Doxorubicin-hyaluronan conjugated super-paramagnetic iron oxide nanoparticles (DOX-HA-SPION) enhanced cytoplasmic uptake of doxorubicin and modulated apoptosis, IL-6 release and NF-kappaB activity in human MDA-MB-231 breast cancer cells

Triple negative breast cancer exhibit increased IL-6 expression compared with matched healthy breast tissue and a strong link between inflammation and cancer progression and metastasis has been reported. We investigated whether doxorubicin-hyaluronan-super-paramagnetic iron oxide nanoparticles (DOX-HA-SPION) would show greater therapeutic efficacy in human triple negative breast cancer cells (TNBC) MDA-MB-231, as was recently shown in drug-sensitive and multidrug- resistant ovarian cancer cells. Therefore, we measured cellular DOX uptake via confocal microscopy; observed morphologic changes: mitochondrial and nuclear changes with electron microscopy, and quantitated apoptosis using FACS analysis after Annexin V and PI staining in MDA-MB-231 cells treated with either DOX alone or DOX-HA-SPION. We also measured both proinflammatory and anti-inflammatory cytokines; IL-6, IL-10 respectively and also measured nitrate levels in the conditioned medium by ELISA. Inaddition, NF-κB activity was measured by luciferase assay. Confocal microscopy demonstrated greater cytoplasmic uptake of DOX-HA-SPION than free DOX. We also demonstrated reduction of Vimentin with DOX-HA-SPION which is significantly less than both control and DOX. DOX-HA-SPION enhanced apoptosis and significantly down regulated both pro-inflammatory mediators IL-6 and NF-κB in comparison to DOX alone. The secretion levels of anti-inflammatory mediators IL-10 and nitrate was not decreased in the DOX or DOX-HA-SPION treatment groups. Our data suggest that DOX-HA-SPION nanomedicine-based drug delivery could have promising potential in treating metastasized and chemoresistant breast cancer by enhancing the drug efficacy and minimizing off-target effects.