Epigenetics and microRNAs
Epigenetics and microRNAs
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DOI：
10.1203/pdr.0b013e3180457684
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发表时间：
2007-05-01
影响因子：
3.6
通讯作者：
Jones, Peter A.
中科院分区：
文献类型：
--
作者：
Chuang, Jody C.;Jones, Peter A.
表观遗传学被定义为基因表达的有丝分裂和减数分裂可遗传的变化，不涉及DNA序列的变化。表观遗传学的两个主要领域——dna甲基化和组蛋白修饰——已知对控制基因表达有深远的影响。DNA甲基化参与正常细胞的表达控制，异常的高甲基化可导致致癌过程中肿瘤抑制基因的沉默。组蛋白修饰控制着细胞内染色质的可及性和转录活性。MicroRNAs （miRNAs）是一种小的RNA分子，长度与22个核苷酸相似，可以在转录后负性地控制其靶基因的表达。目前已知的人类mirna有460多种，预计总数会多得多。最近，miRNA的表达与癌症的发展有明确的联系，miRNA谱可以用来对人类癌症进行分类。mirna在我们的基因组中编码，通常由RNA聚合酶II转录。尽管越来越多的证据表明它们在正常生理中的重要性，但对miRNA表达的调控知之甚少。在这篇综述中，我们将研究mirna与表观遗传学之间的关系。我们研究了miRNA对表观遗传机制的影响，以及表观遗传机制对miRNA表达的控制。表观遗传学被定义为不涉及DNA序列改变的基因表达的可遗传变化。
Epigenetics is defined as mitotically and meiotically heritable changes in gene expression that do not involve a change in the DNA sequence. Two major areas of epigenetics-DNA methylation and histone modifications-are known to have profound effects on controlling gene expression. DNA methylation is involved in normal cellular control of expression, and aberrant hypermethylation can lead to silencing of tumor-suppressor genes in carcinogenesis. Histone modifications control the accessibility of the chromatin and transcriptional activities inside a cell. MicroRNAs (miRNAs) are small RNA molecules, similar to 22 nucleotides long that can negatively control their target gene expression posttranscriptionally. There are currently more than 460 human miRNAs known, and the total number is predicted to be much larger. Recently, the expression of miRNAs has been definitively linked to cancer development, and miRNA profiles can be used to classify human cancers. miRNAs are encoded in our genome and are generally transcribed by RNA polymerase II. Despite the growing evidence for their importance in normal physiology, little is known about the regulation of miRNA expression. In this review, we will examine the relationship between miRNAs and epigenetics. We examine the effects of miRNAs on epigenetic machinery, and the control of miRNA expression by epigenetic mechanisms. Epigenetics is defined as heritable changes in gene expression that do not involve a change in DNA sequence.