MicroRNA mediates DNA demethylation events triggered by retinoic acid during neuroblastoma cell differentiation.
MicroRNA mediates DNA demethylation events triggered by retinoic acid during neuroblastoma cell differentiation.
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DOI：
10.1158/0008-5472.can-10-1534
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发表时间：
2010-10-15
期刊：
影响因子：
11.2
通讯作者：
Stallings RL
中科院分区：
文献类型：
--
作者：
Das S;Foley N;Bryan K;Watters KM;Bray I;Murphy DM;Buckley PG;Stallings RL
神经母细胞瘤是由交感神经系统的前体细胞引起的一种致命的儿科癌症。13-顺式视黄酸被包括在高危疾病患者的治疗方案中，并且类似的衍生物全反式视黄酸（ATRA）导致神经母细胞瘤细胞系经历分化。参与ATRA诱导分化的分子信号通路是复杂的，并且DNA甲基化变化可能发挥的作用是未知的。本研究的目的是评估全基因组范围内的影响，ATRA对DNA甲基化的甲基化DNA免疫沉淀应用于微阵列代表所有已知的启动子和CpG岛。ATRA后402个基因启动子发生去甲基化，88个基因启动子发生高甲基化。mRNA表达微阵列显示，82个去甲基化基因过表达>2倍，而13个高甲基化基因表达不足。基因本体分析表明，去甲基化和重新表达的基因富集的信号转导途径，包括NOS 1，这是所需的神经细胞分化。作为DNA甲基化变化的潜在机制，我们证明了甲基转移酶DNMT 1和DNMT 3B的下调，沿着靶向它们的内源性microRNA的上调。靶向DNMT 1的miR-152的异位过表达也对细胞侵袭性和锚定非依赖性生长产生负面影响，部分促成了分化表型。我们的结论是，功能上重要的，miRNA介导的DNA去甲基化的变化有助于ATRA诱导分化的过程中激活的NOS 1，神经细胞分化的关键决定因素。我们的研究结果说明了在癌细胞分化过程中表观基因组的可塑性和动态性质。
Neuroblastoma is an often fatal pediatric cancer arising from precursor cells of the sympathetic nervous system. 13-Cis retinoic acid is included in the treatment regime for patients with high-risk disease, and a similar derivative, all-trans retinoic acid (ATRA) causes neuroblastoma cell lines to undergo differentiation. The molecular signaling pathways involved with ATRA induced differentiation are complex, and the role that DNA methylation changes might play are unknown. The purpose of this study was to evaluate the genome-wide effects of ATRA on DNA methylation using methylated DNA immunoprecipitation applied to microarrays representing all known promoter and CpG islands. 402 gene promoters became demethylated, while 88 were hypermethylated post-ATRA. mRNA expression microarrays revealed that 82 of the demethylated genes were over-expressed by >2 fold, while 13 of the hyper methylated genes were under-expressed. Gene ontology analysis indicated that de-methylated and re-expressed genes were enriched for signal transduction pathways, including NOS1, which is required for neural cell differentiation. As a potential mechanism for the DNA methylation changes, we demonstrate the down-regulation of methyltransferases, DNMT1 and DNMT3B, along with the up-regulation of endogenous microRNAs targeting them. Ectopic over-expression of miR-152, targeting DNMT1, also negatively impacted cell invasiveness and anchorage independent growth, contributing in part to the differentiated phenotype. We conclude that functionally important, miRNA-mediated DNA de-methylation changes contribute to the process of ATRA induced differentiation resulting in the activation of NOS1, a critical determinant of neural cell differentiation. Our findings illustrate the plasticity and dynamic nature of the epigenome during cancer cell differentiation.