RESUMEN
Objective To investigate the effect of histone deacetylase inhibitor LBH589 on proliferation,apoptosis and drug resistance of chemoresistant acute myeloid leukemia cells HL60/ADM.Methods HL60/ADM cells were treated with LBH589.Proliferation,apoptosis and adriamycin IC50 were evaluated by MTT assay and AnnexinV-FITC/PI stain.The change in MRP1 expression and intercellular adriamycin accumulatiom were analyzed by flow cytometry.Results Effective proliferative inhibition and apoptotic induction in HL60/ADM cells were observed after treatment with 10-80 nmol/L LBH589 with maximal effect detected after treatment with 70 nmol/L LBH589 for 60 hours.However,inhibition ratio remain unchanged with the further increase of drug dose and incubation time (P ＞ 0.05).Downregulation of MRP1 [(93.90±4.20) ％ vs (76.19±6.53) ％],upregulation of adriamycin accumulation [(8.53±0.68) ％ vs (25.67±1.34) ％] and decrease in adriamycin IC50 [(6.833±0.319) μg/ml vs (1.382±0.104) μg/ml] were induced by the treatment with 20 nmol/L LBH589 (P ＜ 0.01),whose reversal fold was 4.9.The expression of acetylated histone 3 after treatment with LBH589 was higher than that before treatment (P ＜ 0.01).However,relative p-Akt levels after treatment for 24 h and 48 h were 1.07±0.09 and 0.59±0.01,respectively,which were lower than that before treatment (2.03±0.12) (P ＜ 0.01).Meanwhile,expression levels of p53 were 0.57±0.04 and 1.31±0.09,respectively,which were higher than that before treatment (0.21 ±0.02) (P ＜ 0.01).Conclusion Treatment with LBH589 has the capability of inhibiting proliferation and inducing apoptosis,as well as increasing intercellular adriamycin accumulation and sensitivity through downregulation of MRP1 expression and inhibition of PI3K-Akt signaling pathway in HL60/ADM cells.