Presence of the seven transmembrane thrombin receptor on human tumour cells: Effect of activation on tumour adhesion to platelets and tumour tyrosine phosphorylation
Presence of the seven transmembrane thrombin receptor on human tumour cells: Effect of activation on tumour adhesion to platelets and tumour tyrosine phosphorylation
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DOI：
10.1046/j.1365-2141.1996.d01-1494.x
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发表时间：
1996-02-01
影响因子：
6.5
通讯作者：
Karpatkin, S
中科院分区：
文献类型：
--
作者：
Nierodzik, MLR;Bain, RM;Karpatkin, S
凝血酶处理的肿瘤细胞在体外增强其与血小板、纤连蛋白和血管性血友病因子的粘附，并在体内增强其在小鼠中的肺转移。最近已克隆了一种独特的跨七个跨膜的凝血酶受体，其在受体的N-末端的凝血酶蛋白水解与栓系配体的暴露之后被激活。通过模拟凝血酶对血小板、内皮细胞和平滑肌细胞的作用，N-末端14聚体（SFLLRNPNDKYEPF）或6聚体（SFLLRN）的栓系配体可以用作凝血酶受体活化肽（TRAP）。我们已经研究了6个人肿瘤细胞系的反应，以TRAP，为存在的凝血酶受体mRNA的RT-PCR，蛋白质的免疫印迹和他们在体外和体内的反应，以TRAP。所有六种细胞系都含有受体mRNA，当用100 μ M 6-mer TRAP或1 u/ml凝血酶处理时，它们与血小板的粘附增加2-3倍。六种细胞系中的四种在暴露于6-mer TRAP或凝血酶后30秒至1分钟内经历酪氨酸磷酸化。因此，肿瘤细胞通过激活它们的七跨膜凝血酶受体来响应凝血酶。
Thrombin-treated tumour cells enhance their adhesion to platelets, fibronectin and von Willebrand factor in vitro, and enhance their pulmonary metastasis in mice in vivo. A unique seven transmembrane spanning thrombin receptor has recently been cloned which is activated following thrombin proteolysis of the N-terminal end of the receptor with exposure of a tethered ligand. An N-terminal 14-mer (SFLLRNPNDKYEPF) or 6-mer (SFLLRN) of the tethered ligand can serve as a thrombin receptor activation peptide (TRAP) by mimicking the action of thrombin on platelets, endothelial cells and smooth muscle cells. We have examined six human tumour cell lines for their response to TRAP, for the presence of this thrombin receptor mRNA by RT-PCR, protein by immunoblot and for their in vitro and in vivo response to TRAP. All six cell lines contain the receptor mRNA, and when treated with 100 mu M 6-mer TRAP or 1 u/ml thrombin increase their adhesion to platelets 2-3-fold. Four of the six cell lines undergo tyrosine phosphorylation within 30s to 1 min after exposure to 6-mer TRAP or thrombin. Thus tumour cells respond to thrombin via activation of their seven transmembrane spanning thrombin receptor.