Wnt/Ca2+ Function in Development and Tumor Suppression

Wnt/Ca2 在发育和肿瘤抑制中的功能

• 批准号: 6853451
• 负责人: DIANE C SLUSARSKI
• 金额: $ 25.28万
• 依托单位: UNIVERSITY OF IOWA
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-07-01 至 2010-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6853451
• 关键词: alternatives to animals in research; biological signal transduction; cadherins; calcium flux; calcium ion; cell motility; gene deletion mutation; gene expression; genetic manipulation; intermolecular interaction; molecular /cellular imaging; mutant; neoplasm /cancer genetics; neoplastic growth; neoplastic transformation; protein metabolism; tumor suppressor genes; zebrafish

DESCRIPTION (provided by applicant): Beta-catenin activity has a profound impact in both development and cancer. Activation of the canonical Wnt path (Wnt/Beta-catenin) results in the accumulation of Beta-catenin. Non-canonical Wnts influence cell movement and modulate calcium release (Wnt/Ca2+). We have demonstrated that genetic depletion of Wnt-5 (pipetail, ppt), a non-canonical Wnt, results in reduced Ca2+ release and increased beta-catenin accumulation in zebrafish. How the different Wnt pathways interact is not well known. We hypothesize that non-canonical Wnts, through Ca2+ modulation, function as negative-regulators of Wnt/Beta-catenin signaling, raising the fascinating possibility that Wnt-5 is a potential tumor suppressor. Our goal is to use molecular-genetic analyses coupled with in vivo imaging to investigate the mechanisms of Wnt/Ca2+ activity in development and in tumor suppression. In Specific Aim 1, we determine if Beta-catenin stabilization in Wnt-5 mutant (ppt) embryos is a direct result of Wnt/Ca2+ function. We will determine whether the facilitated beta-catenin activity in ppt mutants can be suppressed by Wnt-5 misexpression, or by manipulating Ca2+ release. In Specific Aims 2 and 3, we explore several potential mechanisms by which Wnt/Ca2+ activity could be antagonizing Wnt/Beta-catenin activity. We will determine if Wnt-5-mediated phenotypes (gain- and loss-of-function) require the activity of Axin and/or GSK, both key players in canonical Wnt signaling. The antagonistic interactions could be mediated by competition for Dsh (Dishevelled), a protein that signals in both Wnt pathways. We will investigate the role of naked cuticle, a calcium sensor that binds Dsh, as a potential mediator of Dsh sequestration to a particular signaling pathway. And lastly, we have found that Wnt/Ca2+ mutants develop spontaneous tumors. In aim 4, we will characterize the affected tissues and investigate the biological role of Wnt/Ca2+ activity as a potential tumor suppressor. In this new initiative in the lab, we apply our developmental biology expertise with in vivo image analysis of the whole organism to generate new insights into the mechanisms of tumor formation and growth

描述（由申请人提供）：β-catenin活性对发育和癌症都有深远的影响。规范Wnt路径（Wnt/beta-catenin）的激活导致β-catenin的积累。非典型的WNT会影响细胞运动并调节钙释放（Wnt/Ca2+）。我们已经证明了Wnt-5（Pipetail，PPT）（一种非典型的WNT）的遗传耗竭导致斑马鱼中Ca2+释放减少并增加β-catenin的积累。不同的Wnt途径如何相互作用尚不清楚。我们假设通过CA2+调制，非典型的WNT充当Wnt/beta-catenin信号的负调节剂，从而提高了Wnt-5是潜在的肿瘤抑制剂的引人入胜的可能性。 我们的目标是使用与体内成像结合的分子遗传学分析来研究发育和抑制肿瘤中Wnt/Ca2+活性的机制。在特定的目标1中，我们确定Wnt-5突变体（PPT）胚胎中的β-catenin稳定是否是Wnt/Ca2+功能的直接结果。我们将确定PPT突变体中促进的β-catenin活性是否可以通过Wnt-5 Misexpression抑制，或者通过操纵Ca2+释放来抑制。在特定的目标2和3中，我们探讨了几种潜在的机制，通过这些机制，Wnt/Ca2+活性可以拮抗Wnt/beta-catenin活性。我们将确定Wnt-5介导的表型（功能丧失和功能丧失）是否需要Axin和/或GSK的活性，这两个主要参与者都是典型的Wnt信号传导。拮抗相互作用可以是通过竞争DSH（Disshed）的竞争来介导的，DSH（DISSEVELED）是在两个WNT途径中发出信号的蛋白质。我们将研究结合DSH的钙传感器裸角质的作用，它是DSH隔离的潜在介体与特定信号通路的潜在介体。最后，我们发现Wnt/Ca2+突变体发生自发性肿瘤。在AIM 4中，我们将表征受影响的组织，并研究Wnt/Ca2+活性作为潜在肿瘤抑制剂的生物学作用。在实验室的这项新倡议中，我们将我们的发育生物学专业知识与整个生物体的体内图像分析一起应用，以产生对肿瘤形成和生长机制的新见解