Growth inhibitory effects of transforming growth factor-beta 1 in vivo.

Abstract

Transforming growth factor-beta (TGF-beta) can reversibly inhibit the in vitro proliferation of murine and human haemopoietic progenitors and some of their more developmentally restricted progeny. Using an assay for measuring day 8 and day 11 CFU-S, TGF-beta caused a gradual decline in the number of CFU-S undergoing DNA synthesis so that after 5 days of daily treatment only quiescent cells were found. Release of this growth inhibition was seen within 24 hours post-treatment with recovery of all progenitors to normal levels. Similar inhibitory effects of TGF-beta were seen on the cells of the intestinal epithelium, indicating that TGF-beta is a general stem cell growth inhibitor. These results suggest that TGF-beta can be used as a cytostatic agent to protect normal stem cells in patients being treated with cell cycle-specific cytotoxic agents.