Epigenetics: Impacts on Disease Susceptibility and Pharmacotherapy

  Deoxyribonucleic acid (DNA) is a hereditary material comprising of all the genetic information in humans and almost all other living creatures. It is made up of subunits called genes, which have four nucleotides. MicroRNAs comprises of the short noncoding RNA. They are non-protein coding with about 18-22 nucleotides which control gene expression and activities post-transcriptionally. Notably, the whole DNA structure usually coiled itself around a protein called histone moiety. Consequently, any addition of methyl, ethyl, phosphate, Ubiquitin or small ubiquitin-related modifier either directly on the DNA itself or the histone molecule will ultimately change its configuration and stability leading to the epigenetic modifications. Usually, epigenetic changes manifest phenotypically without changing the actual gene sequence. MicroRNAs also play a vital role in the control of the expression epigenetic regulators, such as DNA methyltransferase (DNMT), histone deacetylase, and Polycomb group genes. The implication of this may significantly affect the normal function of an organism and perhaps contribute to the wide-range of disease aetiology. As such, epigenetics linked variations and diseases are inheritable. The landmark achievement in pharmacotherapy involves the possibility of silencing the oncogenes that are cancer provoking genes and possible reactivation of cancer suppression genes that battle with and repress the tumour cells proliferation. Besides these, more genes that are linked to other diseases apart from cancer can be identified, silenced or activated using drugs or diets in order to treat the disease aetiology. This appraisal is to discuss the role of epigenetic changes in the disease susceptibility and drug treatment.