Postirradiation treatment with granulocyte colony-stimulating factor and preirradiation WR-2721 administration synergize to enhance hemopoietic reconstitution and increase survival.
These studies tested whether WR-2721 could be used to protect hemopoietic stem cells, which after irradiation could be stimulated by granulocyte colony-stimulating factor (G-CSF) to proliferate and reconstitute the hemopoietic system. Female C3H/HeN mice were administered WR-2721 (4 mg/mouse, i.p.) 30 min before 60Co irradiation and G-CSF (2.5 micrograms/mouse/day, s.c.) from days 1-16 after irradiation. In survival studies, saline, G-CSF, WR-2721, and WR-2721 + G-CSF treatments resulted in LD50/30 values of 7.85 Gy, 8.30 Gy, 11.30 Gy, and 12.85 Gy, respectively. At these LD50/30 values, the dose reduction factor (DRF) of 1.64 obtained in combination-treated mice was more than additive between the DRF's of G-CSF-treated mice (1.06) and WR-2721-treated mice (1.44). Bone marrow and splenic multipotent hemopoietic stem cell (CFU-s) and granulocyte-macrophage progenitor cell (GM-CFC) recoveries were also accelerated most in mice treated with WR-2721 + G-CSF. In addition, mice treated with WR-2721 + G-CSF exhibited the most accelerated peripheral blood white cell, platelet, and red cell recoveries. These studies (a) demonstrate that therapeutically administered G-CSF accelerates hemopoietic reconstitution from WR-2721-protected stem and progenitor cells, increasing the survival-enhancing effects of WR-2721 and (b) suggest that classic radioprotectants and recombinant hemopoietic growth factors can be used in combination to reduce risks associated with myelosuppression induced by radiation or radiomimetic drugs.
Armed Forces Radiobiology Research Institute, Bethesda, MD 20889-5145.
M L
ML
Patchen
T J
TJ
MacVittie
L M
LM
Souza
D004999:Amifostine / Q000627:therapeutic use*; D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D004357:Drug Synergism; D005260:Female; D016179:Granulocyte Colony-Stimulating Factor / Q000627:therapeutic use*; D006410:Hematopoiesis / Q000187:drug effects*; D051379:Mice; D008809:Mice, Inbred C3H; D011833:Radiation Injuries, Experimental / Q000517:prevention & control / Q000628:therapy*; D016188:Receptors, Granulocyte Colony-Stimulating Factor; D013268:Stimulation, Chemical
D016188:Receptors, Granulocyte Colony-Stimulating Factor; D016179:Granulocyte Colony-Stimulating Factor; D004999:Amifostine