Weber M J
Cell. 1975 Jul;5(3):253-61. doi: 10.1016/0092-8674(75)90100-2.
We have examined the role of proteolytic activity in the genesis and maintenance of the transformed phenotype by growing cultures of chick embryo fibroblasts transfromed by Rous sarcoma virus either in medium containing plasminogen-free serum or in medium to which protease inhibitors were added. Alterations in morphology, adhesiveness, and hexose transport were used as markers for the transformed state. Addition of the trypsin inhibitors NPGB or Soy Bean Trypsin Inhibitor at concentrations which inhibited transformation-associated fibrinolysis restored adhesiveness and morphology to near normal, but did not affect the rate of hexose transport. Growth of Rous-infected cells in plasminogen-free medium blocked the appearance of morphological and adhesive alterations, but allowed the rate of hexose transport to increase to the transformed level. Thus we were able to separate the appearance of transformation-specific changes in morphology and adhesiveness (which apparently require fibrinolytic activity) from the increased rate of hexose transport (which is independent of fibrinolytic activity). Another trypsin inhibitor, TLCK, although it did not inhibit fibrinolysis, was very effective at restoring adhesiveness and morphology as well as hexose transport to normal. This raises the possibility that there is another, perhaps earlier, protease involved in the genesis of the transformed phenotype.
我们通过在含有无纤溶酶原血清的培养基中或添加了蛋白酶抑制剂的培养基中培养经劳氏肉瘤病毒转化的鸡胚成纤维细胞培养物，研究了蛋白水解活性在转化表型的产生和维持中的作用。形态、黏附性和己糖转运的改变被用作转化状态的标志物。添加浓度能抑制与转化相关的纤维蛋白溶解的胰蛋白酶抑制剂NPGB或大豆胰蛋白酶抑制剂可使黏附性和形态恢复到接近正常，但不影响己糖转运速率。在无纤溶酶原培养基中培养劳氏病毒感染的细胞可阻止形态和黏附性改变的出现，但使己糖转运速率增加到转化水平。因此，我们能够将形态和黏附性方面转化特异性变化的出现（显然需要纤维蛋白溶解活性）与己糖转运速率的增加（与纤维蛋白溶解活性无关）区分开来。另一种胰蛋白酶抑制剂TLCK虽然不抑制纤维蛋白溶解，但在使黏附性、形态以及己糖转运恢复正常方面非常有效。这增加了一种可能性，即存在另一种或许更早发挥作用的蛋白酶参与了转化表型的产生。
