Guo Xiu-pu, Yu Jie, Gao Shu-ying
Central Laboratory of Peking University Shenzhen Hospital, Shenzhen PKU-HKUST Medical Center, Shenzhen 518036, China.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi. 2012 Jan;28(1):8-11.
To investigate transcriptional regulatory properties of DNA sequence upstream of the ezrin gene promoter in nasopharyngeal carcinoma CNE2 cells.
A series of reporter gene expression vectors carrying ezrin-1541/-706 sequence were constructed. In forward or reverse orientation, the ezrin -1541/-706 segment was located upstream of the luc gene in pGL3-Basic, upstream of the ezrin promoter or SV40 promoter, or downstream of the luc gene controlled by ezrin promoter or SV40 promoter. These plasmids were transfected into CNE2 cells for luciferase assay.
In CNE2 cells, when the ezrin -1541/-706 was located upstream of luc gene in pGL3-Basic in the forward orientation, it exhibited transcriptional activation about 50% of ezrin promoter; while this transactivation nearly abolished when this segment was reversed. When this segment was located upstream of the ezrin promoter or SV40 promoter in the forward orientation, it dramatically increased luciferase expression. However, the transcriptional enhancement disappeared when this segment was located upstream of promoters in the reverse orientation, or downstream of reporter genes in the forward or reverse orientation.
In CNE2 cells, the DNA sequence upstream of the ezrin promoter could exhibit transcriptional activation and enhancement, in a position- and orientation-dependent manner.
研究鼻咽癌CNE2细胞中埃兹蛋白基因启动子上游DNA序列的转录调控特性。
构建一系列携带埃兹蛋白-1541/-706序列的报告基因表达载体。埃兹蛋白-1541/-706片段以正向或反向的方式，位于pGL3-Basic载体中荧光素酶基因的上游、埃兹蛋白启动子或SV40启动子的上游，或者位于由埃兹蛋白启动子或SV40启动子控制的荧光素酶基因的下游。将这些质粒转染至CNE2细胞中进行荧光素酶检测。
在CNE2细胞中，当埃兹蛋白-1541/-706以正向位于pGL3-Basic载体中荧光素酶基因的上游时，它表现出约为埃兹蛋白启动子50%的转录激活作用；而当该片段反向时，这种反式激活作用几乎消失。当该片段以正向位于埃兹蛋白启动子或SV40启动子的上游时，它显著增加荧光素酶的表达。然而，当该片段以反向位于启动子的上游，或以正向或反向位于报告基因的下游时，转录增强作用消失。
在CNE2细胞中，埃兹蛋白启动子上游的DNA序列能够以位置和方向依赖的方式表现出转录激活和增强作用。
