Appearance of an arachidonic acid 15‐lipoxygenase pathway upon differentiation of the human promyelocytic cell‐line HL‐60

The metabolism of arachidonic acid and 15-HPETE was studied in a human promyelocytic cell line (HL-60). Upon exposure to DMSO, HL-60 cells undergo differentiation and acquire a 15-lipoxygenase activity while undifferentiated cells challenged with either arachidonic acid or 15-HPETE did not enzymatically transform these precursors. Products of the arachidonic acid 15-lipoxygenase pathway were identified by HPLC. UV-absorption and gas chromatography-mass spectrometry. Results indicate that upon differentiation HL-60 cells express a 15-lipoxygenase activity as well as the ability to transform 15-HPETE to 8,15-DHETEs and 14,15-DHETE. Moreover, these findings suggest that products of the 15-lipoxygenase cascade may be generated by a single cell system.