Epigenetic basis of disease

Epigenetics refers to the inheritance of information contained outside the underlying DNA sequence. Post translational epigenetic modifications including DNA methylation, histone modifications and chromatin remodelling are epigenetically inherited. Epigenetic processes enable organisms to repress various gene sets depending on the cell type and are passed from mother to
daughter cells allowing the maintenance of cell identity. Misregulation of epigenetic processes can cause silencing or ectopic expression of genes and this often leads to disease states. Typically the hallmarks of malignancy are genomic rearrangements and gross morphologies. However, epigenetic misregulation is also typically observed in malignant cells - for example, DNA hypermethylation causing promoter silencing of tumor suppressor genes. Genomics, proteomics, metabolomics and transcriptomics are emerging technologies that are part of the 'Omics' umbrella or high throughput technologies. These are now routinely used in cancer research allowing researchers to determine differences in normal compared to disease states. Ultimately, the premise is that these will improve the screening, diagnosis and treatments of cancers. These emerging technologies, which are considered in this chapter, serve as potential tools in early detection of cancers and for identifying biomarkers for high risk individuals.