AN ENZYMATIC FUNCTION ASSOCIATED WITH TRANSFORMATION OF FIBROBLASTS BY ONCOGENIC VIRUSES
AN ENZYMATIC FUNCTION ASSOCIATED WITH TRANSFORMATION OF FIBROBLASTS BY ONCOGENIC VIRUSES
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与致癌病毒转化成纤维细胞相关的酶功能
DOI：
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发表时间：
1973
影响因子：
15.3
通讯作者：
E. Reich
中科院分区：
文献类型：
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作者：
L. Ossowski;J. C. Unkeless;A. Tobia;James P. Quigley;Daniel B. Rifkin;E. Reich
经DNA或RNA病毒转化的鸡、仓鼠、小鼠和大鼠胚胎成纤维细胞在适当的生长条件和适当的介质中显示出纤溶活性，而正常的相应培养物则没有。纤溶酶是由两种蛋白质因子相互作用产生的：其中一种是细胞因子，由转化的细胞释放，当培养物在没有Scrum的情况下孵育时，在培养基中积累。第二个因子，血清因子，是一种特殊的蛋白质，存在于包括人类在内的许多鸟类和哺乳动物的血清中。并不是所有的血清都在与任何给定的转化细胞因子相互作用时产生纤溶酶，而且激活血清的光谱对每种细胞因子都是不同的。这种模式似乎是由细胞类型决定的，而不是由转化的病毒决定的。纤溶酶在致癌转化中起着重要的作用，相关关系如下。(A)在感染RSV温度敏感突变体的鸡成纤维细胞培养物转移到允许温度后，纤溶酶的初始出现先于形态变化。(B)纤溶和形态变化的启动都需要合成新的蛋白质，但不需要合成DNA或rRNA。(C)纤溶酶的活性与SV-40转化的仓鼠细胞中异常形态的保留有关。(D)正常雏鸡的血清有效地激活了转化的鸡细胞中的细胞因子的纤溶作用。相比之下，患有呼吸道合胞病毒肿瘤的雏鸡的血清则没有；这些血清含有纤溶活性的抑制物。
Chick, hamster, mouse, and rat embryo fibroblast cultures, transformed by either DNA or RNA viruses, show fibrinolytic activity under suitable conditions of growth and in appropriate media; normal counterpart cultures do not. The fibrinolysin is produced by the interaction of two protein factors: one of these, a cell factor, is released by transformed cells and accumulates in the medium when cultures are incubated in the absence of scrum. The second factor, the serum factor, is a specific protein that is present in sera of many avian and mammalian species, including man. Not all sera yield fibrinolysin on interaction with any given transformed cell factor, and the spectrum of activating sera is distinctive for each cell factor. This pattern appears to be determined by the cell type, rather than by the transforming virus. An important role for the fibrinolysin in oncogenic transformation is suggested by the following correlations. (a) The initial appearance of fibrinolysin precedes the morphological change after the transfer to permissive temperatures of chick fibroblast cultures infected with a temperature-sensitive mutant of RSV. (b) The initiation of fibrinolysis and of morphological change both require the synthesis of new protein, but not the synthesis of either DNA or rRNA. (c) The activity of the fibrinolysin is correlated with the retention of abnormal morphology in hamster cells transformed by SV-40. (d) The sera of normal chicks effectively activate fibrinolysis with the cell factor from transformed chick cells. In contrast the sera of chicks with RSV tumors do not; these contain an inhibitor of the fibrinolytic activity.