Butyrate activates the WAF1/Cip1 gene promoter through Sp1 sites in a p53-negative human colon cancer cell line
Butyrate activates the WAF1/Cip1 gene promoter through Sp1 sites in a p53-negative human colon cancer cell line
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DOI：
10.1074/jbc.272.35.22199
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发表时间：
1997-08-29
影响因子：
4.8
通讯作者：
Sakai, T
中科院分区：
文献类型：
--
作者：
Nakano, K;Mizuno, T;Sakai, T
丁酸盐是一种众所周知的结肠腔短链脂肪酸，可阻止细胞生长并诱导各种细胞类型的分化。我们研究了丁酸盐对 WAF1/Cip1（一种细胞周期蛋白依赖性激酶的有效抑制剂）表达的影响，及其与 p53 突变的人结肠癌细胞系 WiDr 生长停滞的关系。5 毫摩尔丁酸盐完全抑制 WiDr 的生长并导致 G(1) 期停滞。通过用 5.0 mM 丁酸盐处理，WAF1/Cip1 mRNA 在 3 小时内快速诱导，并检测到剧烈的 WAF1/Cip1 蛋白诱导。使用几个突变的WAF1/Cip1启动子片段，我们发现丁酸响应元件是相对于转录起始位点位于-82和-69的两个Spl位点。我们还发现 -46 处的 TATA 元件以及 -60 和 -55 处两个重叠的共有 Spl 位点对于 WAF1/Cip1 的基础启动子活性至关重要。这些发现表明，丁酸盐通过特定的 Sp1 位点以不依赖于 p53 的方式激活 WAF1/Cip1 启动子，从而阻止 WiDr 的生长。
Butyrate is a well known colonic luminal short chain fatty acid, which arrests cell growth and induces differentiation in various cell types. We examined the effect of butyrate on the expression of WAF1/Cip1, a potent inhibitor of cyclin-dependent kinases, and its relation to growth arrest in a p53-mutated human colon cancer cell line WiDr, Five millimolar butyrate completely inhibited the growth of WiDr and caused G(1)-phase arrest. WAF1/Cip1 mRNA was rapidly induced within 3 h by treatment with 5.0 mM butyrate, and drastic WAF1/Cip1 protein induction was detected. Using several mutant WAF1/Cip1 promoter fragments, we found that the butyrate responsive elements are two Spl sites at -82 and -69 relative to the transcription start site. We also found that a TATA element at -46 and two overlapping consensus Spl sites at -60 and -55 are essential for the basal promoter activity of WAF1/Cip1. These findings suggest that butyrate arrests the growth of WiDr by activating the WAF1/Cip1 promoter through specific Sp1 sites in a p53-independent fashion.