Characterization of the Chromosome 17q23 Amplicon

描述：(申请人提供)在癌症中，基因扩增代表 一种导致基因或基因拷贝数增加的基因改变类型 基因和随后蛋白质表达的增加。当目标是 扩增是一种细胞癌基因，相应地增加 癌蛋白的表达通常会导致肿瘤的发展和/或进展。至 到目前为止，所有全面研究的扩增区域都被发现 含有癌基因，这表明对新扩增片段的表征将 导致发现直接与癌症相关的新的癌基因 乳腺癌的发展。 在过去的两年里，我们已经描述了扩增子的结构 染色体17q23在乳腺癌细胞系和乳腺肿瘤中的表达我们有 在扩增子内发现了七个独立扩增的区域，表明 在这个扩增子中可能有多达七个不同的癌基因。我们有 在这7个扩增的基因中，共鉴定出12个高扩增基因 区域，包括作为癌基因功能的TBX2候选癌基因 抑制衰老，诱导永生。我们还注意到，在 在42%的乳房中，这12个基因中至少有一个基因被扩增 肿瘤，包括DCIS。总而言之，这些数据强烈表明，扩增子 包含其他几个具有致癌特性的基因，可能每个基因都有一个 在七个扩增峰中，这些癌基因可能具有 在乳腺肿瘤的早期进展中起着重要作用。 在这项研究中，我们建议通过确定和 分析扩增子中的癌基因。为了实现这一目标 目的：1)确定人血清白蛋白的表达水平和频率。 在乳腺肿瘤的扩增区域中验证所选择的基因 作为放大的结果，候选被过度表达；2)描述 用一系列方法检测过表达的候选基因的致癌活性 致癌性分析；3)研究癌基因的预后潜力 来自该地区。 为了达到这些目标，我们将测量十二个人的表达水平 肿瘤和细胞中高频率扩增的扩增基因 通过基因芯片分析和定量RT-PCR检测。候选癌基因 扩增和过度表达之间的最佳相关性将是 在一系列永生化，转化，转化， 肿瘤发生、侵袭和转移分析。最后，预言家 从该区域验证的癌基因扩增的相关性将是 通过将患者结果与放大相关进行研究，如通过 荧光原位杂交、结节阴性、结节阳性和DCIS 乳房肿瘤。 这个项目的重要性来自于确定 新的癌基因将加深我们对乳腺肿瘤的理解 进步。必须指出的是，我们正在采取全面的方法来 在该地区发现癌基因，以便充分了解 该区域的扩增与肿瘤进展的相关性可以是 发展起来的。这项研究也很重要，因为它可能会发现 临床上有用的预后分子标志物可能导致 个体化治疗方案。因此，该项目可能涉及一个完整的 从桌面过渡到床边。最后，被放大和过度表达的 基因可能被证明是基因、药理和基因研究的重要靶点 未来的免疫治疗。

DESCRIPTION: (provided by applicant) In cancer, gene amplification represents a type of genetic alteration that results in increased copy number of a gene or genes and subsequent increases in protein expression. When the target of amplification is a cellular oncogene, the corresponding increases in oncoprotein expression often result in tumor development and/or progression. To date, all comprehensively studied regions of amplification have been found to contain oncogenes, suggesting that characterization of novel amplicons will lead to identification of novel oncogenes that contribute directly to development of breast cancer. Over the last two years we have characterized the structure of an amplicon on chromosome 17q23 in breast cancer cell lines and breast tumors. We have identified seven independently amplified regions within the amplicon suggesting that as many as seven different oncogenes may reside in this amplicon. We have identified a total of twelve highly amplified genes in these seven amplified regions, including the TBX2 candidate oncogene that functions as an oncogene by inhibiting senescence and inducing immortalization. We have also noted that at least one of these twelve genes is amplified in 42 percent of all breast tumors, including DCIS. Together, these data strongly suggest that the amplicon contains several other genes with oncogenic properties, perhaps one from each of the seven amplification peaks, and that these oncogenes may have an important role in early progression of breast tumors. In this study we propose to follow up on these observations by identifying and characterizing the oncogenes in the amplicon. In order to achieve this objective we aim to: 1) determine the level and frequency of expression of the genes in the amplified regions in breast tumors to verify that the selected candidates are overexpressed as a result of amplification; 2) characterize the oncogenic activity of the overexpressed candidate genes using a series of oncogenicity assays; 3) investigate the prognostic potential of the oncogenes from the region. To address these aims, we will measure the expression level of the twelve highly and frequently amplified genes from the amplicon in tumors and cell lines by microarray analysis and quantitative RT-PCR. The candidate oncogenes with the best correlation between amplification and overexpression will be assessed for oncogenic activity in a series of immortalization, transformation, tumorigenesis, invasion, and metastasis assays. Finally, the prognostic relevance of amplification of the validated oncogenes from the region will be studied by correlating patient outcome with amplification, as measured by fluorescence in situ hybridization, in node negative, node positive, and DCIS breast tumors. The importance of this project derives from the potential for identification of novel oncogenes that will further our understanding of breast tumor progression. It must be noted that we are taking a comprehensive approach to the identification of oncogenes in the region so that a full understanding of the relevance of amplification of the region to tumor progression can be developed. The study is also important because it may result in discovery of clinically useful molecular markers of prognosis that may lead to individualized treatment regimens. Thus, the project may involve a complete transition from benchtop to bedside. Finally, the amplified and overexpressed genes may prove useful as important targets of gene, pharmacological, and immunological therapy in the future.