Iron-dependent modulation of TfR mRNA levels in primary SCF progenitors compared with erythroleukemic and somatic cell types.

Iron-dependent modulation of TfR mRNA was compared in primary and transformed erythroid (SCF, c-Kit, HD3E22) as well as nonerythroid (MC29-HD11 and LMH) cell types. The cells were cultured under different iron supply for 24 hours; no additional iron, 1 mg/mL Tf (= 25μM Fe), 20 μg/mL FAC (= 63 μM Fe), and 50 μM DFO. TfR mRNA levels were determined as described in the legend of Figure 2. To emphasize the iron-dependent changes in TfR mRNA levels between the different cell types, the respective maximal values were set to 100%. Note that the relatively “small” differences in mRNA abundance (as compared to other reports in the literature) are due to the linear quantification by PhosphoImage analysis used here as compared to densitometric evaluation of autoradiographs, which has a tendency to underestimate both very low as well as very high signal intensities.