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 遗传改变的类型，导致基因的拷贝数增加或 基因和随后的蛋白质表达增加。当目标 扩增是一种细胞致癌基因，相应的增加 癌蛋白表达通常会导致肿瘤的发展和/或进展。到 日期，所有经过全面研究的扩增区域都已 包含癌基因，表明新型扩增子的表征将 导致鉴定出直接促成的新型癌基因 乳腺癌的发展。 在过去的两年中 乳腺癌细胞系和乳腺肿瘤中的17q23染色体。我们有 确定了扩增子内的七个独立放大区域 该扩增子可能存在多达七种不同的癌基因。我们有 在这七个扩增中确定了十二个高度扩增的基因 区域，包括TBX2候选癌基因，可作为癌基因 抑制衰老并诱导永生化。我们还注意到 这些十二个基因中至少有一个在所有乳房中的42％中得到扩增 肿瘤，包括DCIS。这些数据共同表明扩增子 包含具有致癌特性的其他几个基因，也许是一个 在七个扩增峰中，这些发病蛋白可能具有 在乳腺肿瘤早期进展中的重要作用。 在这项研究中，我们建议通过识别和 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 乳腺肿瘤中放大区域的基因，以验证选定的 候选人由于放大而过表达； 2）表征 使用一系列过表达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。 为了解决这些目标，我们将衡量十二个的表达水平 肿瘤和细胞中扩增子的高度和经常放大基因 通过微阵列分析和定量RT-PCR线。候选癌基因 随着扩增和过表达之间的最佳相关性将是 评估了一系列永生化，转化的致癌活性 肿瘤发生，侵袭和转移测定法。最后，预后 从该地区进行验证的肿瘤基因的扩增的相关性将是 通过将患者结局与扩增相关的研究，通过 荧光原位杂交，节点阴性，节点阳性和DCIS中 乳腺肿瘤。 该项目的重要性来自于识别的潜力 新颖的癌症将进一步了解我们对乳腺肿瘤的理解 进展。必须指出的是，我们正在采取一种全面的方法 识别该地区的致癌基因，以便对 该区域与肿瘤进展的相关性可以是 发达。该研究也很重要，因为它可能导致发现 临床上有用的预后分子标记，可能导致 个性化治疗方案。因此，该项目可能涉及一个完整的 从台式台面过渡到床边。最后，放大和过表达 基因可能被证明是基因，药理和 免疫疗法将来。