[Regulation of fibroblast-like cell proliferation in human bone marrow]

The influence of growth factors (GF) and some other biological active molecules on the human bone marrow fibroblast (HBMF) proliferation was studied in the monolayer system. The proliferation of HBMF, like other connective tissue cells, was serum- and GF-dependent. GF tested (EGF, FGF, insulin) produced both positive and negative effects on HBMF proliferation. It was also shown that phorbol ester, which activates protein kinase C, usually inhibited HBMF proliferation. It has been proposed that this feature of HBMF is the cause of GF bifunctional action. It has been suggested that the ability of GF to inhibit HBMF proliferation in some cases permits one to maintain cellular homeostasis in GF rich human bone marrow. HBMF of different hematological patients were characterized by individual differences in GF sensitivity. This may be secondary to the bone marrow cellular composition. For example, HBMF obtained from the bone marrow rich in total cells or megakaryocytes were more responsive to proliferation stimulating effect of GF.