Control of the growth of leukemic cells (L1210) through manipulation of trace metals.

Trace metals have a role in the activity of the enzyme ribonucleotide reductase (RR) which is essential for the synthesis of DNA and the growth of lymphocytes. Manipulation of the intracellular metals of leukemic cells has been proposed for the therapeutic control of cell growth. We studied the effects of prolonged metal deprivation (Fe, Cu, Zn) on cell growth and RR activity of murine leukemic lymphocytes in culture in metal-depleted media. Intracellular metals, cell growth and RR activity were decreased in related and interdependent ways. A metal-chelator (deferoxamine, DFX) had similar effect. In all cases these effects were reversible by metal supplementation. We conclude that it is possible to control RR activity and growth of leukemic cells in vitro by exposing them to a metal-poor environment (eg. through the action of a chelator). These effects are not permanent, but might be beneficial if integrated with more conventional measures (chemotherapy).