Nucleic acids contain a variety of different base modifications, such as decoration at the fifth position of cytosine, which is one of the most important epigenetic modifications. Nucleic acid epigenetics mediate a wide variety of biological processes, including embryonic development and gene regulation, genomic imprinting, differentiation, and X-chromosome inactivation. Furthermore, the modification level can be aberrantly expressed in distinct sets of tissue that can indicate different tumor onsets and canceration. Thus, the analysis of modified nucleobases may contribute to the understanding of epigenetic modification-related biological processes and the correlation of modified nucleobase patterns with disease states for clinical diagnosis and treatment. In addition to 5-methylcytosine, 5-hydroxymethylcytosine, 5-formylcytosine, and 5-carboxycytosine are found in organisms at a low content but are nevertheless extremely important chemical modifications, and 5-hydroxyuracil and 5-formyluracil compounds are also present. 5-Formyluracil is found in bacteriophages, prokaryotes, and mammalian cells. The 5-formyluracil content is higher in certain cancer tissues than in the normal tissues adjacent to the tumor. The content of 5-formyluracil in different cell tissues may have cell type specificity.

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DNA中5-甲酰基胞嘧啶和5-甲酰基尿嘧啶的检测和应用

核酸包含多种不同的碱基修饰，例如胞嘧啶第五个位置的修饰，这是最重要的表观遗传修饰之一。核酸表观遗传学介导各种生物学过程，包括胚胎发育和基因调控，基因组印迹，分化和X染色体失活。此外，修饰水平可以在不同的组织集合中异常表达，表明不同的肿瘤发作和癌变。因此，修饰核碱基的分析可能有助于理解表观遗传修饰相关的生物学过程，以及修饰核碱基模式与疾病状态之间的相关性，以进行临床诊断和治疗。除了5-甲基胞嘧啶，5-羟甲基胞嘧啶，5-甲酰基胞嘧啶外，在生物体中发现5-羟基尿嘧啶和5-羧基胞嘧啶的含量低，但化学修饰极其重要，还存在5-羟基尿嘧啶和5-甲酰基尿嘧啶化合物。5-甲酰尿嘧啶存在于噬菌体，原核生物和哺乳动物细胞中。在某些癌组织中，5-甲酰尿嘧啶的含量高于与肿瘤相邻的正常组织中的含量。不同细胞组织中5-甲酰尿嘧啶的含量可能具有细胞类型特异性。