Uptake of gallium-67 by human leukemic cells: demonstration of transferrin receptor-dependent and transferrin-independent mechanisms. Cancer Res 1987 Aug 01;47(15):3929-34
Date
08/01/1987Pubmed ID
3475168Scopus ID
2-s2.0-0023262160 (requires institutional sign-in at Scopus site) 124 CitationsAbstract
We have studied the role of transferrin and the transferrin receptor in the uptake of 67Ga by the human leukemic cell line HL60. In the absence of transferrin, HL60 cells incorporated about 1% of the 67Ga dose over 6 h. The presence of transferrin increased cellular 67Ga uptake approximately 10-fold. Transferrin-mediated uptake of 67Ga was blocked by an anti-transferrin receptor monoclonal antibody, and decreases in the density of cellular transferrin receptors led to corresponding decreases in the transferrin-dependent uptake of 67Ga. Changes in the cellular ferritin content did not significantly influence the uptake of 67Ga by either transferrin-independent or transferrin-dependent pathways. Regardless of the mechanism of uptake, a significant amount of intracellular 67Ga was found to be associated with immunoprecipitable ferritin as well as with a free pool. This free intracellular 67Ga appeared to be kinetically active since cells released 67Ga back to the media over time. Our results demonstrate the existence of a dual mechanism for the cellular uptake of 67Ga and suggest that the preferential uptake of 67Ga by lymphomas is related to the high density of transferrin receptors known to be expressed by these tumors in vivo.
Author List
Chitambar CR, Zivkovic ZMESH terms used to index this publication - Major topics in bold
Antibodies, MonoclonalBiological Transport
Cell Compartmentation
Cell Line
Ferritins
Gallium Radioisotopes
Iron
Leukemia, Myeloid, Acute
Receptors, Transferrin
Transferrin
