DNA hydroxymethylation increases the susceptibility of reactivation of methylated P16 alleles in cancer cells
DNA hydroxymethylation increases the susceptibility of reactivation of methylated P16 alleles in cancer cells
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DNA 羟甲基化增加癌细胞中甲基化 P16 等位基因重新激活的易感性
DOI：
10.1080/15592294.2019.1700004
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发表时间：
2019-12-06
期刊：
影响因子：
3.7
通讯作者：
Deng，Dajun
中科院分区：
文献类型：
--
作者：
Li，Paiyun;Gan，Ying;Deng，Dajun
摘要 众所周知，哺乳动物细胞基因组DNA中的5-甲基胞嘧啶（5mC）可以被DNA双加氧酶TET氧化成5-羟甲基胞嘧啶（5hmC）和其他衍生物。虽然 5mC 转化为 5hmC 通过进一步的氧化步骤在主动 DNA 去甲基化中发挥着重要作用，但一定比例的 5hmC 仍保留在基因组中。尽管 5hmC 有助于染色质的灵活性并保护二价启动子免受过度甲基化，但 5hmC 对基因转录的直接影响尚不清楚。在本研究中，我们设计了一种基于锌指蛋白的 P16 特异性 DNA 双加氧酶 (P16-TET)，以诱导癌细胞中 P16 羟甲基化和去甲基化。我们的结果首次证明，尽管羟甲基化的 P16 等位基因保持转录失活，但羟甲基化可能会增加甲基化 P16 等位基因重新激活的敏感性。
ABSTRACT It is well established that 5-methylcytosine (5mC) in genomic DNA of mammalian cells can be oxidized into 5-hydroxymethylcytosine (5hmC) and other derivates by DNA dioxygenase TETs. While conversion of 5mC to 5hmC plays an important role in active DNA demethylation through further oxidation steps, a certain proportion of 5hmCs remain in the genome. Although 5hmCs contribute to the flexibility of chromatin and protect bivalent promoters from hypermethylation, the direct effect of 5hmCs on gene transcription is unknown. In this present study, we have engineered a zinc-finger protein-based P16-specific DNA dioxygenase (P16-TET) to induce P16 hydroxymethylation and demethylation in cancer cells. Our results demonstrate, for the first time, that although the hydroxymethylated P16 alleles retain transcriptionally inactive, hydroxymethylation could increase the susceptibility of reactivation of methylated P16 alleles.