Selenium nanoparticles trigger alterations in ovarian cancer cell biomechanics

High dose selenium acts as a cytotoxic agent, with potential applications in cancer treatment. However, clinical trials have failed to show any chemotherapeutic value of selenium at safe and tolerated doses (<90 μg/day). To enable the successful exploitation of selenium for cancer treatment, we evaluated inorganic selenium nanoparticles (SeNP), and found them effective in inhibiting ovarian cancer cell growth. In both SKOV-3 and OVCAR-3 ovarian cancer cell types SeNP treatment resulted in significant cytotoxicity. The two cell types displayed contrasting nanomechanical responses to SeNPs, with decreased surface roughness and membrane stiffness, characteristics of OVCAR-3 cell death. In SKOV-3, cell membrane surface roughness and stiffness increased, both properties associated with decreased metastatic potential. The beneficial effects of SeNPs on ovarian cancer cell death appear cell type dependent, and due to their low in vivo toxicity offer an exciting opportunity for future cancer treatment

Intracellular Fate of Sub-Toxic Concentration of Functionalized Selenium Nanoparticles in Aggressive Prostate Cancer Cells

International audienceSelenium 0 (Se0) is a powerful anti-proliferative agent in cancer research. We investigated the impact of sub-toxic concentrations of Se0 functionalized nanoparticles (SeNPs) on prostate cancer PC-3 cells and determined their intracellular localization and fate. An in-depth characterization of unctionalized selenium nanoparticles composition is proposed to certify that no chemical bias relative to synthesis issues might have impacted the study. Selenium is an extremely diluted element in the biological environment and therefore requires high-performance techniques with a very lowdetection limit and high spatial resolution for intracellular imaging. This was explored with state-of- the-art techniques, but also with cryopreparation to preserve the chemical and structural integrity of the cells for spatially resolved and speciation techniques. Monodisperse solutions of SeNPs capped with bovine serum albumin (BSA) were shown to slow down the migration capacity of aggressive prostate cancer cells compared to polydisperse solutions of SeNPs capped with chitosan. BSA coating could prevent interactions between the reactive surface of the nanoparticles and the plasma membrane, mitigating the generation of reactive oxygen species. The intracellular localization showed interaction with mitochondria and also a localization in the lysosome-related organelle. The SeNPs-BSA localization in mitochondria constitute a possible explanation for our result showinga very significant dampening of the PC-3 cell proliferation capabilities. The purpose of the use of sublethal compound concentrations was to limit adverse effects resulting from high cell death to best evaluate some cellular changes and the fate of these SeNPs on PC-3. Our findings provide newinsight to further study the various mechanisms of cytotoxicity of SeNPs