Bustamante E, Morris H P, Pedersen P L
J Biol Chem. 1981 Aug 25;256(16):8699-704.
Rat liver cytoplasm (postnuclear supernatant) has a low aerobic glycolytic rate in the presence of added glucose, ATP, ADP, Pi, and NAD+, whereas cytoplasm from Ehrlich ascites tumor cells exhibit a high aerobic glycolytic rate which is typical of rapidly proliferating tumor cells. Tumor mitochondria, unlike liver mitochondria, contain bound hexokinase which constitutes about 70% of the total cellular hexokinase activity. The high aerobic glycolytic rate of Ehrlich tumor cytoplasm is reduced markedly if the mitochondria are removed and can be restored almost completely upon addition of the hexokinase-containing tumor mitochondria to tumor cytosol (postmitochondrial supernatant). Addition of tumor mitochondria to liver cytosol can enhance its glycolytic rate to levels approaching those of tumor cytoplasm, whereas added liver mitochondria are without effect on the already low glycolytic rate of liver cytosol. Addition of tumor mitochondria to tumor cytosol increases its glycolytic rate to the level of tumor cytoplasm, as mentioned above, but liver mitochondria added to tumor cytosol actually depress its glycolytic rate to the level of liver cytosol. The stimulatory effect of tumor mitochondria on liver cytosol can be ascribed to its associated hexokinase activity since hexokinase specifically removed from mitochondria of tumor cells can also enhance the glycolytic rate of liver cytosol. The depressing effect of added liver mitochondria on tumor cytosol glycolysis suggests that liver mitochondria can compete more effectively than tumor mitochondria for a common intermediate and/or cofactor. Examination of 12 different tumor cell lines revealed that only those which reached maximum size in 1 month or less, and which have elevated glycolytic activities, had detectable mitochondrially associated hexokinase activity. The studies reported here describe resolution and reconstitution of tumor cytoplasm, supplementation of cytosol with intact mitochondria or mitochondrial hexokinase, and a survey of mitochondrial hexokinase content in various tumors, and provide strong evidence for the view (Bustamante, E., and Pedersen, P. L. (1977) Proc. Natl. Acad. Sci. U. S. A. 74, 3735-3739) that a form of hexokinase with a propensity for mitochondrial binding plays a key role in the high aerobic glycolysis of cancer cells.
在添加葡萄糖、ATP、ADP、磷酸和NAD⁺的情况下，大鼠肝脏细胞质（核后上清液）的有氧糖酵解速率较低，而艾氏腹水瘤细胞的细胞质则表现出较高的有氧糖酵解速率，这是快速增殖肿瘤细胞的典型特征。与肝脏线粒体不同，肿瘤线粒体含有结合型己糖激酶，其占细胞总己糖激酶活性的约70%。如果去除线粒体，艾氏肿瘤细胞质的高有氧糖酵解速率会显著降低，而向肿瘤细胞溶胶（线粒体后上清液）中添加含己糖激酶的肿瘤线粒体后，该速率几乎可以完全恢复。向肝脏细胞溶胶中添加肿瘤线粒体可将其糖酵解速率提高到接近肿瘤细胞质的水平，而添加的肝脏线粒体对肝脏细胞溶胶本就较低的糖酵解速率没有影响。如上文所述，向肿瘤细胞溶胶中添加肿瘤线粒体可将其糖酵解速率提高到肿瘤细胞质的水平，但向肿瘤细胞溶胶中添加肝脏线粒体实际上会将其糖酵解速率降低到肝脏细胞溶胶的水平。肿瘤线粒体对肝脏细胞溶胶的刺激作用可归因于其相关的己糖激酶活性，因为从肿瘤细胞线粒体中特异性去除的己糖激酶也可提高肝脏细胞溶胶的糖酵解速率。添加的肝脏线粒体对肿瘤细胞溶胶糖酵解的抑制作用表明，肝脏线粒体比肿瘤线粒体更有效地竞争共同的中间产物和/或辅助因子。对12种不同肿瘤细胞系的研究表明，只有那些在1个月或更短时间内达到最大尺寸且糖酵解活性升高的细胞系，才具有可检测到的与线粒体相关的己糖激酶活性。此处报道的研究描述了肿瘤细胞质的解析与重组、用完整线粒体或线粒体己糖激酶补充细胞溶胶，以及对各种肿瘤中线粒体己糖激酶含量的调查，并为以下观点提供了有力证据（布斯塔曼特，E.，和佩德森，P. L.（1977年）《美国国家科学院院刊》74，3735 - 3739），即一种倾向于结合线粒体的己糖激酶形式在癌细胞的高有氧糖酵解中起关键作用。
