Azacitidine acts as a hypomethylating agent. It inhibits DNA methyltransferase, an enzyme responsible for adding methyl groups to DNA. This inhibition leads to hypomethylation of DNA, which can reactivate tumor suppressor genes that have been silenced by hypermethylation. Reactivation of these genes can inhibit the growth of cancer cells and induce apoptosis. Additionally, azacitidine can incorporate into RNA, disrupting the production of proteins essential for cancer cell survival.
