1. Characterization of Nuclear Retinoic Acid-Binding Activity in Sensitive Leukemic-Cell Lines - Cell-Specific Uptake of Atra and Rarα Protein Modulation
- Author
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B Gourmel, M. Cornic, N. Cambier, M L Menot, Christine Chomienne, M.P. Gaub, Laurent Degos, A Agadir, P Lefebvre, and M. Jerome
- Subjects
Receptors, Retinoic Acid ,Blotting, Western ,Biophysics ,Retinoic acid ,Tretinoin ,Retinoic acid receptor beta ,Biology ,Transfection ,Biochemistry ,Antibodies ,Cell Line ,Retinoic acid-inducible orphan G protein-coupled receptor ,chemistry.chemical_compound ,Leukemia, Promyelocytic, Acute ,Chlorocebus aethiops ,Tumor Cells, Cultured ,Animals ,Humans ,Retinoic acid binding ,Receptor ,neoplasms ,Molecular Biology ,Cell Nucleus ,Retinoic Acid Receptor alpha ,organic chemicals ,Antibodies, Monoclonal ,Biological Transport ,Cell Differentiation ,Cell Biology ,Retinoic acid receptor gamma ,Flow Cytometry ,Molecular biology ,Recombinant Proteins ,biological factors ,Molecular Weight ,Kinetics ,Retinoic acid receptor ,chemistry ,Retinoic acid receptor alpha ,Electrophoresis, Polyacrylamide Gel - Abstract
The diverse effects of all-trans retinoic acid (ATRA) on growth, differentiation and homeostasis of vertebrate organisms are mediated by three distinct isoforms of retinoic acid receptors (RARs). Although it is not known to what extent each RAR contributes to the different effects of ATRA, several studies have demonstrated that ATRA induced granulocytic differentiation in human myeloid leukemic cell lines is mediated by RAR alpha. In this study, we investigated ATRA binding affinity of the endogenous nuclear receptors of HL-60 and NB4 leukemic cells. Scatchard plot analysis yielded an apparent dissociation constant of 5 +/- 0.3 nM and 1400 +/- 80 receptor sites per cell in HL-60 cells, whereas the NB4 promyelocytic leukemic cell line showed a lower affinity (8.5 +/- 0.5 nM and 900 +/- 30 receptor sites per cell). Modulation of RAR alpha protein (5 fold excess) was found in NB4 cells after 24 hours ATRA exposure, whereas HL-60 cells required a 72-hour culture period to weakly increase the RAR alpha protein level. These data were closely related to the ATRA intracellular concentration and kinetics of terminal differentiation of the cells.
- Published
- 1995
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