Purpose: The effect of recombinant human erythropoietin (Epo) on the radiosensitivity of human tumour xenografts growing in anaemic nude mice was studied.
Methods and materials: Anaemia was induced by total body irradiation (TBI) of mice prior to tumour transplantation. The development of anaemia was prevented by Epo (1000 U/kg s.c.) given 3 times weekly starting 2 weeks prior to TBI (5 Gy). Epo treatment did not influence the growth rate of the tumours, which were transplanted into the subcutis of the hind leg of mice. Thirteen days after TBI (tumour volume of approx. 40 mm3), a single-dose irradiation (12 Gy) of the tumour was performed resulting in a growth delay with subsequent regrowth of the tumours.
Results: In Epo-treated animals the tumour growth delay was significantly longer compared to anaemic mice. However, the radiosensitivity of tumours in non-anaemic animals' (non-Epo-treated) tumours could not fully be restored.
Conclusion: These data give evidence for restored radiosensitivity after correction of anaemia with Epo.