Identification of Id4 as a regulator of BRCA1 expression by using a ribozyme-library-based inverse genomics approach
Identification of Id4 as a regulator of BRCA1 expression by using a ribozyme-library-based inverse genomics approach
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DOI：
10.1073/pnas.98.1.130
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发表时间：
2001-01-02
影响因子：
11.1
通讯作者：
Wong-Staal, F
中科院分区：
文献类型：
--
作者：
Beger, C;Pierce, LN;Wong-Staal, F
乳腺癌和卵巢癌易感基因BRCA1的表达在散发性乳腺癌和卵巢癌病例中下调。因此，识别参与BRCA1表达调控的基因可能会导致对这些肿瘤的发病机制和治疗的新见解。在本研究中，一个“反向基因组学”的方法的基础上，随机核酶基因库的应用，以确定细胞基因调控BRCA 1的表达。将具有随机靶识别序列的核酶基因文库导入在BRCA 1启动子控制下稳定表达选择标记[增强型绿色荧光蛋白（EGFP）]的人卵巢癌衍生细胞中。BRCA1表达被特定核酶上调的细胞通过其伴随的EGFP表达的增加而被选择。其中一个核酶的细胞靶基因被鉴定为显性负转录调节因子Id4。Id4表达的调节导致BRCA 1表达的负调节。此外，Id4表达的增加与细胞表现出锚定非依赖性生长的能力相关，证明了该基因的生物学相关性。我们的数据表明，Id4是一个重要的基因调控BRCA1的表达，因此可能是重要的BRCA1调控途径参与散发性乳腺癌和卵巢癌的发病机制。
Expression of the breast and ovarian cancer susceptibility gene BRCA1 is down-regulated in sporadic breast and ovarian cancer cases. Therefore, the identification of genes involved in the regulation of BRCA1 expression might lead to new insights into the pathogenesis and treatment of these tumors. In the present study, an "inverse genomics" approach based on a randomized ribozyme gene library was applied to identify cellular genes regulating BRCA1 expression. A ribozyme gene library with randomized target recognition sequences was introduced into human ovarian cancer-derived cells stably expressing a selectable marker [enhanced green fluorescence protein (EGFP)] under the control of the BRCA1 promoter. Cells in which BRCA1 expression was up-regulated by particular ribozymes were selected through their concomitant increase in EGFP expression. The cellular target gene of one ribozyme was identified to be the dominant negative transcriptional regulator Id4. Modulation of Id4 expression resulted in inversely regulated expression of BRCA1. In addition, increase in Id4 expression was associated with the ability of cells to exhibit anchorage-independent growth, demonstrating the biological relevance of this gene. Our data suggest that Id4 is a crucial gene regulating BRCA1 expression and might therefore be important for the BRCA1 regulatory pathway involved in the pathogenesis of sporadic breast and ovarian cancer.