Abstract
Proliferating cell nuclear antigen (PCNA), also known as an auxiliary factor of DNA polymerase δand ε, is required in both DNA synthesis and DNA excision repair in eukaryotes. The gene expression of proliferating cell nuclear antigen (PCNA) in mammalian cells was moderately induced by UV irradiation (at 254 nm) at dose dependent manner. In the previously study, we found that p53 is dispensable in UV induction of PCNA expression. In this study, we observed that PCNA gene expression was induced by UV irradiation in a kinetic pattern, which was different from those of p53 inducible gene such as p21WAF1 or GADD45. The UV induction of PCNA or HSP70 was few hours behind that of c-Jun, but few hours before those of p21WAF1 and GADD45. Furthermore, the UV -induced PCNA expression did not depend on the DNA repair since PCNA was UV inducible in UVL-10 and xrs-6 cells, where the nucleotide excision repair and the double stranded repair is largely compromised, respectively. Moreover, despite the fact that no change of reactive oxygen species was observed in UVC-irradiated cells, the induction of PCNA expression was inhibited by antioxidants N-acetyl-L-cysteine and glutathione.