Chhabra Ravindresh
Department of Biotechnology, Panjab University, Department of Biotechnology, Panjab University, Sector-14, Chandigarh 160014 (India).
Chembiochem. 2015 Jan 19;16(2):195-203. doi: 10.1002/cbic.201402449. Epub 2014 Dec 2.
miRNAs and DNA methylation are both critical regulators of gene expression. Aberration in miRNA expression or DNA methylation is a causal factor for numerous pathological conditions. DNA methylation can inhibit the transcription of miRNAs, just like coding genes, by methylating the CpG islands in the promoter regions of miRNAs. Conversely, certain miRNAs can directly target DNA methyltransferases and bring about their inhibition, thereby affecting the whole genome methylation pattern. Recently, methylation patterns have also been revealed in mRNA. Surprisingly, the two most commonly studied methylation states in mRNA (m6A and m5C) are found to be enriched in 3'-UTRs (untranslated regions), the target site for the majority of miRNAs. Whereas m5C is reported to stabilise mRNA, m6A has a destabilising effect on mRNA. However, the effect of mRNA methylation on its interaction with miRNAs is largely unexplored. The review highlights the complex interplay between microRNA and methylation at DNA and mRNA level.
微小RNA（miRNA）和DNA甲基化都是基因表达的关键调节因子。miRNA表达或DNA甲基化异常是众多病理状况的一个致病因素。与编码基因一样，DNA甲基化可通过使miRNA启动子区域的CpG岛甲基化来抑制miRNA的转录。相反，某些miRNA可直接靶向DNA甲基转移酶并导致其受到抑制，从而影响整个基因组的甲基化模式。最近，mRNA中也发现了甲基化模式。令人惊讶的是，mRNA中两个最常研究的甲基化状态（N6-甲基腺苷（m6A）和5-甲基胞嘧啶（m5C））在3'非翻译区（UTR）中富集，而3'非翻译区是大多数miRNA的靶位点。据报道，m5C可使mRNA稳定，而m6A对mRNA具有去稳定作用。然而，mRNA甲基化对其与miRNA相互作用的影响在很大程度上尚未得到探索。这篇综述强调了在DNA和mRNA水平上，微小RNA与甲基化之间复杂的相互作用。
