MiR-495 inhibits proliferation and promotes apoptosis of acute myeloid leukemia cells through targeting Bmi-1

Abstract

Objective To detect the relative expression levels of miR-495 and Bmi-1 in bone marrow samples of patients with acute myeloid leukemia (AML), and to research the effects of up regulation of miR-495 on AML cells HL-60 and the interaction between miR-495 and Bmi-1. Methods The relative expression levels of miR-495 and Bmi-1 in bone marrow samples of AML patients were evaluated by qRT-PCR method. Western-blot assay performed to evaluate the expression of Bmi-1 in the samples. miR-495 mimics and miR-495 scramble were transfected into human leukemia HL-60 cells, following by CCK8 assay to investigate the proliferation of the cells. Later, the apoptosis of HL-60 cells was detected by flow cytometry methods. And the relationship between miR-495 and Bmi-1 was validated by dual luciferase reporter assay. Results The relative expression level of miR-495 in the samples was reduced and the expression levels of Bmi-1 as well as its protein was increased. Compared with the control group and the blank group, the absorbance values of miR-495 group after cultivation for 24, 48, 72, 96 h were significantly lower(P<0.05). Flow cytometry methods showed that additional miR-495 in HL-60 cell line significantly increased cell apoptosis compared with that in control group and blank group (P<0.05). Dual luciferase reporter assay demonstrated that miR-495 could suppress the reporter gene activity through its specific binding with Wt Bmi-1 3’UTR (P<0.05). Conclusions miR-495 can inhibit proliferation of human AML cells and promote its apoptosis by targeting Bmi-1. Key words: miR-495; Bmi-1; Acute myeloid leukemia