RESUMEN
Objective To study the effects of UVR or H2O2 on the expression of p53 in human melanocytes,and that of nutlin-3 and PFT-α on the DNA oxidative damage,and to investigate the role of p53 in the antioxidative stress.Methods The effect of UVR,H2O2,nutlin-3 and PFT-α on the expression of p53 of human melanocytes was detected by Western blot analysis,and that of nutlin-3 and PFT-α on UVR or H2O2 DNA damage assessed by single cell electrophoresis (comet assay).Determination of the effect of nutlin-3 on H2O2 DNA damage was detected by γ-H2AX immunofluorescence.Results UVR and H2O2 could induce p53 protein expression,accompanied by increased phosphorylation of p53 on serine 15 residue,and nutlin-3 and PFT-α could induce and inhibit p53 protein in human melanocytes respectively; nutlin-3 decreased the tail moment of DNA oxidative damage of UVR or H2O2 in human melanocytes,but PFT-α increased the tail moment of DNA oxidative damage of UVR or H2O2 in human melanocytes,and there were significant differences among the control and exposed groups; nutlin-3 decreased expression of γ-H2AX.Conclusions p53 plays a very important role in the antioxidative stress in melanocyte exposed to UV or H2O2.