Adamietz I A, Hasler J, Renner K, Rimpler M
Department of Radiotherapy and Special Oncology, Medical School, Hannover, Federal Republic of Germany.
J Cancer Res Clin Oncol. 1990;116(1):65-8. doi: 10.1007/BF01612642.
Changes of the cell surface proteolytic activity during the cell cycle in vitro were reported. Using an easy assay, with casein as a substrate, the proteolytic activity on the surface of Ehrlich ascites tumor (EAT) cells grown in vivo was determined. The cleavage of casein incubated with EAT cells increased linearly for 20 min and permitted reproducible enzyme activity determinations. If the proliferation of exponentially growing EAT cells was partially synchronized by an intraperitoneal bleomycin injection, a significant increase of the surface enzymatic activity was observed in cells with an increased DNA content. This finding supports the results obtained with transformed cells in vitro, indicating that elevated proteolytic surface activity occurs in the late synthesis phase and prior to mitosis. However, the observed effect may also be due to changes of gene expression caused by bleomycin.
据报道，体外细胞周期中细胞表面蛋白水解活性会发生变化。采用一种简单的检测方法，以酪蛋白作为底物，测定了体内生长的艾氏腹水瘤（EAT）细胞表面的蛋白水解活性。与EAT细胞一起孵育的酪蛋白的裂解在20分钟内呈线性增加，从而能够进行可重复的酶活性测定。如果通过腹腔注射博来霉素使指数生长的EAT细胞的增殖部分同步化，那么在DNA含量增加的细胞中可观察到表面酶活性显著增加。这一发现支持了体外转化细胞所获得的结果，表明蛋白水解表面活性升高发生在合成后期和有丝分裂之前。然而，观察到的这种效应也可能是由于博来霉素引起的基因表达变化所致。
