Transforming Growth Factor fi Selectively Inhibits Normal and Leukemic Human Bone Marrow Cell Growth In Vitro

The effects of transforming growth factor flu or (TGF-/11 or -p2) on the in vitro proliferation and differentiation of normal and malignant human hematopoietic cells were studied. Both forms of TGF-fl suppressed both the normal cellular proliferation and colony formation induced by recombinant human interleukin-3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GM-CSF). In the presence of GM-CSF or IL-3, optimal concentrations of TGF-$ (400 pmol/L) inhibited colony formation by erythroid (BFU-E). multipotential (CFU-GEMM), and granulocyte-macrophage (CFU-GM) progenitor cells by 90% to I 00%, whereas granulocyte or monocyte cluster formation was not inhibited. In contrast. neither form of TGFhad any effect on G-CSF-induced hematopoiesis. The suppressive action appeared to be mediated directly by TGF-/9 since antiproliferative responses were also observed in