[Effect of Hypoxia on the Proliferation and Hypoxia Inducible Factor-1α Expression in Human Leukemia K562 Cells].

OBJECTIVE

To explore the effect of hypoxia on the cell proliferation and expression of hypoxia-inducible factor-1α(HIF-1α) of human leukemia K562 cells.

METHODS

The leukemia cells were divided into 2 groups: hypoxia-treated group and conventional oxygen group as control. The K562 cells in hypoxia-treated group were treated with 50, 200, 400 and 800 µmol/L of CoCl2, while the K562 cells in control group were cultured in conventional oxygen condition, then the K562 cells in 2 groups were colleted after treatment for 24, 48 and 72 hours. The morphological changes of cells were observed by the inverted phase-contrast microscopy, the proliferation-inhibitory rates of cells was detected by MTT method, the expression of HIF-1α at transcription level was detected by real-time fluorescent quantitative PCR.

RESULTS

The cell morphology was changed with increase of CoCl2 concentration and prolonging of treatment time of CoCl2. The MTT assay showed that the inhibitory rate of cell proliferation was enhanced also with increase of CoCl2 concentration and prolonging of treatment time of CoCl2(r=0.435, r=0.389, P<0.05). The real-time fluorescent quantitative PCR showed that the mRNA expression of HIF-1α in K562 cells of hypoxia group was up-regulated in concentration- and time- dependant manners. and displayed the positive correlation with concentration of CoCl2 and treatment time (r=0.954, r=0895).

CONCLUSIONS

The hypoxia can inhibit the proliferation of K562 cells and up-requlate the expression of HIF-1α in cells, but does not induce cell differentiation.