Genome-wide DNA methylation profiling of CpG islands in a morpholino anthracycline derivative-resistant leukemia cell line: p38α as a novel candidate for resistance.
Genome-wide DNA methylation profiling of CpG islands in a morpholino anthracycline derivative-resistant leukemia cell line: p38α as a novel candidate for resistance.
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DOI：
10.1002/prp2.285
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发表时间：
2017-02
影响因子：
2.6
通讯作者：
Fujita A
中科院分区：
文献类型：
--
作者：
Asano T;Narazaki H;Fujita A
有效的白血病治疗受到耐药性的严重阻碍。我们之前发现拓扑异构酶II α基因的异常甲基化导致了依托泊苷耐药白血病细胞的基因表达改变和获得性耐药。在这项研究中，我们分析了耐药白血病细胞的全基因组甲基化状态。我们使用MX2，这是一种吗啉蒽环类衍生物，作为拓扑异构酶II α抑制剂。我们建立了人髓性白血病细胞系K562/P和MX2耐药细胞系K562/MX2。使用这些细胞系，我们研究了全基因组甲基化状态，用微阵列比较了表达谱，并使用Gene Ontology和关键节点分析分析了数据。我们证明了MX2耐药细胞系是全局高甲基化的。基因本体论分析确定了参与免疫反应和基因沉默的基因，这些基因导致耐药细胞中甲基化相关的基因表达改变。关键节点分析表明，p38α丝裂原活化蛋白激酶是一种参与MX2相关耐药的新酶。与MX2敏感性亲本细胞相比，耐药细胞中的p38激酶活性增加。用抑制剂阻断p38α活性和用小干扰RNA敲低p38α可恢复耐药细胞对MX 2的敏感性，p38激酶活性降低，p38α mRNA和磷酸化p38α蛋白表达降低。这些发现可能会为耐药白血病细胞的治疗带来新的策略。
Effective leukemia treatment is seriously hampered by drug resistance. We previously showed that aberrant methylation of the topoisomerase II α gene causes altered gene expression and acquired drug resistance in etoposide‐resistant leukemia cells. In this study, we analyzed the genome‐wide methylation status in resistant leukemia cells. We used MX2, which is a morpholino anthracycline derivative that functions as a topoisomerase II α inhibitor. We established a human myelogenous leukemia cell line (K562/P) and a related cell line with resistance to MX2 (K562/MX2). Using these cell lines, we investigated the genome‐wide methylation status, compared expression profiles with a microarray, and analyzed the data using Gene Ontology and key node analysis. We demonstrate that the MX2‐resistant cell line was globally hypermethylated. Gene Ontology analysis identified genes involved in the immunological response and gene silencing that were responsible for methylation‐related altered gene expression in drug‐resistant cells. Key node analysis showed that p38α mitogen‐activated protein kinase was a novel enzyme involved in MX2‐related resistance. p38 kinase activity in resistant cells was increased compared to MX2‐sensitive parent cells. Blocking p38α activity using inhibitors and p38α knock down with small interfering RNA restored the sensitivity to MX2 in resistant cells with a decrease in p38 kinase activity as well as decreased expression of p38α mRNA and phosphorylated p38α protein. These findings may lead to a new strategy for treatment of drug‐resistant leukemia cells.