DNA methylation: cancer, aging and diet

With the completion of the Human Genome Project, the list of the genes needed to produce a perfect human was completed. Of equal importance is a second system that cells use to determine when and where a particular gene will be expressed during development. However, the situation is far more complex than a simple catalogue of genes. Classical genetics alone cannot explain the existing diversity of phenotype. The concept of epigenetic offers an explanation and description of these phenomena. The best-known epigenetic marker is DNA methylation. In human, DNA methylation occurs at the C-5' position of cytosine within the CpG (5'-CG-3') dinucleotide. Methylation of DNA plays a pivotal role in the control of gene activity and nuclear architecture. Aberrant DNA methylation (Genomic global hypomethylation and region-specific hypermethylation) is frequently observed in aging and especially in the tumorgenesis. Today, epigenetic researches are focused on studying and increasing understanding of the mysteries and ambiguities in the complex biological processes like cancer and aging. Recent studies have shown that dietary factors can modulate DNA methylation and thereby contribute to aging and tumorgenesis. Thus, DNA methylation provides an important common link between aging, cancer and nutrition.