The integrity of human genome is frequently challenged by endogenous and exogenous sources of agents. Endogenously produced byproducts of glycolysis or N-nitroso compounds present in the gastrointestinal tract can both lead to the carboxyalkylation of nucleobases in DNA. Previous studies carried out in this and other laboratories revealed that some of the carboxyalkylated nucleosides are present at significant levels in cells and tissues of humans and laboratory animals. The long-term goal of this project is to understand, at the molecular level, the biological consequences of the carboxyalkylated DNA adducts. In the present application, we propose experiments according to the following four specific aims:
Aim 1, to assess the chemistry of DNA modifications induced by diazoacetate, which is a reactive intermediate arising from endogenously induced N-nitroso compounds.
Aim 2, to quantify the carboxyalkylated DNA adducts in cultured human cells and in diabetic animal models by using LC-MS/MS with the standard isotope dilution method.
Aim 3, to synthesize oligodeoxyribonucleotides harboring a carboxyalkylated lesion at a specific site.
Aim 4, to employ shuttle vector technology and investigate how the carboxyalkylated DNA lesions are replicated in E. coli and human cells. In this respect, the roles of various translesion synthesis DNA polymerases will be delineated by using polymerase-deficient bacterial strains or, for replication studies using mammalian cells, by knocking down the expression of these polymerases with the siRNA technique. The outcome of the proposed research will provide significant new knowledge about the cytotoxic and mutagenic properties of this group of DNA adducts. The proposed research will also reveal the implications of hyperglycemia and exposure to N-nitroso compounds in the etiology of diabetic complications and gastrointestinal tumors. Furthermore, the proposed study may lead to the discovery of novel molecular biomarkers and risk factors for developing these pathological conditions.

Public Health Relevance

Humans are exposed to byproducts of glycolysis and N-nitroso compounds in the gastrointestinal tract, which results in the carboxyalkylation of nucleobases in DNA. The proposed research will reveal the implications of hyperglycemia and exposure to N-nitroso compounds in the etiology of diabetic complications and gastrointestinal tumors, and lead to the discovery of novel molecular biomarkers and risk factors for developing these pathological conditions

National Institute of Health (NIH)
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Research Project (R01)
Project #
Application #
Study Section
Cancer Etiology Study Section (CE)
Program Officer
Jones, Teresa L Z
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
University of California Riverside
Schools of Earth Sciences/Natur
United States
Zip Code
Wu, Jun; Wang, Pengcheng; Li, Lin et al. (2017) Replication studies of carboxymethylated DNA lesions in human cells. Nucleic Acids Res 45:7276-7284
Dai, Xiaoxia; You, Changjun; Wang, Yinsheng (2016) The Functions of Serine 687 Phosphorylation of Human DNA Polymerase ? in UV Damage Tolerance. Mol Cell Proteomics 15:1913-20
Miao, Weili; Xiao, Yongsheng; Guo, Lei et al. (2016) A High-Throughput Targeted Proteomic Approach for Comprehensive Profiling of Methylglyoxal-Induced Perturbations of the Human Kinome. Anal Chem 88:9773-9779
Yu, Yang; Wang, Jianshuang; Wang, Pengcheng et al. (2016) Quantification of Azaserine-Induced Carboxymethylated and Methylated DNA Lesions in Cells by Nanoflow Liquid Chromatography-Nanoelectrospray Ionization Tandem Mass Spectrometry Coupled with the Stable Isotope-Dilution Method. Anal Chem 88:8036-42
You, Changjun; Wang, Yinsheng (2016) Mass Spectrometry-Based Quantitative Strategies for Assessing the Biological Consequences and Repair of DNA Adducts. Acc Chem Res 49:205-13
You, Changjun; Wang, Pengcheng; Nay, Stephanie L et al. (2016) Roles of Aag, Alkbh2, and Alkbh3 in the Repair of Carboxymethylated and Ethylated Thymidine Lesions. ACS Chem Biol 11:1332-8
You, Changjun; Wang, Yinsheng (2015) Quantitative measurement of transcriptional inhibition and mutagenesis induced by site-specifically incorporated DNA lesions in vitro and in vivo. Nat Protoc 10:1389-406
Liu, Shuo; Wang, Yinsheng (2015) Mass spectrometry for the assessment of the occurrence and biological consequences of DNA adducts. Chem Soc Rev 44:7829-54
You, Changjun; Wang, Jianshuang; Dai, Xiaoxia et al. (2015) Transcriptional inhibition and mutagenesis induced by N-nitroso compound-derived carboxymethylated thymidine adducts in DNA. Nucleic Acids Res 43:1012-8
McIntyre, Justyna; McLenigan, Mary P; Frank, Ekaterina G et al. (2015) Posttranslational Regulation of Human DNA Polymerase ?. J Biol Chem 290:27332-44

Showing the most recent 10 out of 34 publications