Basic Fibroblast Growth Factor Radioprotects Bone Marrow and not RIF1 Tumor

Abstract

We examined the potential of bFGF to function as a radioprotector of bone marrow (BM). Total intravenous doses of bFGF ranged from 1 to 24 μg/mouse, in 2 divided doses. Whole body radiation (WBI) was given in a single fraction to C3H mice. Histologic observations were performed on femur BM at various times after bFGF (or placebo) treatment. Thigh radiation in thigh-tumor bearing mice was delivered in a single fraction. bFGF increased the LD_50/30 of mice in a dose dependent fashion, with an apparent maximum protection obtained with ≥6 μg given half 24 h and half 4 h before irradiation. BM histology shows prominent recovery of megakaryocytes and all cell lineages along with less loss in cellularity compared to control irradiated animals. No radioprotection of RIF1 tumors after bFGF was detected. These results indicate that bFGF may be a selective radioprotector of normal tissue.