5-Aza-2′-Deoxycytidine

Cancer is a complex disease manifestation. At its core, it remains a disease of abnormal cellular proliferation and inappropriate gene expression. In the early days, carcinogenesis was viewed simply as resulting from a collection of genetic mutations that altered the gene expression of key oncogenic genes or tumor suppressor genes leading to uncontrolled growth and disease (Virani, S et al 2012). Today, however, research is showing that carcinogenesis results from the successive accumulation of heritable genetic and epigenetic changes. Moreover, the success in how we predict, treat and overcome cancer will likely involve not only understanding the consequences of direct genetic changes that can cause cancer, but also how the epigenetic and environmental changes cause cancer (Johnson C et al 2015; Waldmann T et al 2013). Epigenetics is the study of heritable gene expression as it relates to changes in DNA structure that are not tied to changes in DNA sequence but, instead, are tied to how the nucleic acid material is read or processed via the myriad of protein-protein, protein-nucleic acid, and nucleic acid-nucleic acid interactions that ultimately manifest themselves into a specific expression phenotype (Ngai SC et al 2012, Johnson C et al 2015). This review will discuss some of the principal aspects of epigenetic research and how they relate to our current understanding of carcinogenesis. Because epigenetics affects phenotype and changes in epigenetics are thought to be key to environmental adaptability and thus may in fact be reversed or manipulated, understanding the integration of experimental and epidemiologic science surrounding cancer and its many manifestations should lead to more effective cancer prognostics as well as treatments (Virani S et al 2012).