Solid lipid nanoparticles: Reversal of tamoxifen resistance in breast cancer.

The objective of the present study was to investigate the effect of tamoxifen (Tam) loaded solid lipid nanoparticles (SLNs) on MCF7 Tam-resistant breast cancer cells (MCF7-TamR). Tam-SLNs were produced by the hot homogenization method. The characterization studies of Tam-SLNs demonstrated good physical stability with small particle size. The in vitro cytotoxicity results showed that Tam-SLNs enhanced the efficacy of Tam and reversed the acquired Tam resistance by inducing apoptosis, altering the expression levels of specific miRNA and the related apoptosis-associated target-genes in both MCF7 and MCF7-TamR cells without damaging the MCF10A control cells (p < 0.05). In conclusion, we demonstrated a molecular mechanism of the induction of apoptosis by Tam-SLNs in MCF7 and MCF7-TamR cells, and thus, we demonstrated that Tam-SLNs were more effective than Tam. The present study suggests that the use SLNs may be a potential therapeutic strategy to overcome Tam-resistance in breast cancer for clinical use.