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[Effect of Hypoxia on CD47 Expression in Human Acute Myeloid Leukemia Cell Lines].

OBJECTIVE
To investigate the effect of hypoxia on hypoxia-inducible factor 1α (HIF-1α) and CD47 expression in human acute myeloid leukemia (AML) cell lines.


METHODS
The CD47 expression in AML U937, HL-60, and K562 cells lines were detected by flow cytometry. U937, HL-60, and K562 cells were all divided into hypoxia-treated group and conventional oxygen group. The hypoxia-treated group was cultured with 1% O2, while the conventional oxygen group was cultured with 20% O2, then the cells were collected after 24 hours. Real time PCR was used to examine the mRNA changes of CD47 gene. Western blot assay was applied to detect the protein expression of HIF-1α and CD47.


RESULTS
The expression of CD47 in U937, HL-60, and K562 cells was 98% (98%±0.03%), 99% (99%±0.05%), and 75% (75%±0.11%), respectively. The real time PCR showed that the mRNA expression of CD47 in U937 and HL-60 cells were up-regulated in the hypoxia-treated group (P<0.05), while in K562 cells was not (P>0.05). Western blot result showed that the protein levels of HIF-1α and CD47 of U937, HL-60, and K562 cells in the hypoxia-treated group were increased compared with the conventional oxygen group (P<0.05).


CONCLUSION
The hypoxia can up-regulate the expression of CD47 in acute myeloid leukemia cells, which may be related to HIF-1α.