Sarcoma cells exhibit higher rates of glycolysis than normal tissues and may be dependent on
glucose utilization for growth. Accordingly, we tested the ability of the
glucose antimetabolite 2-deoxy-D-glucose (2-DG) to inhibit the growth of an established
methylcholanthrene-induced rat
fibrosarcoma in three groups of F344 rats with increasing subcutaneous inoculations of
tumor (2 X 10(6) cells, 1 X 10(7) cells, and 1 mm
tumor fragments). Rats were randomized to receive 2-DG or
saline solution at doses of 0.75 gm/kg, 1.5 gm/kg, or 1.75 gm/kg, beginning 3 days after
tumor implantation and continuing for 10 days.
Tumors were removed and weighed on day 14. We measured tissue [14C]-2-DG levels in
tumor, brain, liver, and muscle after
intraperitoneal injection of radiolabeled 2-DG. In these same tissues we determined the activity of
glucose-6-phosphatase (G-6-Pase), an
enzyme which dephosphorylates the intracellular glycolytic inhibitor 2-DG-6-phosphate, thus reversing the antitumor effect of 2-DG. All groups treated with 2-DG had a significant reduction in
tumor weight of 50% to 70% when compared with
saline solution-treated controls. Toxicity was substantial at the highest dose of 2-DG, but minimal toxicity was noted at intermediate and low doses.
Tumor had the greatest uptake of [14C]-2-DG, with low levels of G-6-Pase leading to prolonged retention and highest tissue levels of radiolabeled 2-DG. Use of 2-DG inhibits established
sarcoma growth because it is rapidly transported into
tumors, cannot be metabolized after phosphorylation, and is dephosphorylated and released slowly from
tumor cells. Rat
sarcoma growth is dependent on
glucose utilization and can be effectively inhibited by
glucose antagonism.