Enhancement of radiotherapy by ceria nanoparticles modified with neogambogic acid in breast cancer cells

Abstract

Radiotherapy is one of the main strategies for cancer treatment but has significant challenges, such as cancer cell resistance and radiation damage to normal tissue. Radiosensitizers that selectively increase the susceptibility of cancer cells to radiation can enhance the effectiveness of radiotherapy. We report here the development of a novel radiosensitizer consisting of monodispersed ceria nanoparticles (CNPs) covered with the anticancer drug neogambogic acid (NGA-CNPs). These were used in conjunction with radiation in MCF-7 breast cancer cells, and the efficacy and mechanisms of action of this combined treatment approach were evaluated. NGA-CNPs potentiated the toxic effects of radiation, leading to a higher rate of cell death than either treatment used alone and inducing the activation of autophagy and cell cycle arrest at the G2/M phase, while pretreatment with NGA or CNPs did not improve the rate of radiation-induced cancer cells death. However, NGA-CNPs decreased both endogenous and radiation-induced reactive oxygen species formation, unlike other nanomaterials. These results suggest that the adjunctive use of NGA-CNPs can increase the effectiveness of radiotherapy in breast cancer treatment by lowering the radiation doses required to kill cancer cells and thereby minimizing collateral damage to healthy adjacent tissue.

Keywords:

• ceria nanoparticles
• radiotherapy
• breast cancer cells
• neogambogic acid
• radiosensitization

Acknowledgments

The study was supported by the National Key Basic Research Program of China (973 Program, grant number: 2013CB933904), the National Nature Science Foundation of China (grant number: 31400721), the Nature Science Foundation of Jiangsu Province (grant number: BK20131355), and the Priority Academic Program Development of Jiangsu Higher Education Institutions. The authors thank the College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, and Jiangsu Laboratory for Biomaterials and Devices, Southeast University, for providing technical support for this research.

Disclosure

The authors report no conflicts of interest in this work.