Induction of oxidative DNA damage, cell cycle arrest and p53 mediated apoptosis by calcium titanate nanoparticles in MCF-7 breast cancer cells

Abstract

Background The distinctive properties and high activity of calcium titanate nanoparticles (CaTiO3-NPs) increase their use in many products. However, the cytotoxic and genotoxic effects of CaTiO3-NPs in human cancer cell lines have not been well studied. Therefore, this study was conducted to explore CaTiO3-NPs induced cytotoxicity, genomic instability and apoptosis in human breast cancer (MCF-7) cells. Methods Sulforhodamine B (SRB) and the alkaline comet assays were done to study cell viability and DNA damage induction, respectively. Apoptosis induction and cell cycle distribution were analyzed using flow cytometry. The level of intracellular reactive oxygen species (ROS) was studied, and the expression levels of p53, Bax and Bcl2 genes were also measured. Results The results of the Sulforhodamine B (SRB) cytotoxicity assay showed that viability of MCF-7 cells was not affected by CaTiO3-NPs treatment for 24 h, however, exposure to CaTiO3-NPs for 72 h caused concentrations dependent death of MCF-7 cells. Treatment with CaTiO3-NPs for 72 h caused marked increases in intracellular ROS level and induced DNA damage. Treatment of MCF-7 cells with CaTiO3-NPs also caused MCF-7 cell cycle arrest at the G0 and S phases and s triggered apoptosis of MCF-7 cells by causing simultaneous increases in the expression levels of apoptotic p53 and Bax genes and a decrease in the expression level of anti-apoptotic Bcl2 gene. Conclusion Collectively, it was concluded that CaTiO3-NPs cause time- and concentration-dependent cytotoxic effects in human MCF-7 cells through induction of ROS generation, genomic instability and apoptosis. Thus it is recommended that further in vitro and in vivo studies are therefore recommended to understand the cytotoxic and biological effects of CaTiO3-NPs.