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Objective@#To investigate the effects of miR-23a-3p on proliferation, migration and apoptosis on human acute myeloid leukemia (AML) cells by targeting SMC1A.@*Methods@#Microarray analysis was used to screen differentially expressed microRNAs and mRNAs in human AML cells. Real-time fluorescence quantitative PCR (RT-qRCR) was used to detect the expressions of miR-23a-3p and SMCA in human AML cell line U937. TargetScan database was used to analyze the correlation between miR-23a-3p and SMC1A. Double luciferase reporter gene was used to detect the interaction between miR-23a-3p and SMC1A. The effect of miR-23a-3p expression on the proliferation of U937 cells was detected by clonal assay. The migration, apoptosis, cell cycle and caspase-3 activity of U937 cells regulated by miR-23a-3p were detected by cell scratch assay and flow cytometry, respectively. Western blot was used to detect the expressions of Bax and Bcl-2 in U937 cells.@*Results@#Compared with human normal monocyte SC group (1.00), the expression of miR-23a-3p in U937 cells was up-regulated (2.56±0.78) (P<0.01), while the expression of SMC1A was down-regulated (0.48±0.56, P<0.01). miR-23a-3p specifically bond to SMC1A 3′UTR and regulated the expression activity of SMC1A. Overexpression of miR-23a-3p promoted the proliferation and migration of U937 cells and inhibited the apoptosis of U937 cells, while up-regulation of SMC1A inhibited the proliferation and migration of U937 cells and promoted the apoptosis of U937 cells. The percentages of G0/G1 phase, G2/M phase and S phase cells in the negative control group were (37.48±0.21)%, (16.78±0.18)% and (45.74±0.15)% respectively, and those in the miR-23a-3p mimics group were (19.96±0.11)%, (41.69±0.24)% and (38.24±0.34)%, respectively. The difference was statistically significant (all P<0.05). The proportions of G0/G1 phase, G2/M phase and S phase cells in the group of miR-23a-3p mimics+ pcDNA3.1-SMC1A were (36.88±0.21)%, (30.44±0.33)% and (32.88±0.16)%, respectively, without significant difference when compared with those of the miR-23a-3p mimics group (P>0.05). The relative expression levels of Bax and Bcl-2 protein in the negative control group were 0.55±0.45 and 0.31±0.54, respectively. Overexpression of miR-23a-3p inhibited the expression of Bax protein in U937 cells (0.23±0.13, P<0.001), promoted the expression of Bcl-2 protein (0.50±0.23, P<0.01), while SMC1A increased the expression of Bax protein in U937 cells (0.40±0.11, P<0.01), and inhibited the expression of Bcl-2 protein (0.37±0.15). In the negative control group, caspase-3 activity was (25.82±0.89)%. Overexpression of miR-23a-3p inhibited caspase-3 activity in U937 cells (3.64±0.56)%, P<0.01, while up-regulation of SMC1A promoted caspase-3 activity in U937 cells (15.29±0.85)%, P<0.01.@*Conclusion@#miR-23a-3p can inhibit the proliferation and migration and promote apoptosis of human AML cells by targeting SMC1A.
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Objective To explore the effect of bosutinib on cell differentiation and apoptosis of human acute myeloid leukemia (AML) cell lines including HL-60, THP-1, and U937, and to clarify the related mechanisms. Methods MTT Assay was used to assess the proliferation of HL-60, THP-1, and U937 cells treated with various concentrations of bosutinib (0-20 μmol/L) for 48 h. Cell surface marker CD11b expression was detected by flow cytometry in HL-60, THP-1, and U937 cells treated with bosutinib (0-5 μmol/L) for 72 h. Apoptosis was evaluated by Annexin V-FITC/PI double stainning in the following two sets of experiments: 1 HL- 60, THP-1 and U937 cells were treated with various concentrations of bosutinib (0-10 μmol/L). 2 U937 cells were pretreated with caspases inhibitor benzyloxy-carbonyl-Val-Ala-Asp-fluoromethylketone (Z-VAD-FMK) for 1 h and then exposed to bosutinib for 48 h. Western blot was used to examine the protein expression of differentiation related transcription factors C/EBPβ, P21, and c-Myc, and apoptosis related protein Mcl- 1, Bax, and Caspase 3 in HL- 60 and U937 cells treated with bosutinib for 24 h. Results Bosutinib dose- dependently inhibited AML cell growth. Treatment with various concentrations of bosutinib for 72 h significantly increased CD11b expression and apoptotic rate in AML cells as compared to blank control (P< 0.05 or P < 0.01). Bosutinib effectively upregulated protein expression levels of C/EBPβ and P21 in HL-60 cells, and induced down-regulation of Mcl-1 with up-regulation of Bax protein expression, and activated Caspase 3 in U937 ells. Pretreatment of U937 cells with Z-VAD-FMK significantly inhibited apoptosis induced by bosutinib. Conclusion Bosutinib effectively inhibits cell proliferation and induces cell differentiation with apoptosis in AML cells. It could be a potent therapeutic agent against AML.