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

METHODSThe 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 CoCl, 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.

RESULTSThe cell morphology was changed with increase of CoClconcentration and prolonging of treatment time of CoCl. The MTT assay showed that the inhibitory rate of cell proliferation was enhanced also with increase of CoClconcentration and prolonging of treatment time of CoCl(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 CoCland treatment time (r=0.954, r=0895).

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