Constitutive and selective expression of basic fibroblast growth factor in human leukaemia cell lines

We have previously shown that basic fibroblast growth factor (bFGF) stimulates megakaryocytopoiesis and granulopoiesis in vitro and that normal haematopoietic cells and several leukaemic cell lines express FGF receptors. In this paper, we demonstrate by reverse transcriptase-mediated polymerase chain reaction (RT-PCR) that bFGF mRNA is expressed in two leukaemia cell lines with megakaryocytic features (Meg-01 and K562), in two lymphocytic cell lines (Hut 78 and CA) and in normal human peripheral blood mononuclear cells. In addition, the conditioned media of Meg-01, but not Dami, contained a potent fibroblast-stimulating activity which could be neutralized by bFGF antibodies. Furthermore, bFGF antibody significantly inhibited the autocrine growth of Meg-01 cells in vitro. However, we could not detect cell-associated 18 kDa bFGF or HMW bFGF by immunofluorescence, immunoprecipitation or Western blotting. These data indicate that bFGF is expressed by certain haematopoietic cells and support further a role of this FGF prototype in haematopoiesis.