Shiota M, Fujimoto J, Semba T, Satoh H, Yamamoto T, Mori S
Department of Pathology, University of Tokyo, Japan.
Oncogene. 1994 Jun;9(6):1567-74.
Ki-1 lymphoma is a subtype of human malignant lymphoma characterized by the expression of CD30 (Ki-1) and a peculiar morphology. It is occasionally accompanied by a unique reciprocal chromosomal translocation t(2;5)(p23;q35). A Ki-1 lymphoma cell line, AMS3, was established by maintaining biopsied tumor cells in SCID (severe combined immunodeficiency) mice. To investigate abnormalities of the signal transduction in Ki-1 lymphomas, AMS3 lysate was immunoprecipitated with anti-phosphotyrosine monoclonal antibody, 25.2G4, and the immunoprecipitates were subjected to kinase assay and immuno-blotting with 25.2G4. A unique phosphotyrosine-containing protein of MW 80,000, designated p80, was found only in AMS3 cells and not in other cell lines or mononuclear cells from healthy donors. Subsequent amino acid sequence analysis of its tryptic digests showed that p80 was a hitherto undescribed tyrosine phosphoprotein similar to Ltk (leukocyte tyrosine kinase). Furthermore, physical interaction of p80 with CD30 was suggested from immunoprecipitation experiments with AMS3 lysates.
Ki-1淋巴瘤是人类恶性淋巴瘤的一种亚型，其特征为CD30（Ki-1）的表达和独特的形态学表现。它偶尔会伴有一种独特的相互染色体易位t(2;5)(p23;q35)。通过将活检的肿瘤细胞接种于SCID（严重联合免疫缺陷）小鼠体内，建立了一株Ki-1淋巴瘤细胞系AMS3。为了研究Ki-1淋巴瘤中信号转导的异常情况，用抗磷酸酪氨酸单克隆抗体25.2G4对AMS3裂解物进行免疫沉淀，然后对免疫沉淀物进行激酶分析并用25.2G4进行免疫印迹。发现一种分子量为80,000的独特含磷酸酪氨酸蛋白，命名为p80，仅在AMS3细胞中存在，而在其他细胞系或健康供体的单核细胞中不存在。随后对其胰蛋白酶消化产物进行氨基酸序列分析表明，p80是一种迄今未描述的酪氨酸磷蛋白，类似于Ltk（白细胞酪氨酸激酶）。此外，通过对AMS3裂解物进行免疫沉淀实验提示p80与CD30存在物理相互作用。
