microRNAs (miRNAs) are short single-stranded non-coding RNAs between 21 and 25 nt in length in eukaryotic organisms, which control post-transcriptional gene expression. Through complementary base pairing, miRNAs generally bind to their target messenger RNAs and repress protein production by destabilizing the messenger RNA and translational silencing. They regulate almost all life activities, such as cell proliferation, differentiation, apoptosis, tumorigenesis, and host-pathogen interactions. Methylation modification is the most common RNA modification in eukaryotes. miRNA methylation exists in different types, mainly N⁶-methyladenosine, 5-methylcytosine, and 7-methylguanine, which can change the expression level and biological mode of action of miRNAs and improve the activity of regulating gene expression in a very fine-tuned way with flexibility. In this review, we will summarize the recent findings concerning methylation modifications of miRNA, focusing on their biogenesis and the potential role of miRNA fate and functions.

microRNA (miRNA) 是真核生物中长度在 21 至 25 nt 之间的短单链非编码 RNA，控制转录后基因表达。通过互补碱基配对，miRNA 通常与其目标信使 RNA 结合，并通过破坏信使 RNA 的稳定性和翻译沉默来抑制蛋白质的产生。它们调节几乎所有的生命活动，例如细胞增殖、分化、凋亡、肿瘤发生以及宿主与病原体的相互作用。甲基化修饰是真核生物中最常见的RNA修饰。miRNA甲基化存在不同类型，主要是N ⁶ -甲基腺苷、5-甲基胞嘧啶和7-甲基鸟嘌呤，可以非常精细地改变miRNA的表达水平和生物学作用模式，提高调控基因表达的活性具有灵活性。在这篇综述中，我们将总结有关 miRNA 甲基化修饰的最新发现，重点关注其生物发生以及 miRNA 命运和功能的潜在作用。