰。抗体GCTM-4识别存在于一种69 kDa多肽上的一个决定簇，该多肽与溶酶体区室的一个成分相关，其在胚胎癌细胞中表达，但在测试的其他细胞类型中未表达。因此，该抗体组的结果能够区分人胚胎癌和卵黄囊癌，但提供了这些细胞类型之间密切关系的进一步证据。
