338 



On Respiratory Impairment in Cancer Cells 



glucose catabolism is so rapid in tumors that the normal Channels for disposal of 

 pyruvic acid are overloaded. Many possibilities exist for explaining this high 

 glucose catabolism, which do not involve disturbances in respiration. My colleagues 

 and I are now attempting to unravel the multiplicity of factors concerned with lactic 

 acid production in the intact cell. 



I do not wish to minimize the significance of the high aerobic and anaerobic 

 glycolysis of tumor tissue. It is conceivable that glycolytic activity, though not 

 resulting from a faulty respiration, may play a special role in the neoplastic process. 

 Data are available from the field of lipid metabolism, for example, which suggest 

 that some phase of glucose catabolism in liver is coupled with fatty acid synthesis 10 . 

 The close association of lactic acid production with the neoplastic process, and 

 with growth in general, makes this phenomenon a worthy subject of study. 



Warburg states ( 3 > p- 309 ), "We now understand the chemical mechanism of respi- 

 ration and fermentation almost completely . . ." We have, indeed, learned a great 

 deal of what can happen in cells, and much of this can be credited to Warburg, who 

 has played a large part in expanding our biochemical frontiers. The fact that pro- 

 gress has been so great in the past must make us aware, however, that future pro- 

 gress will also be great, and that our present knowledge is still primitive. Certainly 

 we have much to learn before we can feel we understand the mechanisms that 

 underlie the utilization of metabolic fuels for functional activities of cells. 



References and Notes 



1 Warburg, O., Metabolism of Tumors, translated by 

 F. Dickens (Constable, London, 1930). 



2 Naturwissenschaften 402 (1955), 401. 



3 Science 123 (1956), 309. 



4 BuRK, D., Cold Spring Harbor Symposia Quant. Biol. 

 7 (1939), 420. 



5 Schmidt, C. G., Klin. Wochschr. 33 (1955), 409. 



fi Weinhouse, S., Advances in Cancer Research 3 (1955), 

 269. To save space, original references are not cited, 

 but references are given to the appropriate page of the 



writer's review. This may be consulted for a more 

 detailed discussion of this subject. 



7 Dickens, F., The Enzymes (Academic, New York, 

 1955), vol. II, pt. 1, p. 624. 



8 Wenner, C. E., and Weinhouse, S., Cancer Research 

 15 (1955), 497. 



9 Greenstein, J. P., Biochemistry of Cancer (Academic, 

 New York, 1954). 



10 Gurin, S., Fat Metabolism (Johns Hopkins Press, 

 Baltimore, Md., 1954), p. 138. 



