Related Experiment Videos
Mapping polycyclic aromatic hydrocarbon and aromatic amine-induced DNA damage in cancer-related genes at the sequence
Moon-shong Tang1, Gerd P Pfeifer, Mikhail F Denissenko
1Department of Environmental Medicine, New York University School of Medicine, 57 Old Forge Road, Tuxedo, NY 10987, USA. tang@env.med.nyu.edu
Abstract:
Genomic injury induced by environmental carcinogens, such as polycyclic aromatic hydrocarbons and aromatic amines, is the initial step that can trigger mutagenesis and carcinogenesis. In addition to the physico-chemical property of DNA damaging agents, several important factors such as primary sequence, chromatin structure, methylation, protein association, and transcriptional activity can affect not only the initial level and distribution of DNA damage but also the efficiency of repair. Therefore, mapping the DNA damage induced by environmental agents in cancer-related genes such as p53 and ras at the sequence level provides essential information for assessing their carcinogenic potential. Recently, using the E. coli nucleotide excision enzyme complex, UvrABC nucleases in combination with ligation-mediated polymerase chain reaction, we developed a method to map DNA damage in the p53 and ras genes. These studies led us to conclude that targeted DNA damage, in combination with growth selection, contributes greatly in shaping the mutation spectrum in these genes in human cancer. Here we present the rationale and details of this approach, typical experimental results and necessary precautions.
Insights
Environmental carcinogens cause genomic injury, initiating cancer. Mapping DNA damage in key genes like p53 and ras reveals how this damage shapes cancer mutations.
Area of Science:
- Environmental Health
- Molecular Biology
- Genetics
Background:
- Environmental carcinogens, including polycyclic aromatic hydrocarbons and aromatic amines, initiate mutagenesis and carcinogenesis by causing genomic injury.
- DNA damage levels, distribution, and repair efficiency are influenced by factors like DNA sequence, chromatin structure, methylation, protein binding, and transcriptional activity.
- Understanding DNA damage in critical cancer genes (e.g., p53, ras) is vital for assessing carcinogenic potential.
Purpose of the Study:
- To present a method for mapping DNA damage induced by environmental agents at the sequence level within cancer-related genes.
- To elucidate the role of targeted DNA damage and growth selection in shaping mutation spectra in human cancer genes.
Main Methods:
- Utilized the E. coli UvrABC nuclease enzyme complex.
- Employed ligation-mediated polymerase chain reaction (LM-PCR) for high-resolution DNA damage mapping.
- Applied the method to map DNA damage in the p53 and ras genes.
Main Results:
- Successfully mapped sequence-level DNA damage induced by environmental agents in the p53 and ras genes.
- Demonstrated that targeted DNA damage, coupled with growth selection, significantly influences the mutation spectrum observed in these genes in human cancers.
Conclusions:
- The developed method provides essential information for assessing the carcinogenic potential of environmental agents.
- Targeted DNA damage and subsequent selection are critical determinants of mutational patterns in cancer-associated genes.