Granulocyte colony-stimulating factor-stimulated proliferation of myeloid cells: Mode of cell cycle control by a range of inhibitors

Abstract

The myeloid cell line, NFS-60, is dependent on granulocyte colony- stimulating factor (G-CSF) or interleukin-3 (IL-3) for survival and growth. Long-term G-CSF-dependent proliferation was found to be completely inhibited by interferon-γ (IFN-γ), cyclic AMP, and dimethylamiloride and partially inhibited by IFN-α and lipopolysaccharide. With the exception of IFN-γ, these agents exhibited a corresponding pattern of inhibition of DNA synthesis in quiescent NFS-60 cells stimulated with G-CSF. IFN-γ was only a weak inhibitor of DNA synthesis, suggesting that it may act at a later stage to block proliferation. The addition of G-CSF to NFS-60 cells resulted in phosphorylation of the retinoblastoma pr..