DNA is constantly exposed to endogenous and exogenous agents that damage it producing single strand breaks, double strand breaks, interstrand cross-links and nucleotide modifications known as lesions. DNA damage has tremendous impact on human health. It is associated with aging, and the development of diseases such as cancer, and other genetically based diseases. DNA is also the target of cytotoxic therapeutic agents (e.g. -radiolysis and some antitumor antibiotics). For instance, ionizing radiation is the most common nonsurgical method used to treat cancer. Although the connection between DNA damage and cellular transformation and cytotoxicity is well established, exactly how various types of DNA damage give rise to these endpoints are not well understood. The goals of this research are to understand what the consequences of lesions produced in DNA are. Our efforts are focused on the repair and reactivity of (oxidized) abasic lesions, alkylated DNA, and an under studied lesion produced upon C5'-oxidation. We utilize organic chemistry to synthesize homogeneous nucleic acid substrates containing these molecules, which facilitates examination of their reactivity and interactions with enzymes. Using this approach we intend to look beneath the surface of DNA damage and determine what makes specific forms of DNA damage deleterious. We will examine whether the histone proteins within nucleosomes transform DNA lesions into more deleterious forms of damage and what the downstream biochemical consequences of this catalysis are. For instance, we discovered that histones catalyze DNA chemistry and are modified in the process. We will determine whether this occurs in cells and what the effects of histone modification are. We also ask whether specific forms of DNA damage inhibit repair enzymes. These investigations shed light on the (bio)chemical basis for the cytotoxicity of DNA damaging agents and provide the impetus for the design of new approaches for inducing the biochemical consequences of DNA damage. For instance, we are developing inhibitors that inactivate DNA polymerase and potentiate the effects of a cytotoxic DNA damaging agent. In summary, the project combines organic chemistry, biochemistry, and biology with the goal of understanding how DNA damage affects human health and when opportunities present themselves, to exploit this knowledge.

Public Health Relevance

DNA damage and repair are important chemical processes that significantly impact human health. These chemical processes are associated with aging and a variety of diseases, such as cancer. Understanding the chemistry, biochemistry, and biological effects of damaged DNA enhances our molecular level understanding of the etiology of diseases, as well as the various treatments for which nucleic acids are the target, and provides the motivation for new therapeutic approaches.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM063028-15
Application #
9134773
Study Section
Synthetic and Biological Chemistry A Study Section (SBCA)
Program Officer
Fabian, Miles
Project Start
2001-04-01
Project End
2019-07-31
Budget Start
2016-08-01
Budget End
2017-07-31
Support Year
15
Fiscal Year
2016
Total Cost
Indirect Cost
Name
Johns Hopkins University
Department
Chemistry
Type
Schools of Arts and Sciences
DUNS #
001910777
City
Baltimore
State
MD
Country
United States
Zip Code
21205
Rana, Anup; Yang, Kun; Greenberg, Marc M (2018) Reactivity of the Major Product of C5'-Oxidative DNA Damage in Nucleosome Core Particles. Chembiochem :
Bai, Jing; Zhang, Yingqian; Xi, Zhen et al. (2018) Oxidation of 8-Oxo-7,8-dihydro-2'-deoxyguanosine Leads to Substantial DNA-Histone Cross-Links within Nucleosome Core Particles. Chem Res Toxicol :
Laverty, Daniel J; Greenberg, Marc M (2018) Expanded Substrate Scope of DNA Polymerase ? and DNA Polymerase ?: Lyase Activity on 5'-Overhangs and Clustered Lesions. Biochemistry 57:6119-6127
Yang, Kun; Park, Daeyoon; Tretyakova, Natalia Y et al. (2018) Histone tails decrease N7-methyl-2'-deoxyguanosine depurination and yield DNA-protein cross-links in nucleosome core particles and cells. Proc Natl Acad Sci U S A 115:E11212-E11220
Yang, Kun; Greenberg, Marc M (2018) Enhanced Cleavage at Abasic Sites within Clustered Lesions in Nucleosome Core Particles. Chembiochem 19:2061-2065
Beaver, Jill M; Lai, Yanhao; Rolle, Shantell J et al. (2018) An oxidized abasic lesion inhibits base excision repair leading to DNA strand breaks in a trinucleotide repeat tract. PLoS One 13:e0192148
Laverty, Daniel J; Mortimer, Ifor P; Greenberg, Marc M (2018) Mechanistic Insight through Irreversible Inhibition: DNA Polymerase ? Uses a Common Active Site for Polymerase and Lyase Activities. J Am Chem Soc 140:9034-9037
Jacinto, Marco Paolo; Pichling, Patricio; Greenberg, Marc M (2018) Synthesis of 5-Methylene-2-pyrrolones. Org Lett 20:4885-4887
Wang, Ruixiang; Yang, Kun; Banerjee, Samya et al. (2018) Rotational Effects within Nucleosome Core Particles on Abasic Site Reactivity. Biochemistry 57:3945-3952
Zhang, Yingqian; Zhou, Xiaoping; Xie, Yonghui et al. (2017) Thiol Specific and Tracelessly Removable Bioconjugation via Michael Addition to 5-Methylene Pyrrolones. J Am Chem Soc 139:6146-6151

Showing the most recent 10 out of 72 publications