Table 1 Overview of some DNMT inhibitors with their mechanisms of action

Azacitidine

Ribonucleoside analogue

This drug is a ribonucleoside analogue and it binds to RNA and DNA. This molecule interrupts mRNA translation and when incorporated into DNA inhibits methylation by trapping DNMTs. At relatively higher concentrations this drug results in the formation of high levels of enzyme-DNA adducts.

Decitabine

Deoxyribonucleoside analogue

This drug is a deoxyribonucleoside analogue. For this reason, this molecule does not bind to RNA but only to DNA. When incorporated into DNA inhibits methylation by trapping DNMTs resulting in the reduced methylation of cytosines in DNA synthesized after drug treatment. When used at relatively high concentrations this drug results in the formation of high levels of enzyme-DNA adducts,

Zebularine

Deoxyribonucleoside analogue

This drug is a deoxyribonucleoside analogue. For this reason, this molecule does not bind to RNA but only to DNA. When incorporated into DNA inhibits methylation by trapping DNMTs resulting in the reduced methylation of cytosines in DNA synthesized after drug treatment. When used at relatively high concentrations this drug results in the formation of high levels of enzyme-DNA adducts,

(−)-epigallocatechin-3-gallate

Non-nucleoside analogue

MG98

Non-nucleoside analogue

This antisense oligonucleotide targets the 3 UTR of DNMT1 causing a methylation decrease in cell lines and animal models

RG108

Non-nucleoside analogue

This small molecule is not incorporated into DNA but i bind to the catalytic site of DNMTs causing inhibition of DNA methylation

Procainamide

Non-nucleoside analogue

This molecule reduces DNMT1's affinity

for both DNA and S-adenosyl-methionine causing a decrease in DNA methylation