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Properties and Physiological Roles of Cell Growth Inhibitors Present in Blood

血液中细胞生长抑制剂的特性和生理作用

基本信息

批准号：
60480500
负责人：
MIYAZAKI Kaoru
金额：
$ 4.03万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1985
资助国家：
日本
起止时间：
1985 至 1986
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-60480500/
关键词：
Growth inhibitor growth factor anti-tumor factor cancer cell culture serum platelet 精製

项目摘要

To understand the negative control mechanism of cell growth, growth inhibitory proteins (growth inhibitors) present in blood were surveyed using the non-malignant epithelial cell line from rat liver (BRL) and its malignant transformant (RSV-BRL) as the indicator cells.Rat serum contained a growth inhibitor that inhibited the growth of BRL but hardly that of RSV-BRL. This inhibitor existed as a protein complex with a <M_m> of about 220k and a pI of 5.2, but it was dissociated to an active component of a <M_r> of about 30k in the presence of denaturating reagents. The activity of the 220k inhibitor was increased more than 10-fold by treatment with a mixture of ethanol and acetone or with 1 M acetic acid. The growth inhibitor of 30k was purified about 6,000-fold.From human platelets, a growth inhibitor was extracted with acid-ethanol and purified to homogeniety. The purified growth inhibitor showed 50% inhibition on the growth of BRL at 20 pg/ml (0.7 pM), but hardly influenced the growth of RSV-BRL. Its inhibition was nearly specific for non-malignant epithelial cells. The purified inhibitor had a <M_r> of about 27k and was composed of two apparently identical subunits cross-linked with disulfide bonds. Isoelectric electrophoresis on polyacrylamide gel separated it into two active components with pI of 8.7 and 9.0, respectively.From rabbit serum, growth inhibitors with <M_r> of lower than 10k and pI of 5.0 and 6.5 were purified to homogeniety. Unlike the growth inhibitors from rat serum and human platelets, the growth inhibitors from rabbit serum more strongly inhibited the growth of RSV-BRL than that of BRL. Several human cancer cell lines were also sensive to the growth inhibitors. These results indicate that different species of growth inhibitors are involved in the control of cell growth in vivo.

为了解细胞生长的负调控机制，以大鼠肝脏非恶性上皮细胞系（BRL）及其恶性上皮细胞系（RSV-BRL）为指示细胞，检测了血液中存在的生长抑制蛋白（growth inhibitors，growth inhibitors）。该抑制剂以蛋白质复合物形式存在，a<M_m>约为220 k，pI为5.2，但在<M_r>变性剂存在下解离成a约为30 k的活性组分。用乙醇和丙酮的混合物或用1 M乙酸处理，220 k抑制剂的活性增加超过10倍。从人血小板中用酸-乙醇提取一种生长抑制剂，并纯化至均一。纯化的生长抑制剂在20 pg/ml（0.7 pM）时对BRL的生长显示50%的抑制，但对RSV-BRL的生长几乎没有影响。其抑制作用几乎特异于非恶性上皮细胞。纯化的抑制剂具有<M_r>约27 k的a，并且由两个用二硫键交联的明显相同的亚基组成。经聚丙烯酰胺凝胶等电电泳分离出两种活性成分，pI分别为8.7和9.0，从兔血清中纯化<M_r>出pI分别为5.0和6.5的生长抑制剂，其分子量均小于10 k。与大鼠血清和人血小板生长抑制剂不同，兔血清生长抑制剂对RSV-BRL的抑制作用比BRL强。几种人癌细胞系也对生长抑制剂敏感。这些结果表明，不同种类的生长抑制剂参与体内细胞生长的控制。