白血病抑制因子受体与白血病细胞U937内促分裂原活化蛋白激酶的关系

探讨人白血病细胞系U937白血病抑制因子 (LIF)受体α亚基和另一亚基gp130细胞内区与促分裂原活化蛋白激酶 (MAPK)的关系 ,旨在研究白血病细胞增殖和分化的机制。用基因重组技术将两基因细胞内区互换以构成两嵌合体受体 (190 130 ,130 190 )并分别在U937表达 ,其与野生受体竞争性结合白血病抑制因子 ,用免疫组化和免疫印迹法分析受体细胞内区形成同源性二聚体(190cyt 190cyt,130cyt 130cyt)后的细胞状况和细胞内MAPK的水平。结果表明 ,转染pE190 130后用LIF作用 6h ,U937细胞MAPK表达量增加 ,MAPK形成的二聚体较明显 ,细胞增殖较快 ;而另一嵌合体受体与α亚基形成 190cyt 190cyt时U937细胞MAPK的表达无变化 ,二聚体不明显。说明LIF受体中gp130亚基的细胞内区参与了MAPK的激活及白血病U937细胞增殖信号的传递。

Relation between each subunit of leukemia inhibitory factor receptor and mitogen-activated protein kinase in human leukemia line U937

To investigate the relation of the cytoplasmic region of each subunit of leukemia inhibitory factor (LIF) receptor to protein kinase MAPK in human leukemia line U937 for studying the mechanism of leukemia cell proliferate disorder. We prepared the chimerical receptor exchanged cytoplasmic domain each other(190/130,130/190) and let it separately express on the membrane of U937, then, bind competitively LIF with the wild receptor. Therefore, the cytoplasmic region homodimerization (190cyt?190cyt,130cyt?130cyt) initiates the intracellular signal transduction and the cell proliferation and differentiation. MAPK level was observed by means of immunoblotting and immunobiochemistry. The higher level of MAPK and the faster cell proliferation are determined in group of 190/130 as compared with the wild type receptor and MAPK dimerization is more obvious in the cell transfected with 190/130. It suggests that the cytoplasmic domain of gp130 involve the induction of MAPK activation and the cell proliferation of U937.