PI: Laura Niedernhofer Measuring nucleotide excision repair in human populations Nucleotide excision repair (NER) is a DNA repair mechanism that recognizes and removes bulky, helix- distorting lesions from the nuclear genome. Key substrates for NER are lesions induced by ultraviolet (UV) radiation upon environmental exposure to sunlight and a subset of oxidative DNA lesions produced endogenously implicated in neurodegeneration. Subtle defects in NER, due to, for example, polymorphisms in NER genes, might modestly but significantly impact one?s risk of skin cancer. The greatest barrier to identifying those at risk is the lack of an assay to measure NER that is rapid, inexpensive and applicable to samples safely and easily collected from patients. Historically, UDS measurement required the use of radioactively labeled nucleosides and/or specialized equipment. We developed a method to measure NER that employs the thymidine analog 5-ethynyl-2'-deoxyuridine and Click-iT chemistry for fluorescent detection of UDS by flow cytometry. This project aims to correct gaps in knowledge about variability and heritability of DNA repair capacity through optimization of our functional assay and proof-of concept pilot human studies. Our assay is being applied to existing cohorts of patients seen at the University of Miami Skin Cancer Clinics, the NIH Undiagnosed Diseases Program (UDP) and the Amish Longevity Study to interrogate associations between NER capacity and high risk of skin cancer, early onset neurodegeneration, and within family pedigrees, respectively. The assay could have a significant impact on how risk of squamous cell or basal cell carcinoma of the skin, melanoma, lung or head and neck cancer, neurodegeneration, and resistance to cancer chemotherapy is identified and managed.

Public Health Relevance

The goal of the parent project is to optimize an assay designed to measure an individual?s level of nucleotide excision repair (NER), using human blood or skin cells. The assay will be pilot tested for its applicability to population studies aimed at identifying those at increased risk of skin cancer due to exposure to the environmental carcinogen ultraviolet light. The goal of this supplement is to further advance application of our NER assay to population studies by cross-validating it with other assays, measuring stability of measures over time, and testing multiple cell types from the same patient.

Agency
National Institute of Health (NIH)
Institute
National Institute of Environmental Health Sciences (NIEHS)
Type
Research Project--Cooperative Agreements (U01)
Project #
3U01ES029603-03S3
Application #
10140601
Study Section
Special Emphasis Panel (ZES1)
Program Officer
Heacock, Michelle
Project Start
2018-09-21
Project End
2022-06-30
Budget Start
2020-09-17
Budget End
2021-06-30
Support Year
3
Fiscal Year
2020
Total Cost
Indirect Cost
Name
University of Minnesota Twin Cities
Department
Biochemistry
Type
Schools of Medicine
DUNS #
555917996
City
Minneapolis
State
MN
Country
United States
Zip Code
55455