Most carcinogens and alkylating antineoplastic agents react with DNA to afford a diverse mixture of products. The complexity of the damage is a barrier to being able to quantitatively and qualitatively dissect out the biological role(s) of the individual DNA lesions relative to the mutagenic and toxic potency of the agent. To address this issue, we have prepared groove and sequence selective DNA methylating (Me-lex), ethylating (Et-lex) and 2-chloroethylating (CENU-lex) agents that in vitro and in vivo selectively afford minor groove 3-alkyladenine adducts. Our goal is to use this new class of minor groove alkylating agents to understand the role of 3-alkyladenine lesions in toxicity and mutagenicity.
The Specific Aims are to: (1) Determine using ligation-mediated PCR the in vivo alkylation patterns that are generated by Me-lex, Et-lex and CENU-lex in mouse ES cells that are wild type or null mutant for the glycosylase enzyme (Aag) that repairs 3-alkyladenine lesions; (2 and 3) Determine the relationship between DNA alkylation and apurinic sites, and the induction of mutations using a yeast shuttle vector assay. It is also proposed to evaluate the same endpoints in yeast strains that are deficient: (a) in the glycosylase that removes 3-alkyladenine from DNA; (b) in the AP endonuclease that processes abasic sites; and (c) in mismatch repair; (4) prepare DNA containing a single 3-alkyladenine substitution to determine the stability of 3- alkyladenine in DNA, if the lesions are substrates for nucleotide excision repair, and how DNA polymerization is effected by the presence of the adducts; (5) Determine why specific human cell lines are sensitive to Me-lex by assaying for their ability to repair DNA damage as measured by the time-dependent disappearance of 3-alkyladenine; and (6) Synthesize alkylating agents that will selectively generate the minor groove N3-methylguanine lesion and study their biological activity (toxicity and mutagenicity). In summary, we will be able to relate specific types of DNA damage to the site and type of mutation, and the enzymes that protect from the toxic and/or mutagenic response.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA029088-18
Application #
6375631
Study Section
Chemical Pathology Study Section (CPA)
Program Officer
Poland, Alan P
Project Start
1981-07-15
Project End
2004-04-30
Budget Start
2001-05-01
Budget End
2002-04-30
Support Year
18
Fiscal Year
2001
Total Cost
$245,494
Indirect Cost
Name
University of Nebraska Medical Center
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
City
Omaha
State
NE
Country
United States
Zip Code
68198
Whetstone, Ryan D; Wittel, Uwe A; Michels, Nicole M et al. (2016) Colon carcinogenesis in wild type and immune compromised mice after treatment with azoxymethane, and azoxymethane with dextran sodium sulfate. Mol Carcinog 55:1187-95
Iyer, Prema; Srinivasan, Ajay; Singh, Sreelekha K et al. (2013) Synthesis and characterization of DNA minor groove binding alkylating agents. Chem Res Toxicol 26:156-68
Szulik, Marta W; Voehler, Markus W; Ganguly, Manjori et al. (2013) Site-specific stabilization of DNA by a tethered major groove amine, 7-aminomethyl-7-deaza-2'-deoxyguanosine. Biochemistry 52:7659-68
Srinivasan, Ajay; Wang, Lirong; Cline, Cari J et al. (2012) Identification and characterization of human apurinic/apyrimidinic endonuclease-1 inhibitors. Biochemistry 51:6246-59
Ganguly, Manjori; Szulik, Marta W; Donahue, Patrick S et al. (2012) Thermodynamic signature of DNA damage: characterization of DNA with a 5-hydroxy-2'-deoxycytidine·2'-deoxyguanosine base pair. Biochemistry 51:2018-27
Srinivasan, Ajay; Gold, Barry (2012) Small-molecule inhibitors of DNA damage-repair pathways: an approach to overcome tumor resistance to alkylating anticancer drugs. Future Med Chem 4:1093-111
Singh, Sreelekha K; Szulik, Marta W; Ganguly, Manjori et al. (2011) Characterization of DNA with an 8-oxoguanine modification. Nucleic Acids Res 39:6789-801
Monti, Paola; Broxson, Christopher; Inga, Alberto et al. (2011) 3-Methyl-3-deazaadenine, a stable isostere of N3-methyl-adenine, is efficiently bypassed by replication in vivo and by transcription in vitro. DNA Repair (Amst) 10:861-8
Monti, Paola; Traverso, Ilaria; Casolari, Laura et al. (2010) Mutagenicity of N3-methyladenine: a multi-translesion polymerase affair. Mutat Res 683:50-6
Rubinson, Emily H; Gowda, A S Prakasha; Spratt, Thomas E et al. (2010) An unprecedented nucleic acid capture mechanism for excision of DNA damage. Nature 468:406-11

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