5-methylcytosine (5mC) (5mC)

5-methylcytosine (5mC) is a critical epigenetic modification formed by the covalent attachment of a methyl group to the fifth carbon of the cytosine ring, predominantly within CpG dinucleotides (Moore et al., 2013, PubMed: 23418860). It serves as a key regulator of the genome, typically functioning as a repressive mark that silences gene expression by preventing the binding of transcription factors or recruiting methyl-CpG-binding domain (MBD) proteins (Bird, 2002, PubMed: 11814964). Proper 5mC patterning is essential for normal development, including processes like genomic imprinting and X-chromosome inactivation (Reik et al., 2001, PubMed: 11373667). Aberrant DNA methylation, such as the hypermethylation of tumor suppressor genes or global hypomethylation leading to chromosomal instability, is a hallmark of various cancers and neurological disorders (Robertson, 2005, PubMed: 16127449). Therapeutic strategies targeting 5mC include the use of DNA methyltransferase (DNMT) inhibitors like azacitidine to reverse silencing and emerging CRISPR-based epigenetic editing tools designed to modify methylation at specific genomic loci (García et al., 2010, PubMed: 20107206; Liu et al., 2016, PubMed: 27662091). These interventions aim to restore healthy gene expression profiles by either globally reducing methylation or precisely editing the epigenetic state of a targeted locus.

Other names

5-methyl-2'-deoxycytidinem5CDNA methylation5-MeC

DNA methyltransferase inhibition (García et al., 2010, PubMed: 20107206), Targeted DNA demethylation (Liu et al., 2016, PubMed: 27662091), Targeted DNA methylation