Gene expression profiles of human neuroblastoma cells exposed to CuO nanoparticles and Cu ions

Abstract

Copper oxide nanoparticles (CuO NPs) are one of the most toxic metal oxide nanoparticles, but they have a wide range of applications in the manufacture of industrial and consumer products. While their beneficial aspects are widely acknowledged, the toxic effects of CuO NPs and Cu ions on the neuronal system may limit their use. Here, we propose a molecular mechanism underlying the response of human neuroblastoma SH-SY5Y cells to CuO NP and Cu ion exposure based on cDNA microarray data. SH-SY5Y cells exposed to CuO NPs and CuCl2 for 24 hours showed concentration-dependent cell death with similar IC50 values. The expression level of up-regulated genes in CuCl2-exposed cells was significantly higher than in CuO NP-exposed cells. CuO NP-exposed cells arrested the cell cycle in the G1/S/G2/M phases as a result of an up-regulation of INK4d, CYCE, RB, CDC6, CDC45, GADD45, and BUB1, while CuCl2-exposed cells mostly arrested the cell cycle in the G2/M phases as a result of CYCA, CYCB, CDK1, CDC20, PIK1, and BUB1 up-regulation. Our results suggest that the IC50 value had no significant relation with gene expression changes because the gene expression study may be in part due to cytotoxic mechanisms.