Gold nanoparticles induce apoptosis in MCF-7 human breast cancer cells.

BACKGROUND Gold nanoparticles have recently been investigated with respect to biocompatibility according to their interactions with cells. The purpose of this study was to examine cytotoxicity and apoptosis induction by well-characterized gold nanoparticles in human breast epithelial MCF-7 cells. METHODS Apoptosis was assessed by TUNEL, cytotoxicity by MTT assay and caspase 3, 9, p53, Bax and Bcl expression by real-time PCR assays. RESULTS Gold nanoparticles at up to 200 μg/mL for 24 hours exerted concentration-dependent cytotoxicity and significant upregulation of mRNA expression of p53, bax, caspase-3 and caspase-9, whereas expression of anti- apoptotic bcl-2 was down-regulated. CONCLUSION To the best of our knowledge this is the first report showing that gold nanoparticles induce apoptosis in MCF-7 cells via p53, bax/bcl-2 and caspase pathways.