Luo Yanting, Lu Xuemei, Xie Hehuang
Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China.
Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China ; Epigenomics and Computational Biology Lab, Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, VA 24060, USA ; Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24060, USA.
Biomed Res Int. 2014;2014:784706. doi: 10.1155/2014/784706. Epub 2014 Aug 27.
DNA methylation primarily occurs on CpG dinucleotides and plays an important role in transcriptional regulations during tissue development and cell differentiation. Over 25% of CpG dinucleotides in the human genome reside within Alu elements, the most abundant human repeats. The methylation of Alu elements is an important mechanism to suppress Alu transcription and subsequent retrotransposition. Decades of studies revealed that Alu methylation is highly dynamic during early development and aging. Recently, many environmental factors were shown to have a great impact on Alu methylation. In addition, aberrant Alu methylation has been documented to be an early event in many tumors and Alu methylation levels have been associated with tumor aggressiveness. The assessment of the Alu methylation has become an important approach for early diagnosis and/or prognosis of cancer. This review focuses on the dynamic Alu methylation during development, aging, and tumor genesis. The cause and consequence of Alu methylation changes will be discussed.
DNA甲基化主要发生在CpG二核苷酸上，在组织发育和细胞分化过程的转录调控中发挥重要作用。人类基因组中超过25%的CpG二核苷酸位于Alu元件内，Alu元件是人类最丰富的重复序列。Alu元件的甲基化是抑制Alu转录及随后逆转座的重要机制。数十年的研究表明，Alu甲基化在早期发育和衰老过程中高度动态变化。最近，许多环境因素被证明对Alu甲基化有很大影响。此外，异常的Alu甲基化已被证明是许多肿瘤中的早期事件，并且Alu甲基化水平与肿瘤侵袭性相关。Alu甲基化的评估已成为癌症早期诊断和/或预后的重要方法。本综述聚焦于发育、衰老和肿瘤发生过程中Alu甲基化的动态变化。将讨论Alu甲基化变化的原因和后果。
