Pak1 in Mammary Gland Development and Carcinogenesis

描述：(摘自申请者的摘要)乳腺的能力 腺体的发生受其正常发育的影响， 包括生殖活动。大量的流行病学研究表明 系统的内分泌模式和生殖变化发生在 人类乳房对乳腺癌有重要影响。观察到的 同样的内分泌事件控制着乳房的发育和影响 乳腺癌风险强化了乳腺发育的假说 与肿瘤的发生有着根本的联系。通过以下方式了解这些机制 这些事件调控乳腺癌的发展将需要一个更好的 对控制乳腺细胞增殖和增殖的基因的理解 转移。蛋白激酶是已知的调节基因的最大类别。 真核生物中的生长、分化和发育。我们建议 为了研究p21激活的蛋白激酶(PACI)的影响，一种新的信号转导途径， 丝氨酸/苏氨酸激酶(在运动性、侵袭性、血管形成、 和细胞存活)，对正常乳腺的发育和 与早期恶性和转移性乳腺癌有关的改变。 我们的工作假设是正常需要有功能的pak1通路 乳腺发育与PAK1信号通路失控 在流感侵袭性的发展和维持中起着至关重要的作用 乳腺癌的表型通过支持细胞存活和血管生成。 这项建议的理由是根据 主要研究人员认为(I)pak1的表达控制运动， 乳腺癌细胞的侵袭性和非贴壁生长；(Ii)Pak 1信号调节血管内皮生长因子的表达 因此，它的功能；(Iii)pak1激活通过以下途径支持细胞存活 灭活促凋亡蛋白Bad；和(V)有条件表达 转基因小鼠模型中的PKI死亡导致发育不全、发育迟缓 导管结构，以及导管内间质的强化。这些发现 提示pak1在正常乳腺发育过程中起重要作用 控制几个基本功能，包括细胞运动和 重塑、血管生成和细胞存活。因此，帕克的功能障碍 通路3可能是乳腺癌发生发展的重要一步。 这项建议的具体目的是：(1)确定 目的探讨PAC1基因在转基因小鼠乳腺组织中的表达。 (2)测定体质活性PACI对乳腺的影响 转基因小鼠的生物学特性；(3)确定pak1基因的共表达是否可以 对HRG转基因小鼠乳腺成瘤的影响；(4)测定 Pak1功能对易感性的影响。我们的一个独特的方面 建议使用最近开发的pak1转基因小鼠来获得新的 Paki在正常乳腺中作为关键信号通路的研究进展 腺体发育，并将允许首席调查员验证 以往的组织培养结果与病理生理学相关 使用整个动物的实验环境。

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.