Valiulienė Giedrė, Stirblytė Ieva, Jasnauskaitė Monika, Borutinskaitė Veronika, Navakauskienė Rūta
Department of Molecular Cell Biology, Institute of Biochemistry, Life Sciences Center, Vilnius University, Saulėtekio ave. 7, LT-10257 Vilnius, Lithuania.
Eur J Pharmacol. 2017 Mar 15;799:143-153. doi: 10.1016/j.ejphar.2017.02.014. Epub 2017 Feb 10.
Development of acute myeloid leukemia is usually sustained by deregulated epigenome. Alterations in DNA methylation and histone modifications are common manifestations of the disease. Acute promyelocytic leukemia (APL) is not an exception. Therefore, drugs that target epigenetic processes suggest an appealing strategy for APL treatment. In this study we tested the anti-leukemic activity of histone deacetylase inhibitor (HDACi) Belinostat (PXD101, (2E)-N-Hydroxy-3-[3-(phenylsulfamoyl)phenyl]prop-2-enamide), and histone methyltransferase inhibitor (HMTi) 3-Deazaneplanocin A (DZNep, 5R-(4-amino-1H-imidazo[4,5-c]pyridin-1-yl)-3-(hydroxymethyl)-3-cyclopentene-1S,2R-diol) combined with retinoic acid (RA) in APL cells NB4 and HL-60. We demonstrated that APL cell treatment with combinations of differentiation inductor RA, HDACi Belinostat and HMTi DZNep caused a depletion of leukemia cell growth and viability, initiated apoptosis and exaggerated RA induced granulocytic differentiation. Also an increased expression of transcription factors C/EBPε and PPARγ was demonstrated, while no significant reduction in C/EBPα gene level was detected. Furthermore, combined treatment depleted gene expression levels of EZH2 and SUZ12, especially in HL-60 cells, and diminished protein levels of Polycomb Repressive Complex 2 (PRC2) components EZH2, SUZ12 and EED. In addition, our study has shown that Belinostat and DZNep together with RA caused a depletion in HDAC1 and HDAC2 protein levels, HDAC2 gene expression and increased hyperacetylation of histone H4 in both leukemia cell lines. Using ChIP method we also demonstrated the increased association of hyperacetylated histone H4 with the C/EBPα and C/EBPε promoter regions in HL-60 cells. Summarizing, these findings indicate that combined treatment with RA, Belinostat and 3-Deazaneplanocin A is an effective epigenetic inducer for leukemia cell differentiation.
急性髓系白血病的发展通常由失调的表观基因组维持。DNA甲基化和组蛋白修饰的改变是该疾病的常见表现。急性早幼粒细胞白血病（APL）也不例外。因此，靶向表观遗传过程的药物为APL治疗提供了一种有吸引力的策略。在本研究中，我们测试了组蛋白去乙酰化酶抑制剂（HDACi）贝利司他（PXD101，(2E)-N-羟基-3-[3-(苯基磺酰氨基)苯基]丙烯酰胺）和组蛋白甲基转移酶抑制剂（HMTi）3-脱氮泽兰诺辛A（DZNep，5R-(4-氨基-1H-咪唑[4,5-c]吡啶-1-基)-3-(羟甲基)-3-环戊烯-1S,2R-二醇）与维甲酸（RA）联合作用于APL细胞NB4和HL-60的抗白血病活性。我们证明，用分化诱导剂RA、HDACi贝利司他和HMTi DZNep联合处理APL细胞会导致白血病细胞生长和活力的降低，引发细胞凋亡，并增强RA诱导的粒细胞分化。还证明了转录因子C/EBPε和PPARγ的表达增加，而未检测到C/EBPα基因水平的显著降低。此外，联合治疗降低了EZH2和SUZ12的基因表达水平，尤其是在HL-60细胞中，并降低了多梳抑制复合物2（PRC2）组分EZH2、SUZ12和EED的蛋白水平。此外，我们的研究表明，贝利司他和DZNep与RA一起导致两种白血病细胞系中HDAC1和HDAC2蛋白水平、HDAC2基因表达的降低以及组蛋白H4的高乙酰化增加。使用染色质免疫沉淀（ChIP）方法，我们还证明了在HL-60细胞中，高乙酰化组蛋白H4与C/EBPα和C/EBPε启动子区域的结合增加。总之，这些发现表明，RA、贝利司他和3-脱氮泽兰诺辛A联合治疗是一种有效的白血病细胞分化表观遗传诱导剂。
