DNA adduct

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A DNA adduct is a piece of DNA covalently-bonded to a (cancer-causing) chemical. This has shown to be the start of a cancerous cell, or carcinogenesis. DNA adducts in scientific experiments are used as bio-markers and as such are themselves measured to reflect quantitatively, for comparison, the amount of cancer in the subject, i.e. rats or other living animals. Under experimental conditions for study, such DNA adducts are induced by known carcinogens, of which commonly used is DMBA, chemically structured and named as 7,12-Dimethyl-benz[a] Anthracene . For example, a scientific journal that writes "DMBA - DNA adduct" is referring to a piece of DNA that has the chemical DMBA attached to it. The presence of such adduct indicates the presence of cancer in the subject animal.^[1]

[edit] Examples

Examples of DNA adducts are:

• acetaldehyde (a major component of cigarette smoke)
• M₁G (following lipid peroxidation) ^[2]

[edit] DNA Damage

When a chemical bonds to DNA, the DNA becomes damaged, and proper and complete replication cannot occur to make the normal intended cell. This would be the start of a mutation, or mutagenesis, and without proper DNA repair (DNA repair happens naturally under normal circumstances), this can lead to carcinogenesis, the beginnings of cancer.^[3]

[edit] References

1. ^ Biosciences - DNA Adducts. Lawrence Livermore National Laboratory. Retrieved on 2007-01-19.
2. ^ Lipid peroxidation-DNA damage by malondialdehyde. Marnett LJ.
3. ^ DNA Adducts. www.eclipsescience.com. Retrieved on 2007-01-19.