IRON-RESPONSIVE ELEMENT-BINDING PROTEIN (IRE-BP) IN LEUKEMIC-CELLS - ANALYSIS USING ENZYME-LINKED-IMMUNOSORBENT-ASSAY AND SEMIQUANTITATIVE POLYMERASE CHAIN-REACTION

The level of iron responsive element-binding protein (IRE-BP) in leuke mic cells, which is essential for iron homeostasis and plays an import ant role in cell metabolism and cell growth, was measured using an enz yme-linked immunosorbent assay (ELISA). Comparing the levels in differ ent clinical stages, the levels in CML cells in the chronic phase (mea n +/- S.E., 0.270 +/- 0.110 U/mg protein, n = 9) and those in AML cell s (0.150 +/- 0.104 U/mg) protein, n = 21) were significantly lower tha n that in normal granulocytes (0.628 +/- 0.216 U/mg protein, n = 9, p < 0.001 vs CML and AML). Analysis of IRE-BP mRNA expression in leukemi c cells using semiquantitative polymerase chain reaction showed suppre ssed expression of mRNA as compared to normal bone marrow cells. These observations suggest that there may be dysregulation of IRE-BP expres sion and production in leukemic cells.