Characterization of the Chromosome 17q23 Amplicon

染色体 17q23 扩增子的表征

• 批准号: 6473885
• 负责人: Fergus Joseph Couch
• 金额: $ 28.94万
• 依托单位: MAYO CLINIC ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-06-05 至 2007-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6473885
• 关键词: athymic mouse; breast neoplasms; carcinogenesis; cell transformation; chromosomes; clinical research; fluorescent in situ hybridization; functional /structural genomics; gene expression; genetic mapping; genetic markers; human tissue; lymph nodes; microarray technology; neoplasm /cancer genetics; neoplastic growth; neoplastic process; nucleic acid amplification techniques; nucleic acid sequence; oncogenes; phosphoprotein phosphatase; polymerase chain reaction; tissue /cell culture; transfection

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.

描述：（由申请人提供）在癌症中，基因扩增代表着 导致基因拷贝数增加的遗传改变类型或 基因和随后的蛋白质表达增加。当目标为 扩增是一种细胞癌基因，相应的增加 癌蛋白表达通常导致肿瘤发生和/或进展。到 迄今为止，所有经过全面研究的扩增区域均已被发现 含有癌基因，表明新扩增子的表征将 导致鉴定出直接有助于 乳腺癌的发展。 在过去的两年里，我们对扩增子的结构进行了表征 乳腺癌细胞系和乳腺肿瘤中的染色体 17q23。我们有 确定了扩增子内的七个独立扩增区域，表明 该扩增子中可能存在多达七种不同的癌基因。我们有 在这七个扩增的基因中总共鉴定了十二个高度扩增的基因 区域，包括 TBX2 候选癌基因，其功能是通过 抑制衰老，诱导永生。我们还注意到，在 这十二个基因中至少有一个在 42% 的乳房中被扩增 肿瘤，包括 DCIS。总之，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，也许每个基因都有一个 七个扩增峰，并且这些癌基因可能具有 在乳腺肿瘤的早期进展中发挥着重要作用。 在这项研究中，我们建议通过识别和跟踪这些观察结果 表征扩增子中的癌基因。为了实现这一目标 我们的目标是：1）确定表达的水平和频率 乳腺肿瘤扩增区域中的基因，以验证所选的 候选者因扩增而过度表达； 2）表征 使用一系列的方法检测过表达的候选基因的致癌活性 致癌性测定； 3) 研究癌基因的预后潜力 来自该地区。 为了实现这些目标，我们将测量十二个的表达水平 肿瘤和细胞中扩增子中高度且频繁扩增的基因 线通过微阵列分析和定量RT-PCR。候选癌基因 扩增和过度表达之间的最佳相关性是 评估一系列永生化、转化、 肿瘤发生、侵袭和转移测定。最后，预测 该地区已验证癌基因扩增的相关性将是 通过将患者结果与扩增相关联来研究，如通过测量 荧光原位杂交、淋巴结阴性、淋巴结阳性和 DCIS 乳腺肿瘤。 该项目的重要性源于识别的潜力 新的癌基因将进一步加深我们对乳腺肿瘤的了解 进展。必须指出的是，我们正在采取全面的方法 鉴定该区域的癌基因，以便充分了解 该区域的扩增与肿瘤进展的相关性可以是 发达。这项研究也很重要，因为它可能会发现 临床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 从台式到床边的过渡。最后，扩增并过表达 基因可能被证明是有用的基因、药理学和生物学的重要靶标。 未来的免疫治疗。