FIG. 1.

(A) Long-term treatment of (Z)-1-[2-(2-aminoethyl)-N-(2-ammonioethyl) amino] diazen-1-ium-1,2-diolate (DETA/NO) stimulates melanocyte proliferation and forms foci in cell culture. The photos represent foci formed after 10 weeks. *p<0.05 compared to control. (B) Nitric oxide (NO) stress generated by DETA/NO (100 μM) or L-arginine (2.87 mM) enhanced melanoma proliferation, more evident in metastatic cells. *p<0.05 compared to control. (C) Both ultraviolet (UV) A (3 J/cm²) and UVB (25 mJ/cm²) radiation increased NO levels in primary melanoma wm3211 cells. Results represent the means±SDs of three replicates. *p<0.05 compared to control. (D) Increased total nitric oxide synthase (NOS) activities in melanoma cell lines compared to immortalized MEL-ST melanocytes. Results are expressed in folds of change standardized by Mel-ST cells for three biologic replicates. *p<0.05 compared to Mel-ST cells. (E) Effects of DETA/NO treatment on nNOS expression levels in human melanoma cells. Whole cell lysates were collected after incubation with DETA/NO at different time points, followed by immunoblotting analysis. The relative expression levels of nNOS were normalized by tubulin levels. The presented values were standardized with control.