Streszczenie (autorskie):

Transcription factors (TF) regulate gene expression. TF binding affinity to its DNA motif might be affected by the methylation level of cytosines within that motif. The aim of this study was to verify the hypothesis that TFs would bind more likely to the hypomethylated motifs than to hypermethylated ones. This analysis was done with respect to glioma (brain tumour) grade: pilocytic astrocytoma (PA; grade I), diffuse astrocytoma (DA; grades II and III) and glioblastoma (GB; grade IV) from the Polish patients' samples. Firstly 283 transcription factors motifs in enhancers (distal regulatory regions) were identified and then the level of their methylation was calculated. As a result, some specific regulatory path is proposed that might be responsible for modulating the level of gene expression. This part of the analysis is also a first step for finding very specific genome modification responsible for glioma development. If so, selected DNA modifications would have to be validated by in vitro experiments in the future.