RESUMO
OBJECTIVE: To investigate the effect of miR-22 targeting formin-like protein 2 (FMNL2) on the migration and apoptosis of childhood acute myeloid leukemia (AML) cells. METHOD: Peripheral blood samples from 11 children with AML, 10 children with immune thrombocytopenia, human AML cell lines TF-1a, HL-60, THP-1 and human bone marrow stromal cells HS-5 were used as the research objects. UniCel DxH 800 automatic hematology analyzer detected platelet count, hemoglobin, and white blood cell count in peripheral blood samples, and RT-qPCR detected miR-22 expression in peripheral blood samples and AML cells. HL-60 cells were transfected with LipofectamineTM 2000 kit, the experiments were divided into seven groups: blank (no cells transfected), miR-NC, miR-22 mimics, si-NC, si-FMNL2 , miR-22 mimics+OE-NC and miR-22 mimics+OE-FMNL2 . RT-qPCR was used to detect the expression of miR-22 in each group. Transwell was used to detect cell migration. Flow cytometry was used to detect cell apoptosis. Dual-luciferase reporter gene detection experiments verified the targeting relationship between miR-22 and FMNL2 . Western blot was used to detect the expression of FMNL2 protein. RESULTS: Compared with the control group, the number of leukocytes in the peripheral blood of children with AML was significantly increased (P <0.001), while the concentration of hemoglobin and the number of platelets were significantly decreased P <0.001). The expression level of miR-22 in peripheral blood of children with AML was significantly lower than that in control group (P <0.001). Compared with HS-5 cells, the expression levels of miR-22 in TF-1a, HL-60, and THP-1 cells were significantly decreased (P <0.05), and in HL-60 cells was the lowest. Therefore, HL-60 cells were selected for subsequent experiments. Up-regulation of miR-22 or silencing of FMNL2 could reduce the number of migrating cells and increase apoptosis rate (P <0.05). MiR-22 targeted and negatively regulated the expression of FMNL2 . FMNL2 overexpression reversed the effects of up-regulated miR-22 on migration and apoptosis of HL-60 cells. CONCLUSION: MiR-22 can inhibit the migration and promote apoptosis of HL-60 cells by down regulating the expression of FMNL2 .
