Increased Radiation Efficiency by Metal-Based Nanoparticles in Colorectal Cancer Cells

Abstract

Colorectal cancer (CRC) is diagnosed as one of the most prevalent cancers in the world. The
application of radiotherapy in cancer treatment might be limited due to its radio resistance. Specific
radiosensitizers are important factors in increasing the radiation therapy (RT) efficiency. In this study,
Fe3O4@CuS-PEG nanoparticles in combination with the RT were evaluated for the treatment of CRC cells
(HT-29 cells). HT-29 cells were treated with 2, 4, and 6 Gy of X-ray irradiation and/or a minimal toxic
concentration of Fe3O4@CuS-PEG nanoparticles. The cytotoxic effect of various treatments was evaluated by
MTT assay. Moreover, the malondialdehyde (MDA) level, superoxide dismutase (SOD) activity, and lactic
acid level were assessed in single and combined treatments. Furthermore, the epidermal growth factor receptor
(EGFR) gene expression level was measured by Quantitative Real-time PCR. Based on our results, cytotoxicity
of Fe3O4@CuS-PEG nanoparticles was increased in a dose dependent manner. The nanoparticles were less
cytotoxic in the concentration of 5 mg/mL compared to other examined concentrations. According to the results
of MTT assay, the viability in the combined treatment groups was significantly lower than that of the single
treatment groups. EGFR mRNA expression level was downregulated in radiation+nanoparticles groups in all
examined doses of radiation. The level of MDA increased in the combined treatments compared to the alone
treatments. Moreover, lactic acid level and SOD activity decreased in double agent combination treatments
versus radiation alone. Based on our study, Fe3O4@CuS-PEG nanoparticles can be introduced as an effective
radiosensitizer agent for targeted treatment of CRC cells. Moreover, combination treatment could efficiently
treat cancerous cells and inhibit tumor growth in vitro.