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Cell growth and second messengers

细胞生长和第二信使

基本信息

批准号：
04454071
负责人：
FUKUI Yasuhisa
金额：
$ 3.01万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1992
资助国家：
日本
起止时间：
1992 至 1994
项目状态：
已结题

项目摘要

We studied about cell responses after growth factor or differentiation factor stimulation on the aspect of synthesis of second messengers. Especially on phosphatidylinositol-3 kinase (PI3K), which is activated immediately after growth factor stimulation. First, to see the role of each domains, we produced the monoclonal antibodies to the various part of the 85kD subunit (p85). We have previously produced the antibodies to amino-terminal two third of the alpha type p85, however, there were no antibodies to the carboxyl-terminal portion of p85. We made such antibodies by immunizing mice with the peptides the corresponding to carboxyl-terminal portion of p85. Using the obtained antibodies, we analyzed the expression of p85 in various cell lines obtained from human cancers. One of the cell lines, HCC2998, expressed the smaller p85s instead of the wild type. The study on relationship between cell transformation and the mutation is now underway. For another subunit, p110, we have not succeeded in the production of the monoclonal antibodies.We also studied on the role of PI3K in osteoclasts. Inhibition of PI3K by a specific inhibitor, wortmannin, resulted in blockage of bone resorption.It appeared that the ruffled borders were not formed after inhibition of Pl3K.At the same time, the podosome, an F-actin structure specifically formed in osteoclasts, was lost. Stress fibers in the fibroblasts were not affected. These results suggest that the actin rearrangement is controlled strictly and that PI3K is involved in the control. The relationship between formation of podosomes and ruffled border is being studied.

我们从第二信使的合成方面研究了生长因子或分化因子刺激后的细胞反应。尤其是磷脂酰肌醇 3 激酶 (PI3K)，它在生长因子刺激后立即被激活。首先，为了了解每个结构域的作用，我们生产了针对 85kD 亚基 (p85) 各个部分的单克隆抗体。我们之前已经生产了针对 α 型 p85 氨基末端三分之二的抗体，但是，没有针对 p85 羧基末端部分的抗体。我们通过使用与 p85 羧基末端部分相对应的肽对小鼠进行免疫接种来制备此类抗体。使用获得的抗体，我们分析了从人类癌症获得的各种细胞系中 p85 的表达。其中一种细胞系 HCC2998 表达较小的 p85，而不是野生型。关于细胞转化与突变之间关系的研究正在进行中。对于另一个亚基p110，我们还没有成功生产单克隆抗体。我们还研究了PI3K在破骨细胞中的作用。特异性抑制剂渥曼青霉素对PI3K的抑制导致骨吸收受阻。抑制PI3K后似乎没有形成褶皱边界。同时，破骨细胞中特异形成的F-肌动蛋白结构足小体丢失。成纤维细胞中的应力纤维不受影响。这些结果表明肌动蛋白重排受到严格控制并且PI3K参与了控制。足体的形成和褶边边缘之间的关系正在研究中。