LC-MS/MS analysis of nanoparticle-induced oxidative DNA damages

TOXI 88

Haizheng Hong, haizheng.hong@email.ucr.edu, Environmental Toxicology Graduate Program, University of California at Riverside, 900 University Avenue, Riverside, CA 92521 and Yinsheng Wang, yinsheng.wang@ucr.edu, Department of Chemistry, University of California at Riverside, Mail Drop 027, Riverside, CA 92521-0403.
Nanoparticles are thought to confer genotoxicity via their ability to generate reactive oxygen species (ROS) thus to damage DNA. We present here that LC-MS/MS analysis provides a highly sensitive and specific method to detect DNA base damages, which is of great help to understand the genotoxicity of nanoparticles. The detection limit for several ROS-induced DNA lesions on our LC-MS/MS systems was in fmol range. With the established sensitive quantification method, we measured the amount of oxidative DNA damages in calf thymus DNA which was incubated with several types of nanoparticles, e.g., Fe2O3, ZnO and TiO2, under aerobic conditions. It turned out that the nanoparticles-treated DNA did not have significantly higher level of oxidative DNA base damage than the control untreated DNA, suggesting that these nanoparticles could not generate significant amount of ROS in cell-free system. We are now in the process of examining oxidative DNA damages in cultured cells that are treated with nanoparticles.
 

Poster Session and Awards
6:00 PM-10:00 PM, Tuesday, August 21, 2007 BCEC -- 204 A/B, Poster

Division of Chemical Toxicology

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007