Cytotoxic Effect of Nano-SiO 2 in Human Breast Cancer Cells via Modulation of EGFR Signaling Cascades.

Background/Aim: Silica nanoparticles (nano-SiO2) are widely used in many industrial areas and there is much controversy surrounding cytotoxic effects of such nanoparticles. In order to determine the toxicity and possible molecular mechanisms involved, we conducted several tests with two breast cancer cell lines, MDA-MB-231 and Hs578T. Materials and Methods: After exposure to nano-SiO2, growth, apoptosis, motility of breast cancer cells were monitored. In addition, modulation of signal transduction induced by nano-SiO2 was detected through western blot analysis. Results: Treatment of nano-SiO2 repressed the growth of breast cancer cell lines. It also increased apoptosis and reduced cell motility. Moreover, exposure to nano-SiO2 significantly disturbed the dimerization of epidermal growth factor receptor (EGFR), followed by down-regulation of its downstream cellular sarcoma kinase (c-SRC) and signal transducer and activator of transcription 3 (STAT3) signaling cascades. Conclusion: Nano-SiO2 has a cytotoxic effect on MDA-MB-231 and Hs578T breast cancer cells via modulation of EGFR signaling cascades.