Metabolic characteristics of different malignant cancer cell lines.

Extracellular AMP inhibits cell proliferation of MCF-7 and MDA-MB-453 whereas cell proliferation of the highly malignant Novikoff cell line is not affected. In medium with low glucose supply MDA-MB-453 cells grow well, Novikoff cells are slightly inhibited and MCF-7 cells are totally unable to grow. Isoelectric focusing revealed that a glyclytic enzyme complex exists in all three cell lines. In addition to the glycolytic enzymes, c-Raf-kinase, adenylate kinase, and nucleoside diphosphate kinase are also found within the complex. The differences in glucose in dependence of the three cell lines can be explained by the different constitutions of shuttle enzymes. MDA-MB-453 and Novikoff cells contain cytsolic glycerol 3-phosphate dehydrogenase which is associated with glyceraldehyde 3-phosphate dehydrogenase within the glycolytic enzyme complex and which is responsible for the transport of cytoslic hydrogen in the mitochondria. MCF-7 and Novikoff cells contain the pI 7.8 form of malate dehydrogenase which couples glycolysis with glutaminolysis.