Regulation of glycolipid sulfotransferase by tyrosine kinases in human renal cancer cells
Regulation of glycolipid sulfotransferase by tyrosine kinases in human renal cancer cells
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DOI：
10.1016/0005-2760(95)00193-x
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发表时间：
1996-01-05
期刊：
影响因子：
--
通讯作者：
Makita, A
中科院分区：
文献类型：
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作者：
Balbaa, M;Honke, K;Makita, A
人肾癌细胞系SMKT-R3的糖脂转移酶活性受到ECF、转化生长因子-α和肝细胞生长因子等生长因子的作用，其受体具有酪氨酸激酶区。我们通过使用特定的酪氨酸激酶抑制剂，研究了酪氨酸激酶是否参与了细胞中硫转移酶的调节。金雀异黄素和酪氨酸蛋白51不仅可阻断EGF对硫基转移酶的增强作用，而且还可使硫基转移酶的活性降低到比未处理细胞低得多的水平，而它们在体外并不影响硫基转移酶的活性。金雀异黄素的活性降低作用呈剂量和时间依赖性。金雀异黄素还能抑制SMKT-R3细胞的生长。用抗磷酸酪氨酸单抗进行免疫印迹显示，未处理的细胞中有明显的酪氨酸磷酸化蛋白，其表观分子质量为116 kDa。通过加入EGF，EGF受体被酪氨酸磷酸化。与金雀异黄素共同孵育可减弱116 kDa蛋白和EGF受体的磷酸化。这些结果表明，包括EGF受体在内的酪氨酸激酶参与SMKT-R3细胞的生长，并参与细胞内糖脂转移酶的调节机制。
Glycolipid sulfotransferase activity in a human renal cancer cell line, SMKT-R3, is enhanced by the action of growth factors such as ECF, TGF-alpha and HGF, whose receptors possess tyrosine kinase domains. We investigated whether tyrosine kinases are involved in the regulation of the sulfotransferase in the cells by using specific tyrosine kinase inhibitors. Genistein and tyrphostin 51 not only cancelled the enhancement of the sulfotransferase by EGF but also reduced the enzyme level to a point much lower than that seen in non-treated cells, whereas they did not affect the sulfotransferase activity in vitro. The activity-reducing effects of genistein were dose- and time-dependent. Genistein also inhibited the cell growth of SMKT-R3 cells. Western blotting using anti-phosphotyrosine monoclonal antibody revealed a tyrosine-phosphorylated protein with an apparent molecular mass of 116 kDa in the non-treated cells. The EGF receptor was tyrosine-phosphorylated by the addition of EGF. The phosphorylations of the 116 kDa protein and EGF receptor were attenuated by co-incubation with genistein. These results indicate that tyrosine kinases including the EGF receptor are involved in the growth of SMKT-R3 cells and in the regulatory mechanisms of glycolipid sulfotransferase in the cells.