ABS 083: How DNA Methylation Impacts the Nucleotide Excision Repair Pathway

Nyla Gilkes ¹ , Kyle Johnson ¹ , Dian Xia ¹ , Wentao Li Ph.D ¹

¹ University of Georgia

Van Wickle (2025) Volume 1, ABS 083

Introduction: Epigenetics is a growing field which can affect biological pathways within humans without altering DNA sequences and can happen by environmental factors. A common epigenetic alteration is DNA methylation- a reversible mechanism regulating gene expression. DNA methylation plays a role in many biological processes, but it is unclear of all of its functions and effects. One biological pathway that can be affected is nucleotide excision repair (NER). This is a major pathway that removes bulky DNA lesions from the DNA. These lesions are created by many different environmental factors, such as UV irradiation and cigarette smoke. UV irradiation is a tool used to analyze the specific NER pathway due to it being the primary repair pathway for this type of damage. To investigate how DNA methylation can affects NER when environmental factors are present, we will be using S-adenosylmethionine (SAM) to observe the effects of increased methylation and RG108, an inhibitor of DNMT1, as a methylation inhibitor. This study examines how DNA methylation affects NER when environmental factors are present by exploring whether DNA methylation causes an increase or decrease in NER repair, specifically on UV irradiated DNA. We predict that increased DNA methylation will decrease NER repair while decreased DNA methylation will increase NER repair.