Journal
AMERICAN JOURNAL OF PATHOLOGY
Volume 175, Issue 5, Pages 2171-2183Publisher
ELSEVIER SCIENCE INC
DOI: 10.2353/ajpath.2009.080900
Keywords
-
Categories
Funding
- Japanese Ministry of Health, Labor and Welfare
- Japanese Ministry of Education, Culture, Sports, Science and Technology
- Global COE Program [F03]
- Japan Society for the Promotion of Science
- Japanese Society for the Promotion of Science
Ask authors/readers for more resources
Nanoparticles are prevalent in both commercial and medicinal products; however, the contribution of nanomaterials to carcinogenesis remains unclear. We therefore examined the effects of nano-sized titanium dioxide (TiO2) on poorly tumorigenic and nonmetastatic QR-32 fibrosarcoma cells. We found that mice that were cotransplanted subcutaneously with QR-32 cells and nano-sized TiO2, either uncoated (TiO2-1, hydrophilic) or coated with stearic acid (TiO2-2, hydrophobic), did not form tumors. However, QR-32 cells became tumorigenic after injection into sites previously implanted with TiO2-1, but not TiO2-2, and these developing tumors acquired metastatic phenotypes. No differences were observed either histologically or in inflammatory cytokine mRNA expression between TiO2-1 and TiO2-2 treatments. However, TiO2-2, but not TiO2-1, generated high levels of reactive oxygen species (ROS) in cell-free conditions. Although both TiO2-1 and TiO2-2 resulted in intracellular ROS formation, TiO2-2 elicited a stronger response, resulting in cytotoxicity to the QR-32 cells. Moreover, TiO2-2, but not TiO2-1 led to the development of nuclear interstices and multinucleate cells. Cells that survived the TiO2 toxicity acquired a tumorigenic phenotype. TiO2-induced ROS formation and its related cell injury were inhibited by the addition of antioxidant N-acetyl-L-cysteine. These results indicate that nano-sized TiO2 has the potential to convert benign tumor cells into malignant ones through the generation of ROS in the target cells. (Am J Pathol 2009, 175.2171-2183, DOI: 10.2353/ajpath/2009.080900)
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available