| DNA methylation, histone modification, and ncRNA function are the main epigenetic mechanisms involved in
the regulation of gene expression and there are single nucleotide polymorphisms (SNPs) that may affect them.
Although these SNPs have an important role in connecting genetic and epigenetic levels of gene regulation, they
have not been classified in an independent category until now. Therefore, we introduce the EpiPol concept,
which abbreviates the epigenetic affecting polymorphism and describes those variations in the regulatory sequences of a gene, which may affect epigenetic regulations of its expression. Aryl hydrocarbon receptor (AHR) is
a multifunctional regulator in cell physiology and xenobiotics metabolism and its altered regulation have been
shown to result in adverse developmental and physiological outcomes. Recently, the therapeutic potential of
modulating the methylation status of the AHR promoter has been discussed. Using Bioinformatics approaches,
we aimed to identify the polymorphisms in upstream regulatory sequences of AHR, which may affect the epigenetic regulation of it through the introduction or removal of CpG dinucleotides that act as possible targets for
DNA methylation. The 3000 bp upstream regulatory sequences of AHR, −2700 to +300 relative to the ATG
codon, were obtained from NCBI. The CpG-island identified and all 105 SNPs located in it were retrieved from
dbSNP. After that, 45 SNPs that cause the introduction or removal of CpGs were identified as candidate EpiPols
of AHR. Then, the methylation status of these EpiPols analyzed using Bioinformatics servers, and finally, 13 SNPs
were reported as predicted methylation-affecting EpiPols of the human AHR gene. |