Abstract: Objective To study the roles of microRNA-34a-5p in the erythroid differentiation of K562 cells.Methods K562 cells were transfected with the microRNA-34a-5p mimics and antisense inhibitors specifically targeting microRNA-34a-5p, respectively. The effects of over-expression or knocking-down of microRNA-34a-5p was examined by Quantitative RT-PCR. Flow Cytometry was performed to detect the levels of specific surface marker of erythroid cells. The benzidine staining assay was used to access the differentiation state of K562 cells. Western blot was performed to detect the level of miRNA targets. Results microRNA-34a-5p was down-regulated at the early stage of K562 erythroid differentiation. Over-expression of microRNA-34a-5p in K562 cells attenuates erythroid differentiation, in contrast, inhibition of microRNA-34a-5p accelerates erythroid pheotypes in K562 cells. c-MYB was the direct target of microRNA-34a-5p in erythroid cells.Conclusion microRNA-34a-5p regulates early erythroid differentiation of K562 cells via repressing c-MYB.

Key words: miR-34a-5p, K562, c-MYB, erythroid differentiation