van Zoelen E J, van de Ven W J, Franssen H J, van Oostwaard T M, van der Saag P T, Heldin C H, de Laat S W
Mol Cell Biol. 1985 Sep;5(9):2289-97. doi: 10.1128/mcb.5.9.2289-2297.1985.
Mouse neuroblastoma Neuro-2A cells produce transforming growth factors during exponential growth in a defined hormone-free medium, which, on Bio-Gel columns in 1 M HAc, elute at a molecular size of 15 to 20 kilodaltons (kDa). These neuroblastoma-derived transforming growth factors have strong mitogenic activity, but they do not compete with epidermal growth factor for receptor binding (E. J. J. van Zoelen, D. R. Twardzik, T. M. J. van Oostwaard, P. T. van der Saag, S. W. de Laat, and G. J. Todaro, Proc. Natl. Acad. Sci. U.S.A. 81:4085-4089, 1984). In this study approximately 80% of the mitogenic activity was immunoprecipitated by antibodies raised against platelet-derived growth factor (PDGF). Immunoblotting indicated a true molecular size of 32 kDa for this PDGF-like growth factor. Analysis of poly(A)+ RNA from Neuro-2A cells demonstrated the expression of the c-sis oncogene in this cell line, whereas in vitro translation of the RNA yielded a 20-kDa protein recognized by anti-PDGF antibodies. Separation by reverse-phase high-pressure liquid chromatography demonstrated the presence of two distinct mitogenic activities in neuroblastoma-derived transforming growth factor preparations, one of which is antigenically related to PDGF. Both activities had the ability to induce anchorage-independent growth in normal rat kidney cells, both in the presence and in the absence of epidermal growth factor. It is concluded that Neuro-2A cells express c-sis with concomitant production and secretion of a PDGF-like growth factor, which plays a role in the induction of phenotypic transformation on normal rat kidney cells.
小鼠神经母细胞瘤Neuro-2A细胞在限定的无激素培养基中指数生长期间会产生转化生长因子，这些转化生长因子在1 M醋酸中的生物凝胶柱上以15至20千道尔顿（kDa）的分子大小洗脱。这些源自神经母细胞瘤的转化生长因子具有很强的促有丝分裂活性，但它们不与表皮生长因子竞争受体结合（E. J. J. van Zoelen、D. R. Twardzik、T. M. J. van Oostwaard、P. T. van der Saag、S. W. de Laat和G. J. Todaro，《美国国家科学院院刊》81:4085 - 4089，1984）。在本研究中，约80%的促有丝分裂活性被抗血小板衍生生长因子（PDGF）的抗体免疫沉淀。免疫印迹显示这种PDGF样生长因子的真实分子大小为32 kDa。对Neuro-2A细胞的聚腺苷酸加尾RNA（poly(A)+ RNA）分析表明该细胞系中c-sis癌基因的表达，而该RNA的体外翻译产生一种被抗PDGF抗体识别的20 kDa蛋白质。通过反相高压液相色谱分离表明，神经母细胞瘤衍生的转化生长因子制剂中存在两种不同的促有丝分裂活性，其中一种在抗原上与PDGF相关。两种活性都有能力在正常大鼠肾细胞中诱导不依赖贴壁的生长，无论有无表皮生长因子。结论是Neuro-2A细胞表达c-sis并伴随产生和分泌一种PDGF样生长因子，该因子在诱导正常大鼠肾细胞的表型转化中起作用。
