During radiation therapy of human tumors, the majority of DNA lesions are produced from the radiolysis of water in the vicinity of the DNA molecule. Whether or not these lesions block DNA replication and lead to cell death and therapeutic efficacy or are bypassed resulting in mutations and the possibility of secondary tumors at the site of treatment merits significant consideration. There is a choreography of events that ensue following tumor treatment by ionizing radiation. The damages may be repaired, thus the cancer cells survive. The damages may remain in the DNA molecule, block DNA replication and initiate a cascade of signals leading to cancer cell death. In adjacent irradiated normal cells, unrepaired damages may be bypassed, leading to mutation and potentially secondary cancers. Thus, it is the interaction between an unrepaired lesion and a DNA polymerase that determines the ultimate fate of the cell. In order to maximize therapeutic gain and minimize the formation of second tumors at the same site, it is critical to have a mechanistic understanding of the interaction between DNA polymerases and radiation-induced DNA lesions. The proposed study addresses this question with respect to both DNA polymerase blocking and potentially mutagenic radiation-induced DNA damages. Sites of base loss and thymine glycols are frequently produced and replication blocking DNA damages while 5-hydroxycytosine, 8-oxoguanine and 2-hydroxyadenine are commonly produced premutagenic lesions. All are major lesions produced by ionizing radiation and their structure/function interactions will be studied in the context of replicative and bypass DNA polymerases. This research bears directly on public health since it addresses the fundamental mechanisms underpinning cell killing and mutagenesis by therapeutic levels of ionizing radiation.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA052040-16
Application #
7619473
Study Section
Radiation Therapeutics and Biology Study Section (RTB)
Program Officer
Pelroy, Richard
Project Start
1991-01-01
Project End
2012-04-30
Budget Start
2009-05-01
Budget End
2010-04-30
Support Year
16
Fiscal Year
2009
Total Cost
$67,348
Indirect Cost
Name
University of Vermont & St Agric College
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
066811191
City
Burlington
State
VT
Country
United States
Zip Code
05405
Laverty, Daniel J; Averill, April M; Doublié, Sylvie et al. (2017) The A-Rule and Deletion Formation During Abasic and Oxidized Abasic Site Bypass by DNA Polymerase ?. ACS Chem Biol 12:1584-1592
Malaby, Andrew W; Martin, Sara K; Wood, Richard D et al. (2017) Expression and Structural Analyses of Human DNA Polymerase ? (POLQ). Methods Enzymol 592:103-121
Wood, Richard D; Doublié, Sylvie (2016) DNA polymerase ? (POLQ), double-strand break repair, and cancer. DNA Repair (Amst) 44:22-32
Zahn, Karl E; Averill, April M; Aller, Pierre et al. (2015) Human DNA polymerase ? grasps the primer terminus to mediate DNA repair. Nat Struct Mol Biol 22:304-11
Piret, Jocelyne; Goyette, Nathalie; Eckenroth, Brian E et al. (2015) Contrasting effects of W781V and W780V mutations in helix N of herpes simplex virus 1 and human cytomegalovirus DNA polymerases on antiviral drug susceptibility. J Virol 89:4636-44
Lubula, Mulu Y; Eckenroth, Brian E; Carlson, Samuel et al. (2014) Structural insights into recognition of acetylated histone ligands by the BRPF1 bromodomain. FEBS Lett 588:3844-54
Doublié, Sylvie; Zahn, Karl E (2014) Structural insights into eukaryotic DNA replication. Front Microbiol 5:444
Yousefzadeh, Matthew J; Wyatt, David W; Takata, Kei-Ichi et al. (2014) Mechanism of suppression of chromosomal instability by DNA polymerase POLQ. PLoS Genet 10:e1004654
Lubula, Mulu Y; Poplawaski, Amanda; Glass, Karen C (2014) Crystallization and preliminary X-ray diffraction analysis of the BRPF1 bromodomain in complex with its H2AK5ac and H4K12ac histone-peptide ligands. Acta Crystallogr F Struct Biol Commun 70:1389-93
Eckenroth, Brian E; Fleming, Aaron M; Sweasy, Joann B et al. (2014) Crystal structure of DNA polymerase ? with DNA containing the base lesion spiroiminodihydantoin in a templating position. Biochemistry 53:2075-7

Showing the most recent 10 out of 38 publications