Abstract:

Objective To evaluate the activity of DNA polβpromoter on p53 gene in salivary adenoid cystic carcinoma（ SACC） cells. Methods The luciferase activity was examined and used to evaluate the activity of DNA polβ promoter on SACC- 83 cells. Eukaryotic expression plasmids of p53 gene were constructed and stably transfected into SACC- 83 cells. RT- PCR was used to assess the expression of p53 gene. The SACC- 83 cells were subjected to the treatments of H2O2 , ultraviolet radiation, Bleocin, and affected p53 mRNA and protein level in SACC- 83 cells were characterized with RT- PCR and Western blotting. Results The result of luciferase activity proved that the activity of DNA polβpromoter in SACC- 83 cells was much higher than that of CMV promoter. The results of RT- PCR suggested that p53 gene with different promoters were all expressed effectively, but the expression efficiency was different. It was greater in DNA polβ group than in CMV group. After DNA damage, p53 gene expression increased and DNA polβ promoter could enhance the expression of p53 gene more than CMV promoter. The results of Western blotting indicated that the expression of P53 protein between the two groups did not show any difference. Conclusion In SACC cells, the activity of DNA polβ promoter was increased and DNA polβ promoter could enhance the expression of p53.

Key words: salivary adenoid cystic carcinoma, DNA polβ, p53 gene, DNA damage, gene transfection