Gold nanoparticles induce cell death and suppress migration of melanoma cells

Diverse nanoparticles have been widely applied in different fields, including industries and biomedical sciences. Recent developments in nanotechnology have broadened the potential applications of nanotechnology in clinical diagnosis and medical therapy of malignant and non-malignant diseases. Gold nanoparticles (AuNPs) have been reported to possess unique physico-chemical properties; they have been investigated in studies on tumor growth and metastasis. Here, we explored the possible pharmacological functions of AuNPs on the mouse melanoma cell line, B16F10. We demonstrated that AuNPs of sizes 1-3, 3-5, and 10-15 nm exerted dose-dependent cytotoxic effects after 72-h treatments. AuNPs (4 and 10 ppm) of 1-3 and 35 nm were more cytotoxic than those of 10-15 nm. However, AuNPs of 1-3 nm were more cytotoxic against benign HaCaT keratinocytes than those of 35 nm. Thus, 4 ppm of AuNPs of 3-5 nm was considered relatively safe and an ideal candidate for this study. Further investigations revealed that AuNPs could induce sub-G1 phase accumulation, cleavage of caspase-3 and poly-(ADP-ribose) polymerase, and activation of JNK/p38. The expression of pro-apoptotic protein, Bax, was also induced. Furthermore, platelet-derived growth factor BB-induced migration and motility of melanoma cells were reduced after pretreatment with AuNPs of 35 nm. Adhesion assay showed that AuNPs of 3-5 nm could significantly suppress the adhesion of melanoma cells to collagen. In summary, AuNPs of 3-5 nm might be potential anti-tumor agents, as they were selectively cytotoxic against and inhibited motility of melanoma cells.