## Can endocrine disruptors cause epigenetic changes?

Epigenetics is the study of heritable changes in gene function that occur without altering the DNA sequence (more information is in chapter 7). Thus, epigenetic mechanisms control long-term transcriptional regulation, with epigenetic modifications defined as lasting alterations in gene function that persist after the initial trigger has disappeared, without involving changes to the gene sequence or structure. If EDCs are discussed, they are able to affect epigenetic markers such as DNA methylation, histone modifications or non-coding RNAs.

The most commonly studied mechanism of epigenetic changes is the effect of EDCs on the levels of enzymes that regulate epigenetic patterns, for example, DNA methyltransferases (DNMTs), which catalyse the addition of a methyl group to DNA (see chapter 6 – How the environment can affect our genes). Some studies also describe the effects of EDCs on DNMT expression, at both gene and protein levels. On the other hand, only a few studies examine the mechanism behind these changes. It is assumed, that the mechanism lies in the regulation of mRNA or miRNA expression. However, although there are certain assumptions about epigenetic regulation caused by the influence of endocrine disruptors, we still have relatively little information in this area and therefore further intensive research is needed.