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目的 探讨组蛋白去乙酰化酶抑制剂(HDACi)MS-275对人骨髓瘤细胞U266的凋亡抑制基因生存素(survivin)和核因子-κB(NF-κB)表达的影响.方法 台盼蓝拒染法观察MS-275对细胞活力的影响;瑞氏-姬姆萨染色观察细胞形态学变化;流式细胞仪分析细胞周期;Western blot检测survivin、p21、细胞周期依赖激酶4(CDK4)和NF-κB的抑制蛋白(IKB-α)等的表达,以及凋亡信号通路中caspase-3活化及蛋白聚ADP核糖聚合酶(PARP)裂解情况.结果 MS-275抑制U266细胞增殖,阻断细胞周期于G0/G1期,呈时间-剂量依赖性.MS-275作用U266细胞48 h的IC50为1.39μmol/L.2 μmol/L MS-275作用U266细胞24 h后,G0/G1期细胞所占比例为(64.57±4.09)%;作用36 h后,G0/G1期细胞所占比例为(87.20±2.83)%;瑞氏-姬姆萨染色显示,U266细胞形态发生明显变化.Western blot检测表明,MS-275作用U266细胞后,survivin和CDK4表达下降,p21表达增加,IκB-α磷酸化水平受到明显抑制,caspase-3被裂解活化,其底物蛋白PARP发生剪切,细胞发生凋亡.结论 MS-275可诱导人骨髓瘤细胞系U266凋亡,NF-κB信号通路阻断是凋亡发生的机制之一.

Objective To study the effects of HDACi on the expression of survivin and NF-κB in human myeloma cell line U266 cells. Methods U266 cells were cultured in RPMI 1640 in the presence of MS-275, and the cell viability was evaluated by trypan blue exclusion assay and cell count. The cell morphological changes were observed with Wright-Giemsa staining. The cell cycle was analyzed by flow cytometry, and the proteins of poly (ADP-ribose) polymerase (PARP), caspase-3, survivin, p21,CDK4 and IκB-α were detected by Wostem blotting. Results MS-275 inhibited the growth of U266 cells in a dose-and time-dependent manner. The cell cycle was arrested at G0/G1 phase. After exposure at 1.39 μmol/L MS-275 for 48 hours, the cell viability was decreased to 50%. The cell ratios of G0/G1 phase were increased to (64.57±1.09)% for 24 h and (87.20±2.83)% for36 h after 2 μmol/L MS-275 treatment. The visible morphological changes of U266 cells were confirmed with Wfight-Giemsa staining. Cleaved-PARP, increased expression of p21, downregulation of expression of survivin, CDK4 and the phosphorylation of IκB-α was found by Western blot in MS-275 treated U266 cells. Conclusion MS-275-induced apoptosis of U266 cells is mediated by downregulation of expression of survivin and inactivation of NF-κB survival signalling pathways.