抑制miR-155表达对白血病细胞系THP-1的增殖和凋亡影响及作用机制

Efects of Inhibiting miR-155 Expression on the Proliferation and Apoptosis of Leukemia THP-1 Cells

本研究通过转染miR-155抑制物(inhibitor)下调THP-1细胞的miR-155表达,探讨抑制miR-155表达对THP-1细胞增殖及凋亡的影响及其机制。通过X-treme GENE siRNA Transfection Reagent在THP-1细胞转染miR-155 inhibitor(THP-1I),同时设置未转染组(THP-1C)和转染对照组(THP-1IC);应用实时定量PCR(RT-PCR)检测miR-155转染效率及转染后SHIP1的mRNA基因水平的表达,应用CCK-8法检测对细胞系增殖的影响,流式细胞术检测对凋亡的影响,Western blot法检测转染后的SHIP1、AKT、p AKT蛋白水平的基因表达。结果表明,与THP-1C和THP-1IC相比,THP-1I的miR-155表达水平明显降低(P<0.05);抑制miR-155可导致THP-1细胞的凋亡率明显增高(P<0.05);抑制miR-155对THP-1细胞的SHIP1 mRNA含量无明显影响,但导致SHIP1蛋白水平明显升高(P<0.05),提示miR-155对THP-1细胞的SHIP1可能存在翻译水平的调节;miR-155抑制尽管未导致总AKT(TAKT)的蛋白含量变化,但p AKT蛋白水平明显降低(P<0.05)。结论:抑制miR-155表达可能通过增加SHIP1蛋白含量和抑制PI3K/AKT信号途径促进THP-1细胞凋亡,提示抑制miR-155可能成为抗白血病治疗的新策略。

The aim of this study was to investigate the effects of miR-155 inhibitor transfection on the proliferation and apoptosis of THP-1 cells.The miR-155 inhibitor was transfected into THP-1 cells（ THP-1）Iby using X-treme GENE siRNA transfection reagent.Cells without transfection（ THP-1Cand cells with negative transfection（ THP-1IC）were used as controls.Quantitative real-time polymerase chain reaction（ RT-PCR）was performed to detect the expression of miR-155 and relative expression of SHIP1 mRNA in the cells.Cell proliferation was assayed using CCK-8method.Cell apoptosis were detected by flow cytometry.The expression of SHIP1 TAKT and pAKT in THP-1 cells were detected by Western blot.The results indicated that compared with THP-1C and THP-1ICthe expression of miR-155 in THP-1I cells was significantly reducedmiR-155 inhibition significantly increased apoptosis rate in THP-1 cells（P〈0.05）; miR-155 inhibition in THP-1 cells caused no significant alteration in SHIP1 mRNA level but significantly increased its protein contentindicating some post-transcriptional modulations might exist underlying the modulation of miR-155 to SHIP1 the miR-155 caused significantly reduced protein level of pAKT（ P〈0.05） without interfering TAKT protein content.It is concluded that the miR-155 inhibition may promote THP-1 cell apoptosis through increasing SHIP1 protein content and impairing its downstream PI3 K /AKT signaling pathway.This study suggests that miR-155 inhibition may be a promising therapy strategy for treating acute myeloid leukemia（AML）.