SPECIFIC ROLES FOR D-CYCLINS IN ONCOGENESIS

D-细胞周期蛋白在肿瘤发生中的具体作用

• 批准号: 6329094
• 负责人: Peter Sicinski
• 金额: $ 27.1万
• 依托单位: DANA-FARBER CANCER INST
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-12-21 至 2004-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6329094
• 关键词: breast neoplasms; cell growth regulation; cyclin dependent kinase; cyclins; fibroblasts; genetically modified animals; laboratory mouse; mouse mammary tumor virus; neoplasm /cancer genetics; neoplastic growth; oncogenes; protooncogene; skin neoplasms

D-type cyclins (cyclin D1, D2 and D3) are the ultimate recipients of all mitogenic and oncogenic signals. Aberrant expression of D-cyclins is seen in many human malignancies and virtually all human cancers contain lesions in pathways impacting on D-cyclins. We have generated knockout mouse strains lacking cyclin D1, D2 or D3 using homologous recombination in embryonal stem cells. All three strains are viable and display focused, tissue-specific phenotypes. In the proposed work we will use these mice as a tool to study the role of D-cyclins in tumorigenesis. In the first Specific Aim we will ask whether the loss of cyclin D1 renders mice resistant to breast cancers induced by various oncogenes. Cyclin D1 is overexpressed in the majority of human breast cancers. Importantly, overexpression of cyclin D1 is believed to play a causative role in tumorigenesis, as agents that neutralize cyclin D1 function were shown to shut off the proliferation of breast cancer cells in vitro. Cyclin D1 is normally expressed in nearly all human tissues and, until recently, was thought to be indispensable for proliferation of all cell lineages. However, our unexpected finding that in adult cyclin D1-/- mice the consequences of cyclin D1-ablation are restricted to mammary epithelium, raises the possibility that a specific, anti-cyclin D1 therapy for human breast cancers might be highly selective in shutting off the proliferation of tumor cells while sparing other tissues. As a first step towards this goal we wish to test if the ablation of cyclin D1 prevents cancer formation in vivo. In the second Specific Aim we will take advantage of fibroblasts lacking cyclin D1, D2 or D3 to study the dependence of various oncogenic signal transduction pathways on different D-cyclins at the cellular and molecular level. The studies described in the third Specific Aim take advantage of recently-generated cyclin E greater than D1 "knock-in" mice. In this strain we have deleted the coding exons of cyclin D1 and replaced them by cyclin E cDNA. Analyses of these mice have demonstrated that cyclin E can replace cyclin D1 in driving normal cell proliferation and rescue the phenotypic manifestations of cyclin Dl-deficiency. In this Specific Aim we will ask whether cyclin E can replace cyclin D1 in driving oncogenic growth of cancer cells.

D型细胞周期蛋白(细胞周期蛋白D1、D2和D3)是所有有丝分裂和致癌信号的最终接受者。D-Cyclins的异常表达见于许多人类恶性肿瘤中，几乎所有的人类癌症都在影响D-Cyclins的通路中存在病变。我们利用胚胎干细胞中的同源重组产生了缺乏细胞周期蛋白D1、D2或D3的基因敲除小鼠品系。这三个菌株都是活的，都表现出聚焦的、组织特异性的表型。在这项拟议的工作中，我们将使用这些小鼠作为工具来研究D-细胞周期蛋白在肿瘤发生中的作用。在第一个特定目标中，我们将询问细胞周期蛋白D1的缺失是否会使小鼠对各种癌基因诱导的乳腺癌产生抵抗力。细胞周期蛋白D1在大多数人类乳腺癌中过表达。重要的是，细胞周期蛋白D1的过度表达被认为在肿瘤的发生中发挥了作用，因为在体外，中和细胞周期蛋白D1功能的药物被证明可以阻断乳腺癌细胞的增殖。细胞周期蛋白D1在几乎所有的人类组织中都有表达，直到最近，一直被认为对所有细胞系的增殖都是不可或缺的。然而，我们出人意料的发现，在成年Cyclin D1-/-小鼠中，Cyclin D1-的消融结果仅限于乳腺上皮，这增加了一种针对人类乳腺癌的特异性、抗Cyclin D1疗法可能在高度选择性地切断肿瘤细胞的增殖而保留其他组织的可能性。作为迈向这一目标的第一步，我们希望测试细胞周期蛋白D1的消融是否能防止体内癌症的形成。在第二个特定目标中，我们将利用缺乏细胞周期蛋白D1、D2或D3的成纤维细胞，在细胞和分子水平上研究不同致癌信号转导途径对不同D-细胞周期蛋白的依赖性。在第三个特定目标中描述的研究利用了最近产生的细胞周期蛋白E大于d1“敲入”的小鼠。在该菌株中，我们删除了细胞周期蛋白D1的编码外显子，并将其替换为细胞周期蛋白E的cDNA.对这些小鼠的分析表明，细胞周期蛋白E可以取代细胞周期蛋白D1来驱动正常细胞的增殖，并挽救细胞周期蛋白DL缺乏症的表型表现。在这个特定的目标中，我们将探讨细胞周期蛋白E是否可以取代细胞周期蛋白D1来驱动癌细胞的致癌生长。