Abstract: Objective To study the expression levels and roles of miR-31-5p in acute myeloid leukemia (AML). Methods The relative levels of miR-31-5p in AML patients were evaluated by real-time PCR; THP-1 cells were transfected with the miR-31-5p mimic and control, respectively. The effects of over-expression of miR-31-5p were examined by CCK-8 and FACS analysis; Dual-luciferase and Western blot were performed to detect the levels of target gene HuR expression. siRNAs were used to knock down the endogenous HuR expression. The effects of knock-down of HUR were also examined by CCK-8 and FACS analysis. Results miR-31-5p was down-regulated in AML patients compared to the normal control. Over-expression of miR-31-5p in THP-1 cells reduces cell proliferation and accelerates monocytic differentiation. miR-31-5p could target HuR, and knock-down of HuR inhibits cell proliferation and attenuates monocytic differentiation in THP-1 cells. Conclusions miR-31-5p could regulate AML cell proliferation and monocytic differentiation by targeting HuR.

Key words: microRNA-31-5p, THP-1, HuR, acute myeloid leukemia