Keratinocyte growth factors radioprotect bowel and bone marrow but not KHTsarcoma

Various members of the fibroblast growth factor (FGF) family of proteins ha ve been shown to protect against acute and late radiation damage of normal tissues. Protection of the small bowel, for example, occurs via both increa sed proliferation and reduced apoptosis. Other beneficial effects of FGFs i nclude promotion of bone growth, pneumonitis prevention, and apoptosis supp ression of endothelium in vivo and in vitro after irradiation. This protect ion against radiation requires only low and infrequent doses of FGFs. Two n ewly identified members of the FGF family, FGF7 and FGF10, have effects sim ilar to many of the other FGF family proteins, but with more specificity fo r normal epithelial structures. For this reason, they have also been named keratinocyte growth factors one and two (KGF1 and KGF2, respectively). We t herefore examined the potential utility of KGFs for radioprotection of the bone marrow and small bowel and examined safety issues concerning their adv erse effects on KHT sarcoma. The results suggest that KGFs could be safely used to prevent radiation toxicity of the abdomen or pelvis and may in fact improve tumor response to radiation.