Iron-dependent expression of transferrin receptor (TfR) and UbcH5A mRNA normalized to actin mRNA levels in HepG2 cells.

Panel A shows expression of transferrin receptor (TfR); panel B shows expression of UbcH5A mRNA. Incubation was performed with 50 μM deferoxamine (DFO) for 18 hours and with 65 μM Fe-NTA for 72 hours. For expression analyses, a 2-step, real-time RT-PCR on the LightCycler system was used. TfR/actin and UbcH5A/actin ratios were calculated using the LightCycler Relative Quantification Software Version 1.0 (Roche Molecular Biochemicals), which provides a fully automated efficiency-corrected relative quantification. The mean values from 8 independent experiments are shown. The error bars represent 95% confidence intervals. The differences between TfR/actin ratios are statistically significant (P < .01). UbcH5A/actin ratios do not differ significantly.