Cell Polarity in Epithelial to Mesenchymal Transition

上皮细胞向间质细胞转变中的细胞极性

• 批准号: 7220365
• 负责人: EILEEN L WHITEMAN
• 金额: $ 5.29万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-04-01 至 2009-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7220365
• 关键词: Address; Adherens Junction; Adult; Affect; Animal Model; Apical; Architecture; Biochemical Genetics; Biological; Biological Process; Cadherins; Caenorhabditis elegans; Cancer Cell Growth; Carcinoma; Cell Adhesion; Cell Polarity; Cell membrane; Cell physiology; Cells; Complex; Defect; Development; Down-Regulation; Drosophila genus; E-Cadherin; Embryonic Development; Epithelial; Epithelial Cells; Epithelium; Event; Gene Components; Gene Targeting; Genetic; Human; Laboratories; Localized; Maintenance; Malignant Neoplasms; Mammalian Cell; Mediating; Mesenchymal; Messenger RNA; Methods; Microscopy; Mitotic spindle; Molecular; Morphology; Movement; Neoplasm Metastasis; Phenotype; Physiology; Process; Proteins; Proteomics; Public Health; Sampling; Signal Transduction; Signaling Protein; Site; Snails; Testing; Thinking; Tight Junctions; Tumor Suppressor Proteins; Work; base; basolateral membrane; cancer cell; cancer therapy; cell motility; data modeling; epithelial to mesenchymal transition; gene repression; intracellular protein transport; malignant breast neoplasm; migration; novel; programs; protein localization location; research study; scaffold; seal; snail protein; transcription factor; tumor; tumor progression

DESCRIPTION (provided by applicant): The epithelial to mesenchymal transition (EMT) is a program of events characterized by loss of cell polarity, enhanced cell motility, and increased cell invasion. While this process is essential for normal embryonic development, its deregulation in the adult promotes metastasis. The broad, long term objectives of this proposal are to understand how the epithelial to mesenchymal transition initiates the loss of cellular polarity and how this depolarization might contribute to cancer progression. The central hypothesis is that the transcriptional represser Snail, a key regulator of the EMT, affects the apico-basal polarity complexes Crumbs3-PALS1-PATJ and Par6-Par3-aPKC and that loss of these polarity complexes enhances cancer progression. This hypothesis is based on the long-appreciated observation that the epithelium appears depolarized in many carcinomas, and on data from model organisms demonstrating that loss of proper epithelial architecture results in profound hyperproliferation. Previous work from this laboratory and others has revealed that the Crumbs and Par6 polarity complexes are required for the formation of the tight junction and maintenance of cell polarity. Based on these observations, the experimental focus of this proposal is on the novel Crumbs and Par6 epithelial polarity complexes during EMT. The specific aims are to: (1) Elucidate the specific defects in apico-basal polarity complexes induced by Snail expression in epithelial cells. The study will examine how Snail affects the localization and protein levels of the polarity complexes, if it reduces the expression of the tight junction component genes, if E-cadherin expression can rescue the polarization defects, and if elevated levels of Snail correlate with the suppression of E-cadherin and CrumbsS in human tumor samples. (2) Analyze the biological effects of Snail-induced depolarization in epithelial cells and evaluate whether selective re- expression of CrumbsS modulates proper biological function. The study will investigate if Snail disrupts other cellular processes closely associated with cell polarity such as mitotic spindle pole alignment and cell migration, if re-expression of CrumbsS reverses any functionally altered phenotypes, and whether the specific loss of CrumbsS modulates cancer cell growth or migration. Biochemical, genetic, proteomic, and microscopy-based methods will be used to address these aims. The relevance of this project to public health is that it will further our understanding of the precise molecular mechanisms resulting in cancer cell migration, invasion, and metastasis and potentially identify new targets for cancer therapy.

描述（由申请人提供）：上皮到间质转化（EMT）是一个以细胞极性丧失、细胞运动增强和细胞侵袭增加为特征的事件程序。虽然这个过程对于正常胚胎发育至关重要，但它在成人中的失调会促进转移。该提案的广泛、长期目标是了解上皮细胞向间质细胞的转变如何引发细胞极性的丧失以及这种去极化如何促进癌症进展。核心假设是转录抑制因子 Snail（EMT 的关键调节因子）会影响顶端-基底极性复合物 Crumbs3-PALS1-PATJ 和 Par6-Par3-aPKC，并且这些极性复合物的缺失会促进癌症进展。这一假说基于长期以来备受认可的观察结果，即上皮在许多癌症中出现去极化，并且基于模型生物的数据，表明适当的上皮结构的丧失会导致严重的过度增殖。该实验室和其他实验室之前的工作表明，Crumbs 和 Par6 极性复合物是形成紧密连接和维持细胞极性所必需的。基于这些观察，本提案的实验重点是 EMT 过程中新型 Crumbs 和 Par6 上皮极性复合物。具体目标是：（1）阐明上皮细胞中Snail表达诱导的顶端-基底极性复合物的特异性缺陷。该研究将研究 Snail 如何影响极性复合物的定位和蛋白质水平，它是否会减少紧密连接组成基因的表达，E-钙粘蛋白的表达是否可以挽救极化缺陷，以及 Snail 水平的升高是否与抑制相关人类肿瘤样本中的 E-钙粘蛋白和 CrumbsS。 (2)分析Snail诱导的上皮细胞去极化的生物学效应，并评估CrumbsS的选择性再表达是否调节适当的生物学功能。该研究将调查 Snail 是否会破坏与细胞极性密切相关的其他细胞过程，例如有丝分裂纺锤体极排列和细胞迁移，CrumbsS 的重新表达是否会逆转任何功能改变的表型，以及 CrumbsS 的特定缺失是否会调节癌细胞的生长或迁移。将使用生物化学、遗传学、蛋白质组学和基于显微镜的方法来实现这些目标。该项目与公共卫生的相关性在于，它将进一步加深我们对导致癌细胞迁移、侵袭和转移的精确分子机制的理解，并有可能确定癌症治疗的新靶点。