Published in:
01-10-2011 | Research Article
p53 regulates Ki-67 promoter activity through p53- and Sp1-dependent manner in HeLa cells
Authors:
Mei-Juan Wang, Dong-Sheng Pei, Guo-Wei Qian, Xiao-Xing Yin, Qian Cheng, Lian-Tao Li, Hui-Zhong Li, Jun-Nian Zheng
Published in:
Tumor Biology
|
Issue 5/2011
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Abstract
The expression of the human Ki-67 protein, which is strictly associated with cell proliferation, is regulated by a variety of cellular mediators. In this study, we studied the effects of p53 on Ki-67 promoter in HeLa cells using luciferase reporter assay. The results showed that: (1) p53 inhibited Ki-67 promoter activity in a dose-dependent manner, (2) the p53-binding motifs mediated part of the transcriptional repression of Ki-67 promoter through a sequence-specific interaction with p53, (3) p53 was able to repress the Sp1-stimulated Ki-67 promoter activity, and (4) the Sp1-binding sites were responsible for the p53-mediated transcriptional repression of Ki-67 promoter. In conclusion, p53 inhibited Ki-67 promoter activity via p53- and Sp1-dependent pathways, and the interaction between p53 and Sp1 might be involved in the transcriptional regulatory mechanisms.