INHIBITION OF GROWTH OF THE LYMPHOCYTE LINES BY DEFEROXAMINE UNDER VARIOUS IRON-SUPPLY CONDITIONS

Inhibition of growth of the lymphocyte lines by iron-binding agent def eroxamine under various iron-supply conditions was studied. Three diff erent defined culture media, representing three different iron-supply conditions, were used: (1) ferric citrate (500 muM) medium, (2) transf errin (5 mug/ml) medium, and (3) low-iron medium (this medium without any iron compound added contains 0.6 muM contaminative non-transferrin iron). Mouse B cell line PLV-01, human T cell line Jurkat, and human B cell lines Raji and HSCE- were employed. Raji and HSCE- cells are ab le to grow in low-iron medium but PLV-01 and Jurkat cells do not grow in the medium. For all cell lines tested in ferric citrate medium, a 5 0% growth inhibition was achieved with 440-500 muM deferoxamine. In tr ansferrin medium, deferoxamine concentrations of 4.4-5.5 muM were requ ired for a 50% inhibition of PLV-01, Jurkat and HSCE- cells. For the s ame degree of inhibition of Raji cells, 39 muM deferoxamine was requir ed. In the case of low-iron medium, a 50% inhibition of Raji and HSCE- cells was achieved with about 1.4-2.1 muM deferoxamine. The data demo nstrate that the sensitivity of the lymphocyte lines to deferoxamine d epends on iron-supply conditions. Under the same iron-supply condition s, individual cell lines can exhibit different sensitivity. However, t he sensitivity does not correlate with the ability of the cell lines t o grow in low-iron medium.