Cai J W, Henderson B W, Shen J W, Subjeck J R
Division of Radiation Biology, Roswell Park Cancer Institute, Buffalo, New York 14263.
J Cell Physiol. 1993 Feb;154(2):229-37. doi: 10.1002/jcp.1041540204.
Chronic anoxia, glucose starvation, low pH, and numerous other conditions induce the glucose-regulated system of stress proteins (GRPs), whose principal members are observed at 78, 94, and 170 kDa. These stresses may be expected to occur during growth in untreated tumors. To examine the possibility that GRPs are correspondingly induced, we have examined the protein profiles of small (< 0.1 g), intermediate (0.2-0.8 g), and large (> 1.8 g) radiation-induced fibrosarcoma (RIF) tumors grown on C3H mice. One and two-dimensional gel electrophoresis indicate that the principal GRPs at 78 and 94 are coordinately and substantially increased in large tumor masses, relative to the small, and may be partially increased in the intermediate tumors. Necrotic material removed from large tumors exhibited an identical pattern of GRP induction with no visible indication of protein degradation and also contained a significant fraction of viable cells. Western blot analysis using rabbit antisera raised against the 78 and 170 kDa GRPs also demonstrated the enhanced accumulation of these proteins in the large tumors. The antibody against the 170 kDa GRP was also capable of detecting the induction of this stress protein in large tumors by indirect immunofluorescence analysis. Northern blot studies using a probe for the GRP 78 gene also showed an increase in GRP 78 message in large tumors as well as in RIF cells exposed to anoxic stress in vitro. Two-dimensional gel electrophoresis indicated that the major heat shock proteins at 70 and 90 kDa were not increased in the larger tumors, and the amount of the 90 kDa species was reduced. Finally, the quantity of vimentin and its degradation products is significantly diminished in large tumors and in anoxic cells. This study demonstrates that RIF tumor cells undergo a glucose regulated stress response in situ during tumor growth.
慢性缺氧、葡萄糖饥饿、低pH值以及许多其他条件会诱导应激蛋白的葡萄糖调节系统（GRPs），其主要成员在78、94和170 kDa处被观察到。这些应激情况在未经治疗的肿瘤生长过程中可能会出现。为了研究GRPs是否相应地被诱导，我们检测了在C3H小鼠身上生长的小（<0.1 g）、中（0.2 - 0.8 g）和大（>1.8 g）辐射诱导纤维肉瘤（RIF）肿瘤的蛋白质谱。一维和二维凝胶电泳表明，相对于小肿瘤块，大肿瘤块中78和94 kDa处的主要GRPs协同且显著增加，中等大小肿瘤中可能部分增加。从大肿瘤中去除的坏死物质呈现出相同的GRP诱导模式，没有可见的蛋白质降解迹象，并且还含有相当一部分活细胞。使用针对78和170 kDa GRPs产生的兔抗血清进行的蛋白质印迹分析也证明了这些蛋白质在大肿瘤中的积累增强。针对170 kDa GRP的抗体也能够通过间接免疫荧光分析检测到大肿瘤中这种应激蛋白的诱导。使用GRP 78基因探针进行的Northern印迹研究也显示，大肿瘤以及体外暴露于缺氧应激的RIF细胞中GRP 78信息增加。二维凝胶电泳表明，70和90 kDa处的主要热休克蛋白在较大肿瘤中没有增加，并且90 kDa蛋白的量减少。最后，波形蛋白及其降解产物的量在大肿瘤和缺氧细胞中显著减少。这项研究表明，RIF肿瘤细胞在肿瘤生长过程中在原位经历了葡萄糖调节的应激反应。
