c-myc特异性结合序列增强基因表达的研究  

Investigation on improved gene expression by c myc specific binding sequence

作　　者：孙蕾[1] 王会信[1] 周廷冲[1] 

机构地区：[1]军事医学科学院基础医学研究所

出　　处：《军事医学科学院院刊》1998年第2期125-128,共4页Bulletin of the Academy of Military Medical Sciences

摘　　要：目的：ｃ－ｍｙｃ是一种转录因子，它与其特异性结合序列结合后，可增强下游基因的表达。方法：将４个重复拷贝的ｃ－ｍｙｃ顺式反应元件（ＣＡＣＧＴＧ）４、ＣＭＶ增强子／启动子以及带有ＣＭＶ增强子／启动子的（ＣＡＣＧＴＧ）４分别插入报道基因质粒ｐＢＬＣＡＴ２，得到３种融合报道质粒：ｐＭ４ＣＡＴ２、ｐＣＭＶＣＡＴ、ｐＭ４ＣＭＶＣＡＴ。结果：ＣＡＴ测活表明，在ｃ－ｍｙｃ高表达的ＢＴ３２５细胞中，ｐＭ４ＣＡＴ２的ＣＡＴ活性比ｐＢＬＣＡＴ２增高１０．７倍，而在ｃ－ｍｙｃ低表达的ＨｅＬａ细胞中，仅增高１．１倍；在ＢＴ３２５细胞中，ｐＭ４ＣＡＴ２的ＣＡＴ活性为ｐＣＭＶＣＡＴ的１／４，而ｐＭ４ＣＭＶＣＡＴ的ＣＡＴ活性与ｐＣＭＶＣＡＴ相当。结论：连接了（ＣＡＣＧＴＧ）４的ＴＫ启动子的转录活性依赖于ｃ－ｍｙｃ的扩增情况。而在（ＣＡＣＧＴＧ）４ＴＫ的前面再增加一个强的增强子可进一步增强该启动子的活性。Objective: c myc is a transcription factor, it can improve the gene expression of downstream gene when binding with its specific binding sequence. Methods: Three fusion reporter plasmids named pM4CAT2、pCMVCAT、pM4CMVCAT were constructed by inserting four repeated copies of c myc specific binding squences(CACGTG) 4、CMV enhancer/promoter 、(CACGTG) 4 containing CMV enhancer/promoter into pBLCAT2 respectively. Results: CAT activity detection showed that the CAT activity of pM4CAT2 was 10.7 times higher than that of pBLCAT2 in the c myc high expression BT325 cell, but was only 1.1 times higher in the c myc low expression HeLa cell. In BT325 cell, the CAT activity of pM4CAT2 was one fourth of that of pCMVCAT, but M4pCMVCAT which contained a CMV enhancer/promoter upstream of the (CACGTG) 4 had a similar CAT activity to pCMVCAT. Conclusion: The results suggested that the transcriptional property of TK promoter connected with (CACGTG) 4 depended on c myc gene amplification and that adding an enhancer element ahead of (CACGTG) 4TK could improved the property of this promoter.

关 键 词：C-MYC 特异性综合序列 表达 肿瘤细胞 启动子 

分 类 号：Q756[生物学—分子生物学] R730.2[医药卫生—肿瘤]