ROLE OF THE BRCA1 GENE IN SPORADIC CANCER

遗传性乳腺癌和卵巢癌易感性的鉴定 BRCA1基因的发现提高了人们对这种疾病的认识， 增加对有家族史妇女的监测， 基因突变检测然而，我们对这一角色的了解 该基因在散发性癌症中的作用及其在正常和肿瘤中的功能 增长和发展是稀疏的。这一建议是对 过去两年进行的研究旨在调查这些 问题.在本建议中概述了以下实验：1）由于 BRCA1很少是体细胞突变乳腺癌的靶点，是吗？ 因表达缺失而失活使用显微解剖的正常上皮， 原位癌和浸润性癌，表达和启动子 将使用基于PCR的方法评价甲基化。2)BRCA1 mRNA的表达在细胞周期中受到严格调控。改变 在表达中，无论是时间性质的水平，可能会发现其 功能因此，基础和细胞周期调控启动子元件 将被识别。使用最小启动子片段，鉴定 与特定启动子序列复合的反式作用因子将被 确立了习这些实验将补充和扩展那些建议 在第一个目标。3)很难得到细胞系， 表达BRCA1，以研究与BRCA1相关的表型和分子事件。 和蛋白质。为了克服这个问题，四环素 已经建立了诱导型细胞系。BRCA1在试验诱导下 将启动子引入这些细胞中以研究表型效应 BRCA1过表达的影响，包括细胞周期参数，凋亡， 对DNA损伤的反应和对分化剂的反应。4)使用 在这些相同的细胞系中，由BRCA1表达诱导的基因将被 使用代表性差异分析（RDA）确定。从 这些基因的启动子元件，共同的BRCA1反应元件将是 杰出的

Identification of the hereditary breast and ovarian cancer susceptibility gene, BRCA1, has led to increased awareness regarding the disease, increased surveillance in women with a family history, and the advent of genetic testing for mutations. However, our knowledge regarding the role of this gene in sporadic cancers and its function in normal and neoplastic growth and development is sparse. This proposal is a continuation of studies performed over the past two years designed to investigate these issues. The following experiments are outlined in this proposal: 1) Since BRCA1 is rarely a target for somatic mutation breast cancer, is it inactivated by loss of expression? Using microdissected normal epithelium, carcinoma in situ, and invasive cancers, both expression and promoter methylation will be evaluated employing PCR based methodology. 2) BRCA1 mRNA expression is tightly regulated through the cell cycle. Alterations in expression, either the levels of temporal nature, may find its function. Therefore, the basal and cell cycle regulated promoter elements will be identified. Using the minimal promoter fragment, the identity of trans-acting factors that complex with specific promoter sequences will be established. These experiments will complement and extend those proposed in the first aim. 3) It has been difficult to derive cell lines that over- express BRCA1 in order to study phenotypic and molecular events associated with the protein. In order to overcome this problem, tetracycline inducible cell lines have been established. BRCA1 under the test-inducible promoter will be introduced into these cells to study phenotypic effects of BRCA1 over-expression including cell cycle parameters, apoptosis, response to DNA damage, and response to differentiating agents. 4) Using these same cell lines, genes that are induced by BRCA1 expression will be identified using representational difference analysis (RDA). From the promoter elements of these genes, common BRCA1 response elements will be distinguished.