Effect of cyclic polylactates on tumor cells and tumor bearing mice.

We studied the effect of cyclic polylactates ranging in size from a degree of polymerization number of 3 to 13 on pyruvate kinase, lactic dehydrogenase, anaerobic glycolysis, growth of tumor cells and survival of tumor bearing mice. Pyruvate kinase and lactic dehydrogenase activities were both inhibited by cyclic polylactates, and the inhibition mechanism of cyclic polylactates on lactic dehydrogenase was noncompetitive. About half the anaerobic glycolytic activity of FM3A ascites tumor cells was inhibited and tumor cell growth was also effectively inhibited by cyclic polylactates. Mice, which were treated with cyclic polylactates after inoculation of FM3A ascites tumor cells lived significantly longer than mice, which were treated with vehicle or non mice.