Pak1 in Mammary Gland Development and Carcinogenesis

描述：（扫描自申请人摘要）乳腺癌的能力 腺体发生肿瘤的能力受其正常发育的影响， 包括生殖活动。大量流行病学研究表明 系统内分泌模式和生殖变化发生在 人类乳房对乳腺癌具有重要意义。观察 同样的内分泌活动控制着乳房的发育， 乳腺癌的风险加强了乳腺发育的假设， 和肿瘤的发生有着根本的联系。通过以下方式了解机制 这些事件调节乳腺癌的发展将需要更好的方法 了解控制乳腺细胞增殖的基因， 转移蛋白激酶是已知的调节蛋白激酶活性的最大一类基因。 真核生物的生长、分化和发育。我们提出 为了研究p21激活激酶（Paki）， 丝氨酸/苏氨酸激酶（在运动性，侵袭性，血管生成， 和细胞存活），对正常乳腺的发育， 与早期恶性和转移性乳腺癌有关的改变。 我们的工作假设是，功能性Pak 1通路是正常的 乳腺发育与Pak 1信号通路失调 在流感侵袭性疾病的发展和维持中起着重要作用， 通过支持细胞存活和血管生成来改善乳腺癌的表型。 提出这项建议的理由是基于联合国人权事务高级专员最近提出的意见。 主要研究者认为（i）Pak 1的表达控制运动， 乳腺癌细胞的侵袭性和非贴壁依赖性生长;（ii）Pak 1信号调节血管内皮生长因子的表达， 因此其功能;（iii）Pak 1激活支持细胞存活， 使促凋亡蛋白Bad失活;和（v）条件性表达促凋亡蛋白Bad， 在转基因小鼠模型中激酶死亡的巴基斯坦人导致发育不全，发育迟缓 乳腺导管内基质增强。这些发现 表明Pakl在正常乳腺发育中具有重要作用， 控制几种基本功能，包括细胞运动， 重塑、血管生成和细胞存活。因此，巴基斯坦的功能失调 pathwa 3可能构成乳腺癌发展的重要步骤。 本提案的具体目标是：（1）确定 显性阴性Pakl在转基因小鼠乳腺中的表达; (2)确定组成性活跃的巴基斯坦人对乳腺的影响 （3）确定Pakl的共表达是否可以在转基因小鼠中表达; 影响HRG转基因小鼠乳腺肿瘤发生;和（4）确定 Pak 1功能对易感性的影响。我们独特的一面 建议是使用最近开发的Pak 1转基因小鼠获得新的 Paki作为正常乳腺癌关键信号通路的作用 腺体发育，也将允许主要研究者验证 病理生理学相关的先前组织培养结果 使用整个动物的实验设置。

DESCRIPTION: (Scanned from the applicant's abstract) The ability of the mammary gland to undergo tumorigenesis is influenced by its normal development, including reproductive events. Numerous epidemiological studies have suggested that systemic endocrine patterns and reproductive changes occurring in the human breast have important implications for breast cancer. The observation that the same endocrine events control mammary development and influence breast-cancer risk strengthens the hypothesis that mammary gland development and tumorigenesis are fundamentally linked. Understanding the mechanisms by which these events regulate breast cancer development will require a better understanding of the genes that control mammary cell proliferation and metastasis. Protein kinases are the largest class of genes known to regulate growth, differentiation, and development in eukaryotic organisms. We propose here to investigate the influence of p21-activated kinase (Paki), a serine/threonine kinase (with roles in motility, invasiveness, angio genesis, and cell survival), on the development of the normal mammary gland and alterations involved in early malignant and metastatic breast cancer. Our working hypotheses are that functional Pak1 pathway is required for normal mammary gland development and that deregulation of the Pak1 signaling pathway plays an essential role in the progression and maintenance of flu invasive phenotype in breast cancer by supporting cell survival and angiogenesis. The rationale for this proposal is based on observations recently made by the Principal Investigator that (i) expression of Pak1 controls motility, invasiveness and anchorage-independent growth of breast cancer cells; (ii) Pak 1 signaling regulates the expression of vascular endothelial growth factor and consequently its function; (iii) Pak1 activation supports cell survival by inactivating the proapoptotic protein Bad; and (v) conditional expression of a kinase-dead Paki in a transgenic mouse model leads to hypoplasia, retardation of ductal structures, and enhancement of intraductal stroma. These findings suggest that Pakl has a significant role in normal mammary development by controlling several essential functions, including cell motility and remodeling, angiogenesis, and cell survival. Thus dysfunctions in the Pakl pathwa3 may constitute an important step in breast cancer development. The Specific Aims of this proposal are to: (1) determine the influence of expression of dominant-negative Pakl in the mammary gland of transgenic mice; (2) determine the influence of constitutively active Paki on mammary gland biology in transgenic mice; (3) determine whether co-expression of Pakl can influence mammary gland tumorigenesis in HRG transgenic mice; and (4) determine the influence of Pak1 functions on the susceptibility. A unique aspect of our proposal is the use of recently developed Pak1 transgenic mice to gain novel insights about the role of Paki as critical signaling pathway in normal mammary gland development, and will also allow the Principal Investigator to validate the previous tissue culture findings in the pathophysiologically relevant experimental setting by using whole animals.