Metabolic characteristics of different malignant cancer cell lines

Extracellular AMP inhibits cell proliferation of MCF-7 and MDA-MB-453 where as cell proliferation of the highly malignant Novikoff cell line is not aff ected. In medium with low glucose supply MDA-MB-453 cells grow well, Noviko ff cells are slightly inhibited and MCF-7 cells are totally unable to grow. Isoelectric focusing revealed that a glyclytic enzyme complex exists in al l three cell lines. In addition to the glycolytic enzymes, c-Raf-kinase, ad enylate 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 S-phosphate dehydrogenase within th e glycolytic enzyme complex and which is responsible for the transport of c ytoslic hydrogen in the mitochondria. MCF-7 and Novikoff cells contain the pI 7.8 form of malate dehydrogenase which couples glycolysis with glutamino lysis.