Detecting DNA methylation for cancer diagnostics and prognostics

DNA methylation is an epigenetic process that has roles in many normal cellular processes and dysregulation of which can result in diseases such as cancer. The most well studied form of mammalian DNA methylation is the addition of a methyl group to the number 5 carbon of cytosine in CpG dinucleotides. Gene regulatory elements, such as gene promoters and enhancers associated with dense CpGs, are sensitive to DNA methylation silencing. Multiple studies have shown that promoter methylation profiling of cancer genes may be useful as biomarkers of cancer. DNA methylation information has the potential to provide information on a patient's cancer subtype, treatment response and prognosis. Current DNA methylation detection techniques can be broadly grouped into sodium bisulfite, restriction enzyme and methylated DNA enrichment based techniques. However, techniques for detection DNA methylation have largely been tailored to research purposes and may not be well suited for routine clinical use. In this chapter, some of these common DNA methylation detection methods are reviewed for their suitability in diagnostics. Also discussed are ways how some of these techniques may be or have been adapted for clinical and point-of-care applications. Emerging techniques that have evolved from classical research methods are also introduced