Date of Graduation
8-2014
Document Type
Dissertation (PhD)
Program Affiliation
Cancer Biology
Degree Name
Doctor of Philosophy (PhD)
Advisor/Committee Chair
Mien-Chie Hung Ph.D.
Committee Member
Dihua Yu, M.D., Ph.D.
Committee Member
Pierre D. McCrea, Ph.D.
Committee Member
Bin Wang, Ph.D.
Committee Member
Shiaw-Yih Lin, Ph.D.
Abstract
Ataxia telangiectasia-mutated (ATM) mediates DNA damage response by controlling irradiation (IR)-induced foci formation, cell cycle checkpoint, and apoptosis. However, how upstream signaling regulates ATM is not completely understood. Here, we show that upon IR stimulation, ATM associates with and is phosphorylated by epidermal growth factor receptor (EGFR) at Y370 at the site of double-strand breaks. Depletion of endogenous EGFR impairs ATM-mediated foci formation, homologous recombination, and DNA repair. Moreover, ATM Y370F mutant or pretreatment with an EGFR kinase inhibitor gefitinib blocks EGFR and ATM association, hinders CHK2 activation and subsequent foci formation, and increases radio-sensitivity. Thus, we reveal a critical mechanism by which EGFR directly regulates ATM activation in DNA damage response and ATM Y370 phosphorylation may serve as a biomarker for radiation and anti-EGFR combinational therapies.
Keywords
EGFR, ATM, DNA Damage Response