Breast cancer oncogenes on the 8p11 amplicon

8p11 扩增子上的乳腺癌癌基因

• 批准号: 8266528
• 负责人: STEPHEN P. ETHIER
• 金额: $ 34.77万
• 依托单位: MEDICAL UNIVERSITY OF SOUTH CAROLINA
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-06-01 至 2015-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8266528
• 关键词: 8p11; Anchorage-Independent Growth; Breast Cancer Cell; Cancer cell line; Cells; Code; Development; Disease; Drug Delivery Systems; ERBB2 gene; Epithelial Cells; Event; Exhibits; Gene Combinations; Gene Expression; Gene Expression Profile; Genes; Grant; Growth; Growth Factor; Histones; Human; In Vitro; Malignant Neoplasms; Mammary gland; Mediating; Methylation; Morphogenesis; Mus; Oncogene Proteins; Oncogenes; PWWP Domain; Pathogenesis; Patients; Phase; Phenotype; Property; Protein Isoforms; Proteins; SET Domain; Testing; Therapeutic; Tissues; Work; base; bone; cancer stem cell; cell transformation; gene function; in vivo; malignant breast neoplasm; matrigel; novel; novel therapeutics; public health relevance; research study; self-renewal; tumor

DESCRIPTION (provided by applicant): In the previous project period, we performed an extensive analysis of the 8p11-p12 amplicon in human breast cancer cell lines and tissues to identify and validate novel breast cancer oncogenes. Using statistical analysis of copy number increase and over expression, we identified a subset of 21 genes as candidate oncogenes. Next, we directly tested the transforming function of these genes in human mammary epithelial cells. From these experiments, we identified four genes that are potently transforming in MCF-10A cells and three other genes with more modest transforming function. The most potently transforming genes identified, which include DDHD2, SPFH2, LSM1 and WHSC1L1, induce growth factor independent proliferation, anchorage-independent growth, invasive capacity, and altered morphogenesis in Matrigel. In addition, we identified gene combinations that effect the expression of transformed phenotypes. In the next phase of this work, we will perform experiments to understand the mechanistic basis for the transforming potential of these oncogenes, and we will examine their transforming function in human breast cancer cells in vitro, and in human and mouse mammary epithelial cells in vivo. The specific aims of the work in the next project period are: 1) To determine if the seven genes that induce transformed phenotypes in MCF-10A cells are directly transforming, and to determine if transformation is a common or a rare event in cells over expressing the oncogene; 2) To determine if the genes from the 8p11 region that are amplified and over expressed in human breast cancer cell lines are required for growth and survival of these breast cancer cells compared with normal mammary epithelial cells or breast cancer cells without the amplicon. We will also test the hypothesis that some oncogenes on the 8p11 amplicon cooperate to influence the transformed growth potential of human breast cancer cells; 3) To determine the influence of 8p11 oncogene over expression in the in vivo growth potential of human mammary epithelial cells, and to determine if these oncogenes can transform mouse mammary epithelial cells in vivo; 4) To test the hypothesis that over expression of the short isoform of WHSC1L1 alters the histone methylation code and gene expression profile, resulting in cells that exhibit properties of tumor initiating cells, including enhanced self-renewal capacity, expression of markers of cancer stem cells, and ability to form mammospheres in culture. We will also test the hypothesis that induction of these altered phenotypes requires an intact PWWP domain and does not require the SET domain of the protein. It is essential to demonstrate unequivocally that newly discovered 8p11 transforming genes are bone fide breast cancer oncogenes, and to elucidate the mechanism by which they induce cell transformation in order to develop therapeutic strategies that target these oncogenes. PUBLIC HEALTH RELEVANCE: This project is aimed at developing a mechanistic understanding of newly discovered breast cancer oncogenes. New targeted drugs against cancer are most effective clinically when they attack the products of oncogenes that are responsible for cancer development. In order to develop new therapeutic strategies against breast cancer, it is essential that we clearly identify the oncogenes that drive the disease in different patients, and develop therapeutic strategies to more effectively treat patients with breast cancer. The work in this grant is directly relevant to the development of new targeted drugs against breast cancer.

描述（由申请人提供）：在上一个项目期间，我们对人类乳腺癌细胞系和组织中的 8p11-p12 扩增子进行了广泛分析，以鉴定和验证新型乳腺癌癌基因。通过对拷贝数增加和过度表达的统计分析，我们确定了 21 个基因的子集作为候选癌基因。接下来，我们直接测试了这些基因在人乳腺上皮细胞中的转化功能。从这些实验中，我们鉴定出了在 MCF-10A 细胞中具有有效转化作用的 4 个基因以及具有更温和转化功能的其他 3 个基因。已鉴定的最有效的转化基因，包括 DDHD2、SPFH2、LSM1 和 WHSC1L1，可诱导基质胶中生长因子非依赖性增殖、贴壁非依赖性生长、侵袭能力和改变的形态发生。此外，我们还鉴定了影响转化表型表达的基因组合。在这项工作的下一阶段，我们将进行实验来了解这些癌基因转化潜力的机制基础，我们将检查它们在体外人类乳腺癌细胞中以及在体内人类和小鼠乳腺上皮细胞中的转化功能。下一个项目期工作的具体目标是：1）确定MCF-10A细胞中诱导转化表型的7个基因是否直接转化，并确定转化是癌基因过度表达的细胞中常见还是罕见的事件； 2) 确定与正常乳腺上皮细胞或没有扩增子的乳腺癌细胞相比，在人乳腺癌细胞系中扩增和过度表达的8p11区域的基因是否是这些乳腺癌细胞生长和存活所必需的。我们还将测试以下假设：8p11 扩增子上的一些癌基因协同影响人类乳腺癌细胞的转化生长潜力； 3）确定8p11癌基因过表达对人乳腺上皮细胞体内生长潜能的影响，并确定这些癌基因是否能够在体内转化小鼠乳腺上皮细胞； 4) 测试以下假设：WHSC1L1 短亚型的过度表达会改变组蛋白甲基化密码和基因表达谱，从而导致细胞表现出肿瘤起始细胞的特性，包括增强的自我更新能力、癌症干细胞标记物的表达以及在培养物中形成微球的能力。我们还将测试以下假设：诱导这些改变的表型需要完整的 PWWP 结构域，而不需要蛋白质的 SET 结构域。有必要明确证明新发现的 8p11 转化基因是真正的乳腺癌癌基因，并阐明它们诱导细胞转化的机制，以便开发针对这些癌基因的治疗策略。 公共健康相关性：该项目旨在对新发现的乳腺癌癌基因形成机制理解。当新的抗癌靶向药物攻击导致癌症发展的癌基因产物时，它们在临床上最有效。为了开发针对乳腺癌的新治疗策略，我们必须清楚地识别在不同患者中驱动疾病的癌基因，并制定治疗策略以更有效地治疗乳腺癌患者。这笔资助的工作与开发针对乳腺癌的新靶向药物直接相关。