Non-CpG methylation-a key epigenetic modification in cancer

The methylation of cytosine residues that precede adenine/thymine or other cytosine nucleotides instead of guanine in DNA is known as non-CpG methylation. It is a pronounced epigenetic modification with a central role in gene regulation similar to CpG methylation. Due to technological limitations, the locus-specific role of non-CpG methylation was scarcely understood. At present, high-throughput analyses and improved enrichment methods can elucidate the role of genome-wide non-CpG methylation distributions. Although the functional basis of non-CpG methylation in regulating gene expression control is known, its role in cancer development is yet to be ascertained. This review sheds light on the possible mechanism of non-CpG methylation in embryos and developed tissues with a special focus on cancer development and progression. In particular, the maintenance and alteration of non-CpG methylation levels and the crucial factors that determine this level of non-CpG methylation and its functional role in cancer are discussed.

Automated summary

Non-CpG methylation, a distinct epigenetic modification in DNA, plays a crucial role in gene regulation. Advances in technology have allowed for a better understanding of its genome-wide distribution, but its specific role in cancer development remains unclear. This review focuses on the mechanism of non-CpG methylation in embryos and tissues, particularly its relevance to cancer progression.