5-氮杂脱氧胞苷增强苯丁酸钠对Kasumi-1细胞的诱导分化和凋亡作用

5-Aza-2′-deoxycytidine enhances differentiation and apoptosis induced by phenylbutyrate in Kasumi-1 cells

目的 探讨组蛋白脱乙酰化酶抑制剂苯丁酸钠 (PB)联合DNA甲基化抑制剂 5 氮杂脱氧胞苷 (5 Aza CdR)阻断AML1 ETO的生物学功能 ,消除AML1 ETO的转录抑制 ,诱导t(8;2 1)急性髓系白血病细胞系Kasumi 1细胞的分化和凋亡作用。方法 应用四甲基偶氮唑蓝 (MTT)比色法观察PB单药或联合 5 Aza CdR对细胞生长的抑制作用 ;流式细胞术分析细胞周期和检测髓系分化抗原CD11b和CD13的表达 ,判断细胞分化 ;AnnexinV和碘化丙啶 (PI)双标记 ,经流式细胞术分析细胞早期凋亡。结果 (1) 5 Aza CdR可增强PB对Kasumi 1细胞的生长抑制作用 ,半数抑制浓度 (IC50 )下降为 1.95mmol/L。 (2 )PB处理使Kasumi 1细胞阻滞于G0 /G1期 ,5 Aza CdR与PB联合则使细胞阻滞于G2 /M期。 (3)低剂量 5 Aza CdR增强PB诱导Kasumi 1细胞髓系分化抗原CD11b和CD13的表达。 (4)低剂量 5 Aza CdR不能增强PB诱导的Kasumi 1细胞凋亡 ,而高剂量 5 Aza CdR增强PB诱导的Kasumi 1细胞早期凋亡。结论 DNA甲基化抑制剂 5 Aza CdR增强脱乙酰化酶抑制剂PB抑制Kasumi 1细胞生长、诱导分化和凋亡的作用。

Objective To investigate whether phenylbutyrate(PB) combined with 5 aza 2′ deoxycytidine(5 Aza CdR)could inhibit transcription repression and induce t(8;21) acute myelogenous leukemia (AML) Kasumi 1 cells to differentiate and undergo apoptosis. Methods Kasumi 1 cells were treated with PB and 5 Aza CdR at different concentrations in suspension culture. Cellular proliferation was determined by the MTT assay, expression of myeloid specific differentiation antigen and cell cycles were analyzed by flow cytometry. Cell apoptosis were assessed using AnnexinV/PI staining and flow cytometry. Results Treatment of Kasumi 1 cells with PB caused a dose dependent inhibition of proliferation, with an IC 50 of 2.3 mmol/L. When combined with 5 Aza CdR, PB resulted in a greater growth inhibition with an IC 50 of 1.95 mmol/L. Treatment of Kasumi 1 cells with PB resulted in cell cycle arrest at G 0/G 1, while combined treatment with PB and 5 Aza CdR led to cell cycle arrest at G 2/M. Expression of myeloid cell differentiation antigens CD11b and CD13 induced by PB was enhanced when Kasumi 1 cells were pretreated with low dose of 5 Aza CdR. High, but not low, concentrations of 5 Aza CdR could enhance early apoptosis of Kasumi 1 cells induced by PB. Conclusion Phenylbutyrate, when combined with 5 Aza CdR, inhibits AML cell in vitro proliferation and increases apoptosis in a synergistic fashion.