CONICET | Buscador de Institutos y Recursos Humanos

Background: T47D and MCF7 are two human hormone-dependent breast cancer cell lines which are widely used as experimental models for in vitro and in vivo breast cancer studies. Silver nanoparticles have been discovered to exert cytotoxicity and induce apoptosis in cancer cells. However few studies have investigated the different cyto-toxicity of two types of silver nanoparticles in two similar tumour breast cells. Methods: This study investigated the cytotoxicity of normal silver nanoparticles (AgNps) and Chitosan-Ag Nanoparticles composite (Q-AgNps) in human MCF7 and T47D breast cancer cells, using normal human MCF10 breast cell line as a control. Growth inhibition, cell nucleus morphology changes, cellular uptake, apoptosis induction by Anexin V and expression of procaspase 9, p53 and Bcl-2 as well as the activity of caspase 3 were analyzed. Results: The antitumor activity of the silver nanoparticles was closely related to particle type, and the antiproliferative effect was more significant for Q-AgNps than that of AgNps. The silver nanoparticles were also cytotoxic in a dose- and time-dependent manner. However, the silver nanoparticles showed only slight toxicity in the T47D y MCF10 control cells, Moreover, in MCF7 cells, apoptosis were induced after exposure to two types of silver nanoparticles. Expression of p53 and caspase-3 increased, and expression of Bcl-2 and procaspase-9 decreased in a dose-dependent manner. Conclusion: A mitochondrial-dependent pathway triggered may be involved in apoptosis induced by silver nanoparticles, and hence cytotoxicity in human MCF7 breast cancer cells for other hand the cells with lower growth rate do not have this effect.