Isolation and characterisation of dimethylsulphoxide resistant variants from the human promyeloid cell line HL60

The HL60 line can be induced to differentiate into neutrophils by 1.25% dimethylsulphoxide (DMSO) or monocytes by 12-O-tetradecanoylphorbol-13-acetate (TPA). Seven variants of this line have been isolated which do not respond to 1.25% DMSO. Five of these lines can be induced to mature into neutrophils using DMSO concentrations of 1.75% (HL60 m2, m4, Sp1 and Ast3) and 2.0% (HL60 Ast25). Two lines, HL60 Ast1 and 4, showed minimal differentiation even at a concentration of 2.0% DMSO, and 2.25% DMSO was toxic to these cells. Of the seven variant lines, HL60 Ast3, Ast4 and Sp1 failed to differentiate into monocytes in response to TPA. Sublines from HL60 that either require higher concentrations of DMSO to induce maturation or fail to differentiate into neutrophils, such as those described above, can be used to investigate how genetically determined properties within HL60 cells affect the ability to mature into neutrophils.