Uptake of Ga-67 by Cultured Cells: Transferrin-dependent and Transferrin-independent Mechanisms.
- Author:
Myung Hee SOHN
1
;
Seok Tae LIM
;
Jae Yong KWAK
;
Chang Yeol YIM
Author Information
1. Deparments of Nuclear Medicine, Chonbuk National University Medical School, Chonju, Korea.
- Publication Type:Original Article
- Keywords:
Ga-67;
Transferrin;
Mechanism;
Cultured cells;
Transformation
- MeSH:
Antibodies;
Cells, Cultured*;
Phenotype;
Radioactivity;
Transferrin;
Trypsin
- From:Journal of the Korean Cancer Association
2000;32(4):742-749
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
PURPOSE: We determined whether the uptake of Ga-67 by cultured cells occur by both transferrin (Tf)-dependent and independent mechanisms and the mechanism and magnitude of its uptake may vary as the degree of expression of the transformed phenotype. MATERIALS AND METHODS: Uptake of Ga-67 between the tansformed and untransformed cells was compared. Cells were incubated with Ga-67 in either the presence or absence of Tf and with complete medium containing Ga-67 after preincubating with anti-Tf receptor antibodies at 37oC in 8% CO2. Monolayers of cells were washed and trypsinized. Radioactivity and protein content of the samples were determined. RESULTS: Uptake of Ga-67 by cultured cells occurred both in Tf-bound and ionic form and was increased with radioactivity and time. The magnitude for the uptake of Tf-bound form was approximately 3 and 6-fold greater than ionic form. In the presence of Tf, uptake of Ga-67 was 2-fold greater in the transformed cells. Conversely, In the absence of Tf, it was 1.5-fold greater in the untransformed cells. Regardless of blocking the Tf receptor by anti-Tf receptor antibodies, a significant amount of intracellular Ga-67 uptake was found. CONCLUSION: Dual mechanisms exist for the uptake of Ga-67 by cultured cells. The primary important one was the Tf-dependent system. Tf-dependent and independent mechanisms and the magnitude operated oppositely in the transformed cells when compared to their untransformed counterpart.
