DNA damage detection

A practical approach for toxicity screening combines bioactivation and DNA damage detection into a single biosensor for toxicity screening. To make these types of sensors, ultrathin films (20—4-0 nm thick) containing myoglobin or cytochrome P450cam and DNA were... 

Martin, E.A. et al., Tamoxifen DNA damage detected in human endometrium using accelerator mass spectrometry, Cancer Res., 63(23), 8461, 2003. 

Altered chemical, physicochemical, and structural properties of damaged DNA are reflected in its redox behavior, which is utilized in numerous techniques of DNA damage detection. Electrochemical DNA-based biosensors have been used not only to detect but also to induce and control DNA damage at the electrode surface via electrochemical generation of the damaging (usually radical) species [13]. This way, chemicals and drugs such as niclosamide, adriamycin. 

In recent years increased attention has been focused on the ways in which hazard compounds and anti-cancer drugs interact with DNA, with the goal of understanding the toxic as well as chemotherapeutic effects of many molecules. The development of fast and accurate methods of oxidative DNA damage detection is important. 

Keywords Carbon electrodes Chemical carcinogens DNA biosensors DNA damage detection Drugs Oxidative stress Review Supramolecular chemistry... 

Recently, various reviews of electrochemical DNA biosensors have been reported [1, 11-20]. The present review will focus on the most widely used strategies in the technology of electrochemical DNA biosensors, with the special emphasis placed on their construction and application in the field of DNA damage detection and investigation of supramolecular interactions between xenobiotic compounds and DNA. Our results, obtained during the last 5 years in the field of novel electrochemical DNA biosensors utilizing carbon-based transducers as substrates for immobilization of DNA, will serve as illustrative examples. 

Shigenaga, M.K., Park, J.W., Cundy, K.C., Cimeno, C.J. and Ames, B.N. (1990). In pim oxidative DNA damage, measurement of 8-hydroxy-2 -deoxyguanosine in DNA and urine by high-performance liquid chromatography with electrochemical detection. Meth. Enzymol. 186, 521-530. 

DNA CT also permits chemistry at a distance. Oxidative DNA damage and thymine dimer repair can proceed in a DNA-mediated reaction initiated from a remote site. These reactions too are sensitive to intervening DNA dynamical structure, and such structures can serve to modulate DNA CT chemistry. The sensitivity of DNA CT to base pair stacking also provides the basis for the design of new DNA diagnostics, tools to detect mutations in DNA and to probe protein-DNA interactions. 

The cycloreversion experiments showed a clean Tf=T-DNA to T/T-DNA transformation. No by-products were detected, which supports the idea that DNA may be more stable towards reduction compared to oxidation. Even heating the irradiated DNA with piperidine furnished no other DNA strands other then the repaired strands, showing that base labile sites - indicative for DNA damage - are not formed in the reductive regime. The quantum yield of the intra-DNA repair reaction was therefore calculated based on the assumption that the irradiation of the flavin-Tf=T-DNA strands induces a clean intramolecular excess electron transfer driven cycloreversion. The quantum yield was found to be around 0=0.005, which is high for a photoreaction in DNA. A first insight into how DNA is able to mediate the excess electron transfer was gained with the double strands 11 and 12 in which an additional A T base pair compared to 7 and 8 separates the dimer and the flavin unit. 

Nestmann ER, Douglas GR, Matula TI, Grant CE, Kowbel DJ (1979) Mutagenic activity of rhodamine dyes and their impurities as detected by mutation induction in Salmonella and DNA damage in Chinese hamster ovary cells. Cancer Res 39 4412-4417... 

Bprresen, A.-L. (1996) Constant denaturant gel electrophoresis (CDGE) in mutation screening. In Pfeifer, G.P. (ed.) Technologies for Detection of DNA Damage and Mutations. Plenum Press, New York. 

Hachiya N, Sato M, Takizawa Y. 1984. Detection of DNA damage in mutagen-treated mammalian tissues by alkaline elution assay. Mutat Res 130 363. 

Luminescent bacteria also allow detection of the carcinogenic effect of ge-notoxics. A dark mutant of a Photobacterium or Vibrio strain that can revert back to luminescence at an increased rate in the presence of base-substitutes or frame-shifts agents, DNA-damaging agents, DNA synthesis inhibitors, and DNA intercalating agents can be employed [171, 172],... 

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