[Hypoxia promotes erythroid differentiation of human K562 cells by upregulating endothelial PAS domain-containing...

Objective To investigate the role of endothelial PAS domain-containing protein 1 (EPAS1) gene encoded hypoxia-inducible factor 2α (HIF-2α) in erythroid differentiation of K562 human erythroleukemia cells under hypoxic conditions. Methods K562 cells were treated with 40 μmol/L of hemin and 0.1 ng/mL of cytarabine for erythroid differentiation. After normoxic and hypoxic(50 mL/L O₂) incubation, the ratio of CD235a⁺CD71⁺ cells was detected by flow cytometry. The percentage of hemoglobin-positive cells was detected by benzidine staining. The level of cell proliferation was detected by CCK-8 assay. The mRNA and protein levels of EPAS1, insulin receptor substrate 2 (IRS2) and γ-globin were detected by real-time quantitative PCR and Wester blot analysis. Besides, the changes in the erythroid differentiation of K562 cells were evaluated after knockdown of EPAS1. Results Hypoxia promoted the erythroid differentiation of K562 cells and upregulated the expression of EPAS1. After EPAS1 kncokdown, the ratio of CD235a⁺CD71⁺ cells and hemoglobin-positive cells decreased, and the expressions of IRS2 and γ-globin declined significantly. Conclusion Hypoxia can significantly up-regulate the expression of EPAS1 in K562 cells and promote the erythroid differentiation.