Transcriptional activation by p53 of the human type IV collagenase (gelatinase A or matrix metalloproteinase 2) promoter
Transcriptional activation by p53 of the human type IV collagenase (gelatinase A or matrix metalloproteinase 2) promoter
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DOI：
10.1128/mcb.17.11.6330
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发表时间：
1997-11-01
影响因子：
5.3
通讯作者：
Sun, Y
中科院分区：
文献类型：
--
作者：
Bian, JH;Sun, Y
p53是一种肿瘤抑制因子和转录因子，已显示转录激活参与调节细胞生长、DNA损伤、血管生成和凋亡的许多重要基因的表达。在计算机搜索其他潜在的p53靶基因中，我们在人IV型胶原酶（也称为72-kDa明胶酶或基质金属蛋白酶2 [MMP-2]）基因的启动子中确定了一个完美的p53结合位点。在凝胶迁移分析中发现该p53结合位点特异性结合p53蛋白。用由IV型胶原酶基因的启动子或增强子驱动的荧光素酶报告基因进行的转录测定揭示了（i）启动子活性的激活在p53阳性细胞中是p53结合位点依赖性的，而在p53阴性细胞中不是，和（ii）野生型p53，而不是通常在人类癌症中发现的p53突变体，反式激活由IV型胶原酶启动子以及启动子中含有p53位点的增强子元件驱动的荧光素酶表达。值得注意的是，内源性IV型胶原酶的表达也受p53的控制。用常见的p53诱导剂依托泊苷处理含有野生型p53的成骨肉瘤细胞系U2-OS，以时间依赖性方式诱导p53 DNA结合和反式激活活性。IV型胶原酶表达的诱导遵循p53激活模式。在相同的实验条件下，在p53阴性的Saos-2细胞中没有检测到IV型胶原酶表达的诱导。所有这些体外和体内测定都强烈表明IV型胶原酶基因是p53靶基因，并且其表达受到p53调节。我们的发现将p53与MMP基因的一个成员联系起来，MMP基因是一个涉及滋养层植入、伤口愈合、血管生成、关节炎和肿瘤细胞侵袭的基因家族。p53可能通过上调IV型胶原酶的表达来调节这些过程。
p53, a tumor suppressor and a transcription factor, has been shown to transcriptionally activate the expression of a number of important genes involved in the regulation of cell growth, DNA damage, angiogenesis, and apoptosis. In a computer search for other potential p53 target genes, we identified a perfect p53 binding site in the promoter of the human type IV collagenase (also called 72-kDa gelatinase or matrix metalloproteinase 2 [MMP-2]) gene. This p53 binding site was found to specifically bind to p53 protein in a gel shift assay. Transcription assays with luciferase reporters driven by the promoter or enhancer of the type IV collagenase gene revealed that (i) activation of the promoter activity is p53 binding site dependent in p53-positive cells but not in p53-negative cells and (ii) wild-type p53, but not p53 mutants commonly found in human cancers, transactivates luciferase expression driven by the type IV collagenase promoter as well as by a p53 site-containing enhancer element in the promoter. Significantly, expression of the endogenous type IV collagenase is also under the control of p53. Treatment of U2-OS cells, a wild-type p53-containing osteogenic sarcoma line, with a common p53 inducer, etoposide, induced p53 DNA binding and transactivation activities in a time-dependent manner. Induction of type IV collagenase expression followed the p53 activation pattern. No induction of type IV collagenase expression can be detected under the same experimental conditions in p53-negative Saos-2 cells. All these in vitro and in vivo assays strongly suggest that the type IV collagenase gene is a p53 target gene and that its expression is subject to p53 regulation. Our finding links p53 to a member of the MMP genes, a family of genes implicated in trophoblast implantation, wound healing, angiogenesis, arthritis, and tumor cell invasion. p53 may regulate these processes by upregulating expression of type IV collagenase.