User:Cgarutti/Cancer epigenetics

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Epigenetic Therapy

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Epigenetic therapy of cancer has shown to be a promising and possible treatment of cancerous cells. Epigenetic inactivation is an ideal target for cancerous cells because it targets genes imperative for controlling cell growth, specifically cancer cell growth. It is crucial for these genes to be reactivated in order to suppress tumor growth and sensitize the cells to cancer curing therapies. Typical chemotherapy aims to kill and eliminate cancer cells in the body. Cancer initiated by genetic alterations of cells are typically permanent and nearly impossible to reverse, this differs from epigenetic cancer because the cancer causing epigenetic aberrations have the capability of being reversed, and the cells being returned to normal function. The ability for epigenetic mechanisms to be reversed is attributed to the fact that the coding of the genes being silenced through histone and DNA modification is not being altered.

There are two primary types of epigenetic alterations in cancer cells, these are known as DNA methylation and Histone modification. It is the goal of epigenetic therapies to inhibit these alterations. DNA Methyltransferases (DNMTs) and Histone Deacetylases (HDAC) are the primary catalyzes of the epigenetic modifications of cancer cells. The goal for epigenetic therapies is to repress this methylation and reverse these modifications in order to create a new epigenome where cancer cells no longer thrive and tumor suppression is the new function. Synthetic drugs are used as tools in epigenetic therapies due to their ability to inhibit enzymes causing histone modifications and DNA methylations. Combination therapy is one method of epigenetic therapy which involves the use of more than one synthetic drug, these drugs include a low dose DNMT inhibitor as well as an HDAC inhibitor. Together, these drugs are able to target the linkage between DNA methylation and Histone modification.

The goal of epigenetic therapies for cancer in relation to DNA methylation is to both decrease the methylation of DNA and in turn decrease the silencing of genes related to tumor suppression. The term associated with decreasing the methylation of DNA will be known as hypomethylation. The Food and Drug Administration (FDA) has currently approved one hypomethylating agent which, through the conduction of clinical trials, has shown promising results when utilized to treat patients with Myelodysplastic Syndrome (MDS). This hypomethylating agent is known as the doozy analogue of 5-azacytidine and works to promote hypomethylation by targeting all DNA methyltransferases for degradation.