[Effect of hypoxia on the proliferation and hypoxia inducible factor-1α expression in human leukemia HL-60 cells]

To explore the effects of hypoxia on the proliferation of human leukemia HL-60 cells and the cellular expression of hypoxia inducible factor-1α (HIF-1α).

Human acute myeloid leukemia HL-60 cells with exponential growth in routine culture were exposed to 50, 200, 400, 800 µmol/L CoCl(2) to mimic hypoxic conditions. At 24, 48, and 72 h, the cells were collected for morphological observation, MTT assay, and real-time quantitative PCR for HIF-1α mRNA expression.

Compared with the cells without CoCl(2) treatment, the cells with CoCl(2) exposure exhibited obvious morphological changes and a significant growth inhibition which increased with CoCl(2)concentration and exposure time. At low concentrations (50-200 µmol/L), CoCl(2) treatment caused a dose- and time-dependent enhancement of HIF-1α expression in HL-60 cells.

Hypoxia mimicked by CoCl(2) exposure significantly inhibits the proliferation of HL-60 cells, and at the non-toxic doses, CoCl(2) dose- and time-dependently increases the expression of HIF-1α. The mimicked hypoxic conditions do not cause differentiation of HL-60 cells.