Differential Effects of Recombinant Human Granulocyte Colony-Stimulating Factor (rhG-CSF) on the Radiation Sensitivity of Normal Versus Leukemic Bone Marrow Progenitor Cell Populations

Abstract

We examined the effects of recombinant human granulocyte colony-stimulating factor (rhG-CSF), interleukin 3 (rhIL-3) and interleukin 6 (rhIL-6) on the radiation sensitivity of normal and leukemic bone marrow progenitor cell populations. Conditioning of leukemic progenitor cells (LPC) from acute lymphoblastic leukemia (ALL) patients with rhG-CSF enhanced their radiation sensitivity, whereas conditioning with rhIL-3 or rhIL-6 had the opposite effect. In contrast to its effects on LPC derived from ALL patients, rhG-CSF reduced the radiation sensitivity of normal myeloid progenitor cells as well as LPC from acute myeloblastic leukemia (AML) patients. Differential modulation of the radiation sensitivity of LPC by rhG-CSF may provide the basis for better total body irradiation (TBI) regimens for ALL patients undergoing autologous bone marrow transplantation (BMT).

Key Words:

• Recombinant human G-CSF
• radiation sensitivity
• bone marrow progenitors
• normal progenitors
• leukemic progenitors