Epigenetic Mechanisms in Cancer

Abstract

After the completion of the human genome, a need was identified by scientists to look for a functional map of the human genome. Epigenomics provided functional characteristics of genes identified in the genome. Epigenetics is the alteration in gene expression (function) without changing the nucleotide sequence. Both activation and inactivation of cancer-associated genes can occur by epigenetic mechanisms. The major players in epigenetic mechanisms of gene regulation are DNA methylation, histone deacetylation, chromatin remodeling, small noncoding RNA expression and gene imprinting. In the last few years, epigenetic mechanisms have been studied in a number of tumor types and epigenetic markers have been identified that are suitable for cancer detection, diagnosis, follow-up of treatment and screening high-risk populations. One interesting aspect of epigenetics is the reactivation of genes by successful reversion of some epigenetic changes using chemicals. The reversibility of epigenetic aberrations has made them attractive targets for cancer treatment with modulators that demethylate DNA and inhibit histone deacetylases, leading to the reactivation of silenced genes. In this article, we have described the current status of this powerful science and discussed the challenges in the clinical fields where epigenetic approaches in cancer are applied.

Tanshinones Inhibit the Growth of Breast Cancer Cells through Epigenetic Modification of Aurora A Expression and Function

“…Epigenetic alterations of the genome such as DNA promoter methylation and chromatin remodeling play an important role in tumorigenesis [34], [35]. Recent findings also indicate epigenetic modifications as key factors in breast carcinogenesis, and as important targets for preventative care and therapeutics because of their potential for reversal [36], [37].…”

Effects of Down-regulation of HDAC6 Expression on Proliferation, Cell Cycling and Migration of Esophageal Squamous Cell Carcinoma Cells and Related Molecular Mechanisms

“…Epigenetic regulation can affect the gene transcription and do not change the DNA sequence. It includes DNA methylation and modifications of chromosomal histone such as methylation, acetylation, phosphorylation, ubiquitination, etc (Banerjee et al, 2009).…”

Next-Generation Sequencing: From Understanding Biology to Personalized Medicine

“…The studying of epigenetic mechanisms in different tumor types revealed that cytosine methylation is one of the earliest events in tumorigenesis. Consequently, several epigenetic markers have been identified for cancer detection, diagnosis and treatment [135], and the exploration of epigenetic alterations in other human diseases has become a special focus of current research. However, surprisingly few studies have addressed the role of epigenetic regulation in the pathogenesis of cardiovascular disease, although it is commonly recognized that not only the genetic background, but lifestyle and yet unknown factors influence cardiovascular morbidity [136,137].…”