Punt C J, Rijksen G, van Oirschot B A, Kester-Schipper G P, van der Heijden M C, Dekker A W, Staal G E
Department of Medical Oncology, University Hospital Nijmegen, The Netherlands.
Anticancer Res. 1992 Nov-Dec;12(6B):2075-84.
We have examined several aspects of protein tyrosine kinase (PTK)-activity in the cytosolic and membrane fractions of both normal and malignant lymphoid cells. The expression of the PTK-encoding oncogenes fes, abl and src, was investigated with the use of antibodies generated to their respective gene products. These antibodies recognized proteins in all cell types examined, most frequently in both the cytosolic and the membrane fraction. PTKs were partially characterized by FPLC. PTK-activities of column fractions were assayed using a non-radioactive dot blot assay. Cytosolic and membrane fractions showed FPLC patterns with a constant as well as a variable part in both normal and malignant cells, suggestive of PTKs with specialized functions in normal cell growth and transformation. Lastly, using antibodies to phosphotyrosine, we found that cytosolic fractions contained the majority of proteins phosphorylated at tyrosine in all cell types. Normal peripheral blood lymphocytes and B-lymphoma cells showed a great similarity in tyrosine phosphorylation pattern, while in tonsillar lymphocytes a clearly different pattern was found. These methods further characterize PTK-activities in lymphoid cells, and the results give evidence that PTKs in normal and malignant cells have both similar and different aspects.
我们研究了正常和恶性淋巴细胞的胞质和膜组分中蛋白酪氨酸激酶（PTK）活性的几个方面。利用针对各自基因产物产生的抗体，研究了编码PTK的癌基因fes、abl和src的表达情况。这些抗体在所有检测的细胞类型中均能识别蛋白质，最常见于胞质和膜组分中。通过快速蛋白质液相色谱（FPLC）对PTK进行了部分表征。使用非放射性斑点印迹法检测柱级分的PTK活性。胞质和膜组分在正常和恶性细胞中均显示出FPLC图谱，既有恒定部分也有可变部分，这表明PTK在正常细胞生长和转化中具有特定功能。最后，使用抗磷酸酪氨酸抗体，我们发现胞质组分在所有细胞类型中都含有大部分酪氨酸磷酸化的蛋白质。正常外周血淋巴细胞和B淋巴瘤细胞在酪氨酸磷酸化模式上表现出很大的相似性，而在扁桃体淋巴细胞中发现了明显不同的模式。这些方法进一步表征了淋巴细胞中的PTK活性，结果表明正常细胞和恶性细胞中的PTK既有相似之处也有不同之处。
