Cancer Epigenetics Laboratory, Institute of Oncology of Asturias (IUOPA), HUCA, Universidad de Oviedo, Oviedo, Spain.
Nanomaterials and Nanotechnology Research Center (CINN-CSIC)-Universidad de Oviedo-Principado de Asturias, El Entrego, Spain.
Ageing Res Rev. 2017 Aug;37:28-38. doi: 10.1016/j.arr.2017.05.002. Epub 2017 May 10.
DNA methylation at the fifth position of cytosines (5mC) represents a major epigenetic modification in mammals. The recent discovery of 5-hydroxymethylcytosine (5hmC), resulting from 5mC oxidation, is redefining our view of the epigenome, as multiple studies indicate that 5hmC is not simply an intermediate of DNA demethylation, but a genuine epigenetic mark that may play an important functional role in gene regulation. Currently, the availability of platforms that discriminates between the presence of 5mC and 5hmC at single-base resolution is starting to shed light on the functions of 5hmC. In this review, we provide an overview of the genomic distribution of 5hmC, and examine recent findings on the role of this mark and the potential consequences of its misregulation during three fundamental biological processes: cell differentiation, cancer and aging.
在哺乳动物中，第五位胞嘧啶的 DNA 甲基化（5mC）代表了一种主要的表观遗传修饰。最近发现的 5-羟甲基胞嘧啶（5hmC）是由 5mC 氧化产生的，这重新定义了我们对表观基因组的认识，因为多项研究表明 5hmC 不仅仅是 DNA 去甲基化的中间产物，而是一种真正的表观遗传标记，可能在基因调控中发挥重要的功能作用。目前，能够以单碱基分辨率区分 5mC 和 5hmC 存在的平台的出现，开始揭示 5hmC 的功能。在这篇综述中，我们概述了 5hmC 的基因组分布，并探讨了最近关于该标记在三个基本生物学过程中的作用及其调控异常的潜在后果的发现：细胞分化、癌症和衰老。
