Transforming growth factor beta (TGF-beta) was tested for its ability to stimulate a chemotactic response in two clonal rat osteosarcoma (ROS) cell lines, 17/2 and 25/1. TGF-beta stimulated dose-dependent chemotaxis in both cell lines. In serum-containing media, maximal response was seen at a concentration of 500 fg (10(-15)g)/mL for the ROS 17/2 cells and 25 fg/mL for the ROS 25/1 cells. In serum-free media, the maximal chemotactic response to TGF-beta occurred at 5 fg/mL for both the ROS 17/2 and 25/1 cells. TGF-beta was not mitogenic at these dosages. The results indicate that TGF-beta could act as a chemoattractant for osteogenic cells in both demineralized bone matrix induced osteogenesis and in normal bone remodeling.