Electronic Thesis and Dissertation Repository


Master of Science




Dr. Joseph Torchia


Prompted by findings that TGFβ stimulates thymine DNA glycosylase (TDG) dependent rapid DNA demethylation and activation of the CDKN2B gene, I investigated the global role of TDG and DNA demethylation in TGFβ signaling in HaCaT cells. Using dot blot analysis, I show that TGFβ treatment increases the global levels of 5-formylcytosine, an intermediate metabolite of active DNA demethylation. Characterization of genomic regions that undergo DNA demethylation and recruitment of TDG indicate that they are both frequent events, but only overlap at 11 genomic locations. I identified 440 TGFβ upregulated genes, 40 of which were bound by TDG and 169 that exhibited DNA demethylation. Distribution of the location of TDG peaks and DNA demethylation regions to the gene promoter suggests that these events occur at distal elements. These results suggest that TDG and DNA demethylation could be important factors involved in TGFβ’s regulation of gene expression.