Characterization of a novel regulator of cell migration

描述(由申请人提供)：细胞迁移对动物发育和器官发生至关重要，而不适当的细胞迁移会导致疾病的进展，如转移性癌症。我们正在使用两种特殊的线虫细胞--远端细胞(DTC)的迁移作为体内模型系统，以阐明细胞将细胞外线索转换为细胞迁移行为的机制。控制DTC迁移的基因，包括金属蛋白酶、整合素和RAC GTP酶，与转移过程中所需的基因惊人地相似。这项研究的目的是阐明W03H9.4的作用机制，W03H9.4是一种新的体内细胞迁移调节因子，需要正确的DTC转弯时间和正确的DTC路径寻找。我们的工作假设是，基于初步证据，W03H9.4通过调节蛋白质的表达模式或亚细胞定位来控制DTC的细胞极性和定向细胞迁移，包括Netrin导向信号和/或Netrin受体蛋白质，这导致RAC GTPase信号改变和细胞导向缺陷。首先，通过对表达GFP融合蛋白的转基因动物的分析，以及与1W03H9.4抗体的免疫荧光，将确定需要W03H9.4才能发挥功能的细胞类型和发育阶段。其次，通过对W03H9.4(Tm3042)突变动物的转基因挽救、W03H9.4的细胞型特异性过表达以及RNAi对W03H9.4的细胞型特异性缺失，研究W03H9.4的作用机制。最后，将研究Netrin信号系统W03H9.4和Rac家族GTP酶之间的遗传相互作用，并确定W03H9.4水平中断对这些信号蛋白定位或表达的影响。W03H9.4和RAC GTP酶之间令人兴奋的联系使这项研究具有巨大的潜力，有助于我们更好地理解动物发育过程中细胞迁移的基本调控以及在转移癌等病理条件下的细胞迁移。公共卫生相关性：我们正在使用线虫中的迁移细胞作为模型系统来研究与细胞迁移过程有关的基因，特别是那些与转移癌症相关的基因。这项研究将确定一种名为W03H9.4的新基因如何帮助细胞正确解释细胞外信号，这些信号让细胞知道何时迁移，何时停止迁移。W03H9.4与已知的信号级联之间的联系使这项研究具有巨大的潜力，有助于我们更好地理解动物发育过程中细胞迁移的基本调控以及在转移癌等病理条件下的细胞迁移。

DESCRIPTION (provided by applicant): Cell migration is critical for animal development and organogenesis, and inappropriate cell migration contributes to progression of diseases such as metastatic cancer. We are using migration of two specialized C. elegans cells, the distal tip cells (DTC), as an in vivo model system to elucidate the mechanisms by which cells convert extracellular cues to cell migratory behaviors. The genes controlling DTC migration, including metalloproteases, integrins, and Rac GTPases, are strikingly similar to the genes required during metastasis. The goal of the proposed study is to elucidate the mechanism of action of W03H9.4, a novel regulator of in vivo cell migration required for correct timing of DTC turns and correct DTC pathfinding. Our working hypothesis, based on preliminary evidence, is that W03H9.4 controls the cell polarity and directional cell migration of the DTC by regulating the expression pattern or sub-cellular localization of proteins, including netrin guidance cues and/or netrin receptor proteins, which results in altered Rac GTPase signaling and defective cell guidance. First, the cell types and developmental stages that require W03H9.4 for function will be determined through analysis of transgenic animals expressing GFP fusion proteins and immunofluorescence with 1W03H9.4 antibodies. Secondly, the mechanism of W03H9.4 action will be investigated through transgenic rescue of W03H9.4(tm3042) mutant animals, cell-type specific overexpression of W03H9.4, and cell-type specific depletion of W03H9.4 by RNAi. Finally, genetic interactions between W03H9.4, the netrin signaling system, and Rac family GTPases will be investigated, and the effect of disrupted W03H9.4 levels on localization or expression of these signaling proteins will be determined. The exciting connection between W03H9.4 and Rac GTPases gives this study tremendous potential to improve our understanding of the fundamental regulation of cell migration during animal development and in pathologic conditions such as metastatic cancer. PUBLIC HEALTH RELEVANCE: We are using migratory cells in the nematode C. elegans as a model system to study genes involved in cell migration processes, particularly those genes that are relevant to metastatic cancer. This study will determine how a novel gene, W03H9.4, helps cells correctly interpret the extracellular cues that let cells know when to migrate and when to stop migrating. The connection between W03H9.4 and known signaling cascades gives this study tremendous potential to improve our understanding of the fundamental regulation of cell migration during animal development and in pathologic conditions such as metastatic cancer.