Evaluation of radio-sensitizing effect of TiO2 nanoparticles on human gastric cancer cell line

Nowadays، cancer is the second cause of mortality in the world. Gastric cancer has a high mortality rate (about 70%) which is more common in men and has a higher incidence in eastern Asian countries. One of the methods for cancer treatment is radiotherapy، in which to enhance the efficiency of radiation therapy some of radio-sensitizer agents can be used to enhance tumor cell radiosensitivity. Some nanoparticles can be considered as a sensitizer because of enhancing the cytotoxicity to oxidative stress and increasing free radicals especially ROS within cells، resulting to cell death. In this study، synergistic effect of TiO2 nanoparticles as a radio-sensitizer agent was evaluated in the presence of cobalt-60 gamma rays on human gastric cancer cell line. After cell culture، MKN-45 cells were exposed to 2 Gy of radiation and 30 µg/ml concentration of nanoparticles. Viability was calculated using MTT assay. Exposing cultured cells to nanoparticles alone resulted to a mean decrease of 70% in cell survival. Viability of cells in presence of gamma radiation and nanoparticles was significantly reduced compared to the viability of cells exposed only to radiation or nanoparticle، alone. The effect was dependent both on the nanoparticle crystal type and concentration. Discussion & Nano-TiO2 increased the sensitivity of gastric cancer cells to gamma radiation، due to an increase in the ROS production and cytotoxicity. Anatase crystals have more severe effects than rutile crystal because of having a larger surface area and creation of more free radicals. Therefore، this nanoparticle has the potential to be used as a radio-sensitizer.