Epigenetic changes of DNA and their research methods

Abstract

All the information, which determine the structure and function of the human body, is carried by the human DNA. However, the development of several human diseases is not primarily originated from the changes of this genetic information, which laid into the DNA. For example, only 5-10% of the developed cancers are caused primarily by mutations. Changes in the three-dimensional structure of the chromatin, beside the genetic alterations in the nu-cleotide level and structural variants of the genome, also take part in the development of phenotype through the modification of transcription and signal transduction. The human DNA is continuously rearranged by epigenetic regulation. In this process, the nucleotide sequence and the coding information are not changing in the DNA, only the active and inactive state of the regulatory and coding regions according to the actual need of the physiological and age-dependent conditions. This regulated rearrangement of the DNA, which is called remodeling, ensures the optimal transcription of the necessary proteins and genes. The effectiveness of this function, however, is decreasing during the aging process and thus resulted in several diseases as a consequence of an unbalanced epigenetic regula-tion. There are several old and new ideas and methods to research and measure the epigenetic changes, which diag-nostic applications could support the early prediction of the development of diseases. The aim of our review article is to summarize the complexity of the epigenetic regulation, highlight the role of some key molecules and hormones in the process of aging, and related diseases as well. Moreover, we describe the newest methods analysing the epige-netic changes, like chromatin immunoprecipitation (ChIP), detection of the open chromatin regions, detection of DNA methylation level, which could be applied as diagnostic methods in the near future.