FRY基因抑制乳腺癌的机制及基因敲除小鼠的构建

Breast cancer remains the most prevalent cancer among women. Although numerous genetic alterations and molecular pathways are implicated in the pathogenesis of breast cancer, significant gaps remain in our knowledge regarding the biology, etiology, and genetic susceptibility to this disease. Genetic factors play a vital role in the development and the overall genetic susceptibility of breast cancer. However, genetic linkage studies in high-risk families identified BRCA1 and BRCA2, which are implicated in less than 10% of all breast cancers and account for only a fraction of familial breast cancers. Thus, it is critical to identify other genetic risk factors that modify the susceptibility of breast cancer, which can lead to a new, genetic, era of prediction, prevention, and treatment for breast cancer...Human linkage analysis is complicated and difficult, even in high-risk families; we thus applied an alternative approach to identifying breast cancer susceptibility genes by conducting linkage analysis in inbred rat mammary tumor models. Using this strategy, we identified FRY as a putative mammary carcinoma susceptibility gene. FRY, the first putative human tumor suppressor discovered by linkage analysis in rodents, suppresses tumor growth and invasiveness of human tumor cells in nude mice, and its decreased expression and nuclear localization decreased in human breast, cancers are associated with more aggressive histopathological phenotypes and poor clinical outcomes. ..However, there remain significant gaps in our understanding of the molecular mechanisms of FRY in inhibiting breast cancer development and progression. We thus propose to conduct a series of in vitro and in vivo carcinogenesis assay to further test the capacity of FRY in suppressing the growth and invasiveness of different types of breast cancer. Moreover, we propose to generate FRY constitutive knockout and mammary tissue conditional knockout mice. These knockout mice will act as the important tool for studying the biological role of FRY gene and its association with the development of breast cancer. In addition, we will utilize genomic and proteomic approach to identify potential partners in FRY associated cell signaling cascades and thus understand the biological function of FRY and its role in tumor development. ..We expect that findings from this study will provide convincing data that FRY may represent a new target for cancer screening, therapeutic interventions targeting epithelial cancers, and gene therapy.

乳腺癌是女性最常见的恶性肿瘤之一，寻找乳腺癌易感生物标志物是国际上预防、诊断和靶向治疗的热点。经过多年的研究，我们利用大鼠乳腺肿瘤动物模型和遗传连锁分析，在大鼠上定位并初步识别和确定Furry homolog (Drosophila) 基因(FRY)，为全新的乳腺癌肿瘤抑癌基因。在这些前期工作的基础上，本项目拟通过体外和体内致癌试验, 进一步研究FRY基因与乳腺肿瘤发展和恶性变间的关系。并利用基因敲除技术构建FRY基因全敲除和乳腺特异敲除小鼠，来确证FRY基因的分子功能和确定FRY基因缺失与乳腺肿瘤发展的关系。在此基础上，并运用蛋白质组学和基因组学等技术，识别与FRY基因相互作用的靶基因和细胞信号通路，确定FRY基因抑癌的内在分子机制。这些结果将为最终应用FRY基因作为乳腺癌诊断和治疗反应及预后预测的生物标志物，以及作为治疗乳腺癌的靶向位点提供理论基础。

乳腺癌是女性最常见的恶性肿瘤，90%以上乳腺癌相关的死亡是由于恶性肿瘤转移导致无法手术治疗引起的。在恶性肿瘤的转移过程中，上皮 - 间质转化（EMT）是一个早期和关键的步骤，其涉及多种蛋白质的表达和活性改变，导致细胞信号通路改变。确定参与肿瘤转移/侵袭的遗传因子在EMT中的作用，可以帮助阐明肿瘤发生和发展机制，特别是针对致命的侵袭性转移性乳腺癌的机制。同时，研究和发展新的预防和治疗的策略也对转移性乳腺癌非常关键。我们通过对传性乳腺肿瘤近交动物模型的连锁分析，发现 Fry基因，可能是一个新的肿瘤抑制基因。在国家自然基金的资助下，我们进行的体外和体内实验数据表明：FRY可能是控制EMT的基本组织病理学变化，参与肿瘤入侵/转移的关键因子之一。我们的研究表明， FRY介导的蛋白激酶信号通路激活，可以抑制肿瘤细胞增殖，移动和侵袭。更为重要的是在动物模型上，我们观察到FRY有抑制肿瘤生长和转移的能力。对正常乳腺上皮（FRY敲除）和肿瘤（FRY诱导）细胞的进一步分析表明，FRY可以调节上皮细胞结构，分化和迁移，在上皮 - 间质转化（EMT）过程中起关键的作用。我们对人群乳腺肿瘤病人开展的研究中，初步分析表明， 乳腺组织FRY蛋白水平降低与乳腺肿瘤发展和恶性变直接相关。乳腺癌不是单一的一种疾病，而是由许多“内在”亚型组成，有不同的发展和预后。我们的研究表明，FRY是乳腺肿瘤发展和恶性变的关键因子之一，也是乳腺癌预后的可靠标志。在此研究的基础上，结合其他已知的遗传和生活方式的因素，可以为乳腺癌的早期检测和针对恶性乳腺癌的靶向治疗提供新的策略，最终为降低恶性乳腺癌死亡率做出贡献。