Cisplatin is a probable human carcinogen. Platinum compounds such as oxaliplatin have shown promise for the treatment of cisplatin resistant tumors, but their potential mutagenicity is unknown. The mutagenicity of these compounds is likely to be determined in part by the DNA polymerase(s) which catalyze error-prone translesion synthesis past Pt-DNA adducts. The identity if these polymersases is not currently known, but pol beta, pol zetu, and pol eta have all been shown to perform translesion synthesis past Pt-DNA adducts in vitro. Cell lines exist which under- or over-express each of these polymersases. Thus, we plan to determine the effects of pol beta, pol zetu, and pol eta expression on the mutagenicity and cytotoxicity of cisplatin and oxaliplatin adducts (Aim 1). An analysis of the conformational differences of the adducts formed by these compounds is likely to be essential for understanding the mechanisms which determine their mutagenicity and efficacy. Thus, we plan to use a combination of NMR and molecular modeling to characterize the adducts formed by these compounds (Aim 2). Detailed information on the efficiency and fidelity of translesion synthesis by purified DNA polymerases is important for confirming the contribution of those polymersases to error-prone translesion synthesis in vivo (Aim 1) and for modeling their interaction with the adducts (Aim 4). Thus, the efficiency and fidelity of translesion synthesis past cisplatin and oxaliplatin adducts by pol beta, pol zetu, and/or pol eta will be determined in vitro (Aim 3). It is likely that the conformation and mutagenicity of Pt-DNA are affected by their binding to the active site of the polymerases involved in error-prone translesion synthesis. Based on the conformational data on the adducts (Aim 2) and the known crystal structures of pol beta, molecular dynamics simulations will be used to model the interactions of pol beta with each of the adducts (Aim 4). This project will define the role of pol beta, pol zetu, and pol eta in error-prone replicative bypass of Pt-DNA adducts. It will also result in models of Pt-DNA adduct conformation and polymerase-adduct interaction that will be useful in understanding the mechanism(s) of mutagenesis by these and other Pt complexes.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA084480-03
Application #
6514320
Study Section
Chemical Pathology Study Section (CPA)
Program Officer
Lees, Robert G
Project Start
2000-07-01
Project End
2004-03-31
Budget Start
2002-07-01
Budget End
2004-03-31
Support Year
3
Fiscal Year
2002
Total Cost
$261,228
Indirect Cost
Name
University of North Carolina Chapel Hill
Department
Biochemistry
Type
Schools of Medicine
DUNS #
078861598
City
Chapel Hill
State
NC
Country
United States
Zip Code
27599
Ding, Feng; Lavender, Christopher A; Weeks, Kevin M et al. (2012) Three-dimensional RNA structure refinement by hydroxyl radical probing. Nat Methods 9:603-8
Bhattacharyya, Debadeep; Ramachandran, Srinivas; Sharma, Shantanu et al. (2011) Flanking bases influence the nature of DNA distortion by platinum 1,2-intrastrand (GG) cross-links. PLoS One 6:e23582
Hajdin, Christine E; Ding, Feng; Dokholyan, Nikolay V et al. (2010) On the significance of an RNA tertiary structure prediction. RNA 16:1340-9
Baskerville-Abraham, Irene M; Boysen, Gunnar; Troutman, J Mitchell et al. (2009) Development of an ultraperformance liquid chromatography/mass spectrometry method to quantify cisplatin 1,2 intrastrand guanine-guanine adducts. Chem Res Toxicol 22:905-12
Ramachandran, Srinivas; Temple, Brenda R; Chaney, Stephen G et al. (2009) Structural basis for the sequence-dependent effects of platinum-DNA adducts. Nucleic Acids Res 37:2434-48
Ding, Feng; Sharma, Shantanu; Chalasani, Poornima et al. (2008) Ab initio RNA folding by discrete molecular dynamics: from structure prediction to folding mechanisms. RNA 14:1164-73
Sharma, Shantanu; Ding, Feng; Dokholyan, Nikolay V (2008) iFoldRNA: three-dimensional RNA structure prediction and folding. Bioinformatics 24:1951-2
Chen, Yiwen; Ding, Feng; Nie, Huifen et al. (2008) Protein folding: then and now. Arch Biochem Biophys 469:4-19
Sharma, Shantanu; Gong, Peng; Temple, Brenda et al. (2007) Molecular dynamic simulations of cisplatin- and oxaliplatin-d(GG) intrastand cross-links reveal differences in their conformational dynamics. J Mol Biol 373:1123-40
Wu, Yibing; Bhattacharyya, Debadeep; King, Candice L et al. (2007) Solution structures of a DNA dodecamer duplex with and without a cisplatin 1,2-d(GG) intrastrand cross-link: comparison with the same DNA duplex containing an oxaliplatin 1,2-d(GG) intrastrand cross-link. Biochemistry 46:6477-87

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