A hypomethylating agent (or demethylating agent) is a drug that inhibits

DNA methylation DNA methylation is a biological process by which methyl groups are added to the DNA molecule. Methylation can change the activity of a DNA segment without changing the sequence. When located in a gene promoter, DNA methylation typically acts ...

: the modification of DNA nucleotides by addition of a methyl group. Because DNA methylation affects cellular function through successive generations of cells without changing the underlying DNA sequence, treatment with a hypomethylating agent is considered a type of

epigenetic therapy Epigenetic therapy is the use of drugs or other epigenome-influencing techniques to treat medical conditions. Many diseases, including cancer, heart disease, diabetes, and mental illnesses are influenced by epigenetic mechanisms. Epigenetic ther ...

. Currently available hypomethylating agents block the activity of

DNA methyltransferase In biochemistry, the DNA methyltransferase (DNA MTase, DNMT) family of enzymes catalyze the transfer of a methyl group to DNA. DNA methylation serves a wide variety of biological functions. All the known DNA methyltransferases use S-adenosyl m ...

(DNA methyltransferase inhibitors / DNMT inhibitors). Currently two members of the class,

azacitidine Azacitidine, sold under the brand name Vidaza among others, is used for the treatment of myelodysplastic syndrome, myeloid leukemia, and juvenile myelomonocytic leukemia. It is a chemical analog of cytidine, a nucleoside in DNA and RNA. Azacit ...

and

decitabine Decitabine, sold under the brand name Dacogen among others, acts as a nucleic acid synthesis inhibitor. It is a medication for the treatment of myelodysplastic syndromes, a class of conditions where certain blood cells are dysfunctional, and for ...

, are FDA-approved for use in the United States in

myelodysplastic syndrome A myelodysplastic syndrome (MDS) is one of a group of cancers in which immature blood cells in the bone marrow do not mature, and as a result, do not develop into healthy blood cells. Early on, no symptoms typically are seen. Later, symptoms may ...

and are being investigated for use in a number of

tumor A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...

Clinical use

Two hypomethylating agents are approved for the treatment of

by the United States FDA *

Also has EU approval for

acute myeloid leukemia Acute myeloid leukemia (AML) is a cancer of the myeloid line of blood cells, characterized by the rapid growth of abnormal cells that build up in the bone marrow and blood and interfere with normal blood cell production. Symptoms may inclu ...

(AML). *

Mechanism of action

DNA methylation is the modification of DNA nucleotides by addition of a methyl group. These methyl groups are associated with changes in the ability of the corresponding DNA to be used. Patterns of DNA methylation are stable during cellular division. Methylation of

tumor suppressor A tumor suppressor gene (TSG), or anti-oncogene, is a gene that regulates a cell during cell division and replication. If the cell grows uncontrollably, it will result in cancer. When a tumor suppressor gene is mutated, it results in a loss or re ...

genes in some cancers contributes to the growth and survival of the cancer. Hypomethylating agents decrease the amount of cellular DNA methylation, allowing for tumor suppressor gene expression.

References

Antineoplastic drugs {{antineoplastic-drug-stub

Clinical use

Mechanism of action

See also

References