ANALYSIS OF DNA METHYLATION AND CHROMATIN CONFORMATION IN G-QUADRUPLEX REGIONS IN GENE c-MYC

Abstract

G-quadruplex structures (G4) have been suggested as potential epigenetic regulators. In addition, recent studies have shown that the formation and stabilization of G4 depend on the chromatin status since the presence or absence of G4 in the same genomic sequence is cell-type specific. The enrichment of G4 in the promoters of proto-oncogenes has been widely demonstrated, especially in the c-MYC promoter. C-MYC gene is unregulated in most types of tumors. This proto-oncogene is under strict transcriptional control, as is its mRNA and the MYC protein. Classically, the regulation of this gene involves many regulatory transcriptional motifs found in its proximal promoter region. Recently, great attention has also been given to a regulatory region distal to c-MYC, an enhancer. Enhancers have extensively studied in recent years as changes in their dynamics controlling gene expression have been associated with the development of diseases, especially cancer. In the present project, we propose to investigate whether G4 structures are able to change chromatin dynamics, specifically the frequency of enhancer / promoter interaction in the c-MYC gene, which is enriched by G4 in its promoter and enhancer regions. In addition, we intend to investigate if the stabilization of these structures through the use of G4 stabilizing drug can alter this interaction. G4 stabilizing drugs are considered a potentially antitumoral agent since they have the ability to inhibit proliferating tumor cells. We also intend to investigate whether the stabilization of these structures can alter the epigenome, specifically the DNA methylation pattern, in regulatory regions. Today the 3D genome organization and its promoter-enhancer interactions have been focused by many studies. The more we know about this mechanism of gene regulation, the easier it becomes to understand the roles of genetic polymorphisms and the epimutations present in these regions, besides it facilitates the possible use of drugs that can modulate this mechanism. In addition, as the studied gene is relevant in cancer research, understanding its regulation and possible modulation through a drug that acts on the structures present in this gene are of great importance for the research. (AU)