A biologically active fragment of the differentiation factor of the HL-60 line cells: Identification and properties

Six-membered peptide fragment TGENHR (HLDF-6) was identified in the HL-60 c ell culture of human promyelocyte leukemia treated with retinoic acid when studying the differentiation factor HLDF of this cell line. HLDF-6 retains the ability of the full-size factor to induce the differentiation and arres t the proliferation of the starting HL-60 cells. It was shown that the synt hetic peptide HLDF-6 has no specific receptors on the surface of the HL-60 cells but can affect the binding of interleukin IL-1 beta, a cytokine invol ved in proliferation, to the cell surface. It was found on a model of trans plantable NSO myeloma that HLDF-6 has an antitumor activity.