Identification of a retinoic acid responsive aldoketoreductase expressed in HL60 leukaemic cells

Neutrophil and monocyte differentiation can be induced in HL60 leukaemia ce lls by all-trans-retinoic acid (ATRA) and 1 alpha,25-dihydroxyvitamin D-3 ( D-3), respectively, whose differentiating effects can be enhanced by exposu re to 'anti-inflammatory agents' and steroids. We have provided evidence th at this potentiation is via inhibition of the activity of an enzyme of the aldoketoreductase (AKR) family, but had failed to identify expression of kn own AKRs in HL60 cells. In this study, me have identified a previously uncl assified aldoketoreductase family member (termed HAKR e) that is expressed in HL60 cells. HAKR e is dramatically and transiently upregulated in HL60 c ells within 24 h of exposure to ATRA, further supporting the proposition th at a member(s) of this family of enzymes play(s) a role in controlling cell growth and/or differentiation. (C) 1998 Federation of European Biochemical Societies.