Phosphorylated intermediates in tumor glycolysis; isolation of phosphate esters from tumors.

In an investigation to determine whether phosphorylated intermediates are concerned in tumor glycolysis a series of analyses was carried out for the esters and related components of the EmbdenMeyerhof glycolysis scheme (3). The methods used were dependent upon specific properties of these metabolites, shown to be dependable for analyses in certain differentiated tissues by isolations and experiments with the pure compounds. In order to establish whether these same methods were valid for analyses of tumor tissue it was advisable to attempt isolation of certain of the metabolites. To obtain the pure materials in high yield would indicate dependability of the assays. I t was also desired to investigate whether certain esters, apparently unrelated to the phosphorylative glycolysis, were present in tumors obtained by in situ freezing, namely aminoethyl phosphate and 1,2propanedioI phosphate. Outhouse (5, 6) reported the presence of aminoethyl phosphate as some 20 per cent of the acidsoluble organic phosphorus of malignant tumors. Colowick and Cori (2) later found it could be isolated in similar amount from intestinal mucosa. In a recent publication Lindberg (4) reported the presence of a new ester, 1,2-propanediol phosphate, in brain and other organs. I t appeared to constitute 5 per cent of the acid-soluble organic phosphorus of brain, 1 to 2 per cent in liver and kidney. He presented evidence that it was concerned in the metabolism of sugars, and indicated that it might 9 play a part in ribose formation. Since ribose is a necessary constituent of nucleotides and nucleic acids, it was of interest to determine whether this ester was present in tumors.