Advancements in the delivery of epigenetic drugs

Abstract

Introduction Advancements in epigenetic treatments are not only coming from new drugs but from modifications or encapsulation of the existing drugs into different formulations leading to greater stability and enhanced delivery to the target site. The epigenome is highly regulated and complex; therefore it is important that off-target effects of epigenetic drugs be minimized. The step from in vitro to in vivo treatment of these drugs often requires development of a method of effective delivery for clinical translation. Areas covered This review covers epigenetic mechanisms such as DNA methylation, chromatin remodeling and small RNA mediated gene regulation. There is a section in the review with examples of diseases where epigenetic alterations lead to impaired pathways, with an emphasis on cancer. Epigenetic drugs, their targets and clinical status are presented. Advantages of using a delivery method for epigenetic drugs as well as examples of current advancements and challenges are also discussed. Expert opinion Epigenetic drugs have the potential to be very effective therapy against a number of diseases, especially cancers and neurological disorders. As with many chemotherapeutics, undesired side effects need to be minimized. Finding a suitable delivery method means reducing side effects and achieving a higher therapeutic index. Each drug may require a unique delivery method exploiting the drug's chemistry or other physical characteristic requiring interdisciplinary participation and would benefit from a better understanding of the mechanisms of action.

Direct and Indirect Targeting of HOXA9 Transcription Factor in Acute Myeloid Leukemia

“…Moreover, besides being an attractive strategy to control HOXA9 expression at the epigenetic level, it is worth noting that most, if not all, of the epigenetic drivers presented here have an effect on the expression of many other genes. Consequently, such approaches that change the epigenetic marks may not exclusively be active on the leukemic cells of AML patients, but may also present side-effects and off-target effects by altering normal cells [299,300,301,302]. Moreover, such epigenetic targeting would not be restricted to HOXA9 but be also active on other members of the posterior HOXA locus, namely HOXA5 to HOXA11, which are usually epigenetically co-expressed.…”

Epigenetics in cancer therapy and nanomedicine

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Nanomedicine of synergistic drug combinations for cancer therapy – Strategies and perspectives

“…However, epidrugs are unstable in vivo and has transient antiproliferative effect [138, 139]. To safely and effectively deliver epidrugs, nanocarriers have been employed to extend dosing regimen and improve PK profiles.…”