2-Desoxyl-D-glucose as an inhibitor of anaerobic glycolysis in tumor tissue

NOTES FROM THE BIOCHEMICAL RESEARCH FOUNDATION ELLICE McDONALD, DIRECTOR 2-DESOXY-D-GLUCOSE

AS A N I N H I B I T O R O F A N A E R O B I C G L Y C O L Y S I S IN TUMOR TISSUE BY

GLADYS E. WOODWARD AND FRANCIS B. CRAMER

It has recently been shown that 2-desoxy-D-glucose (2DG), acting as an analogue of glucose, competitively inhibits the fermentation (anaerobic metabolism) of glucose by whole yeast(I). Preliminary experiments have now shown that 2DG also inhibits the anaerobic metabolism of glucose by surviving tumor cells in tissue slices. Fresh Walker 256 rat carcinoma was sliced to a thickness of 0.5 ram. in a Stadie-Riggs microtome. The slices were suspended in an isotonic mixture of Ringer's solution and sodium bicarbonate in a Warburg apparatus(z). Approximately the same amount of fresh tissue (about 20 rag. dry weight) was used in each flask. The rate of anaerobic glucose metabolism was determined by measurement of the COs liberated from bicarbonate by lactic acid elaborated by the tumor cells, following Warburg's procedure.

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I n h i b i t o r y effect of 0.05 r~ 2 D G on glycolysis b y W a l k e r 256 t u m o r slices in b i c a r b o n a t e - R i n g e r ' s m e d i u m c o n t a i n i n g 0.05 M glucose. 259

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The exper:imental data obta!ined are presented graphically in Fig. 1. Curve A (con.Lrol) represent,~ the rate of COs evolution in a bicarbonateRinger's solution containing 0.05 :~ glucose. Curw.' B shows the lowered rate of CO~ evolution in the medium containing 0.05 M glucose when 0.05 M 2DG was also present be.fore measurements were begun. Comparison of Curves A anti B indicates that glucose metabolism was inhibited 63 per cent by an equi-molar quantity of 2DG. Curve C represents the ,effect produced by the addition of an equimolar quantity of 2DG to a system in active glycolysis, similar to the control experiment. After 24 minutes, sufficient 2DG was tipped in from the side-arm to establish the conditions of the experiment represented by Curve B. A period of about 20 minutes was required before the full inhibitory effect of the 2DG was established. Comparison of the rates of CO2 evolution before and after addition of 2DG indicates 60 per cent inhibition of the anaerobic metabolism of glucose by an equi-molar quantity of 2DG. This is in good agreement with the value (63 per cent) obtained by comparison of Curves A and B. Additional experiments have confirmed these results. The inhibitory effect of 2DG on glycolysis by Walker 256 tumor cells was slightly less than the inhibition (78 per cent) of the fermentation of glucose by whole yeast(l). The delayed response following addition of 2DG to the mixture in active glycolysis (Curve C) is probably due to the approximately 50-cell thickness of the tissue slices as contrasted with the immediate response to added 2DG in the individual-cell suspension of yeast. Insufficient data are available to determine whether the inhibition of tumor glycolysis follows the laws of competitive inhibition. Additional work with a more satisfactory (less necrotic) tumor is being undertaken at this laboratory. SUMMARY

Anaerobic glucose metabolism of slices of Walker 256 rat carcinoma was found to be inhibited approximately 60 per cent by an equi-molar quantity of 2-desoxy-D-glucose. REFERENCES

(1) F. B. CRAMER AND G. E. WOODWARD,JOUR. FRANKLIN INST., 253, 354 (1952). (2) O. WARBURG, "The Metabolism of Turnouts," London, Constable and Co., Ltd., 1930.