Effect of platelet-derived growth factor and bone marrow-conditioned medium on the proliferation of human bone marrow-derived fibroblastoid colony-forming cells.

The effects of various human sera, platelet lysates and platelet-derived growth factor (PDGF) on the proliferation of human bone marrow-derived fibroblastoid colony-forming cells (CFU-F) were examined. We obtained nearly identical growth curves of fibroblastoid colonies with sera, platelet lysates and PDGF as stimulants and concluded that PDGF was a main growth factor for CFU-F in human serum. In contrast to colony size, CFU-F number was irrelevant to the concentration of PDGF. Removal of culture medium containing hemopoietic cells after short-term incubation of bone marrow cells reduced both colony number and size in CFU-F cultures. When each of bone marrow-conditioned medium (BMCM), peripheral blood mononuclear cells (MNC) and phytohemagglutinin-stimulated leukocyte-conditioned medium (PHA-LCM) was added to the cultures, CFU-F number and colony size recovered. The role of PDGF and the factors present in BMCM, MNC and PHA-LCM in the growth of CFU-F and their precursor cells were discussed.