RT Journal Article
SR Electronic
T1 Expression of the Hemochromatosis (<em>HFE</em>) Gene Modulates the Cellular Uptake of <sup>67</sup>Ga
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 943
OP 946
VO 44
IS 6
A1 Chitambar, Christopher R.
A1 Wereley, Janine P.
YR 2003
UL http://jnm.snmjournals.org/content/44/6/943.abstract
AB Recent studies have revealed that the wild-type hemochromatosis protein (HFE) interacts with the transferrin receptor (TfR) and modulates TfR-mediated iron uptake by cells. Because of similarities in the transport of gallium and iron and the use of 67Ga scanning in lymphoid malignancies, we examined the effect of HFE expression on 67Ga uptake. Methods: 67Ga and 59Fe uptakes were measured in HeLa cells transfected with a FLAG-tagged wild-type HFE (fHFE) gene under control of a tetracycline-repressible promoter. fHFE and TfR protein levels were measured by Western blotting; cellular transferrin (Tf) binding sites were measured by 125I-Tf binding assay. Results: Induction of fHFE expression produced an increase in TfR protein that was accompanied by a decrease, rather than an increase, in cellular 67Ga and 59Fe uptake. The difference in 67Ga uptake between fHFE-expressing and fHFE-nonexpressing cells was markedly increased in the presence of Tf. Although fHFE expression produced an increase in cellular TfR protein, cell surface and intracellular Tf binding sites were actually decreased in these cells. Conclusion: Our studies suggest that expression of wild-type HFE in cells produces a decrease in 67Ga uptake due to a reduction in available Tf binding sites for 67Ga-Tf on the TfR. These results imply that 67Ga uptake by cells with wild-type HFE may differ from cells with the HFE C282Y mutation.