Publication Date
2025
Document Type
Thesis
Committee Members
Michael George Kemp, Ph.D. (Advisor); Ravi P. Sahu, Ph.D. (Committee Member); Yong-jie Xu, M.D., Ph.D. (Committee Member)
Degree Name
Master of Science (MS)
Abstract
This study examines the role of Ataxia Telangiectasia and Rad3-related kinase in quiescent human keratinocytes exposed to solar-simulated UV radiation (SSL). The ATR inhibitor VE-822 did not significantly affect cell viability in the absence of UV exposure, showing that ATR kinase activity is not essential for quiescent cell survival in the absence of additional genotoxic stress. After SSL exposure, ATR inhibition did not impact acute cell viability but reduced the cells’ long-term ability to proliferate. Western blot analysis demonstrated that VE-822 potently suppressed phosphorylation of ATR target proteins KAP1 and CHK2 in a dose-dependent manner after SSL exposure, confirming strong ATR inhibition. γH2AX levels were also reduced, indicating impaired DNA damage signaling. Time-course experiments showed delayed and reduced activation of these repair proteins with VE-822 treatment. Additionally, the increased retention of PCNA on chromatin following SSL exposure alone suggested problems with the resolution of the DNA repair complex in the presence of VE-822. These findings demonstrate that ATR kinase is critical for DNA repair and cell survival in quiescent keratinocytes exposed to SSL, and that VE-822 is an effective and potent ATR inhibitor in this context. Understanding the ATR function could help develop new strategies to protect skin cells from UV damage
Page Count
81
Department or Program
Department of Pharmacology and Toxicology
Year Degree Awarded
2025
Copyright
Copyright 2025, all rights reserved. My ETD will be available under the "Fair Use" terms of copyright law.
