依维莫司和LBH589对耐药急性髓系白血病细胞增殖、凋亡及多药耐药相关蛋白表达的影响

目的 探讨雷帕霉素衍生物依维莫司(RAD001)或联合组蛋白去乙酰化酶抑制剂LBH589对耐药急性髓系白血病细胞株HL-60/ADM细胞增殖、凋亡和逆转耐药的影响.方法 采用不同浓度RAD001或联合LBH589处理HL-60/ADM细胞,四甲基偶氮唑盐(MTT)法检测细胞增殖活力,Hoechst33342染色法和AnnexinV-FITC/PI染色流式细胞仪检测细胞凋亡、阿霉素摄取率和多药耐药相关蛋白1(MRP1)表达评估逆转耐药效应.进一步检测处理前后细胞信号通路蛋白变化,探讨其机制.结果 10～50 μmol/L RAD001均能够抑制HL-60/ADM细胞增殖、诱导凋亡,在作用48和72 h时30 μmol/L药物浓度达到最大抑制效果,进一步增加药物浓度细胞增殖抑制率并没有明显增加(P＜0.05).不同浓度RAD001和LBH589联合处理HL-60/ADM细胞,没有明显的协同抑制增殖作用[协同指数(CI)≥1.0].10 μmol/LRAD001处理HL-60/ADM细胞可以明显下调细胞表面MRP1表达(93.90%±4.20%比79.10%±3.28%,P＜0.05),提高HL-60/ADM细胞阿霉索蓄积率(8.53%±0.68%比15.37%±1.46%,P＜0.01).深入机制研究表明,RAD001可以阻断PI3K/AKT/mTOR信号通路活性,通过上调P53抑制MRP1蛋白的活性.结论 RAD001与LBH589联合没有协同抑制HL-60/ADM细胞增殖作用.但RAD001单药能够有效抑制HL-60/ADM细胞增殖,诱导凋亡,通过阻断PI3K/AKT/mTOR信号通路抑制细胞MRP1蛋白的表达,提高细胞阿霉素摄取率而逆转耐药.

Abstract：

Objective To investigate the effects of everolimus ( RAD001 ) or plus panobinostat (LBH589) on the proliferation, apoptosis and drug resistance in chemoresistant acute myeloid leukemic cells.Methods HL-60/ADM cells were treated with RAD001 alone or with LBH589.Proliferation and apoptosis were evaluated by 3-( 4, 5 ) -dimethylthiahiazo ( -z-y1 )-3, 5-di-phenytetrazoliumromide ( MTT )assay, Hoechst33342 and AnnexinV-FTTC/PI stain.The altered expressions of multidrug resistance-associated protein 1 ( MRP1 ) and intercellular adriamycin accumulation were analyzed by flow cytometry.The change in protein level was analyzed by Western blot.Results Effective proliferative inhibition and apoptotic induction in HL60/ADM cells were observed in the treatment of 10 -50 μmol/L RAD001.The maximal effect was shown for the concentration of 30 μmol/L RAD001 at 48 and 72 hours.The inhibition ratio remained unchanged with the adjustment of drug doses (P ＜0.05).Moreover, there was no synergistic effects in the treatment with different concentration of RAD001 and LBH589 (CI ≥ 1.0).A down-regulation of MRP1 (93.9% ±4.2% vs 79.10% ± 3.28% ) and an up-regulation of adriamycin ( 8.53% ± 0.68% vs 15.37% ± 1.46% ) were induced by the treatment with 10 μmol/L RAD001 ( both P ＜ 0.01 ).RAD001 inhibited the p53-dependent expression of MRP1 via an inhibition of phosphoinositide 3-kinase (PI3K)/AKT/mTOR signaling pathway.Conclusion The combined treatment of RAD001 and LBH589 has no synergistically inhibitory effect on HL60/ADM cells.But the sole treatment of RAD001 may inhibit proliferation, induce apoptosis and accumulate intercellular adriamycin through a down-regulated expression of MRP1 in HL60/ADM cells via an inhibition of PI3K/AKT/mTOR signaling pathway.

Effect of RAD001 or plus LBH589 on the proliferation, apoptosis and drug resistance in chemoresistant acute myeloid leukemic cells

Objective To investigate the effects of everolimus ( RAD001 ) or plus panobinostat (LBH589) on the proliferation, apoptosis and drug resistance in chemoresistant acute myeloid leukemic cells.Methods HL-60/ADM cells were treated with RAD001 alone or with LBH589.Proliferation and apoptosis were evaluated by 3-( 4, 5 ) -dimethylthiahiazo ( -z-y1 )-3, 5-di-phenytetrazoliumromide ( MTT )assay, Hoechst33342 and AnnexinV-FTTC/PI stain.The altered expressions of multidrug resistance-associated protein 1 ( MRP1 ) and intercellular adriamycin accumulation were analyzed by flow cytometry.The change in protein level was analyzed by Western blot.Results Effective proliferative inhibition and apoptotic induction in HL60/ADM cells were observed in the treatment of 10 -50 μmol/L RAD001.The maximal effect was shown for the concentration of 30 μmol/L RAD001 at 48 and 72 hours.The inhibition ratio remained unchanged with the adjustment of drug doses (P ＜0.05).Moreover, there was no synergistic effects in the treatment with different concentration of RAD001 and LBH589 (CI ≥ 1.0).A down-regulation of MRP1 (93.9% ±4.2% vs 79.10% ± 3.28% ) and an up-regulation of adriamycin ( 8.53% ± 0.68% vs 15.37% ± 1.46% ) were induced by the treatment with 10 μmol/L RAD001 ( both P ＜ 0.01 ).RAD001 inhibited the p53-dependent expression of MRP1 via an inhibition of phosphoinositide 3-kinase (PI3K)/AKT/mTOR signaling pathway.Conclusion The combined treatment of RAD001 and LBH589 has no synergistically inhibitory effect on HL60/ADM cells.But the sole treatment of RAD001 may inhibit proliferation, induce apoptosis and accumulate intercellular adriamycin through a down-regulated expression of MRP1 in HL60/ADM cells via an inhibition of PI3K/AKT/mTOR signaling pathway.