曲古菌素A对HL-60细胞组蛋白乙酰化水平和凋亡的作用

本研究旨在探讨曲古菌素A(trichostatinA ,TSA)高效低毒的抗癌机理。应用细胞培养、MTT法 ,免疫细胞化学技术和Annexin V FITC PI双标流式细胞术观察TSA对HL 6 0细胞和正常人外周血单个核细胞 (normalhumanperipheralbloodmononuclearcell,NPBMNC)的生长抑制 ,组蛋白乙酰化水平以及诱导凋亡的影响。结果表明 :TSA能够以时间、剂量依赖性方式抑制HL 6 0细胞增殖 ,36小时IC50 为 10 0ng ml。TSA能够诱导HL 6 0细胞凋亡 ,其作用也呈时间、剂量依赖性。TSA在显著诱导HL 6 0细胞凋亡的浓度和时间范围内对NPBMNC无明显的诱导凋亡作用。TSA处理 4小时后 ,HL 6 0细胞和NPBMNC组蛋白乙酰化水平上调显著高于未用TSA各组 (P<0 .0 5 ) ,但两者之间无显著性差异 (P >0 .0 5 )。结论 :TSA对HL 6 0细胞有明确的抑制增殖能力 ;TSA有明确的诱导HL 6 0细胞凋亡的能力 ,这可能是TSA体外抑制白血病细胞系HL 6 0生长和发挥抗白血病作用的主要机理之一 ;与NPBMNC相比较 ,TSA能够选择性诱导HL 6 0细胞凋亡 ;TSA选择性抑制HL 6 0细胞的机理与TSA调控HL 6 0细胞和NPBMNC组蛋白乙酰化水平的差异无关。

Effect of Trichostatin A on Histone Acetylation Level and Apoptosis in HL-60 Cells

In order to explore the underlying mechanism of high effects and low toxicity of trichostatin A (TSA),the effect of TSA on growth inhibition,histone acetylation level and apoptosis in HL-60 cells and normal human peripheral blood mononuclear cells (NPBMNC) were examined using MTT method,immunocytochemistry technology,and Annexin-V-FITC/PI double staining flow cytometry. The results showed that TSA inhibited growth of HL-60 in time-and dose-dependent manners,and the IC 50 of 36 hours was 100 ng/ml. The apoptosis induction effect of TSA in HL-60 cells was also time-and dose-dependent. Besides,the dose of TSA showing significant apoptotic cytotoxicity in HL-60 cells did not demonstrate apparent apoptosis induction in NPBMNC within definite dose and time range. The histone acetyl- ation level in HL-60 cells and NPBMNC both showed remarkable increase(P<0.05) after incubated with 100 ng/ml TSA for 4 hours without statistical difference between them is detected (P>0.05). It is concluded that TSA shows effects of definite and significant growth inhibition and apoptosis induction on HL-60 cells in time-and dose-dependent manners. TSA is able to selectively induce apoptosis in HL-60 cells with low toxicity in NPBMNC at the same time. The mechanism of this selectivity can not be ascribed to the differential regulation of histone acetylation level between HL-60 cells and NPBMNC.