Identification of a human VPF/VEGF 3′ untranslated region mediating hypoxia-induced mRNA stability
Identification of a human VPF/VEGF 3′ untranslated region mediating hypoxia-induced mRNA stability
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DOI：
10.1091/mbc.9.2.469
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发表时间：
1998-02-01
影响因子：
3.3
通讯作者：
Detmar, M
中科院分区：
文献类型：
--
作者：
Claffey, KP;Shih, SC;Detmar, M
缺氧是恶性肿瘤的显著特征，其特征在于血管生成和血管通透性过高。血管通透性因子/血管内皮生长因子（VPF/VEGF）已被证明是在坏死的肿瘤区域附近上调，和缺氧有效地诱导VPF/VEGF表达在几种肿瘤细胞系在体外。在这里，我们报告说，缺氧诱导的VPF/VEGF的表达介导的转录和mRNA的稳定性增加在人M21黑色素瘤细胞。RNA结合/电泳迁移率变动分析鉴定了3'非翻译区中形成缺氧诱导的RNA-蛋白质复合物的单个125-bp AU富集元件。含有该125-bp富含AU的缺氧稳定区的嵌合荧光素酶报告基因构建体的缺氧诱导表达显著高于含有相邻的3'非翻译区元件而没有RNA结合活性的构建体。使用紫外线交联研究，我们已经确定了一系列的缺氧诱导的蛋白质的90/88 kDa，72 kDa，60 kDa，56 kDa，和46 kDa的结合到缺氧稳定区元件。90/88-kDa和60-kDa物质特异性地被过量的缺氧稳定区RNA竞争。因此，由缺氧诱导的VPF/VEGF mRNA稳定性增加至少部分地由3'非翻译区中确定的mRNA稳定性序列与人肿瘤细胞中不同的mRNA结合蛋白之间的特异性相互作用介导。
Hypoxia is a prominent feature of malignant tumors that are characterized by angiogenesis and vascular hyperpermeability. Vascular permeability factor/vascular endothelial growth factor (VPF/VEGF) has been shown to be up-regulated in the vicinity of necrotic tumor areas, and hypoxia potently induces VPF/VEGF expression in several tumor cell lines in vitro. Here we report that hypoxia-induced VPF/VEGF expression is mediated by increased transcription and mRNA stability in human M21 melanoma cells. RNA-binding/electrophoretic mobility shift assays identified a single 125-bp AU-rich element in the 3' untranslated region that formed hypoxia-inducible RNA-protein complexes. Hypoxia-induced expression of chimeric luciferase reporter constructs containing this 125-bp AU-rich hypoxia stability region were significantly higher than constructs containing an adjacent 3' untranslated region element without RNA-binding activity. Using UV-cross-linking studies, we have identified a series of hypoxia-induced proteins of 90/88 kDa, 72 kDa, 60 kDa, 56 kDa, and 46 kDa that bound to the hypoxia stability region element. The 90/88-kDa and 60-kDa species were specifically competed by excess hypoxia stability region RNA. Thus, increased VPF/VEGF mRNA stability induced by hypoxia is mediated, at least in part, by specific interactions between a defined mRNA stability sequence in the 3' untranslated region and distinct mRNA-binding proteins in human tumor cells.