MOLECULAR CLONING AND EXPRESSION OF MIDKINE RECEPTOR

这项拟议研究的长期目标是定义分子 中期因子信号转导通路的结构与功能 它调节细胞增殖和分化，特别是 这项工作的重点放在分子克隆上 我们有的细胞表面中期因子信号转导受体 用生化方法鉴定一株Wilms~肿瘤细胞系 技巧。最近的研究已经证实了 中期因子在肾母细胞瘤、肾细胞癌和肺癌中的表达 结肠癌和肝细胞癌。我们的研究还表明 中期因子在常染色体显性遗传性多囊肾病中的表达 (ADPKD)及其作为上皮细胞重要调节因子的作用 肾脏器官发生过程中的分化。 我们的假设是中期因子起着自分泌或旁分泌的作用。 它调节着几个生物过程，包括生长 ADPKD及其致癌过程中上皮细胞的调控 肾母细胞瘤的转化及其分化机制 调节肾小球系祖细胞在肾脏过程中的上皮转化 发展。我们计划用一种方法克隆中期因子受体基因 表达克隆法或配基亲和层析法 纯化MK受体蛋白。此外，我们还计划 研究中期因子信号转导途径，然后定义基本的 ALL在肾脏发育模式中的表达 中期因子信号转导通路的组成部分包括 中期因子受体的表达与其配体的关系。

The long term aim of the proposed research is to define the molecular structure and function of the midkine signal transduction pathway which regulates cellular proliferation and differentiation Special emphasis in this effort is placed on the molecular cloning of the cell surface Midkine signal transduction receptor which we have recently identify from a Wilms~ tumor cell line using biochemical techniques. Recent studies have established the importance of Midkine expression in Wilms~ tumor, renal cell carcinoma and lung, colon and hepatocellular carcinoma. Our studies have also shown Midkine expression in autosomal dominant polycystic kidney disease (ADPKD) and its role as an important mediator in epithelial differentiation during kidney organogenesis. Our hypothesis is that Midkine functions as an autocrine or paracrine which regulates several biological processes including the growth regulation of epithelial cells in ADPKD as well as in oncogenic transformation in Wilms~ tumor and in differential mechanisms which regulate epithelial conversion of renal progenitor cells during renal development. We plan to clone Midkine receptor gene using either an expression cloning approach or ligand affinity chromatography to purify the MK receptor protein. Additionally, we also plan to examine Midkine signal transduction pathway, then define the basic developmental pattern in the kidney of expression of all identified components of the midkine signal transduction pathway including expression of the Midkine receptor in relation to its ligand.