Granulocyte colony-stimulating factor receptors in human acute myelocytic
leukemia
LM Budel, IP Touw, R Delwel and B Lowenberg
Dr Daniel den Hoed Cancer Center, Rotterdam, The Netherlands.
The binding of granulocyte colony-stimulating factor (G-CSF) to normal and
human acute myeloid leukemia (AML) cells was investigated with radiolabeled
recombinant human G-CSF (rhG-CSF). In all 14 cases of primary AML specific
receptors for G-CSF were demonstrated on purified blast cells. The average
numbers of G-CSF receptors ranged from very low to 428 receptors per cell
(mean). Normal granulocytes showed G-CSF binding sites on their surface at
higher densities (703 to 1,296 sites per cell). G-CSF receptors appeared to
be of a single affinity type with a dissociation constant (kd) ranging
between 214 and 378 pmol/L for AML blasts and 405 to 648 pmol/L for
granulocytes. In 12 of 14 cases, including those with relatively low
specific binding, G-CSF was a potent inducer of DNA synthesis of blasts in
vitro; therefore, apparently relatively few receptors are required to
permit activation of AML cell growth. However, in two cases cell cycling
was not activated in response to G-CSF despite G-CSF receptor availability.
The results show that G-CSF receptors of high affinity are frequently
expressed on the blasts of human AML, but their presence may not be a
strict indicator of the proliferative responsiveness of the cells to G-
CSF.
Volume 74,
Issue 8,
pp. 2668-2673,
12/01/1989
Copyright © 1989 by The American Society of Hematology
